is time travel possible to the future

Is Time Travel Possible?

We all travel in time! We travel one year in time between birthdays, for example. And we are all traveling in time at approximately the same speed: 1 second per second.

We typically experience time at one second per second. Credit: NASA/JPL-Caltech

NASA's space telescopes also give us a way to look back in time. Telescopes help us see stars and galaxies that are very far away . It takes a long time for the light from faraway galaxies to reach us. So, when we look into the sky with a telescope, we are seeing what those stars and galaxies looked like a very long time ago.

However, when we think of the phrase "time travel," we are usually thinking of traveling faster than 1 second per second. That kind of time travel sounds like something you'd only see in movies or science fiction books. Could it be real? Science says yes!

Image of galaxies, taken by the Hubble Space Telescope.

This image from the Hubble Space Telescope shows galaxies that are very far away as they existed a very long time ago. Credit: NASA, ESA and R. Thompson (Univ. Arizona)

How do we know that time travel is possible?

More than 100 years ago, a famous scientist named Albert Einstein came up with an idea about how time works. He called it relativity. This theory says that time and space are linked together. Einstein also said our universe has a speed limit: nothing can travel faster than the speed of light (186,000 miles per second).

Einstein's theory of relativity says that space and time are linked together. Credit: NASA/JPL-Caltech

What does this mean for time travel? Well, according to this theory, the faster you travel, the slower you experience time. Scientists have done some experiments to show that this is true.

For example, there was an experiment that used two clocks set to the exact same time. One clock stayed on Earth, while the other flew in an airplane (going in the same direction Earth rotates).

After the airplane flew around the world, scientists compared the two clocks. The clock on the fast-moving airplane was slightly behind the clock on the ground. So, the clock on the airplane was traveling slightly slower in time than 1 second per second.

Credit: NASA/JPL-Caltech

Can we use time travel in everyday life?

We can't use a time machine to travel hundreds of years into the past or future. That kind of time travel only happens in books and movies. But the math of time travel does affect the things we use every day.

For example, we use GPS satellites to help us figure out how to get to new places. (Check out our video about how GPS satellites work .) NASA scientists also use a high-accuracy version of GPS to keep track of where satellites are in space. But did you know that GPS relies on time-travel calculations to help you get around town?

GPS satellites orbit around Earth very quickly at about 8,700 miles (14,000 kilometers) per hour. This slows down GPS satellite clocks by a small fraction of a second (similar to the airplane example above).

Illustration of GPS satellites orbiting around Earth

GPS satellites orbit around Earth at about 8,700 miles (14,000 kilometers) per hour. Credit: GPS.gov

However, the satellites are also orbiting Earth about 12,550 miles (20,200 km) above the surface. This actually speeds up GPS satellite clocks by a slighter larger fraction of a second.

Here's how: Einstein's theory also says that gravity curves space and time, causing the passage of time to slow down. High up where the satellites orbit, Earth's gravity is much weaker. This causes the clocks on GPS satellites to run faster than clocks on the ground.

The combined result is that the clocks on GPS satellites experience time at a rate slightly faster than 1 second per second. Luckily, scientists can use math to correct these differences in time.

Illustration of a hand holding a phone with a maps application active.

If scientists didn't correct the GPS clocks, there would be big problems. GPS satellites wouldn't be able to correctly calculate their position or yours. The errors would add up to a few miles each day, which is a big deal. GPS maps might think your home is nowhere near where it actually is!

In Summary:

Yes, time travel is indeed a real thing. But it's not quite what you've probably seen in the movies. Under certain conditions, it is possible to experience time passing at a different rate than 1 second per second. And there are important reasons why we need to understand this real-world form of time travel.

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May 14, 2020

Time travel into the future is totally possible

by Paul M. Sutter, Universe Today

Believe it or not, time travel is possible.

In fact, you're doing it right now. Every single second of every single day, you are advancing into your own future. You are literally moving through time, the same way you would move through space. It may seem pedantic, but it's a very important point. Movement through time is still movement, and you are reaching your own future (whether you like it or not).

And what's even cooler is that you can skip forward in time if you feel like it.

Well, let me be clear, you need to do a little bit of engineering first.

We know through the physics of Einstein's special theory of relativity that you can trade motion in space for motion in time. If you're standing perfectly still, you're moving through the dimension of time at a particular speed (the speed of light , for those of you who are curious). As soon as you start moving through space, however, you slow down your rate of moving through time.

In other words, the faster you move in space , the slower you move in time.

This means that moving objects, like a clock on a rocket, run a little bit slow. One second for someone in a moving spaceship lasts a little bit longer than a second for someone staying still.

The trick is that in order for this to have any sort of noticeable impact, you have to get close to the speed of light, which is really hard to do—to give you some perspective, astronauts that orbit the Earth at tens of thousands of miles per hour are off by only a microsecond or so from our clocks on the ground.

Our fastest human spacecraft don't even crack a tenth of a percent of the speed of light. But if you could somehow spend a good amount of time hugging close to that ultimate speed limit in the universe, the slower your clock will run. You will travel through time into the future. Nothing will feel different for you, but after a couple of years' journey you would return to the Earth to find our clocks advanced by thousands or even tens of thousands of years, depending on how fast you go.

So the future is yours, and you get to choose how quickly you reach it.

Source Universe Today

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Time travel is theoretically possible, calculations show. But that doesn't mean you could change the past.

Time travel is possible based on the laws of physics, according to researchers.
But time-travelers wouldn't be able to alter the past in a measurable way, they say.
And the future would essentially stay the same, according to the reseachers.

Imagine you could hop into a time machine, press a button, and journey back to 2019, before the novel coronavirus made the leap from animals to humans.

What if you could find and isolate patient zero? Theoretically, the COVID-19 pandemic wouldn't happen, right?

Not quite, because then future-you wouldn't have decided to time travel in the first place.

For decades, physicists have been studying and debating versions of this paradox: If we could travel back in time and change the past, what would happen to the future?

A 2020 study offered a potential answer: Nothing.

"Events readjust around anything that could cause a paradox, so the paradox does not happen," Germain Tobar, the study's author previously told IFLScience .

Tobar's work, published in the peer-reviewed journal Classical and Quantum Gravity in September 2020, suggests that according to the rules of theoretical physics, anything you tried to change in the past would be corrected by subsequent events.

The grandfather paradox

Physicists have considered time travel to be theoretically possible since Albert Einstein came up with his theory of relativity. Einstein's calculations suggest it's possible for an object in our universe to travel through space and time in a circular direction, eventually ending up at a point on its journey where it's been before – a path called a closed time-like curve.

Still, physicists continue to struggle with scenarios like the coronavirus example above, in which time-travelers alter events that already happened. The most famous example is known as the grandfather paradox: Say a time-traveler goes back to the past and kills a younger version of his or her grandfather. The grandfather then wouldn't have any children, erasing the time-traveler's parents and, of course, the time-traveler, too. But then who would kill Grandpa?

A take on this paradox appears in the movie "Back to the Future," when Marty McFly almost stops his parents from meeting in the past – potentially causing himself to disappear.

To address the paradox, Tobar and his supervisor, Dr. Fabio Costa, used the "billiard-ball model," which imagines cause and effect as a series of colliding billiard balls, and a circular pool table as a closed time-like curve.

Imagine a bunch of billiard balls laid out across that circular table. If you push one ball from position X, it bangs around the table, hitting others in a particular pattern.

The researchers calculated that even if you mess with the ball's pattern at some point in its journey, future interactions with other balls can correct its path, leading it to come back to the same position and speed that it would have had you not interfered.

"Regardless of the choice, the ball will fall into the same place," Dr Yasunori Nomura, a theoretical physicist at UC Berkeley, previously told Insider.

Tobar's model, in other words, says you could travel back in time, but you couldn't change how events unfolded significantly enough to alter the future, Nomura said. Applied to the grandfather paradox, then, this would mean that something would always get in the way of your attempt to kill your grandfather. Or at least by the time he did die, your grandmother would already be pregnant with your mother.

Back to the coronavirus example. Let's say you were to travel back to 2019 and intervene in patient zero's life. According to Tobar's line of thinking, the pandemic would still happen somehow.

"You might try and stop patient zero from becoming infected, but in doing so you would catch the virus and become patient zero, or someone else would," Tobar said, according to Australia's University of Queensland , where Tobar graduated from.

Nomura said that although the model is too simple to represent the full range of cause and effect in our universe, it's a good starting point for future physicists.

Watch: There are 2 types of time travel and physicists agree that one of them is possible

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Paradox-Free Time Travel Is Theoretically Possible, Researchers Say

Matthew S. Schwartz

A dog dressed as Marty McFly from Back to the Future attends the Tompkins Square Halloween Dog Parade in 2015. New research says time travel might be possible without the problems McFly encountered. Timothy A. Clary/AFP via Getty Images hide caption

A dog dressed as Marty McFly from Back to the Future attends the Tompkins Square Halloween Dog Parade in 2015. New research says time travel might be possible without the problems McFly encountered.

"The past is obdurate," Stephen King wrote in his book about a man who goes back in time to prevent the Kennedy assassination. "It doesn't want to be changed."

Turns out, King might have been on to something.

Countless science fiction tales have explored the paradox of what would happen if you went back in time and did something in the past that endangered the future. Perhaps one of the most famous pop culture examples is in Back to the Future , when Marty McFly goes back in time and accidentally stops his parents from meeting, putting his own existence in jeopardy.

But maybe McFly wasn't in much danger after all. According a new paper from researchers at the University of Queensland, even if time travel were possible, the paradox couldn't actually exist.

Researchers ran the numbers and determined that even if you made a change in the past, the timeline would essentially self-correct, ensuring that whatever happened to send you back in time would still happen.

"Say you traveled in time in an attempt to stop COVID-19's patient zero from being exposed to the virus," University of Queensland scientist Fabio Costa told the university's news service .

"However, if you stopped that individual from becoming infected, that would eliminate the motivation for you to go back and stop the pandemic in the first place," said Costa, who co-authored the paper with honors undergraduate student Germain Tobar.

"This is a paradox — an inconsistency that often leads people to think that time travel cannot occur in our universe."

A variation is known as the "grandfather paradox" — in which a time traveler kills their own grandfather, in the process preventing the time traveler's birth.

