Time travel

[Lost 1,410]

Earthlings will never invent time travel. Discuss...

 

 

 

I've come to the conclusion that while I believe time travel will be invented at some point, possibly by humans, earthlings will never invent or use it, if we did invent it then someone would have already come back in time to stop us destroying our environment ( after all destroying it now makes it worse for the people of the future). I do however think that it will exist sometime, but after the point that we either have died out as a species or after we have already moved on to other planets and completely forgotten about earth.

 

 

So, thoughts?

[Blue Moon 6,341]

If humans were giving the ability of time travel, I would like to see how long we could last before messing up. I can literally picture the space time continuum crumbling apart five minutes after we time travel. 

[WingMcCallister 368]

lol Another topic that could go in 'Ask a Particle Physicist' (shameless I am). Time travel is just a difficult subject. Usually, when people ask me this (they're generally students), I counter with what is time? There are so many people who cannot answer that question. It is really abstract. Space is easy to travel through because we have a general basic intuition as to what it is. Our bodies are designed to travel through it at variable rates. Time is a completely different thing.

 

Now, I've studied ze physics enough to know the numerous things that make time travel the craphole it s, but on just philosophical grounds, I don't see us time traveling without a better understanding of what time is. We can go into GR and say, "Hey, spacetime is a four dimensional blah blah blah," but that still doesn't answer the fundamental question posed. 

Edited April 29, 2013 by WingMcCallister

[Golurk 468]

Oh, time travel. How thine paradoxes and implications are the bane of logic!

 

In theory, yes, time travel is possible. However, in order to make it work, we'd need to be able to generate wormholes. And since we're not even sure if wormholes EXIST yet... I think you can do the math.

 

And even if we did create a machine to do it, it could maximally take something back to the time it was created. Due to some complex physics that not even I fully comprehended, it would be impossible for something to go back before it existed. I assume something to do with the law of conservation of mass, or something similar.

 

Regardless, it all depends on being able to make wormholes, which is technology we're thousands, if not millions of years from doing, assuming it can be done at all. As unfortunate as it sounds, time travel is science fiction given what humanity's capable of.

[I used to be a stranger 7,993]

If we invent time travel, it will make space travel look like swimming. And that would be needlessly unfair to umpteen thousands of wicked-awesome pieces of equipment. With the greatest possible respect, I still prefer jets and rockets to the TARDIS, in regards of appearances.

Figure 1: Science-ing

[Estella 88]

It's a hard topic to speak of. Personally, like most of the people think, within five minutes of us using time-travel, we'd destroy the space-time continuum. It'd probably be hilarious, dastardly, crazy, and insane all at the same time. Now, for a logical take on the subject.

 

In my opinion, if humans could invent time travel, I'd be awestruck, for multiple reasons. 1: Seeing as time controls everything, and, according to scientists, everything is affected by time, there'd be a LOT more than just time-travel involved with the making.

2: The time travel device used would have to be insanely large, maybe something as big as the Eiffel Tower.

3: Because of the large size, we couldn't confirm whether it worked or not, because the person wouldn't be able to just come back.

4: I'd probably have a heart attack, a stroke, and a seizure just from the confusion, shock, and pain of humans creating a time machine.

[Aaramus 449]

As long as time works in the same way as it does in Doctor Who (Wibbly Wobbly) and it manages to repair itself as long as fixed points in time aren't affected then I guess it would possible. 

 

As for creating a machine that does so, I don't think we will have the technology to do so. The TARDIS engine is an exploding star held in stasis, I'm not quite sure we can get one of those. Then again we've seen time machines run off old rubbish from a bin...

[Keylise<3 488]

Maybe they have come back and changed stuff. We wouldn't notice, since it would be forever changed... *Twilight Zone Soundtrack playing*

I believe that I think that there's a possibility of time traveling to be invented.

But seriously, think about that first thing I said. We wouldn't notice them going back.

[mehguy22 64]

Alright, first off let me say that time travel is likely never going to be possible.

Now to get to my actual opinion about it. Even if time travel was possible, it would be absolutely stupid to use it. Why? See this example:

 

You time travel back to the time of Alexander the Great. Say you scoot a pebble 2 inches. What if that pebble crashed Alexander the Great's chariot when he rode to battle after you moved it?

 

Next example:

 

You time travel back to the time of King Tut of Egypt. Say you squash a mosquito and then go back. What if that was the mosquito that gave Tut his fatal mosquito bite? (if you believe in that theory of his death)

 

If either of those came true, it would change the world a lot. Just by doing something while you are back in time as simple as squashing a bug or scooting a pebble you can save many lives and/or kill many people, and you could even change the modern world drastically just by doing that. That is why time travel is illogical if not impossible. 

[angrysalamence 49]

Hmm, time travel, the most confusing with, yet simple thing you will find. In theory, we are traveling through time as we speak. The speed of time depends on the viewer as time flows differently for everyone. Either that or you can hijack a Delorean and hit 88 miles per hour, but thats another story...

[RazzyJam 1,519]

Unfortunately, however, time travel is not possible. This is widely because time is an invented instrument; an abstract idea created by man to indicate a change in position, generally in harmonic motions, but aplicable to all parts of physics.

 

Were time an actual, manipulable field... Well, I dont know! The implications are limitless

[Tia Is Best Pony 310]

time is an illusion made up by humans in order to understand the universe

 

its an artificial idea a system based on the idea that events occur in a linear direction at all times always forward never back, is the concept of time correct, is the idea of time relevant??  

