Is it possible to travel through time ?

[dalem]

Trust me guys, photons do NOT have mass.

They impart momentum via energy from impact.

-dale

[huh_what]

Time dilation might be irreversible but it is well understood and proven. Special relativity says that the combined speed of motion through space plus the motion through time is always equal to the speed of light.

People in the mir space station who orbited the Earth for 1 year at speeds of 27000 km/h gained four seconds.

In other words, there is no such thing as absolute time, we all operate inside our own temporal universe. Time travel into the future is a one-way ticket, so whatever you see, you wont be able to tell your friends about it, unless you find a way to travel back in time, but that get too confusing.

[mac-hfd-eng]

i wish it was 1st i would go back in time and shoot j/c then go foward 2 hundred years and shoot the other ! someone buy me a dardis please !

[SnowLeopard]

Depends on how you do it and which way you want to go.

Ie, there was a story that approached a series of rape/murders and it turned out their killer was a vampire who went inactive for number of years in suspended antimation, woke up, did the dirty, and then went inactive again.

He was described in the story as a forward traveling time traveler. Outlandish way of seeing things, the point? Well, remember we bury time capsules and in a way, they are a time traveling device. Further, they are a device that in a sense can go both ways.

Ie, if something in the time capsule had consciousness, then that consciousness would be in the future. If the time capsule is complete enough, theoretically complete, then it could show the future or the present that it is opened in exactly like what life like in the past. The present could experience that kind of life, in various degrees, but they wouldn't be able to make changes to history. That is, in a sense, what a pryamid is.

In various levels of degrees. One of the problems with going back in the past is that the present attitude of the mind is not that of the mind of the past. How can the mind of bibical times understand what the world is from orbit, what it means to fly, to cross oceans, to travel in five days (by car) a trip that would take them months, when most of them probably never leave their village in their life time. How does the modern person traveling back lose that appreciation?

Travel in time like H.G. Wells? Perhaps not. Travel in time like Arthur Clarke's "All the Time in the World" or the Trancers (I, II) where the consciousness is sent back, perhaps yes.

It all depends on how one wants to do it, when one wants to go.
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("Now which way do we go?"--Dorothy at crossroads
"That way is a very nice way."--Scarecrow, (wtte), "The Wizard of Oz")

[ArmchairGeneral]

Travel in time like Arthur Clarke's "All the Time in the World" ...
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Is that the short story where aliens slow down time for one man during the last milliseconds before an super weapon is tested that will destroy Earth? So he in effect has an eternity to live, only it's actually within a second or two of real time? I liked that story, unlike much of Clarke's other work. Too depressing for me.

[SnowLeopard]

Is that the short story where aliens slow down time for one man during the last milliseconds before an super weapon is tested that will destroy Earth? So he in effect has an eternity to live, only it's actually within a second or two of real time? I liked that story, unlike much of Clarke's other work. Too depressing for me.

That's the story! It was in a collection that was given to me as a child and it is one of my favorite stories and favorite books. Still have it!

Only ...... they didn't slow time down for him but speeded him up in it. There was a line or two of how they were from the future and they had "rented" bodies in his present that their time traveling consciousness could use.
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("Well, your powers work by affecting the speed that molecules move. Before, they just slowed them down where they stopped moving. Now, you can also speed them up to the point that they explode."--Leo explaining to Piper how her powers are advancing, (wtte), "Charmed")

[Bill]

Is it possible to travel through time?

Classical Physics says yes, though one has to approach the speed of light to do so. String/Superstring/M theory makes it theoretically much easier, though still centuries away at best, lol(if the crazy theory is even right).

[Dreadnought]

Yes it is just drop a few e bombs and watch yourself wake up days later and hours later...LMAO ;)

[Sombra]

Is it possible to travel through time?

Classical Physics says yes, though one has to approach the speed of light to do so. t).

If you approach the speed of light time will pass more slowly. This isnt the same as travel ´backwards through time IMO.

[YellowFever]

Damn... I love you guys!!! :)

[highsea]

If you approach the speed of light time will pass more slowly. This isnt the same as travel ´backwards through time IMO.

Agreed. Travel back in time actually implies entropy reversal. Something that we can imagine in QM equations, but not in the real universe.

[Bill]

Agreed. Travel back in time actually implies entropy reversal. Something that we can imagine in QM equations, but not in the real universe.

QM is the real universe....On a very small scale.

LOL

[highsea]

Yeah, divided by infinity as in QM renormalization, lol.

[ArmchairGeneral]

Agreed. Travel back in time actually implies entropy reversal. Something that we can imagine in QM equations, but not in the real universe.

That's a very interesting way of looking at it. What if entropy actually increased backwards in time when you travel backward as well as forwards when we travel forward? Or do the equations not allow that? (I only really started to understand entropy during my second semester of Organic Chemistry. Or at least I think I understood it, LOL.)

[highsea]

That's a very interesting way of looking at it. What if entropy actually increased backwards in time when you travel backward as well as forwards when we travel forward? Or do the equations not allow that?

I'm not sure I understand your question. QM is not time-sensitive (the equations work both ways), but entropy is.

If you are traveling back in time, you are traveling into a contracting universe. IOW, it's going to a more ordered state- reversal of entropy. If you go far enough, you get to the "Big Crunch".

The closed-universe model has this feature also- when the universe starts contracting, does entropy reverse? It would seem so, so what effect does this have on time?

/brain teaser