The logical paradox has given researchers a headache, in part because according to Einstein's theory of general relativity, "closed timelike curves" are possible, theoretically allowing an observer to travel back in time and interact with their past self — potentially endangering their own existence.

But these researchers say that such a paradox wouldn't necessarily exist, because events would adjust themselves.

Take the coronavirus patient zero example. "You might try and stop patient zero from becoming infected, but in doing so, you would catch the virus and become patient zero, or someone else would," Tobar told the university's news service.

In other words, a time traveler could make changes, but the original outcome would still find a way to happen — maybe not the same way it happened in the first timeline but close enough so that the time traveler would still exist and would still be motivated to go back in time.

"No matter what you did, the salient events would just recalibrate around you," Tobar said.

The paper, "Reversible dynamics with closed time-like curves and freedom of choice," was published last week in the peer-reviewed journal Classical and Quantum Gravity . The findings seem consistent with another time travel study published this summer in the peer-reviewed journal Physical Review Letters. That study found that changes made in the past won't drastically alter the future.

Bestselling science fiction author Blake Crouch, who has written extensively about time travel, said the new study seems to support what certain time travel tropes have posited all along.

"The universe is deterministic and attempts to alter Past Event X are destined to be the forces which bring Past Event X into being," Crouch told NPR via email. "So the future can affect the past. Or maybe time is just an illusion. But I guess it's cool that the math checks out."

time travel
grandfather paradox

Time travel: Is it possible?

Science says time travel is possible, but probably not in the way you're thinking.

time travel graphic illustration of a tunnel with a clock face swirling through the tunnel.

Albert Einstein's theory

General relativity and GPS
Wormhole travel
Alternate theories

Science fiction

Is time travel possible? Short answer: Yes, and you're doing it right now — hurtling into the future at the impressive rate of one second per second.

You're pretty much always moving through time at the same speed, whether you're watching paint dry or wishing you had more hours to visit with a friend from out of town.

But this isn't the kind of time travel that's captivated countless science fiction writers, or spurred a genre so extensive that Wikipedia lists over 400 titles in the category "Movies about Time Travel." In franchises like " Doctor Who ," " Star Trek ," and "Back to the Future" characters climb into some wild vehicle to blast into the past or spin into the future. Once the characters have traveled through time, they grapple with what happens if you change the past or present based on information from the future (which is where time travel stories intersect with the idea of parallel universes or alternate timelines).

Related: The best sci-fi time machines ever

Although many people are fascinated by the idea of changing the past or seeing the future before it's due, no person has ever demonstrated the kind of back-and-forth time travel seen in science fiction or proposed a method of sending a person through significant periods of time that wouldn't destroy them on the way. And, as physicist Stephen Hawking pointed out in his book " Black Holes and Baby Universes" (Bantam, 1994), "The best evidence we have that time travel is not possible, and never will be, is that we have not been invaded by hordes of tourists from the future."

Science does support some amount of time-bending, though. For example, physicist Albert Einstein 's theory of special relativity proposes that time is an illusion that moves relative to an observer. An observer traveling near the speed of light will experience time, with all its aftereffects (boredom, aging, etc.) much more slowly than an observer at rest. That's why astronaut Scott Kelly aged ever so slightly less over the course of a year in orbit than his twin brother who stayed here on Earth.

Related: Controversially, physicist argues that time is real

There are other scientific theories about time travel, including some weird physics that arise around wormholes , black holes and string theory . For the most part, though, time travel remains the domain of an ever-growing array of science fiction books, movies, television shows, comics, video games and more.

Scott and Mark Kelly sit side by side wearing a blue NASA jacket and jeans

Einstein developed his theory of special relativity in 1905. Along with his later expansion, the theory of general relativity , it has become one of the foundational tenets of modern physics. Special relativity describes the relationship between space and time for objects moving at constant speeds in a straight line.

The short version of the theory is deceptively simple. First, all things are measured in relation to something else — that is to say, there is no "absolute" frame of reference. Second, the speed of light is constant. It stays the same no matter what, and no matter where it's measured from. And third, nothing can go faster than the speed of light.

From those simple tenets unfolds actual, real-life time travel. An observer traveling at high velocity will experience time at a slower rate than an observer who isn't speeding through space.

While we don't accelerate humans to near-light-speed, we do send them swinging around the planet at 17,500 mph (28,160 km/h) aboard the International Space Station . Astronaut Scott Kelly was born after his twin brother, and fellow astronaut, Mark Kelly . Scott Kelly spent 520 days in orbit, while Mark logged 54 days in space. The difference in the speed at which they experienced time over the course of their lifetimes has actually widened the age gap between the two men.

"So, where[as] I used to be just 6 minutes older, now I am 6 minutes and 5 milliseconds older," Mark Kelly said in a panel discussion on July 12, 2020, Space.com previously reported . "Now I've got that over his head."

General relativity and GPS time travel

Graphic showing the path of GPS satellites around Earth at the center of the image.

The difference that low earth orbit makes in an astronaut's life span may be negligible — better suited for jokes among siblings than actual life extension or visiting the distant future — but the dilation in time between people on Earth and GPS satellites flying through space does make a difference.

Can wormholes take us back in time?

General relativity might also provide scenarios that could allow travelers to go back in time, according to NASA . But the physical reality of those time-travel methods is no piece of cake.

Wormholes are theoretical "tunnels" through the fabric of space-time that could connect different moments or locations in reality to others. Also known as Einstein-Rosen bridges or white holes, as opposed to black holes, speculation about wormholes abounds. But despite taking up a lot of space (or space-time) in science fiction, no wormholes of any kind have been identified in real life.

Related: Best time travel movies

"The whole thing is very hypothetical at this point," Stephen Hsu, a professor of theoretical physics at the University of Oregon, told Space.com sister site Live Science . "No one thinks we're going to find a wormhole anytime soon."

Primordial wormholes are predicted to be just 10^-34 inches (10^-33 centimeters) at the tunnel's "mouth". Previously, they were expected to be too unstable for anything to be able to travel through them. However, a study claims that this is not the case, Live Science reported .

The theory, which suggests that wormholes could work as viable space-time shortcuts, was described by physicist Pascal Koiran. As part of the study, Koiran used the Eddington-Finkelstein metric, as opposed to the Schwarzschild metric which has been used in the majority of previous analyses.

In the past, the path of a particle could not be traced through a hypothetical wormhole. However, using the Eddington-Finkelstein metric, the physicist was able to achieve just that.

Koiran's paper was described in October 2021, in the preprint database arXiv , before being published in the Journal of Modern Physics D.

Alternate time travel theories

While Einstein's theories appear to make time travel difficult, some researchers have proposed other solutions that could allow jumps back and forth in time. These alternate theories share one major flaw: As far as scientists can tell, there's no way a person could survive the kind of gravitational pulling and pushing that each solution requires.

Infinite cylinder theory

Astronomer Frank Tipler proposed a mechanism (sometimes known as a Tipler Cylinder ) where one could take matter that is 10 times the sun's mass, then roll it into a very long, but very dense cylinder. The Anderson Institute , a time travel research organization, described the cylinder as "a black hole that has passed through a spaghetti factory."

After spinning this black hole spaghetti a few billion revolutions per minute, a spaceship nearby — following a very precise spiral around the cylinder — could travel backward in time on a "closed, time-like curve," according to the Anderson Institute.

The major problem is that in order for the Tipler Cylinder to become reality, the cylinder would need to be infinitely long or be made of some unknown kind of matter. At least for the foreseeable future, endless interstellar pasta is beyond our reach.

Time donuts

Theoretical physicist Amos Ori at the Technion-Israel Institute of Technology in Haifa, Israel, proposed a model for a time machine made out of curved space-time — a donut-shaped vacuum surrounded by a sphere of normal matter.

"The machine is space-time itself," Ori told Live Science . "If we were to create an area with a warp like this in space that would enable time lines to close on themselves, it might enable future generations to return to visit our time."

Amos Ori is a theoretical physicist at the Technion-Israel Institute of Technology in Haifa, Israel. His research interests and publications span the fields of general relativity, black holes, gravitational waves and closed time lines.

There are a few caveats to Ori's time machine. First, visitors to the past wouldn't be able to travel to times earlier than the invention and construction of the time donut. Second, and more importantly, the invention and construction of this machine would depend on our ability to manipulate gravitational fields at will — a feat that may be theoretically possible but is certainly beyond our immediate reach.

Graphic illustration of the TARDIS (Time and Relative Dimensions in Space) traveling through space, surrounded by stars.

Time travel has long occupied a significant place in fiction. Since as early as the "Mahabharata," an ancient Sanskrit epic poem compiled around 400 B.C., humans have dreamed of warping time, Lisa Yaszek, a professor of science fiction studies at the Georgia Institute of Technology in Atlanta, told Live Science .

Every work of time-travel fiction creates its own version of space-time, glossing over one or more scientific hurdles and paradoxes to achieve its plot requirements.

Some make a nod to research and physics, like " Interstellar ," a 2014 film directed by Christopher Nolan. In the movie, a character played by Matthew McConaughey spends a few hours on a planet orbiting a supermassive black hole, but because of time dilation, observers on Earth experience those hours as a matter of decades.

Others take a more whimsical approach, like the "Doctor Who" television series. The series features the Doctor, an extraterrestrial "Time Lord" who travels in a spaceship resembling a blue British police box. "People assume," the Doctor explained in the show, "that time is a strict progression from cause to effect, but actually from a non-linear, non-subjective viewpoint, it's more like a big ball of wibbly-wobbly, timey-wimey stuff."

Long-standing franchises like the "Star Trek" movies and television series, as well as comic universes like DC and Marvel Comics, revisit the idea of time travel over and over.

Related: Marvel movies in order: chronological & release order

Here is an incomplete (and deeply subjective) list of some influential or notable works of time travel fiction:

Books about time travel:

A sketch from the Christmas Carol shows a cloaked figure on the left and a person kneeling and clutching their head with their hands.

