Is time travel to the past possible!

[Einstein]

Theories are just a fictional cover story concealing the facts. That is the state of Physics today. You certainly can't refer to fiction as evidence.

 

[PaulaJedi]

The state of physics to-date is that there are no viable theories that allow time travel to the past. I'm sorry but that is the current state of the science. Is it possible that in the future we will discover that it actually is possible? Yes, it is possible. For now, however, the evidence clearly says no.

I actually agree. It's very possible that we have not discovered how to YET. However, if we have discovered how in the future, then it technically exists because time travelers could be visiting at the moment. Time is tricky concept. Backwards time travel could exist and not exist at the same time.

Thank you @KerrTexas for enlightening me on the "is" and "is not" concept.

Theories are just a fictional cover story concealing the facts. That is the state of Physics today. You certainly can't refer to fiction as evidence.

Theories are just a fictional cover story concealing the facts. That is the state of Physics today. You certainly can't refer to fiction as evidence.

Yes, it's hard not to look at Star Trek, isn't it?

 

[Mylo.X.]

I actually agree. It's very possible that we have not discovered how to YET. However, if we have discovered how in the future, then it technically exists because time travelers could be visiting at the moment. Time is tricky concept. Backwards time travel could exist and not exist at the same time.

I sort of agree with the general gist of your comment here, but it seems like you have misworded the sentiment you wish to convey (imo).
However, if we have discovered how in the future, then it technically exists because time travelers could be visiting at the moment.




Because the future has not actually occurred yet (from our vantage point of April 2015) then technically time-travel does NOT exist at the moment, from our vantage point. If time-travel to the past IS possible in, lets say, 2063, then YOUR comment will make perfect sense.

So what I'm saying, is that your comment could be correct in 2063, but as of 2015, its not correct imo.


Backwards time travel could exist and not exist at the same time.

I actually like the quantumness nature of this comment. (and yes, I did make that word up, lol).

 

[PaulaJedi]

Because the future has not actually occurred yet (from our vantage point of April 2015) then technically time-travel does NOT exist at the moment, from our vantage point. If time-travel to the past IS possible in, lets say, 2063, then YOUR comment will make perfect sense.

I'm probably wording it wrong, tangling myself in a web. But I consider time something that exists all at once.
Everything we do in life already "exists". I want to say "has happened", but I'm not sure that would work, either.

I personally think that we can still make changes, so it isn't set in stone. Our conciousness could be what helps us not experience everything in one single flash. That's how I think about it. So, with that in mind, it either exists or it doesn't, even in our perceived future.

 

[Mylo.X.]

I'm probably wording it wrong, tangling myself in a web. But I consider time something that exists all at once.Everything we do in life already "exists". I want to say "has happened", but I'm not sure that would work, either.I personally think that we can still make changes, so it isn't set in stone. Our conciousness could be what helps us not experience everything in one single flash. That's how I think about it. So, with that in mind, it either exists or it doesn't, even in our perceived future.

Yes, there is a saying along the lines of, "Time is what prevents everything from happening in an instant".

I think what you're saying is that time has happened (in the past, present and future).

 

[Darby]

No theories concerning to future please.I only wanna know about the past

ZeroZ,
The correct answer to your question is we do not currently have a viable solution to General Relativity that allows time travel to the past. Note the emphasis on viable. Technically there is a large number of mathematical solutions to General Relativity that allow time travel to the past. In the real world, however, you have to take into account all of the effects that occur when you implement the solution and not just cherry pick the "good parts" because you like them.

To date every such solution runs up against a wall that negates its usability (blue walls, collapsed throats to wormholes, mouths of wormholes forever lay in the future light cone of the would be time traveler thus preventing entry into the hole, the assumptions about the world in the theory does not describe our universe, etc.). Stephen Hawking has proposed the Chronology Protection Conjecture. Yes, it is a conjecture, not a theory. Hawking has noticed that every theory meets the above walls and has humorously given the conjecture the name because it appears to him that we might naively conclude that the universe conspires against time travel to the past.

But its not just him joking and tossing spaghetti against the wall to see what sticks. It's real physics behind the humorous title. Hawking goes a long way toward pointing out the impediments to each known solution. Rather than me listing all of them I suggest that you Google Chronology Protection Conjecture and discover the information for yourself. It's more satisfying that way and you don't run the risk of me adding editorial notes to the explanation.

Does this mean that it is impossible to travel to the past? No. It just means that we haven't a clue about how to do it, if in fact it can be done at all.