Time-travel possible?

[japanpimp]

If someone knows what time is, I'd love to here your explanation.

Satan, the definition of time is still being argued and explored by people. But a widely held view of time is here:
http://en.wikipedia.org/wiki/Time
And this is interesting too:
http://www.wired.com/wiredscience/2010/02/what-is-time/

If I could explain time to you then I would be a very very very rich man.

[Satan]

Satan, the definition of time is still being argued and explored by people.

Exactly. How could we "time travel" when we don't even know what time is?

[Holeypaladin]

In relativistic physics, as you approach the speed of light, time slows down, eventually to a half when you reach C. Theoretically, if you can exceed the speed of light, you'd actually start traveling backwards in time.

I think that's how they did it in Back to the Future. Except that dang flux capacitor kept breaking.

[Satan]

In relativistic physics, as you approach the speed of light, time slows down, eventually to a half when you reach C. Theoretically, if you can exceed the speed of light, you'd actually start traveling backwards in time.

I think that's how they did it in Back to the Future. Except that dang flux capacitor kept breaking.

That's all great, but it's all in theory. Massive theory. Again, I ask the question, what is time? "Time" is diffirent for every single person because light, speed, touch, every single sense in the human body works at a different speed.

Time doesn't exist. It's just a way of letting everyone understand the massive complexities of the universe. The only way "time travel" is by Rodri's theory, and even then, it wouldn't be like you changing anything, you would just be a super far away observer.

[japanpimp]

Exactly. How could we "time travel" when we don't even know what time is?

Good point. In general I think that we (humans) are complete morons. For us to even think for 1 second that we have things figured out is insanity. Look at the universe, and dimensions and energy, etc.... Then look at our tiny little planet in the middle of nowhere. We dont have even .00000001% of stuff figured out yet.
But its fun to imagine and ponder and come up with ideas.
But to answer your question, I would say that we are basing time travel on the most widely help view of its definition.

[Soulstrife]

What is time? Just wondering.

this is a hard one to try and explain

time is relative
we calcutate time by the speed of it here right now and the speed that light moves
it is not so much this that is the confusing part is we cannot really calculate no movement because the earth spins and moves around the sun and the solar system moves around the galaxy and the galaxy flys through the universe

to calculate what i would call the true passage of time we would have to know how fast our galaxy is moving away from the point of origin (big bang theory)
then figure out how fast we are moving relative to the speed of light from that point

since we do not know where this is we only have theory for all we know we could be moving at half the speed of light as it is

we are already time travelling relative to the point of no movement

note--this all theory with my own views put in as well
hope i was able to explain in such a way it was semi understandable

[Alusair]

The most neutral definition I can currently think of for time is a measurement of a physical property of matter.

[Rodri]

Time is an abstract construct but it is also measurable by the use of atomic clocks with extreme accuracy.

Going back in history, when there were no clocks, we measured time by the seasons and the length of the day. Then we developed ways to measure the passage of the sun across the sky using sun dials. Then we developed mechanical clocks but it is interesting that the earliest clocks only had one hand. That is because their primary use was to measure the hours of the day for the purpose of calling the congregation to prayer.

As we have developed more accurate ways of measuring time we have reached an agreed set of values for the measuring of time in years, months, weeks, days, hours, minutes and seconds. That is the abstract construct which is a human construct of convenience, so we can have an agreed set of values that we all can understand. It saves confusion.
Our measures relate to our history on this planet and it's messy orbit and wobble. What we think of as a year, as the time it takes for the earth to complete a full orbit of the sun is only relevant on this planet. On other planets a year is longer or shorter. A day is 24 hours but that is really only a day length on this planet.

At least with an atomic clock we have found an accurate way to measure a previously agreed upon measure (one second) and that has allowed us to develop finer and more accurate measures for scientific research. We may not understand exactly what time is but we do now have an accurate standard measuring device. So it is really only people's perceptions of time passing that are different, not the actual event itself.

[Rota]

The most neutral definition I can currently think of for time is a measurement of a physical property of matter.

I said the same thing in an old grade-school science paper. Time is the 5th dimension of existence.


The first 3 are the typical height, width, and depth. The 4th is mass, because you can have a box that is 1 foot cubed, but it has to be made of "something" in order to tangibly exist. The 5th is time, because if the box did not exist before now, and it doesn't exist at this moment, and it will never exist any time after now, then the box simply does not exist. The 6th and 7th dimensions I came up with determine the difference between inanimate nothing existence, and living/conscious existence. But, I can't recall what I labeled those dimensions, nor their exact description. I don't even know if I still have that paper stored away. I'll look around for it this week, sometime... maybe

[Deathslayr]

I don't think its possible, because time is not a physical thing, it is only a measurement of what has happened.