Rip Van Winkle (Cornelius S. Van Winkle, 1819) by Washington Irving
A Christmas Carol (Chapman & Hall, 1843) by Charles Dickens
The Time Machine (William Heinemann, 1895) by H. G. Wells
A Connecticut Yankee in King Arthur's Court (Charles L. Webster and Co., 1889) by Mark Twain
The Restaurant at the End of the Universe (Pan Books, 1980) by Douglas Adams
A Tale of Time City (Methuen, 1987) by Diana Wynn Jones
The Outlander series (Delacorte Press, 1991-present) by Diana Gabaldon
Harry Potter and the Prisoner of Azkaban (Bloomsbury/Scholastic, 1999) by J. K. Rowling
Thief of Time (Doubleday, 2001) by Terry Pratchett
The Time Traveler's Wife (MacAdam/Cage, 2003) by Audrey Niffenegger
All You Need is Kill (Shueisha, 2004) by Hiroshi Sakurazaka

Movies about time travel:

Planet of the Apes (1968)
Superman (1978)
Time Bandits (1981)
The Terminator (1984)
Back to the Future series (1985, 1989, 1990)
Star Trek IV: The Voyage Home (1986)
Bill & Ted's Excellent Adventure (1989)
Groundhog Day (1993)
Galaxy Quest (1999)
The Butterfly Effect (2004)
13 Going on 30 (2004)
The Lake House (2006)
Meet the Robinsons (2007)
Hot Tub Time Machine (2010)
Midnight in Paris (2011)
Looper (2012)
X-Men: Days of Future Past (2014)
Edge of Tomorrow (2014)
Interstellar (2014)
Doctor Strange (2016)
A Wrinkle in Time (2018)
The Last Sharknado: It's About Time (2018)
Avengers: Endgame (2019)
Tenet (2020)
Palm Springs (2020)
Zach Snyder's Justice League (2021)
The Tomorrow War (2021)

Television about time travel:

Image of the Star Trek spaceship USS Enterprise

Doctor Who (1963-present)
The Twilight Zone (1959-1964) (multiple episodes)
Star Trek (multiple series, multiple episodes)
Samurai Jack (2001-2004)
Lost (2004-2010)
Phil of the Future (2004-2006)
Steins;Gate (2011)
Outlander (2014-2023)
Loki (2021-present)

Games about time travel:

Chrono Trigger (1995)
TimeSplitters (2000-2005)
Kingdom Hearts (2002-2019)
Prince of Persia: Sands of Time (2003)
God of War II (2007)
Ratchet and Clank Future: A Crack In Time (2009)
Sly Cooper: Thieves in Time (2013)
Dishonored 2 (2016)
Titanfall 2 (2016)
Outer Wilds (2019)

Additional resources

Explore physicist Peter Millington's thoughts about Stephen Hawking's time travel theories at The Conversation . Check out a kid-friendly explanation of real-world time travel from NASA's Space Place . For an overview of time travel in fiction and the collective consciousness, read " Time Travel: A History " (Pantheon, 2016) by James Gleik.

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Vicky Stein is a science writer based in California. She has a bachelor's degree in ecology and evolutionary biology from Dartmouth College and a graduate certificate in science writing from the University of California, Santa Cruz (2018). Afterwards, she worked as a news assistant for PBS NewsHour, and now works as a freelancer covering anything from asteroids to zebras. Follow her most recent work (and most recent pictures of nudibranchs) on Twitter.

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Will it ever be possible for time travel to occur? – Alana C., age 12, Queens, New York

Have you ever dreamed of traveling through time, like characters do in science fiction movies? For centuries, the concept of time travel has captivated people’s imaginations. Time travel is the concept of moving between different points in time, just like you move between different places. In movies, you might have seen characters using special machines, magical devices or even hopping into a futuristic car to travel backward or forward in time.

But is this just a fun idea for movies, or could it really happen?

The question of whether time is reversible remains one of the biggest unresolved questions in science. If the universe follows the laws of thermodynamics , it may not be possible. The second law of thermodynamics states that things in the universe can either remain the same or become more disordered over time.

It’s a bit like saying you can’t unscramble eggs once they’ve been cooked. According to this law, the universe can never go back exactly to how it was before. Time can only go forward, like a one-way street.

Time is relative

However, physicist Albert Einstein’s theory of special relativity suggests that time passes at different rates for different people. Someone speeding along on a spaceship moving close to the speed of light – 671 million miles per hour! – will experience time slower than a person on Earth.

People have yet to build spaceships that can move at speeds anywhere near as fast as light, but astronauts who visit the International Space Station orbit around the Earth at speeds close to 17,500 mph. Astronaut Scott Kelly has spent 520 days at the International Space Station, and as a result has aged a little more slowly than his twin brother – and fellow astronaut – Mark Kelly. Scott used to be 6 minutes younger than his twin brother. Now, because Scott was traveling so much faster than Mark and for so many days, he is 6 minutes and 5 milliseconds younger .

Some scientists are exploring other ideas that could theoretically allow time travel. One concept involves wormholes , or hypothetical tunnels in space that could create shortcuts for journeys across the universe. If someone could build a wormhole and then figure out a way to move one end at close to the speed of light – like the hypothetical spaceship mentioned above – the moving end would age more slowly than the stationary end. Someone who entered the moving end and exited the wormhole through the stationary end would come out in their past.

However, wormholes remain theoretical: Scientists have yet to spot one. It also looks like it would be incredibly challenging to send humans through a wormhole space tunnel.

Paradoxes and failed dinner parties

There are also paradoxes associated with time travel. The famous “ grandfather paradox ” is a hypothetical problem that could arise if someone traveled back in time and accidentally prevented their grandparents from meeting. This would create a paradox where you were never born, which raises the question: How could you have traveled back in time in the first place? It’s a mind-boggling puzzle that adds to the mystery of time travel.

Famously, physicist Stephen Hawking tested the possibility of time travel by throwing a dinner party where invitations noting the date, time and coordinates were not sent out until after it had happened. His hope was that his invitation would be read by someone living in the future, who had capabilities to travel back in time. But no one showed up.

As he pointed out : “The best evidence we have that time travel is not possible, and never will be, is that we have not been invaded by hordes of tourists from the future.”

Telescopes are time machines

Interestingly, astrophysicists armed with powerful telescopes possess a unique form of time travel. As they peer into the vast expanse of the cosmos, they gaze into the past universe. Light from all galaxies and stars takes time to travel, and these beams of light carry information from the distant past. When astrophysicists observe a star or a galaxy through a telescope, they are not seeing it as it is in the present, but as it existed when the light began its journey to Earth millions to billions of years ago.

NASA’s newest space telescope, the James Webb Space Telescope , is peering at galaxies that were formed at the very beginning of the Big Bang, about 13.7 billion years ago.

While we aren’t likely to have time machines like the ones in movies anytime soon, scientists are actively researching and exploring new ideas. But for now, we’ll have to enjoy the idea of time travel in our favorite books, movies and dreams.

Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to [email protected] . Please tell us your name, age and the city where you live.

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Is time travel possible? An astrophysicist explains

Time travel is one of the most intriguing topics in science.

Will it ever be possible for time travel to occur? – Alana C., age 12, Queens, New York

But is this just a fun idea for movies, or could it really happen?

Time is relative

Related: The speed of light, explained

However, wormholes remain theoretical : Scientists have yet to spot one. It also looks like it would be incredibly challenging to send humans through a wormhole space tunnel.

Time travel paradoxes and failed dinner parties

As he pointed out : “The best evidence we have that time travel is not possible, and never will be, is that we have not been invaded by hordes of tourists from the future.”

Telescopes are time machines

NASA’s newest space telescope, the James Webb Space Telescope , is peering at galaxies that were formed at the very beginning of the Big Bang, about 13.7 billion years ago.

This article first appeared on the Conversation. You can read the original here .

Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to [email protected] . Please tell us your name, age and the city where you live.

And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.

There are more than 40 holes on Mars. The drill aboard the Curiosity rover created the hole in a rock investigators call Mammoth Lakes. The bright spot to the left of the hole is where the rover smoothed a small area to collect spectroscopic data. Credit: NASA/JPL-Caltech/MSSS

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Is time travel even possible? An astrophysicist explains the science behind the science fiction

Published: Nov 13, 2023

By: Magazine Editor

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Written by Adi Foord , assistant professor of physics , UMBC

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to [email protected] .

Will it ever be possible for time travel to occur? – Alana C., age 12, Queens, New York

But is this just a fun idea for movies, or could it really happen?

Time is relative

However, wormholes remain theoretical: Scientists have yet to spot one. It also looks like it would be incredibly challenging to send humans through a wormhole space tunnel.

Paradoxes and failed dinner parties

As he pointed out : “The best evidence we have that time travel is not possible, and never will be, is that we have not been invaded by hordes of tourists from the future.”

Telescopes are time machines

NASA’s newest space telescope, the James Webb Space Telescope , is peering at galaxies that were formed at the very beginning of the Big Bang, about 13.7 billion years ago.

This article is republished from The Conversation under a Creative Commons license. Read the original article and see more than 250 UMBC articles available in The Conversation.

Tags: CNMS , Physics , The Conversation

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Is Time Travel Even Possible? An Astrophysicist Explains The Science Behind The Science Fiction

If traveling into the past is possible, one way to do it might be sending people through tunnels in space..

multiple-red-alarm-clocks-drifiting-in-a-spiral-of-cosmic-matter

But is this just a fun idea for movies, or could it really happen?

Time is relative

Time isn’t the same everywhere.

However, wormholes remain theoretical: Scientists have yet to spot one. It also looks like it would be incredibly challenging to send humans through a wormhole space tunnel.

Paradoxes and failed dinner parties

As he pointed out : “The best evidence we have that time travel is not possible, and never will be, is that we have not been invaded by hordes of tourists from the future.”

Telescopes are time machines

NASA’s newest space telescope, the James Webb Space Telescope , is peering at galaxies that were formed at the very beginning of the Big Bang, about 13.7 billion years ago.

Adi Foord is an Assistant Professor of Astronomy and Astrophysics at the University of Maryland, Baltimore County. This article is republished from The Conversation under a Creative Commons license . Read the original article .

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Is time travel possible? Why one scientist says we 'cannot ignore the possibility.'

A common theme in science-fiction media , time travel is captivating. It’s defined by the late philosopher David Lewis in his essay “The Paradoxes of Time Travel” as “[involving] a discrepancy between time and space time. Any traveler departs and then arrives at his destination; the time elapsed from departure to arrival … is the duration of the journey.”

