Time Travel | Science | Astro Physics | Space
If Time is Money, ATM is a Time Machine?
Time Travel; A Spacetime Odyssey
Nothing is as far away as one minute ago — Jim Bishop
Have you ever wondered if you could travel through time? Ever wished to meet Amelia Earhart or the human computers? Maybe it wouldn’t matter if you ate that last piece of chocolate in the fridge; instead you could go back and eat the entire bar.
What if I told you, that time travel is possible? In the loosest sense imaginable, albeit. But it still counts!
Time travel theories date back to 9th century BCE, where most Greek philosophers agreed that time is continuous and intrinsic. In fact, until the 1800s (when the first sci-fi movies and books were published) the concept of time travel was not popularized.
Alright now let’s delve a little bit into Einstein’s Theory of Relativity, which stated that time and space were linked. Essentially, the faster you move, the slower you experience time.
Clocks on airplanes and satellites travel at different speeds than those on Earth.
An experiment used two clocks set to the exact same time. One on earth, and the other on a plane going around the world in the same direction as the rotation of the Earth.
They discovered that the clock on the airplane was slower in time by one second per second — which is not very long if you think about it.
Black Holes
Moving on.
Yes.
Black Holes.
Black holes are regions in space where an enormous amount of mass is packed into a teeny tiny volume. This creates a gravitational pull so strong, that not even light can escape.
Going back to Einstein’s General Theory of Relativity, the only place where time and space can end is in a so-called ‘singularity’, which involves gravitational forces becoming so intense that space and time lose all meaning — AKA a black hole.
When we think of time travel through a black hole, we know it’s possible. Theoretically. For elementary particles with an accelerator one billion kilometers long.
Looking at the diagram above, the extreme curvature of spacetime near a blackhole results in something called ‘time dilation’, which means that time slows down to the same speed as on Earth, enabling us to travel to the future. An object on the edge of a black hole, would appear frozen in time.
Teleportation, and travelling through time is thought to be possible through wormholes (which are blackholes that host multitudes of monstrous worm-aliens) :D
Wormholes are bipolar black holes that link different regions of the universe.
But one year in a blackhole could mean 80 years on Earth (Hello time dilation!). Time travelling though black holes is dangerous, due to the instability of black hole phenomena. So basically it’s a no-return policy. Too bad for the ATM.
What About Man-Made Black Holes?
A black hole is created when a star or some other celestial body collapses in on itself, drawing in matter.
Man-made black holes wouldn’t be too dangerous right? Well, scientists created a lab-grown black hole to test a Stephen Hawking theory. It began glowing after simulating an event horizon.
But there’s no way a penny-sized black hole would mimic the vacuum of an authentic space-y black hole.
The Lightspeed Rocket
So, unless a space rocket — with the power to surpass the speed of light and not spontaneously combust from combined pressure and heat travelled through a wormhole and broke free of the vacuum and successfully managed to locate the area of spacetime it is in, and all the time relaying back to the base station — was created, we can kiss time travel goodbye.
Rockets and satellites travelling at the speed of light is again theoretically (I’m sick of this word already) possible, granted, if you have roughly a year to spare and limitless thrust.
So… Here We Are Again. The Million-Dollar Question
Is time travel possible?
If any of you readers have noticed, I’ve taken you round the whole topic in a full circle. First with Einstein’s Theory of Relativity, then Black Holes, followed by Man-Made Black Holes, and the Lightspeed Rocket, now back to where we started.
So what I’ve essentially done, is taken you through a CTC (Closed, Timelike Curve).
Closed Timelike curves (CTCs) are a theoretical — Ugh — concept in physics from Einstein’s General Theory of Relativity. They describe a path through spacetime that curves back on itself, allowing an object to travel back in time.
But time is a spiral and not a circle. If it was a circle, then I’d be obliged to explain to you the grandfather paradox.
You go back in time and meet your grandfather as a child.
You kill your gramps by accident.
This means your dad won’t be born and you won’t exist.
Yet, there you are. You just killed your grandfather and you obviously exist, but according to the laws of time you shouldn’t.
Hence, the laws of the universe prevent the creation of CTCs (also known as the Second Law of Thermodynamics).
So, after mentioning the word time a whopping 37 times and the entire family of the word theory 10 times, I give you my answer.
If time travel were possible, we’d already be doing it. One can argue that it is forbidden by the laws of physics and that there are numerous technical challenges: it would involve vast amounts of energy.
If you enjoyed this post please leave a👏 and follow me :)
