The idea of time travel has long been a fascination for people. From the first stories of Rip van Winkle to H.G. Wells’s The Time Machine and beyond, humans have always wanted to go back and change something in the past-to either fix a mistake or just live through an event again. But is it possible? Is there any way that we could actually go back in time and experience something ourselves? And if so, how would we do it? Let’s explore some of those theories!
First of all, what is time?
Most people think that “time” is a fixed thing-all of the clocks in the world agree on what time it is, for example. But really, there are three different ways of looking at this idea.
The first way sees time as fixed and unchangeable-just like things were back in the days when everybody who traveled used horses or wagons to get around. If you set out on your journey during daylight hours, then by the time you found your destination, it had already become nighttime. It was just impossible to get anywhere without experiencing nightfall!
Nowadays we can travel so fast that we don't even notice day or night anymore; whether you travel by car, plane, train, or even by boat, you're still traveling in one direction through time.
In fact, everything is always moving forward in time it's just that when we look around us at the world and see certain things changing all of the time, it seems like we have changed location somehow. But really it's just time going by so quickly for us that we can't keep up with how fast it's passing!
The second idea about time sees it as a fourth physical dimension in addition to the three dimensions that most people are familiar with-width, height, and depth. Just imagine a long ladder reaching from the ground back into space somewhere behind you.
Now imagine there was another person standing on the other end of this ladder. If both of you stood still, you would probably be able to see each other quite clearly and the length of the ladder wouldn't matter too much in that case!
But then imagine if this person started walking away from you up the ladder into space. What would happen?
Well, at first it would seem like they were just getting smaller and smaller until eventually, you couldn't tell whether they were slipping behind the ladder or whether they’d gone so far away that your eyes had become worse at picking them out against the background behind them!
But by moving along a fourth dimension-height instead of width, depth or length-they have effectively disappeared from view altogether with no possibility of return.
gif source: Wikipedia
So does this mean there are four dimensions rather than three?
And is this fourth dimension the same as time as we usually think of it?
Well, actually some scientists think that some form of time travel might be possible-especially if there are parallel universes where everything is basically the same as here but just a little different. There even seems to be a way of testing this theory by firing neutrinos very, very quickly from a particle accelerator at a detector on the other side of the world and checking to see whether they arrive before or after those that have been fired more slowly.
If you're interested in finding out more about this idea, then check out an article published by energy digital on how fast neutrinos really are!
But what about going back in time?
Can people really go back and earn more than one PhD? How about deciding not to marry your ex-boyfriend or girlfriend and actually.
Well, even though it might seem a little complicated, there is a way that we could go back in time if we really wanted to. But it would only work if there were parallel universes where everything was basically the same as here but just a little different.
In other words, going back in time isn't as simple as hopping on a plane and flying off to any place or time that you want. That's because even if an infinite number of universes can exist, then they must all be very closely related to each other in some way.
No one really knows, but most scientists agree that it is something like a fourth dimension. It’s not like space; people can move forward and back in space. But time has only one direction: forward.
So when we talk about time travel, what we mean is traveling to points in the future or past (not through them). This is actually possible if you are traveling near the speed of light-but don’t try this at home!
There are no real scientific limitations to going back in time though at least. Physicists Stephen Hawking and Kip Thorne both did experiments to see if they could go back to before things actually happened, their results were inconclusive. But if you look at the math behind it all, they come up with an interesting result: even if someone goes back to before something happened, what makes our universe different is that this action creates new parallel universes (universes that are slightly different than ours) where things had already taken place differently.
So, in theory, if someone wanted to return to a previous time and alter the past, they could come back with no harm done because another reality would exist where their actions had already taken place.
There is only one problem: we just don't know. As I said earlier, there are theories that imply this can happen, but there are also theories that say it's impossible. Plus most scientists agree that even though some form of time travel might be possible especially if there are parallel universes where everything is basically the same as here but just a little different isn’t a way to actually do it.
Time travel and the possibility has always been a fascination for me. It does seem fraught with problems, of course, because altering the past so dramatically alters the future. It is sort of like considering my parents. They were married for 17 years when finally they decided splitting up was the best option. But what if my dad went back in time and made sure that relationship never happened?
Effectively he'd have wiped me off the face of the earth. And at the same my sister. And with that course he also would have wiped out my three nephews, my niece, and her son. And what of all of the lives I have touched through the years? What of my sister's? What of our contributions that lead to this thing or that thing having happened for someone else?
Changing even the tiniest thing has so many effects on what the future looks like. It changes not just the one thing. It changes everything.
And so, while time travel is fascinating, it is also quite a bit horrifying.
There is one theory that I think sort of solves the problem. I cannot remember where I read it. But the author basically suggested that you CANNOT change the future. Your future. If a new future is to occur based on a change to an old past, it simply creates a new dimension, a new timeline, ANOTHER parallel universe in which you cannot exist because it's not your universe.
At the end of the day no one knows. Will it ever be possible? Somehow I think it might be, but to what end when we figure out how to do it?