Time travel is usually understood by most as going back to a bygone era or jumping forward to a point far in the future . But how much of the idea is based in reality? Is it possible to travel through time?

Is time travel possible?

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According to NASA, time travel is possible , just not in the way you might expect. Albert Einstein’s theory of relativity says time and motion are relative to each other, and nothing can go faster than the speed of light , which is 186,000 miles per second. Time travel happens through what’s called “time dilation.”

Time dilation , according to Live Science, is how one’s perception of time is different to another's, depending on their motion or where they are. Hence, time being relative.

Dr. Ana Alonso-Serrano, a postdoctoral researcher at the Max Planck Institute for Gravitational Physics in Germany, explained the possibility of time travel and how researchers test theories.

Space and time are not absolute values, Alonso-Serrano said. And what makes this all more complex is that you are able to carve space-time .

“In the moment that you carve the space-time, you can play with that curvature to make the time come in a circle and make a time machine,” Alonso-Serrano told USA TODAY.

She explained how, theoretically, time travel is possible. The mathematics behind creating curvature of space-time are solid, but trying to re-create the strict physical conditions needed to prove these theories can be challenging.

“The tricky point of that is if you can find a physical, realistic, way to do it,” she said.

Alonso-Serrano said wormholes and warp drives are tools that are used to create this curvature. The matter needed to achieve curving space-time via a wormhole is exotic matter , which hasn’t been done successfully. Researchers don’t even know if this type of matter exists, she said.

“It's something that we work on because it's theoretically possible, and because it's a very nice way to test our theory, to look for possible paradoxes,” Alonso-Serrano added.

“I could not say that nothing is possible, but I cannot ignore the possibility,” she said.

She also mentioned the anecdote of Stephen Hawking’s Champagne party for time travelers . Hawking had a GPS-specific location for the party. He didn’t send out invites until the party had already happened, so only people who could travel to the past would be able to attend. No one showed up, and Hawking referred to this event as "experimental evidence" that time travel wasn't possible.

What did Albert Einstein invent?: Discoveries that changed the world

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USA TODAY is exploring the questions you and others ask every day. From "How to watch the Marvel movies in order" to "Why is Pluto not a planet?" to "What to do if your dog eats weed?" – we're striving to find answers to the most common questions you ask every day. Head to our Just Curious section to see what else we can answer for you.

This article originally appeared on USA TODAY: Is time travel possible? Why one scientist says we 'cannot ignore the possibility.'

Albert Einstein’s theory of relativity says that time and motion are relative to each other, and nothing can go faster than the speed of light, which is 186,000 miles per second.

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Time travel: five ways that we could do it

Cathal O’Connell

Cathal O'Connell is a science writer based in Melbourne.

In 2009 the British physicist Stephen Hawking held a party for time travellers – the twist was he sent out the invites a year later (No guests showed up). Time travel is probably impossible. Even if it were possible, Hawking and others have argued that you could never travel back before the moment your time machine was built.

But travel to the future? That’s a different story.

Of course, we are all time travellers as we are swept along in the current of time, from past to future, at a rate of one hour per hour.

But, as with a river, the current flows at different speeds in different places. Science as we know it allows for several methods to take the fast-track into the future. Here’s a rundown.

1. Time travel via speed

This is the easiest and most practical way to time travel into the far future – go really fast.

According to Einstein’s theory of special relativity, when you travel at speeds approaching the speed of light, time slows down for you relative to the outside world.

This is not a just a conjecture or thought experiment – it’s been measured. Using twin atomic clocks (one flown in a jet aircraft, the other stationary on Earth) physicists have shown that a flying clock ticks slower, because of its speed.

In the case of the aircraft, the effect is minuscule. But If you were in a spaceship travelling at 90% of the speed of light, you’d experience time passing about 2.6 times slower than it was back on Earth.

And the closer you get to the speed of light, the more extreme the time-travel.

Computer solves a major time travel problem

The highest speeds achieved through any human technology are probably the protons whizzing around the Large Hadron Collider at 99.9999991% of the speed of light. Using special relativity we can calculate one second for the proton is equivalent to 27,777,778 seconds, or about 11 months , for us.

Amazingly, particle physicists have to take this time dilation into account when they are dealing with particles that decay. In the lab, muon particles typically decay in 2.2 microseconds. But fast moving muons, such as those created when cosmic rays strike the upper atmosphere, take 10 times longer to disintegrate.

2. Time travel via gravity

The next method of time travel is also inspired by Einstein. According to his theory of general relativity, the stronger the gravity you feel, the slower time moves.

As you get closer to the centre of the Earth, for example, the strength of gravity increases. Time runs slower for your feet than your head.

Again, this effect has been measured. In 2010, physicists at the US National Institute of Standards and Technology (NIST) placed two atomic clocks on shelves, one 33 centimetres above the other, and measured the difference in their rate of ticking. The lower one ticked slower because it feels a slightly stronger gravity.

To travel to the far future, all we need is a region of extremely strong gravity, such as a black hole. The closer you get to the event horizon, the slower time moves – but it’s risky business, cross the boundary and you can never escape.

And anyway, the effect is not that strong so it’s probably not worth the trip.

Assuming you had the technology to travel the vast distances to reach a black hole (the nearest is about 3,000 light years away), the time dilation through travelling would be far greater than any time dilation through orbiting the black hole itself.

(The situation described in the movie Interstellar , where one hour on a planet near a black hole is the equivalent of seven years back on Earth, is so extreme as to be impossible in our Universe, according to Kip Thorne, the movie’s scientific advisor.)

The most mindblowing thing, perhaps, is that GPS systems have to account for time dilation effects (due to both the speed of the satellites and gravity they feel) in order to work. Without these corrections, your phones GPS capability wouldn’t be able to pinpoint your location on Earth to within even a few kilometres.

3. Time travel via suspended animation

Another way to time travel to the future may be to slow your perception of time by slowing down, or stopping, your bodily processes and then restarting them later.

Bacterial spores can live for millions of years in a state of suspended animation, until the right conditions of temperature, moisture, food kick start their metabolisms again. Some mammals, such as bears and squirrels, can slow down their metabolism during hibernation, dramatically reducing their cells’ requirement for food and oxygen.

Could humans ever do the same?

Though completely stopping your metabolism is probably far beyond our current technology, some scientists are working towards achieving inducing a short-term hibernation state lasting at least a few hours. This might be just enough time to get a person through a medical emergency, such as a cardiac arrest, before they can reach the hospital.

In 2005, American scientists demonstrated a way to slow the metabolism of mice (which do not hibernate) by exposing them to minute doses of hydrogen sulphide, which binds to the same cell receptors as oxygen. The core body temperature of the mice dropped to 13 °C and metabolism decreased 10-fold. After six hours the mice could be reanimated without ill effects.

Unfortunately, similar experiments on sheep and pigs were not successful, suggesting the method might not work for larger animals.

Another method, which induces a hypothermic hibernation by replacing the blood with a cold saline solution, has worked on pigs and is currently undergoing human clinical trials in Pittsburgh.

4. Time travel via wormholes

General relativity also allows for the possibility for shortcuts through spacetime, known as wormholes, which might be able to bridge distances of a billion light years or more, or different points in time.

Many physicists, including Stephen Hawking, believe wormholes are constantly popping in and out of existence at the quantum scale, far smaller than atoms. The trick would be to capture one, and inflate it to human scales – a feat that would require a huge amount of energy, but which might just be possible, in theory.

Attempts to prove this either way have failed, ultimately because of the incompatibility between general relativity and quantum mechanics.

5. Time travel using light

Another time travel idea, put forward by the American physicist Ron Mallet, is to use a rotating cylinder of light to twist spacetime. Anything dropped inside the swirling cylinder could theoretically be dragged around in space and in time, in a similar way to how a bubble runs around on top your coffee after you swirl it with a spoon.

According to Mallet, the right geometry could lead to time travel into either the past and the future.

Since publishing his theory in 2000, Mallet has been trying to raise the funds to pay for a proof of concept experiment, which involves dropping neutrons through a circular arrangement of spinning lasers.

His ideas have not grabbed the rest of the physics community however, with others arguing that one of the assumptions of his basic model is plagued by a singularity, which is physics-speak for “it’s impossible”.

The Royal Institution of Australia has an Education resource based on this article. You can access it here .

Related Reading: Computer solves a major time travel problem

Originally published by Cosmos as Time travel: five ways that we could do it

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Quantum Mechanics Proves 'Back to the Future' Is B.S.

But the Avengers' method of time travel totally checks out.

zurueck in die zukunft, back to the future

Like in certain mathematical conditions , the timeline can overcome some disruptions.
No one can take Back to the Future away from you.

In trippy new research, scientists say they’ve confirmed what they call the Avengers: Endgame model of time travel.

They did this by running a quantum time travel simulation that runs backward and forward, letting them “damage” the past and see what resulted. And, as they say, the devil is in the details—the experiment involves an extremely simplified idea of a “world,” and is only the very first step toward demonstrating any big ideas about causality.

🤯 The universe is a mindf#!@. Let's explore it together.

In a statement, sponsoring Los Alamos National Laboratory likens the movie Back to the Future , where Marty McFly must carefully not disrupt the timeline of his own inception, to the idea of the “butterfly effect.” The idea is simple: Because of the complex way time moves and how causality “ripples out” in unexpected or just unfathomable ways, stepping on a butterfly in the past could change the entire world you try to return to.

Games with procedurally generated worlds use a reverse butterfly effect to create those worlds—a randomized “seed,” which is a string of characters that determines different variables. In Songbringer , for example, the player makes up their own six-letter seed and then plays through the world they created. Since the randomness is an illusion based on high numbers, entering the same seed makes the same world over and over.

christopher lloyd in 'back to the future'

But what if the world is, to some extent, self healing? This is where the Endgame version of events comes into play, and where the quantum experiment begins. In this version of events, no matter what “seed” shifted the world—what information was included, left out, or examined—the timelines would all eventually converge. The Avengers can go back, gently meddle, and return to the present without making a ripple.

This may sound like the same narrative handwaving that enables all time travel stories, but the Los Alamos experiment came to the same conclusion.

Here’s the scenario: Alice and Bob, two agents in a system, each have a piece of data—a qubit , or quantum bit. Alice sends her data backward in time, where Bob measures it, altering it in accordance with the Heisenberg uncertainty principle. What happens when the qubit returns?

