Anybody care to explain? Remember, I am not a physics professor or anything, so keep it simple.

- Goat

The passage of time can be measured by the generation of (tangible) history books.

Meow Purr.

Haha.

I meant time itself, as in many time travel hypothesis's time is manipulated.

So you're sort of asking.. "what is time" ?

Hah... glad to see you're steering clear of the hard questions.

Einstein seemed to suggest that time - as we normally experience it - is a perceptual illusion. Time is bound up with space (in the sense of height, width and depth) to form the physical universe.

Apparantly Steven Hawkings had a good explanation of it in his book "A brief history of time", but I never made it past page 27. I really must dig that book out again.

Meow Purr.

Thanks for being informative and not trying to argue. Seriously, it happens alot.

-Goat

Time, you said keep it simple, I like that, so time is really just another theory! tick tock.

I suppose, in the sense of 'manipulating' time you could refer to time as information. However, to travel through time to the past (assuming time is information) would require you to have all the information about the state of everything at the time you wished to travel to...quite a feat if anyone wishes to try to accomplish it.

Time travel (to the past) is not travelling to a 'date', it's travelling to when everything was in a specific state. Personally I don't see how it could be possible, but I'm no Stephen Hawking!

Time Travel, not the type associated with travelling great velocities, or of going into some sort of hibernation, but genuine moving about through history, always caused me to wonder:

Since the Planet Earth orbits the sun at about 75,000 mph, and the sun itself orbits the center of our galaxy, and that galaxy is also busy travelling away from every other galaxy, if one was able to, say, ‘leap forward’ ten minutes, that would put him either in molten iron at the Earth’s core, or in the middle of the vacuum of outer space, or someplace else completely unpredictable...lol.

Like Leo stated, travel would be pretty tricky, imo!

I've read that one physically possible time machine is a wormhole where one end has moved relativistically with respect to the other. If you create a wormhole, accelerate one end to close the speed of light and take it on a few trips round the nearest star, then return; one end of the wormhole might have aged several years (call this the old-end (OE)), the other several minutes (the young-end (YE)).

If you enter the OE, you will emerge from the YE in the future, if you jump in the YE you will emerge from the OE in the past.

Note, however, that it is not possible to travel into the past to a point before the wormhole was constructed (there would be no OE to emerge from) or to the future to a point after the wormhole collapses (similarly, no YE).

There has (supposedly) also been some progress in creating a static time loop, altho I think so far it's only working at the subatomic level. Pretty sure I read something about this about a year ago or so. Basically it's a machine, that while it's on, causes time to bend back on itself, so, concievably, by entering the machine and waiting a set period of time, you can emerge at any point in time while the machine was on, (ie turn it on, wait a week, get in, wait a few hours, get out right after you turned it on). I'll see if i can rummage up the info on it.


Edit:

here we go, these two sum it up pretty well:

http://www.physorg.com/news63371210.html

http://www.spacedaily.com/news/timetravel-01a.html

Ok, here's my five penneth worth, but I'm not a professer, either...

Time itself is a man made concept, it was not created by the Universe as such.

We created time as a concept simply to allow us to record events from just a few seconds to milllenia.

Therefore, time is tangible, only because we made it so and record it for our own purposes in an attempt to organise.

Time as a concept from the Universe is not actually a proveable theory, just a mad made creation.

Put another way, we do rely on time as much as we rely on metric/imperial systems, both of which we created - even though we did not create time or length, we have systems to record them.

Ergo, if we can record them, they are tangible.

Corthos, I saw that too, it was an outstanding piece of work. Link it if you can as I'd like to see it again.

Could you duplicate yourself doing this?

Ooooo- that's a very interesting way of putting it Sassuges... I like it .

I believe that HG Wells first popularised the idea that "the past" or "the future" where actually concrete "places", as opposed to abstract concepts, and that with the right 'machine', you could actually step INTO those "places". (this was in his book "The Time Machine".) Prior to that, I don't believe that people viewed 'time' in this way. (at least, not in popular culture).

I still havn't found the Hawkins book.... I may have to go out and buy it again

Meow Purr.

You will already have noted that there are philosophical and scientific answers to this question, and both vary acording to the authors knowledge and perception.

My answer is that time is not just a construct of man, but that it exists independently. We may measure and quantify it for our own purpose, and the increments/ measurements may be conceptual , but time began before life began, and will go on after life ceases.

Time is most obvious in the presence of life, because life presents physical indcators of the passage of time, but entropy and radioactive decay, or the development of overlaying craters on the moon, illustrate that time moves along independent of life.

At its simplest, time exists as; past, present and future. The fact that all three can not exist simultaneously, indicates the linear nature of time under most circumstances.

I think so, if you were to turn the machine on, then get into it tomorrow, you could step out next to yourself today.