How many times have you made a mistake andwished you could go back and change the past? Or how often have you dreamed about what thefuture might be like? The idea of time travel has been enchantingpeople for generations, even though it’s usually assumed to belong only to the worldof science-fiction.
But is it really as farfetched as it sounds? This is Unveiled, and today we’re uncoveringthe extraordinary reality of time travel in real life.
Are you a fiend for facts? Are you constantly curious? Then why not subscribe to Unveiled for moreclips like this one? And ring the bell for more fascinating content! One of the easiest ways you can accomplishtime travel is by simply looking into the night sky.
Because it takes so long for a beam of lightto reach us from other parts of the universe, nothing you see in the sky is a true reflectionof reality.
In fact, some of those distant stars mightnot even exist anymore… in the time it has taken for their light to reach us, they couldhave blossomed into spectacular supernovas or faded away completely.
To look at it another way, it’s often saidthat were aliens to today observe the Earth from sixty-five million lightyears away, thenthey’d be able to see precisely what killed the dinosaurs – provided they had a powerfulenough telescope.
While that fact doesn’t mean a great dealto us (since we have no way of getting sixty-five million lightyears away to look back at ourown planet), we may someday see the equivalent of this mind-bending phenomenon play out somewhereelse in the universe, as the ancient precursors of a different planet roam its landscape withus as witness.
With regard to whether this truly counts as“time travel”, however, we wouldn’t be physically going anywhere… It depends on whether you rank being ableto see into the past as a type of time travel in its own right? As far as actual movement goes, all you reallyneed to get to the future is speed.
The faster an object is moving, the slowerit perceives time relative to a stationary object; this is time dilation.
This means that if someone goes to space witha rocket, by the time they come back to Earth they would have effectively visited the future.
This phenomenon is especially well-documented…so well-documented, in fact, that GPS systems have to account for it to stay accurate – sincethe satellites they use to navigate move so quickly in orbit.
Every astronaut who’s ever been to spacehas been affected by the same thing, though not so much that they would notice.
In 2015, the cosmonaut Gennady Padalka brokethe “time in space” record – with 879 days over multiple missions… and it’sbeen said that, overall, his combined time spent moving at a higher velocity means hemoved 1/44th of a second further into the future than if he’d just stayed on Earth.
This is a tiny amount, but not so tiny thatPadalka isn’t a time traveller.
He has, after all, travelled 1/44th of a secondfurther into the future than most other people have! For all astronauts on board the InternationalSpace Station, their tiny amount of time travel happens because the ISS is moving throughspace at a speed of 17, 100 miles per hour.
But the ISS could never be a convenient modefor time traveling distances of any notable length.
For instance, it would take an estimated 100years aboard it for an astronaut to go just one second into the future.
The fastest manned spacecraft in history, the Charlie Brown command module from the 1969 Apollo 10 mission, traveled at a record-breaking24, 791 miles per hour… which is quicker than the ISS, but it would still take decadesto move more than an increment into the future.
Even the fastest man-made objects ever wouldn’tstand a chance.
NASA’s Parker Solar Probe exceeds speedsof 150, 000 miles per hour during its mission around the sun… Of course, there aren’t any passengers onit, and we’re very far away from a time when a manned ship could travel at those speeds…but, even if we could propel astronauts at 150, 000 miles per hour, we’re still talkingyears on board for a few seconds worth of time travel.
Moving through time is no easy feat! Elsewhere, the fundamental force of gravitycan also affect time.
The stronger a gravitational pull on an objectis, the slower it moves through spacetime; it’s actually another reason for the temporaldiscrepancy between everyone on Earth and astronauts.
It’s been proven that an atomic clock closerto the Earth’s surface ticks slower than one that’s further away.
Apply that on a larger scale and many sci-ficreators have speculated that by utilizing the gravitational pull of a big enough objectwe could provide the necessary forward momentum for a trip to the far future.
The idea is that you could travel to somethingexceptionally massive – a black hole, for example – orbit it for a while, and its intensegravity would mean that by the time you left… you’d have zapped yourself into the future.