In their simulations, the researchers found the qubit didn't change—or even affect—the original timeline. They used a series of quantum logic gates and an operator called a Hamiltonian, which in quantum mechanics is a measurement of potential and kinetic energy. Here’s where the idea stops being the stuff of sci-fi watercooler talk and starts to sound real. From the paper :

“The evolution with a complex Hamiltonian generally leads to information scrambling. A time-reversed dynamics unwinds this scrambling and thus leads to the original information recovery. We show that if the scrambled information is, in addition, partially damaged by a local measurement, then such a damage can still be treated by application of the time-reversed protocol.”

In other words, the nature of the time-affected operator they studied is such that it ends up affecting information that travels through it, and for some far-off application like quantum internet, that fact could end up making a big difference.

If researchers know they can “rewind” the information to see how it looked originally without changing the outcome, they may be able to guarantee fidelity of data in a situation previously thought to result in, well, some digital broken eggs.

preview for Pop News: Airports, Lava Floors and Movie Stunts

Caroline Delbert is a writer, avid reader, and contributing editor at Pop Mech. She's also an enthusiast of just about everything. Her favorite topics include nuclear energy, cosmology, math of everyday things, and the philosophy of it all.

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October 21, 1999

According to current physical theory, is it possible for a human being to travel through time?

As several respondents noted, we constantly travel through time--just forward, and all at the same rate. But seriously, time travel is more than mere fantasy, as noted by Gary T. Horowitz, a professor of physics at the University of California at Santa Barbara:

"Perhaps surprisingly, this turns out to be a subtle question. It is not obviously ruled out by our current laws of nature. Recent investigations into this question have provided some evidence that the answer is no, but it has not yet been proven to be impossible."

Even the slight possibility of time travel exerts such fascination that many physicists continue to study not only whether it may be possible but also how one might do it.

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One of the leading researchers in this area is William A. Hiscock, a professor of physics at Montana State University. Here are his thoughts on the matter:

"Is it possible to travel through time? To answer this question, we must be a bit more specific about what we mean by traveling through time. Discounting the everyday progression of time, the question can be divided into two parts: Is it possible, within a short time (less than a human life span), to travel into the distant future? And is it possible to travel into the past?

"Our current understanding of fundamental physics tells us that the answer to the first question is a definite yes, and to the second, maybe.

"The mechanism for traveling into the distant future is to use the time-dilation effect of Special Relativity, which states that a moving clock appears to tick more slowly the closer it approaches the speed of light. This effect, which has been overwhelmingly supported by experimental tests, applies to all types of clocks, including biological aging.

"If one were to depart from the earth in a spaceship that could accelerate continuously at a comfortable one g (an acceleration that would produce a force equal to the gravity at the earth's surface), one would begin to approach the speed of light relative to the earth within about a year. As the ship continued to accelerate, it would come ever closer to the speed of light, and its clocks would appear to run at an ever slower rate relative to the earth. Under such circumstances, a round trip to the center of our galaxy and back to the earth--a distance of some 60,000 light-years--could be completed in only a little more than 40 years of ship time. Upon arriving back at the earth, the astronaut would be only 40 years older, while 60,000 years would have passed on the earth. (Note that there is no 'twin paradox,' because it is unambiguous that the space traveler has felt the constant acceleration for 40 years, while a hypothetical twin left behind on a spaceship circling the earth has not.)

"Such a trip would pose formidable engineering problems: the amount of energy required, even assuming a perfect conversion of mass into energy, is greater than a planetary mass. But nothing in the known laws of physics would prevent such a trip from occurring.

"Time travel into the past, which is what people usually mean by time travel, is a much more uncertain proposition. There are many solutions to Einstein's equations of General Relativity that allow a person to follow a timeline that would result in her (or him) encountering herself--or her grandmother--at an earlier time. The problem is deciding whether these solutions represent situations that could occur in the real universe, or whether they are mere mathematical oddities incompatible with known physics. No experiment or observation has ever indicated that time travel is occurring in our universe. Much work has been done by theoretical physicists in the past decade to try to determine whether, in a universe that is initially without time travel, one can build a time machine--in other words, if it is possible to manipulate matter and the geometry of space-time in such a way as to create new paths that circle back in time.

"How could one build a time machine? The simplest way currently being discussed is to take a wormhole (a tunnel connecting spatially separated regions of space-time) and give one mouth of the wormhole a substantial velocity with respect to the other. Passage through the wormhole would then allow travel to the past.

"Easily said--but where does one obtain a wormhole? Although the theoretical properties of wormholes have been extensively studied over the past decade, little is known about how to form a macroscopic wormhole, large enough for a human or a spaceship to pass through. Some speculative theories of quantum gravity tell us that space-time has a complicated, foamlike structure of wormholes on the smallest scales--10^-33 centimeter, or a billion billion times smaller than an electron. Some physicists believe it may be possible to grab one of these truly microscopic wormholes and enlarge it to usable size, but at present these ideas are all very hypothetical.

"Even if we had a wormhole, would nature allow us to convert it into a time machine? Stephen Hawking has formulated a "Chronology Protection Conjecture," which states that the laws of nature prevent the creation of a time machine. At the moment, however, this is just a conjecture, not proven.

"Theoretical physicists have studied various aspects of physics to determine whether this law or that might protect chronology and forbid the building of a time machine. In all the searching, however, only one bit of physics has been found that might prohibit using a wormhole to travel through time. In 1982, Deborah A. Konkowski of the U.S. Naval Academy and I showed that the energy in the vacuum state of a massless quantized field (such as the photon) would grow without bound as a time machine is being turned on, effectively preventing it from being used. Later studies by Hawking and Kip S. Thorne of Caltech have shown that it is unclear whether the growing energy would change the geometry of space-time rapidly enough to stop the operation of the time machine. Recent work by Tsunefumi Tanaka of Montana State University and myself, along with independent research by David Boulware of the University of Washington, has shown that the energy in the vacuum state of a field having mass (such as the electron) does not grow to unbounded levels; this finding indicates there may be a way to engineer the particle physics to allow a time machine to work.

"Perhaps the biggest surprise of the work of the past decade is that it is not obvious that the laws of physics forbid time travel. It is increasingly clear that the question may not be settled until scientists develop an adequate theory of quantum gravity."

John L. Friedman of the physics department at the University of Wisconsin at Milwaukee has also given this subject a great deal of consideration:

"Special relativity implies that people or clocks at rest (or not accelerating) age more quickly than partners traveling on round-trips in which one changes direction to return to one's partner. In the world's particle accelerators, this prediction is tested daily: Particles traveling in circles at nearly the speed of light decay more slowly than those at rest, and the decay time agrees with theory to the high precision of the measurements.

"Within the framework of Special Relativity, the fact that particles cannot move faster than light prevents one from returning after a high-speed trip to a time earlier than the time of departure. Once gravity is included, however, spacetime is curved, so there are solutions to the equations of General Relativity in which particles can travel in paths that take them back to earlier times. Other features of the geometries that solve the equations of General Relativity include gravitational lenses, gravitational waves and black holes; the dramatic explosion of discoveries in radio and X-ray astronomy during the past two decades has led to the observation of gravitational lenses and gravitational waves, as well as to compelling evidence for giant black holes in the centers of galaxies and stellar-sized black holes that arise from the collapse of dying stars. But there do not appear to be regions of spacetime that allow time travel, raising the fundamental question of what forbids them--or if they really are forbidden.

"A recent surprise is that one can circumvent the 'grandfather paradox,' the idea that it is logically inconsistent for particle paths to loop back to earlier times, because, for example, a granddaughter could go back in time to do away with her grandfather. For several simple physical systems, solutions to the equations of physics exist for any starting condition. In these model systems, something always intervenes to prevent inconsistency analogous to murdering one's grandfather.

"Then why do there seem to be no time machines? Two different answers are consistent with our knowledge. The first is simply that the classical theory has a much broader set of solutions than the correct theory of quantum gravity. It is not implausible that causal structure enters in a fundamental way in quantum gravity and that classical spacetimes with time loops are spurious--in other words, that they do not approximate any states of the complete theory. A second possible answer is provided by recent results that go by the name chronology protection: One supposes that quantum gravity allows microscopic structures that violate causality, and one shows that the character of macroscopic matter forbids the existence of regions with macroscopically large time loops. To create a time machine would require negative energy, and quantum mechanics appears to allow only extremely small regions of negative energy. And the forces needed to create an ordinary-sized region with time loops appear to be extremely large.

"To summarize: It is very likely that the laws of physics rule out macroscopic time machines, but possible that spacetime is filled with microscopic time loops.

Science Fiction or Fact: Is Time Travel Possible?

In this weekly series, Life's Little Mysteries rates the plausibility of popular science fiction concepts.

In the first "Back to the Future" movie, all it took to travel through time was 1.21 gigawatts and a flux capacitor (packed into a DeLorean sports car for style points). Despite centuries of dreams and decades of bona fide research, flux capacitors remain beyond our grasp, as do any other time travel-enabling devices.

From a pure physics point of view, travel into the future is not at all impossible and in fact happens all the . . . time. With all due respect to Doc Brown, however, backward time travel stacks up as a much tougher proposition.

"We can travel at different rates to the future," said Seth Lloyd, a professor of quantum mechanical engineering at the Massachusetts Institute of Technology. "To go into the past and mess around with it, that's more controversial."

My watch or yours?

For a real, everyday example of time travel, consider the satellites of the Global Positioning System . Were it not for built-in calibrations, the GPS atomic clocks would gain 38 microseconds over terrestrial timepieces every day, throwing off their location accuracy by several miles. "Clocks on Earth tick a tiny bit slower than satellites out in space," said Lloyd.

The reason: time dilation, as described by Einstein's two theories of relativity. According to the special theory, the faster an object moves relative to another object, the slower it experiences time. For GPS satellites zooming around Earth at nearly 9,000 mph (14,000 kph), this effect cuts seven microseconds off their clocks daily (relative to clocks on Earth).

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The second effect, explained by the general theory of relativity, involves gravity. Clocks closer to the center of a gravitational mass, such as Earth, tick more slowly than those farther away. GPS satellites orbit 12,500 miles (20,100 km) above the ground, and as a result have 45 microseconds tacked onto their clocks per day. The net result of the two relativistic phenomena is 38 microseconds, which engineers have accounted for with GPS technology.