 

answer THAT then discus time travel 

[mehguy22 64]

time is an illusion made up by humans in order to understand the universe

 

its an artificial idea a system based on the idea that events occur in a linear direction at all times always forward never back, is the concept of time correct, is the idea of time relevant??  

 

answer THAT then discus time travel 

Alright, first, excellent point. But, let me express my opinion on your statement. 

 

Sight, smell, touch, taste, and hearing are all senses. Senses are simply sensors in our body that give the brain information. The way that the brain displays this information is basically showing an illusion to itself, because without the brain having some way to interpret sense, sense is nothing. The way that the sense is interpreted then, is basically, again, the brain showing itself an illusion.

 

People also tend to sense if a long time has passed, therefore someone could presume that time is also an illusion just like the other senses. Therefore, if time is irrelevant because it IS an illusion, then who's to say our senses are irrelevant? Well, the senses are indeed relevant, so possibly time is relevant as well, even though it is an illusion as well. 

 

Using all my observations above along with some common sense and understanding, one could concur that since time can be sensed as well, it therefore runs parallel to the senses of the body which are relevant. So, how could something so irrelevant run parallel to something so relevant? Answer: Time is indeed relevant. Otherwise how could it run parallel to the senses?

 

Long story short, to answer Luna forever's question, "... is the idea of time relevant??" 

My answer is "Yes."

 

P.S. Is this a bit too complicated? 

Edited April 29, 2013 by mehguy22

[Aberyst 18]

The main theory I've heard for time travel is this example:
 

Say you have a perfectly straight train track that goes around the earth, and a train that can reach near the speed of light. When at near-light speed, what would happen if one of the passengers were to run down the carriage in the direction of travel?

Theoretically, time would slow down, so as not to allow the speed of light to be exceeded. Time would pass slower on the train and its passengers.

 

...I Dunno... can't see light speed trains happening anytime soon.

 

And there was a rather intense debate a few weeks ago between our physics class about time travel, when someone, in their contemplative whimsy, brought up the question:

"Is sleeping technically time travel?"

For hours we all argued back and forth. He was the only one claiming it was, when people were arguing against it saying, the period between falling asleep and waking up, CANNOT be time travel because your body can be affected in that time - you could bump your head in your sleep. With time travel, you wouldn't expect to be affected physically in any way between time-point A and time-point B.

He insisted that it was technically time travel because your mind isn't perceiving the time between point A and point B in a linear fashion.

 

We were all 

[Dimitri Hammer 3,645]

Listen: If time travel was being used in the future we'd go through considerable changes. I mean...I'd be your overbearing, love-able, Chairman of the United Communist Communes of Dimitri's Earth. Fluttershy would be best pony and people would be regularly pulled off the streets by men in black suits driving black vans.

 

Sadly that hasn't happened. Oh, and by the way...I'm keeping tabs on all of you...watch yourselves.

 

 

 

[WingMcCallister 368]

Listen: If time travel was being used in the future we'd go through considerable changes. I mean...I'd be your overbearing, love-able, Chairman of the United Communist Communes of Dimitri's Earth. Fluttershy would be best pony and people would be regularly pulled off the streets by men in black suits driving black vans.

 

Sadly that hasn't happened. Oh, and by the way...I'm keeping tabs on all of you...watch yourselves.

Or it already happened, and you're really Czar Putin. What about that, huh? Time travel wouldn't produce an observable effect... we'd just live our lives in the consistent reality that always existed. 

 

lol I'm going to go back to what about time. I had a very interesting discussion with the head of AD at Fermilab about this once. We got a little crazy, and I started throwing out multiple dimensions of time and how they break quantum mechanics. lol Mah bad.

[hawkflame 3,310]

Well, it depends on whether or not you're talking about going back in time, or leaping forward. According to relativity, it should be possible to leap forward, with the effects of time dilation and whatnot. But I'm not aware of any particular theory for traveling *back* through time.

 

But another interesting thing about time travel that no one really thinks about but is kind of obvious in retrospect: When you time travel, you might not be traveling through space, but the Earth is. Which means that if you go back in time six months, you'll find the earth about 190 million miles away on the other side of the sun.

 

Hope you packed a space suit.

[WingMcCallister 368]

Meh, I do not sign on the time is merely an abstract idea bandwagon. We already know that is a load because of Special Relativity. How we perceive time - aka the second - certainly is an arbritrary shitstick, but time is a fundamental part of a system's four-vector. It's essentially inverse energy if we set hbar to 1 -- as we all should . To hell with SI; natural units win.

 

Another probing question to ask is what does the universe look like to a photon? This is another interesting thought experiment that leads one to the interesting connection between space, time and mass.  

[Xander 16]

We know time travel is already possible because we are already travelling forward in time at a rate of one second per second. Or faster, if you're travelling fast enough in space. Sorry, couldn't resist giving that answer.

As for what you're actually asking, I reckon backwards time travel might be possible but I doubt that humans will ever figure out how to do it. If we do though, I believe the Novikov self consistency conjecture would hold ground and prevent paradoxes.

[Lunas Husband 2,777]

If we got a hold of something like that.. oh man the end of the world would be very soon... more then likely a few secs after we got it.. because knowing humans we would do something stupid and buck everything up.

[Untitled Goose Q 5,137]

To those worrying that we would go back and change every thing... we wouldn't. If I went back in time and shot someone, I would always have gone back and shot that person. You can't actually change anything, all you can do is make things happen the way they happened anyway.

 

As to if we will ever have time machines..... Maybe. It is certainly possible, in theory.