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Author Topic: Is time travel possible?  (Read 436 times)

Offline jackie

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Is time travel possible?
« on: 26/05/2016 10:17:50 »
Is time travel possible?


 

Offline PmbPhy

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Re: Is time travel possible?
« Reply #1 on: 26/05/2016 13:47:21 »
Quote from: jackie
Is time travel possible?
It's unknown to date. However I do know of a way that its been theorized. It requires the use of two straight parallel cosmic strings passing by each other and near light speeds. However we don't know of cosmic strings exist or not and if they did then we'd have no way to control them.
 

Offline JohnDuffield

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Re: Is time travel possible?
« Reply #2 on: 26/05/2016 14:10:03 »
Is time travel possible?
No. Sorry. I love all those time travel movies, but time travel is science fiction, and it always will be.

Why? Well, if you look into what a clock really does, you'll notice that it counts or accumulates some kind of regular cyclical motion, such as that of a pendulum or a vibrating quartz crystal. Then it gives you some kind of cumulative display, such as the physical position of two rotating pointers, or a set of electronic digits. The thing you call "the time" is just a cumulative measure of this regular cyclical motion. As such, time is a dimension in the sense of measure, not a dimension that offers freedom of motion. I can hop forward a metre, but you can't hop forward a second. Time just isn't something you can move through, either forward or backward. You can't literally travel to another time just as I can't literally climb to a higher temperature.   

Note that time dilation is not time travel. When you move fast through space you suffer time dilation, but you aren't travelling forward through time faster. Travelling through time is just a figure speech, as is the flow of time. A clock is not some kind of cosmic gas meter with time flowing through it. Your time dilation is like being in slow-motion mode, that's all. A nice example of this taken to the limit is given by the stasis box. Like time travel, it's science fiction, but it's kind to nice to fight fire with fire. Anyway, no motion of any kind occurs in the stasis box. Light doesn't move, electrochemical signals don't move, nothing moves. So when I shut you inside the stasis box for five years then open the door, you think I opened it immediately. You "travelled to the future" by not moving at all while everything else did
 

Offline PmbPhy

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Re: Is time travel possible?
« Reply #3 on: 26/05/2016 14:56:29 »
Quote from: JohnDuffield
No. Sorry. I love all those time travel movies, but time travel is science fiction, and it always will be.
Please ignore John's replies. His understanding of physics is very poor and he usually, if not always, leads people in the wrong direction as he's doing here.

John: Please stop doing this. You're totally misrepresenting what the scientific community has to say on this subject. You're once again passing off your beliefs as that of the physics community and the OP is not interested in a single persons belief but what the physics community has to say on the subject and you're misrepresenting them completely. Time travel is in no way merely the science fiction. To be pure science fiction the subject must never have been the subject of study and publication in science journals and texts, which in this case it most certainly is.


Jackie: In fact one of the leaders in this field is Dr. Kip Thorne of Cal Tech who wrote a paper on the subject. Simply go to Google and do a search on "closed timelike curve + Kip S. Thorne" and download and read the article Closed Timelike Curves. That's all I have to say regarding John. He'll argue endlessly and unscientifically and I have no patience for that. E.g. the argument he gave was total nonsense.

 

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Re: Is time travel possible?
« Reply #3 on: 26/05/2016 14:56:29 »

 

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