Future, here we come

Both of these time dilation pathways — motion through space or a strong gravity well — permit time travel into the future.

A popular imagining of the first scenario involves astronauts cruising aboard a rocket ship at extremely high speed to a distant star. Upon their return, the ship's occupants will have aged mere years while centuries have passed on Earth. (An unintended version of this situation befalls Charlton Heston and his crew in the original 1968 movie " Planet of the Apes .")

Pulling off such a feat is really only a matter of investment, technology and will. "Doing 'century hopping' via relativity will require some engineering solutions to things like building rocket engines with enough fuel supplies for very prolonged trips," said Jeff Tollaksen, a professor of physics at Chapman University in Orange, Calif. [ 7 Everyday Things That Happen Strangely in Space ]

Going to a distant star and back would not even be necessary — all that is required is motion. The time-traveling effect would be achieved by simply getting whirled in a giant centrifuge at near-light speeds, Tollaksen said (though it would kill whoever attempted it).

The second, gravity-based scenario poses similar lethality, at least for someone wanting an appreciable difference in his relative time frame. If you stood on a neutron star for a few years, a decade would elapse on Earth. Of course, you would not survive the supermassive star's crushing, rending gravity, making this approach truly a "Rip" van Winkle method.

Yesteryears

What of diving into the past? According to general relativity, a rotating black hole can warp space-time, forming paths to previous moments. "You have these so-called timelike curves that you could follow that would take you back to your past," said Lloyd. [ What Would It Be Like to Travel Faster than the Speed of Light? ]

Quantum mechanics has opened up strange avenues as well. Experiments have shown that measuring a particle property at an initial and end stage can modify its middle value, but only if the last measurement takes place. Such clues toward a possible "backwards causality" continue to be investigated.

A major showstopper for traveling back in time, however, is common sense. A classic example is the grandfather paradox , in which a time traveler goes into the past and murders his grandfather, thus preventing the time traveler from ever being born.

Yet there might be ways around this mind-bender. Lloyd has conducted quantum mechanical experiments in the last few years that suggest timelines remain self-consistent. The tests served as "the moral equivalent of sending a photon a few billionths of a second backwards in time and having it try to kill its former self," Lloyd said.

In Lloyd's experiment, as photons got ever closer to interfering with themselves, the probability of the experiment succeeding grew ever lower. "Our theory has an automatic censorship of things which are completely inconsistent," said Lloyd. "When you go back [in time], no matter how hard you try, you cannot change the thing you try to change."

In theory, then, Grandpa lives, no matter what.

Space-time busters?

A couple of other domains offer hope for would-be time travelers. Moving faster than light — the universal reference point — would do the trick, hence the excitement over last year's finding in Europe of superluminal neutrinos , a seemingly impossible finding that has been widely faulted.

Wormholes — theoretical "tunnels" through space-time — also could burrow into the past or future just as they might connect different regions in the cosmos.

Neither of these alternatives seems particularly likely. As much as many of us might hate to admit it, the past, with all of its mistakes, could remain sealed off from our efforts to redo it.

"Even if the laws of physics allowed visiting the past," Lloyd said, "it is not clear how it might actually happen in our universe."

Plausibility score: A one-way ticket to the future requires a hefty budget and a heck of a lot of engineering know-how. Voyaging into the past, however, looks to be near impossible, so we give time travel two out of four Rocketboys.

This story was provided by Life's Little Mysteries , a sister site to LiveScience.

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Is Time Travel Actually Possible?

We all know how time travel works, right? You step into a gyroscopic chamber in a secret science research facility, a dude in a white lab coat hits a switch, the chamber spins and makes "bwa wa wa" sounds as arcs of blue "energy" crackle around, and snap: You're face-to-face with Arnold Schwarzenegger circa 200 million B.C.E. for a mission to shoot up dinosaurs with robo gun arms. Pew-pew!

Well, it's time to dash to pieces all of our beloved, sci-fi-conjured time travel visions from "Star Trek," "Back to the Future," "Avengers: Endgame," "The Terminator," and even classy, supposedly more grounded fare like "Interstellar." No, you won't be going back in time to chat up Julius Caesar in English, sire your own grandfather , or save humanity with the power of semi-clever plot contrivances. And yet, sites like Scientific American say that time travel is possible. What gives?

When physicists say that "time travel is possible," they mean that time passes differently for different observers based on speed and distance — i.e., "time is relative," ala Albert Einstein's famed E = mc 2 theory of special relativity. They also mean that "there's nothing mathematically preventing time from moving in reverse." But we experience time unidirectionally because molecules tend to move from higher to lower states of order, as Quanta Magazine outlines — i.e., "Time's Arrow." Putting these two together means: 1) No one refutes that forward-moving time travel is possible, and, 2) Backward-moving time travel is impossible.

Space, not time

It sounds like a perfectly typical, baseless, first-year philosophy student proclamation: "You see — time ... doesn't exist!" Cue the smoke bomb and rapturous facial expression. Well, it's time to blow everyone's minds and confirm that, yeah, that statement is kinda-sorta true. Except, it's only true because time isn't time. Time is space, which means time travel is really space travel.

In his 1905 theory of special relativity, Albert Einstein noted that as objects approach the speed of light , they experience time more slowly. As Live Science overviews, this is referred to as "time dilation." But to that fast-moving object, everyone else is slow. Hence: Time is relative and not the same for all observers.

Four years later in 1909, German mathematician Hermann Minkowski coined the term "space-time" to refer to the unified spatial and temporal nature of reality. Time, he concluded, is just another aspect — a dimension — of space. You can move through space at the expense of time, or vice-versa, like how you can turn right at the expense of turning left, per Big Think . To the perspective of light particles — the massless, fastest objects in the universe — time doesn't exist, as Forbes explains.

So, if you want to time travel? You've got to travel through space at near-lightspeed. And as the rest of reality zips by, you slow down. Presto: You're in the future. But you can't go back, as Live Science details. Past physical space no longer exists.

Forward, not backward

"You can never go home again," the somewhat cryptic statement goes. But while that statement refers to an inability to recapture the magical fancies of youth, it could also just as easily refer to time travel.

"Why can't you travel backward in time?" the somewhat consternated headline on Ars Technica asks. Well, because the past doesn't exist in any physical sense with which we could ever interact. It's a psychological construct composed of memories that don't live outside of your head — sorry. The only place the "past" exists is in the far reaches of telescopic sight, like when the James Webb Space Telescope sees light from the early universe that's just reaching us now. In that moment, we're viewing the remote past.

When considering why we can't travel backward in time, we really have to ask, "Why can't molecules spontaneously rearrange themselves into former compositions?" If that happened, then a cracked egg would reform, or spilled milk would slide back up into a glass. But as the second law of thermodynamics says, entropy in a closed system must always increase. Entropy is the tendency for the arrangement of molecules to grow evermore disordered over time, and the universe is a closed system because nothing exists outside of it. And as Popular Mechanics overviews, entropy has continued to increase since the formation of the cosmos. There's simply no way to slip into any previous molecular arrangement, because remember: Time isn't time. Time is space.

Hitching on a ride with the black hole express

There's one viable time travel method on which physicists can agree: Hitching a ride with a black hole . Or more specifically: Moving past its outer, spinning accretion disc and toward the central event horizon from which nothing can escape. As described by Royal Museums Greenwich , this process will most certainly kill you by "spaghettifying" your body. So once again, we're talking about a one-way trip.

Remember we said that as you approach the speed of light, time dilates, i.e., slows down? Well, black holes spin at near-light speed. This is something that one movie — "Interstellar" — got right. But no, you won't get sucked into a 4D library to push some books off of Murph's bookshelf (it's complicated — watch the movie). As Astronomy says, a person stuck in the event horizon of a black hole would observe the rest of the universe aging much faster. That person, strictly speaking, would be in "the future." Now, if we could escape from a black hole? We'd have a workable solution for future-bound time travel.

And yet, as The Conversation reports, some researchers believe black holes can do the impossible: Send someone backward in time. If a celestial object was so massive that it "dragged" spacetime with it, it could create a closed timelike curve (CTC) that could pull someone into "the past." Still, folks like renowned physicist Stephen Hawking thought this was nonsense.

Feasibly impossible

There are a couple of other weird addendums to the "Is time travel possible?" discussion. Chiefly, as physicist Sabine Hossenfelder says on her YouTube channel: "You need a receiver station for time travel." This is something fictional time travel always leaves out and gets wrong. Earth isn't sitting in space like a stone on the ground. As Scientific American says, it's rotating at about 1,000 miles per hour while revolving around the sun at 67,000 miles per hour. On top of this, our entire solar system is spinning through the Milky Way at 490,000 miles per hour. So if you time traveled just one second forward or backward, but didn't account for planetary motion? You'd teleport right into empty space. And so, like we've said: Time travel is space travel .

And finally, there's quantum entanglement : That thing that you've heard about that no one understands. Quanta Magazine explains how quantum entanglement — the codependence of molecular attributes over distances — gives rise to time's arrow. We'll save you the headache by saying: If it was possible to manipulate the attributes of individual atoms, we could reconstruct "the past." This, however, is whackadoodle fantasy absurdity that necessitates digging into further and further realms of unfounded speculation.

So, is time travel possible? Mathematically, yes. Forward, yes. Backward, no. But is it feasible? Let's put it this way: Best focus on the present, because by the time humanity untangles time travel, our present will be nothing but the memory of entropy's future.

Money blog: How to split housework fairly - and the things you shouldn't say

Welcome to the Money blog, your place for personal finance and consumer news and tips. Enjoy our Weekend Money content below and we'll be back with live updates on Monday. Let us know your thoughts on any of the topics we're covering using the comments box below.

