Physicist Definitively Rules Time Travel Impossible

[Kamehapa]

If I invent a machine that reconstructs the universe so that all the mass and energy have the same properties that they did at some time in the past and used it, would it be any different than a time machine?

 

[DJ_DEnM]

Actually, he's not ruled out time travel into the future, which is sort-of possible. The faster you're moving, the slower time goes for you. Here's an example

You have 2 (theoretically) identical clocks. One stays in the exact same spot in on the planet, moving at the speed of the earth's orbit, whilst one is sent round the earth at such a speed that it returns to to its starting position (next to the other clock) in exactly one hour. The clock that orbited the earth in an hour would be slightly behind the other one, as it travelled faster.

Sure, it's not instant time-travel, but it's similar

Im sorry, I could hardly take that seriously with your pic xD. It's epic. But I do sort of understand what you mean.

 

[Wildflowers]

This guy is clearly playing within the linear constraints of regular matter and not in the constraints of strange matter - matter flowing faster than the speed of light but still with form. You only need to exit the brane by slipping outside of the light cone (hello, black hole factor). Supermassive gravity wells can result, if used properly, in strange matter. But then, Steven Hawking said that black holes already emit strange particles. So.. Im not sure what THIS guy is talking about.

 

[6037084]

o'rly? as far as I know time travel to the future is not only possible but super easy fly a plane or something along those lines really fast for some time and BAM you're in the future (too bad with our technological limits it's only a few minutes at best but greater speeds = greater time traveled) time travel to the past should as far as I know be impossible though. Now that i think about it you can just jump into a black hole and if it evaporates before you fall in you should be hundreds of millions if not billions of years in the future.

 

[DasDestroyer]

Traveling forward in time is quite possible - just accelerate to relativistic speeds and time will slow down for you. As for going back - I read or saw some theory about it being possible using some part of the string theory - as far as I remember it basically had something to do with moving the object in question out of the flow of time for a short while, and coming back to a world where time has already flow away... or something of the sort.

 

[superline51]

I like the idea of alternate realities. We'll fuck up their timelines, but keep our one pristine.

What's stopping them from doing the same to us?

Dammit!

Now we gotta create an Interdimentional Defence Initiative.

I smell sitcom!

Really? I smell sci-fi action game/tv show/movie.

I smell Jet Li's The One

 

[MK Tha Rebel]

See, way back, I had watched an interview on TV, and this guys said that traveling back in time is possible, but doing so would destroy the universe. Either way, for the sake of the universe, don't travel back in time. I kinda like existing.

 

[the conartist]

There are an infinite number of equal universes. This is known as the multiverse. Everything is certain, because everything has happened, and that's an effect of this multiverse. Differences in these multiverses can be as minute as a single atom of hydrogen in space. Because there are an infinite number of said multiverses. The closest you can get to time travel is making a time-loop, where (And I'll not go into the schematics) Light creates So much mass, that time-space swirls around inside this "Time-loop" and entering would cause you to enter exit at the point the machine powered on, but in another universe.

 

[TimeLord]

I call bullshits. Time travel is impossible with the current understanding and discoveries in temporal physics. What if we go into space and find a black hole that can make a ship travel in time? Space is huge, nothing is impossible while the universe is unexplored.

Also, as soon as a scientist says something is impossible, they are instantly wrong. It's called sods law.

 

[Vankraken]

With our current technology it is way too soon to rule out time travel. Somebody is trying to get on the fame boat and cash in on a statement based on hypothetical and limited data. Its practically trolling science.

 

[Something Amyss]

Looking at the article, it's all to do with creating a spatial analogy to time, and showing that in that model you can't bend light back on itself. But at no point is reflection ruled out.

I want a time mirror (that is now my phrase/name for it. No-one steal it please!)

The Quantum Mirror is cooler. >.>

 

[Horben]

Proving a negative is the same thing as saying "I did not perform the proper kind of work to prove that the phenomenon is true". Because of this no one can prove a negative unless all possible methods of testing are exhaustive- and there is always an extant method that simply hasn't been thought of.

Touche, goodsir.

 

[theheroofaction]

So, I can't say, go back in time and kill hitler, and then go back in time to stop myself and then go back in time to stop myself from stopping myself, and then go back in time to stop that, and so on...?

 

[Addendum_Forthcoming]

I like the idea of alternate realities. We'll fuck up their timelines, but keep our one pristine.

Couldn't we also, then, hypothesise also that dimensional travel is impossible because we don't have dimensional travelers invaded our reality?

Also, what if another reality is nicer than ours? Would you still fuck it up, or simply just move there and fuck it up through natural progression of time? ^_^ then move on like the locusts I reckon we are ;P

But the one thing I don';t get is that ... if all material in the universe in finite, and if the universe is in an environment that is universal (i.e big vacuum), then wouldn't logic dictate that given all the material in the universe has always been, and therefore, like a chemistry experiment where all the tested reagents are the same, an alternate dimensional universe would just simply be exactly like our own?

I mean ... if I add `1 part salt to 1 part water I end up with 2 parts salt and water, right? And no matter how many times I add 1 part salt to one part of water I will always, inevitably, end up with 2 parts salt and water.

Why would the universe be any different? Or alternate dimensions to our universe more to the point? x.x

 

[gyroscopeboy]

I'm still holding hope for good ol' Teleportation though...don't take that away from me!

 

[beema]

Wasn't that theory already around -- that you can time travel, just that it would be to another dimension. Based on quantum mechanics and such.
Surprising something like this came out of UMD and not MIT or oxford or something. Looks like they are moving up on the world.

 

[Crazie_Guy]

Well ****, I managed to get as far as the tvtropes link in the first paragraph, and then was stuck there reading for 3 hours before I got back here. Use tropes responsibly dammit!

 

[DaKiller]

I like to think that time travel may be possible if and only if molecules all over the universe are rearranged to the exact state and position they were at the intended time minus the time traveler, kind of like a pseudo time travel.

 

[NotSoNimble]

Sweet, the laws of reality he can prove and/or believe in reassure him of that.

I never thought it possible either, but if he thinks he proved it, good for him and everyone else who believes his logic is sound.