Scientifically and mathematically speaking, this almost definitely checks out, but it’s still an imperfect method for real-life timetravel.
For a start, even something as massive asa supermassive black hole might only slow you down by about fifty percent- so ten yearsnear a black hole might equate to twenty years for people back on Earth.
Sure, a decade-long trip to move another decadeinto the future shouldn’t be sniffed at… but it wouldn’t be all that practical.
And the other big problem we have are thedistances at play.
Say, as a means of time travel, you used thesupermassive black hole believed to be at the Milky Way’s galactic centre.
It’s about 26, 000 lightyears away from us…so, if you were somehow traveling at the speed of light, it would take you 26, 000 years toget there.
Upon arrival you perform your “turning tenyears into twenty” trick, and jet off back home… by the time you finally got back toEarth, well, you’d find it more than 50, 000 years into the future rather than the measlytwenty you were hoping for – thanks to sheer journey time.
So, while black hole time travel is a theoreticalpossibility, don’t expect to be harnessing its power any time soon.
For it to work, the black hole would haveto be right next to us from the outset… but if a black hole really was that close, it would probably have destroyed us and the solar system long before we could manipulateit for temporal displacement.
Of course, when we imagine a time machine, we don’t just want a device that can take us to the future only – we also want the possibilityof visiting the past (or at least of returning home from the future!).
Generally speaking, most theories on backwardtime travel concede that it’d only be possible if we were ever able to break the speed oflight… which would break the laws of physics and is generally held to be impossible.
But, are there any other ways to take a tripto the past? The astrophysicist Ron Mallett thinks thatthere are, and he’s dedicated most of his career pursuing a lifelong interest in provingthat time travel is possible.
Mallett specializes in the famous theoriesof Albert Einstein and has suggested a means for backward time travel which involves “twisting”spacetime rather than needing to reach the speed of light.
Mallett says that by creating a gravitationalfield with a ring of lasers you could twist spacetime into a ring shape, allowing youto travel the loop you’d made… and ultimately go to the past.
If this sounds too good to be true, it’sbecause there is a big catch: using Mallett’s method, you could only travel to the pastas far back as to the moment the machine itself was switched on.
That means that we wouldn’t be able to zapback in time to the dinosaurs, or miraculously prevent past events already committed to historyfrom happening.
But such a machine would still be incrediblyuseful.
Any future event worth a redo could be givenone, and Mallett’s ring of lasers would make forward time travel much less risky, as well; it would allow a traveler to the future a way to get back home, to their originaltime, rather than effectively “disappearing” from the present.
It should be said, though, that Mallett’sideas have been criticized by his colleagues, and he himself stresses that the technologyis extremely far away from becoming a reality.
Finally, real-life time travel would meanreal-life time travellers, too.
But, might they already be among us? While nobody attended Stephen Hawking’sfamous “party for time travellers”, plenty of people have claimed over the years thatthey are from the future.
One notable case was that of John Titor, whoallegedly came to the 2000s in search of an IBM 5100 computer.
Titor had a compelling story but his predictionsnever came true, and he’s since been written off as a complete hoax.
Others have come forward to tell their storyto the press or to make cryptic blog posts and viral videos, though none have been ableto truly convince the wider public that their time traveling tales are the real deal.
Nevertheless, there have been various imagesof supposed time travelers that appear throughout history, as well… and some of the more unusuallikenesses have peaked public interest.
For many, the fact that there are no confirmedtime travellers is enough to prove that time travel will never exist.
For others, though, our tendency to be suspiciousof time travel claims means that, even if we did one day invent backward time travel, we probably wouldn’t believe the people lucky enough to use it.
For now, we can take some solace in the factthat, ultimately, we are all traveling through time, every day… into the future at a constantrate of one second per second.
It’s not quite as glamorous as it is inthe movies, but at least there’s no real risk of us getting stuck in a far-flung futureor a land that time forgot.
What do you think? Is there anything we missed? Let us know in the comments, check out theseother clips from Unveiled, and make sure you subscribe and ring the bell for our latestcontent.