Saturday 29 June 2024 09:20, UK

Weekend Money

How to split housework fairly with your partner
Price of popular food at Wimbledon has stayed same for 14 years - and it's fairly affordable
Ofgem urged not to lift ban on acquisition-only energy tariffs
Your comments : Paying off a mortgage into retirement and new cars turning faulty

Essential reads

A week when probable future of mortgage rates became clearer
Savings Guide: What to look for with 5% rates still available on easy access accounts
Cheap Eats : Great British Menu legend picks out favourites at home and in North Yorkshire
Women in Business : How accident in cafe and £400 turned into a genius business idea that's about to go global
Money Problem : 'I bought a new car but it's been back six times with same fault - what can I do?'
How to stop your car from being stolen - or even 'cannibalised'
Best of the Money blog - an archive

Ask a question or make a comment

By Jess Sharp , Money team

Splitting up household jobs, whether that be cleaning, washing or life admin, is an issue that affects a lot of couples.

Starling Bank found women do a total of 36 hours of household tasks and admin per week - equivalent to a full-time job.

This is nine hours more than men - and yet men believe they do the majority in their household. The average man estimates they do 52% of work overall.

It's the discrepancy between perception and reality (and, of course, this can work both ways) that leads to arguments.

Couples who don't divide the housework equally have roughly five arguments about housework each month - rising to eight for couples who rely on just one person for the work.

We spoke to relationship expert Hayley Quinn about the best ways to split household work - and how to deal with arguments should they arise with your partner.

She explained that it's necessary to be "transparent" when deciding how to split the workload - but also to be flexible in order to find a solution that suits all involved.

While a 50/50 split might be your idea of perfection, Hayley said it was "almost inevitable that one partner may take on slightly more of the load" at different periods of time.

"Striving for perfect 50/50 fairness at all times is a really nice ideal, but it just may not be that practical for modern life," she said.

She said some jobs may be more visible than others, like cleaning, sorting out the washing, and taking the bins out.

Other jobs can take up just as much time and resource, but will fly under the radar. She gave the examples or sorting out travel insurance or changing over internet provider.

How should you approach a conversation with your partner about splitting the work?

To start off, Hayley said you should enter the conversation with a positive mindset - think how you are both contributing to the relationship in different ways.

"When you're having these conversations, it's not that many people are sitting around feeling like they're not contributing," Hayley said.

"In fact, I think if there's a discrepancy in how people contribute, it's just due to a lack of awareness as to what the other partner does, and some chores are just more obviously visible than others."

Try to avoid starting the chat with the perspective that you are working a lot harder than your partner and they're not pulling their weight.

"That way, you start from a place of we're all on the same team," she said.

"When you're doing that as well, it's really important not to make statements which assume what the other partner is thinking, feeling, or contributing.

"So, for instance, saying something like 'I'm always the one that's picking the kids up from school and you never do anything', becomes easily very accusational, and this is when arguments start.

"Instead, most partners will be much more receptive if you simply ask for more help and assistance."

When asking for help, Hayley said it's important to ask in a way that's verbal and clear - don't assume your partner is going to intuitively know what share of household chores to take on if you just complain.

"In a nice way, explicitly ask for what you want. It could be something like saying, 'Look, I know that we're both working a long week, but I feel like there's so much to do. It would be really helpful if... I'd really appreciate it if you take over lunch,'" she explained.

"Again, start from a place of appreciation. Acknowledge what your partner contributes already, and be explicitly clear as to what you would like them to do. Phrase it as a request for their help."

She also said some people can feel protective of how jobs are completed, and learning to relinquish that control can be helpful.

"If you want it to feel more equitable, you have to let your partner do things in their own way," she said.

What happens if that doesn't work?

If you find the conversations aren't helping, you can always try organising a rota, Hayley said.

She recommended using Starling Bank's Share the Load tool to work out your chore split.

However, she said if you feel there are constant conversations and nothing is changing then the issue is becoming more about communication than sharing the workload.

"It's actually about someone not hearing what you're trying to communicate to them, so it's more of a relationship-wide issue," she said.

She advised sitting down and trying to have another transparent verbal conversation, making it clear that you have spoken about this before and how it's making you feel in a factual way, without placing blame.

Using phrases like "I've noticed" or "I've observed" can help, she said.

If after all that, the situation still isn't getting better, she said it's time to consider confiding in friends or family for support, or seeing a relationship counsellor.

The oldest and most prestigious tennis event in the world returns on Monday, with the best of the best players to battle over two weeks to be named champion.

Crowds in their thousands will flock to Wimbledon to enjoy a spot of sport - as well as the range of food and drink on offer.

It's not the cheapest day out, with a cool cup of Pimms setting you back just under £10 and a bottle of water coming in at nearly £3.

But did you know that despite souring inflation in recent years sending food prices through the roof, one fan favourite - the quintessentially British strawberries and cream combo - has stayed at the same price since 2010?

A pot of the sweet snack costs just £2.50, making it one of the more affordable offerings at the All England Club. It has been served up there since the very first Wimbledon tournament in 1877.

Perdita Sedov, Wimbledon's head of food and beverage, previously told The Telegraph the price freeze "goes back to a long-standing tradition" of strawberries and cream being associated with the championship.

"It's about being accessible to all," she said.

According to the Wimbledon website, each year more than 38.4 tonnes of strawberries are picked and consumed during the tournament.

Ofgem is being urged not to lift a ban on acquisition-only energy tariffs (deals that are available only to new customers, not existing ones).

A coalition of consumer organisations and energy companies led by Which? has penned a letter to the government regulator for electricity and gas warning it of the risk of a "return to a market which discriminates against loyal customers".

They have also raised the potential impact on customers in debt, who may not be able to switch but could also find themselves struggling to access a better deal with their current supplier under the plans.

The letter also notes the "very recent history" when more than 30 suppliers went bust - many after trying to win customers with unsustainably cheap tariffs.

Ofgem has said it could remove the ban on acquisition-only tariffs from 1 October but consumer choice website Which? has research that shows the public are opposed to cheap deals that exclude existing customers, with 81% feeling it would be unfair if their supplier was offering cheaper deals to new customers only.

The consumer champion has signed the letter to Ofgem alongside E.ON, Octopus, So Energy, Rebel Energy, End Fuel Poverty Coalition, Citizens Advice and Fair by Design.

Two topics dominated our inbox this week.

Many readers got in touch about our Weekend Money feature on older Britons who face having to work past pension age to pay off long-term mortgages.

Lots of you share the fears of those we spoke to in the feature...

I am in my 70s with still about five years to go on my mortgage. It stands at 30k on a 300k house. The mortgage repayments are £800 a month, this doesn't sound much but on a static pension it is massive and I am literally on the point of not having sufficient money to pay it. Red

I was supposed to retire in 2.5 years at 66 and 4 months, my mortgage finishes when I'm 70. I was paying off extra (double) on my previous rate to reduce an interest only mortgage, but the recent increases in mortgage rates have meant I'm paying off hardly any. AVB

I'm 67 and still trying to pay off a mortgage that has another five years to run. I can't stop working and do over 10 hours a day, 5 days a week. Keith

My problem is going to be paying off an interest-only mortgage. More than anything I wish I hadn't changed when I had my twins but we couldn't make ends meet at the time. Sazavan

Six years ago I reached the age of 70 and my interest-only mortgage ended - to extend it was impossible with the conditions attached. This then threw me into the rental market, paying more than my mortgage. Now I am facing eviction from the rental due to it being sold. Marianj

We also heard from a mortgage adviser, whose recommendations matched those of Gerard Boon, the managing director of online mortgage broker Boon Brokers, who we spoke to for the feature...

I am a mortgage adviser in Leicestershire and have found an increasing number of people asking to go as long as possible past normal retirement age. I always point out that it's great to have lower payments in the short term but you will need to work to 75. There's no choice. Semaine

Onto the second topic that dominated your correspondence, and we were sorry to learn that lots of you face similar issues as reader Adam, who has had to take his faulty car back to the garage six times - and is still not convinced it is fixed.

Scott Dixon, from The Complaints Resolver , was on hand to help break down what Adam could do for our Money Problem feature - read his advice here:

Same thing happened to me, except that they didn't let me refund the vehicle and claimed it was my fault even though I told them about the issue during the six months' warranty multiple times... they barely replied. K

I have bought a used car and there is an engine management light on. The garage where I bought it from has since changed name and moved premises (found out by accident). When I call to book in I am told to expect a call back or the mechanic will ring me but they never do. Andy D

I have taken my car to Halfords four times in the last 14 months. Each time they guarantee me it's fixed and within a week it's back to normal. Can I get it repaired elsewhere and bill Halfords? Simon

I have a JAG SVR that's been faulty since day one, the garage sent me home with it faulty and not working correctly. I have tried to reject it but the finance company are playing David versus Goliath... we can prove issues from day one, we have two vehicle reports to back it up. Jezza

Have a Nissan Juke, which has a seat issue where it sinks on its own… Nissan saying it's not a manufacturing fault, but "user error". Where do I stand in getting it fixed? Technical team keeps fobbing it off as our fault. Esmith97

If you're in a position like this, do check out Scott Dixon's advice in the feature above.

The Money blog is your place for consumer news, economic analysis and everything you need to know about the cost of living - bookmark news.sky.com/money.

It runs with live updates every weekday - while on Saturdays we scale back and offer you a selection of weekend reads.

Check them out this morning and we'll be back on Monday with rolling news and features.

The Money team is Bhvishya Patel, Jess Sharp, Katie Williams, Brad Young, Ollie Cooper and Mark Wyatt, with sub-editing by Isobel Souster. The blog is edited by Jimmy Rice.

Starting from next month, gamers will be able to play Xbox titles like Fallout 4, Starfield and Fortnite using Amazon Fire TV.

A new upgrade coming to the Fire TV 4K devices transforms your television into a console, thanks to Xbox Cloud Gaming.

You'll need to be a member of Xbox Game Pass Ultimate to take advantage, plus you'll need a compatible controller and a solid internet connection.

"One of the biggest benefits of cloud gaming is the ability to play premium games without needing a console," Amazon explained.

"The Fire TV Stick may be compact, but it can stream and run graphically intense Xbox games like Senua's Saga: Hellblade II.

"This portability also means you can easily move your cloud gaming setup from the living room TV to a different room or even take it on the road.

"As long as you have a solid internet connection and your compatible Fire TV Stick, and a compatible controller, you can take your Xbox Game Pass games and saved progress travels with you."

