Is Time Travel Really Possible?
There is something about time travel that is so alluring that we just can’t let the idea go. Maybe it’s because of the ability to undo any wrongs that it offers or the ability to foresee everything in advance.
That’s why it has been one of the hottest trends (and kind of overused) in our countless movies, TV shows and novels and we just can’t wait for it to actually happen in reality.
Well technically, we are constantly time travelling into the future, every second, every minute. But that’s not the kind of time travel we’re interested in, are we? We want the good stuff, to be able to travel to any time, forward or back.
So, could time travel ever be possible? Do the laws of physics allow it to happen? Or are we going to always have to satisfy our time travelling cravings watching movies? Well, the answer is: yes, it’s possible. But don’t get excited just yet.
Time Travel To The Future
Let’s look at time travel to the future. While there are many theories as to how it can be done, let me talk about the two most common ones. I will try to keep it as simple as possible.
Travelling Close To The Speed of Light
Einstein’s theory of special relativity states that time passes at different rates for two people who are moving relative to one another. However, this difference only becomes noticeable when the speeds involved are closer to the speed of light.
You might already know that speed of light is the fastest anything can travel in the universe and it is very, very difficult to reach that speed, technologically speaking.
But let’s say, you did manage to build a spaceship that can travel at like, 99.5% speed of light. Then you leave Earth and cruise at that speed for 5 years before returning home. Upon returning, you would notice that, the world has not advanced 5 years but 50 years! And all your friends have become old.
This happens because as you are travelling at speeds closer to the speed of light, time slows down for you considerably relative to the people back home, for whom, it stays the same. Therefore, you experience just 5 years of time while they experience 50 years! This essentially means that you travelled into the future.
Orbiting A Black Hole
If you have watched the movie Interstellar, you must be aware of this already. Basically what happens is that objects in the universe with an extreme gravitational pull also slow down time considerably for any objects that are near to them.
Black holes have some of the strongest gravitational pulls in the universe. The greater the pull, the greater the difference in time. So, in theory, you could use this to travel to the future.
For this, you would need to locate the nearest black hole and head in its direction. Once there, you would need to orbit around it and head back home. Depending on its gravity, that one orbit could be months or years for people on Earth while you would experience only a fraction of that time.
If you wanted to travel even further into the future, all you need to do would be to take more revolutions around the black hole. You would need to be in perfect orbit though or you would get sucked in!
Time Travel To The Past
This one is where things get really tricky. While technically, time travel to the past may not be impossible per say, but for all intents and purposes, it sure looks that it is highly improbable.
Many scientists believe that it is just impossible and that time flows in only one direction. This also explains why we have yet to meet a time traveller from the future because nature just doesn’t let it happen.
There would be all sorts of paradoxes if people could travel to the past, the most famous being the grandfather paradox where if you went to the past and killed your grandfather, you wouldn’t be born and therefore you couldn’t have gone to the past to kill him in the first place.
There is one theory that allows for it but it is a highly speculative one which involves creating a wormhole and accelerating one mouth of that wormhole to the speed of light. That would still not allow you to travel further back in time than the point it was created. So, I see no point. Plus it is just technologically impossible at this point.
Yes Time Travel is possible but only forward, backward is impossible.
That's what I said too :)
I would just want to tell myself in the past to buy all the BTC I could afford :)
wouldn't we all? :D
I remember an exercise I had given to my students long time ago, where they computed that reaching a speed of 0.999999998 times the speed of light would allow to get to the center of our galaxy in less than 40 years. On Earth, this would have meant more than 60000 years ;)
The tricky part of the calculation is that the spacecraft cannot accelerate too quickly, without killing the people on board because of too many g's in their face. Therefore, you need to account for this. In principle, it takes a year to reach speeds close to the speed of light if the acceleration equals 1 g.
From there, the only problem can be the energy necessary to maintain an acceleration equal to 1g during a year.
oh yes, I remember Stephen hawking talk about this as well. Forgot to mention that part in the post. Thanks for pointing this out :)
I didn't know about Stephen Hawking mentioning this. But the exercise is very common in special relativity books. I have by far not invented it ;)
hehe sounds interesting. I would like to learn it too :D
The only reference I have is a book in French. I cannot find anything on the web. I may write a post on it next week, if you want. That is a funny topic :)
@sauravrungta
Very well compiled and really intresting.
In fact, in India mythology, there are very interesting stories on time travel.
By reading the article, especially the Einsteen's theory, I recollected one of the stories related to King "Kakudmi"
Revati was his Daughter and was so beautiful that when she was at marriageable age, Kakudmi, the king, thinking no one upon earth was worthy enought to marry her and went to the Creator himself, Lord Brahma, to seek his advice about a suitable husband for his daughter.
When they arrived, Brahma was listening to a musical performance, so they waited patiently. After the performance was finished, Kakudmi made his request and presented the list of his shortlisted candidates.
Brahma laughed loudly, and explained that time runs differently on different planes of the existence. During that short time of musical performance, 27 chatur-yugas (a cycle of four yugas, totalling 108 yugas, or Ages of Man) had passed on earth.
Brahma said to Kakudmi, "O King, all those whom you may have decided within the core of your heart to accept as your son-in-law have died in the course of time. Twenty-seven chatur-yugas have already passed. Those upon whom you may have already decided are now gone, and so are their sons, grandsons and other descendants. You cannot even hear about their names.
I believe so, some even say aliens/extra-terrestrials/inter-dimensionals are humans (or an evolved form of humans) from the far distant future. If you believe in aliens that is.
In my opinion linear time is an illusion, all threads of time are connected, the past/present/future is happening this very moment.
Ever heard of the Mandela effect? This would probably be an example of other dimensional activities taking place. Different dimensional time-lines start to overlap one another.
Of course, this is all to entertain ones own thoughts, it's up to you to decide what to believe or not.
Oh yeah, I have heard of that theory before and is really fascinating, isn't it?
"DOC, DOC!!!"
"What is it Marty??"
"In the future there is something called Steemit which has cryto currency!"
"Great Scott!"
Is it from Doctor Who? Coz I haven't watched it.
That's Back to the Future ;)
There's 3 movies 1985 to 1990, all three are quite fun!
Nah It's Back to the future, it's an awesome classic! But they got almost everything wrong for 2015
Nice!
I like your work keep it up
I follow you, let's work together!
Thanks :)
Time travel is always very intresting .
Upvoted.
Yes, it's fascinating :)
Laws are ment to be broken. So is it for the "laws of nature" too. Or better said: We don´t fully understand the laws yet, so there can be a way to do this we don´t know yet.
I agree with the later part. It might be that we don't fully understand the laws yet and things could change.
I am not sure if we can brake the laws of nature, but i am sure with a better understanding we can use them to our advantage.
We have had experiences close to this. We drove to Vermont, two hours away. We had breakfast and did some sightseeing, then decided to drive back home. We left Vermont at 1:00 p.m. and looked down at the clock.....it was already 3:30 p.m. and we had only gone about 45 to 50 miles...we hadn't stopped anywhere......this has happened to us several times on several different trips away from home where we have hours we cannot account for?????
I wonder what it could be!! That sounds strange.
We have no clue. We take pictures on our outings and check the times they were taken....we note gas stops, or food stops. There are hours unaccounted for and we still aren't sure. One day was a 9 hour drive and only 6 can be accounted for.....where were we??
That sounds really creepy! Maybe you should video record the whole journey. That might help.
Good idea!!! I will post about it if we do ;)
Cool :)