Once downloaded, the Xbox app is designed to offer a smooth and seamless experience. Here’s how it works:

Install and launch the Xbox app from your Fire TV device;
Sign in with your Microsoft account to play. If you’re an Xbox Game Pass Ultimate member, you’ll have instant access to hundreds of cloud-enabled games;
Connect a Bluetooth-enabled wireless controller. Controllers like the Xbox Wireless Controller, Xbox Adaptive Controller, PlayStation DualSense, or DualShock 4 controller are all compatible.

A new Amazon Fire TV Stick 4K will set you back £59.99 on Amazon, while a new Xbox Wireless Controller costs £49.59.

Xbox Game Pass Ultimate currently costs £1 for the first 14 days for new members, then is billed at £12.99 per month.

House prices are overvalued by thousands of pounds, according to a major property company.

The typical property is £20,000 more than is affordable to the average household, says Zoopla.

But rising incomes and longer mortgage terms mean the "over-valuation" is expected to disappear by the end of the year.

Zoopla's report said: "House prices still look expensive on various measures of affordability.

"We expect house price inflation to remain muted, likely to rise more slowly than household incomes over the next one to two years."

The average house price is around £264,900 – but according to Zoopla's calculations, the affordable price is £245,200.

"A new government will add a dimension of political stability when the autumn market starts in September and even if the [Bank of England base] rate is not lower by then, a cut will be imminent," said Tom Bill, head of UK residential research at estate agent Knight Frank.

"Given that mortgage rates will steadily reduce as services inflation comes under control, we expect UK house prices to rise by 3% this year."

Zoopla's over-valuation estimate was reached by comparing the actual average house price in its index with an "affordable" price, which was calculated based on households' disposable incomes, average mortgage rates and average deposit sizes for home buyers.

It's one of the most iconic and popular music festivals in the world, and it's notoriously hard to get a ticket.

Glastonbury has rolled around once again and roughly 210,000 people have flocked to Somerset this year as Dua Lipa, Coldplay and SZA headline the UK's biggest festival this weekend.

Those in the crowd are in the lucky minority — an estimated 2.5 million people tried to get tickets for this year's event, meaning the odds really aren't in your favour if you fancy going.

Tickets routinely sell out within an hour of going on sale, and that demand is unlikely to decrease next year, given the festival will likely take a fallow year in 2026.

So, if you're feeling jealous this year, how do you get tickets for Glastonbury 2025, and how can you give yourself the best possible chance?

We've run through all the available details as well as some tips so you're best prepared when the time comes.

Registration details: Before potential festivalgoers get the chance to buy tickets, they must register on the official website.

One of the reasons this is done is to stop ticket touting, with all tickets non-transferable. Each ticket features the photograph of the registered ticket holder, with security checks carried out to ensure that only the person in the photograph is admitted to the festival.

Registration is free and only takes a few minutes. You will be asked to provide basic contact details and to upload a passport-standard photo.

Registration closes a few weeks before tickets are released.

Where to buy tickets: Tickets can be bought exclusively at glastonbury.seetickets.com once they become available.

No other site or agency will be allocated tickets, so if you see anyone else claiming to have Glastonbury tickets available for purchase, it's most likely a scam.

When tickets go on sale: We don't know the details for next year yet - but Glastonbury ticket sales usually take place in October or November of the year before the festival.

This year's ticket sales began, following a delay, in November 2023. Coach tickets typically go on sale a few days before (traditionally on a Thursday), with general admission tickets following on the Sunday morning a few days later.

For those that miss out, there's also a resale that takes place in April for tickets that have been returned or for those with a balance that has not been paid.

This year's April resale took place on 18 April (for ticket and coach travel options) and 21 April (general admission tickets and accommodation options).

How much it costs: General admission tickets for this year's festival cost £355 each, plus a £5 booking fee. That's an increase on last year's price of £335 each, which was also an increase on the 2022 price of around £280.

So, we can probably assume that ticket prices will go up once again for next year's festival.

Remember, there are options to pay for your ticket in instalments, so you won't have to pay the full price in one go if you don't want to. All tickets are subject to a £75 deposit, with the remaining balance payable by the first week of April.

It's also worth noting that Glastonbury is a family festival, and that's reflected in the fact that children aged 12 and under when the festival takes place are admitted free of charge.

TIPS FOR THE BIG TICKET SALE DAY

The scramble for tickets when they go on general sale is nothing short of painstaking, with demand far outweighing supply.

Here are some tips to give you the best possible chance of bagging tickets:

Familiarise yourself with the website: You may see a reduced, bare-looking version of the booking page once you gain entry. The organisers say this is intentional to cope with high traffic and does not mean the site has crashed, so be sure not to refresh or leave the page.

Once you reach the first page of the booking site, you will need to enter the registration number and registered postcode for yourself and the other people you are attempting to book tickets for.

When you proceed, the details you have provided will be displayed on the next page.

Once you have double checked all of your information is correct, click 'confirm' to enter the payment page, where you will need to check/amend your billing address, confirm your payment information, accept the terms and conditions, and complete the checkout within the allocated time.

Timekeeping: You can get timed out if you don't act fast, so it's a good idea to have your details saved on a separate document so you can copy and paste them over quickly.

You might also have to approve your payment, which could mean answering security questions from your card issuer. Have a device on hand to ensure you're ready for this.

Internet connection: This should go without saying, but you won't stand a chance without a solid internet connection.

Avoid trying to rely on your mobile phone signal, and politely ask those you might share the internet with to delay any online activity that might slow your connection.

Don't give up: Until the page tells you that tickets have sold out, you still have a chance.

Shortly before that point, there will be a message saying 'all available tickets have now been allocated,' which users often think means their chances are up.

What it actually means is that orders are being processed for all the tickets that are available. But if somebody whose order is being processed doesn't take our previous advice and runs out of time, their loss could be your gain.

Multiple tabs and devices: Glastonbury advises against its customers trying to run multiple tabs and devices to boost their chances of getting a ticket.

Glastonbury's website says running multiple devices simultaneously is "a waste of valuable resources, and doesn't reflect the ethos of the festival".

"Please stick to one device and one tab," it adds, "so that you can focus on entering your details without confusing your browser and help us make the ticket sale as quick and stress free as possible for all."

Shoppers have been buying bigger TVs to enjoy this summer's European Championships, according to the electrical retailer Currys.

The chain said UK sales were up by more than 30% in the past month, with "supersize" screens — 85-inch and above — selling well in the run-up to the Euros.

"Having a third of the TV market and the Euros being a big event for many people, we're seeing that super-sizing trend keep on giving," said Currys chief executive Alex Baldock.

The most popular, and also cheapest, 85-inch TV on the Currys website costs £999.

The most expensive super-size TV is a 98-inch offering from Samsung that will set you back £9,499.

Currys reported adjusted pre-tax profits of £118m for the year to 27 April. That represented a 10% increase from the previous year's profits of £107m.

Like-for-like sales for Currys UK and Ireland declined by 2% to £4.97bn in the 12 months to 27 April, with consumer confidence knocked by high inflation levels and rising interest rates.

"We can see our progress in ever-more engaged colleagues, more satisfied customers and better financial performance," Mr Baldock added.

Selling your home can be expensive, with the range of fees that come as part of the selling process meaning costs can really rack up.

Those costs are usually present whether you visit a bricks and mortar estate agents on the high street or if you go online, although Purplebricks has marketed itself as an exception to the rule.

Since December, it has launched a new pricing structure that enables sellers to list their homes without paying a penny, making it the only completely free online estate agent in the UK.

Purplebricks previously charged a fixed fee of £1,349 (including VAT) to sell your house, with that figure rising to £2,999 for those based in and around London.

That needed to be paid upfront or not later than 10 months after the property was first advertised, even if it went unsold.

Now, after being bought out by rival online estate agency Strike last year, Purplebricks is offering a free service, no strings attached.

Is there a catch, though?

There's no such thing as a free lunch or, it seems, a totally free way to sell your house.

If you'd like to pay more to unlock extras and upgrades, you can do so, with a 'Boost' and 'Full House' package costing £899 and £1,499 respectively.

All estate agents are also required by law to carry out anti-money laundering checks on everyone selling a property.

Typically, that cost is incorporated by estate agents into their service fees. However, as Purplebricks' service is free, it has implemented a separate £60 Anti-Money Laundering (AML) fee for sellers.

What's more, there's also no Rightmove listing included as part of its free service.

As the UK's biggest property portal market, attracting more buyers and sellers than anyone else, Rightmove can help sell your home much faster.

Purplebricks does include a free Zoopla listing, but adding Rightmove is an optional add-on that will set you back £299.

So, how does Purplebricks make money?

Add-ons and extras.

Purplebricks will be hoping to make money by customers opting for optional extras or premium services.

As well as the Rightmove example mentioned above, professional photographs and a floorplan will cost £699, while hosted viewings of your property will come at a charge of £899.

Purplebricks can also work with sellers and buyers to help them find the right mortgage deal and by offering them conveyancing services.

It's important to remember that there is no obligation to buy any of the add-on services, though some will undoubtedly come in handy.

Purplebricks is clear about its up-selling tactics too. This is what its website says:

We’re fully transparent about what little extras we offer and where your money is going – so it really is your choice. When our agent speaks to you, they’ll talk you through the options, and then you can decide if it’s right for you.

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Is Time Travel Possible?
In Summary: Yes, time travel is indeed a real thing. But it's not quite what you've probably seen in the movies. Under certain conditions, it is possible to experience time passing at a different rate than 1 second per second. And there are important reasons why we need to understand this real-world form of time travel.
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[Clip: Back to the Future: "This is what makes time travel possible. The flux capacitor!"] The flux capacitor!"] Moskowitz: I get it—no one has yet conceived of a way to journey to the past.
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His hope was that his invitation would be read by someone living in the future, who had capabilities to travel back in time. But no one showed up. ... "The best evidence we have that time travel is not possible, and never will be, is that we have not been invaded by hordes of tourists from the future. ...
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But we experience time unidirectionally because molecules tend to move from higher to lower states of order, as Quanta Magazine outlines — i.e., "Time's Arrow." Putting these two together means: 1) No one refutes that forward-moving time travel is possible, and, 2) Backward-moving time travel is impossible.
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Scott says it's possible the person you bought from could have copies of the keys, allowing them to steal your car or break in. ... (for ticket and coach travel options) and 21 April (general ...

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Time travel is theoretically possible, calculations show. But that doesn't mean you could change the past.

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