[Kowboy]

Everybody would love to have a time machine right? Well we already do. We have tons of them. A time machine is something that warps time. Back when the cavemen were here they walked. Say there was a place they had to go, 3 miles away. Well walking at 5 miles and hour for 3 miles would take .6 hours. Now we have cars. They can move at 60 miles an hour, 3 miles away, .05 hours. Thus, we are already warping time.


Edit~ My calculations are more than likely off.

[Crescens]

I really don't think cars "warp" time. They enable humans to move through space faster and spend less time travelling, but they really don't warp time at all. Meh.

[obiwan22]

I agree with Crescens, with cars, we are just moving faster, thus we are moving farther in the same time period.

[Kowboy]

Well it was proposed by Newton (I think) that any movement, falling, dropping, throwing, etc...of an object is warping time.

[Neraphym]

If that is so, I got a cool time machine, too. It is called a clock! It can actually tell you what time it is! Try me!

[Cspace]

Actually Crescens... HeadHunter is correct

Hehe, this is going to take a while to explain, I'll try to make it as simple as possible...

Ok, the basis of this almost-proven theory is in the theory of relativity which states that light moves at the same constant for every body in the universe. This is a really strange concept, but here's a little scenario which can help one visualize it:

Imagine that you're driving a car at 100,000 miles per second (a random number) and you decide to turn your headlights on (I don't know what good they would do... but yeah ). Anyway, if the speed of light being emitted from the bulbs were measured, it would be 186,000 miles per second (the speed of light) relative to the spacecraft. Not too strange, for if you threw a water balloon at five meters per second out the window it would be moving at five meters per second relative to you as well, though actually 5 meters per second greater than the velocity of the car (and incinerate everything in a straight line of it for a few hundred thousand miles...). The strangeness is when a bystander measures the speed of the light being emitted from the homicidal car: You would expect that it would be moving at a rate of 286,000 miles per second (the sum of the velocity of the car and the light, as with the water balloon). This is not the case! Due to the basis of Einstein's theory (which I can explain later if you'd like, it would be another large post that I don't have time to write now), light will always be moving at the same speed relative to everyone. This means that the light is moving at a velocity of 186,000 miles per second relative to both the car and the bystander, which is quite a strange concept (that actually makes perfect sense).

So, how would this explain time travel? Now visualize an entirely new scenario:

With the above situation in mind, imagine a long tube (yeah, a tube) which is 186,000 miles long and has two perfectly reflective mirrors at each end. Now start a photon of light to travel back and forth through the tube, being reflected perpetually by the mirrors. It would basically be a clock, with the photon being reflected once every second.

Now, with the photon moving up and down through the tube everything is fine until we introduce motion in a direction perpendicular (if the photon is moving up and down, the introduced motion would be to the left or right) to the tube. Actually, the direction can be anything other than parallel, though let's imagine perpendicular for this.

Now what we have happening is that the clock is working the same; it is still 186,000 miles long and the photon is still reflecting back and forth off the mirrors. Light moves at 186,000 miles per second, so the clock should still measure one second per reflection right? Nope

Most probably know of the Pythagorean Theorem: The law that the square of the hypotenuse of a right triangle (one with a 90 degree angle) is equal to the sum of both legs squared (a^2 + b^2 = c^2). If you haven't learned about this yet, all you have to know is that the hypotenuse is the longest side: the one which is slanted. Anyway, if you are traveling with the clock (hanging on, inside, or whatever), the photon of light would be moving straight up and down for you and everything is fine (you'll just see the vertical motion since you are moving horizontally with it). It will measure one second per reflection. Now if you are the bystander however, things will be a little different...

When horizontal motion is added to the vertical motion, what you have is basically that the photon is moving diagonally relative to a bystander at rest:

<- Don't laugh, hehe, I made this in a few seconds. The blue lines are the tube at different time intervals, the photon is the yellow dot, and the black line is the direction traveled relative to the bystander.

By adding the concept of the Pythagorean Theorem to this, you will see that the distance traveled is greater than the length of the tube. Light must move at 186,000 miles per second relative to everything, and this cannot be an exception. As a result, the clock will be a little slow for the bystander since the photon would need to travel a larger distance at the same relative velocity. It is only slow, however, in the eyes of the bystander.

This means that time will slow down for the person hanging onto the clock relative to the bystander! This concept has nothing to do with the photon moving up and down, the clock he/she is riding or whatever, or anything actually relating to the clock. It relates to the fact that the person is traveling at a significantly different velocity, and therefore will age slower and will travel through time at an accelerated rate.

Now I can talk about the fourth dimension and why this works, but that would be another long post. It's important though, so I'll summarize it:

Basically the larger the magnitude of velocity is for a body in the universe, the slower it moves through time. Imagine a regular two-dimensional plane with an x and y axis: The y axis is 'time' and the x axis is 'displacement' (distance). The scale for the x axis would be very small so every-day travel would not really cause any translation in the x direction (won't move to the left or right), and time would continually move upward. A body at rest would just move upward on the graph at a constant rate, basically showing time passing. A body moving at an extreme velocity however would move to the right on the graph as well as up (up through time, and to the right through space). What you would have is a slanted line (linear for constant velocity, logarithmic I think for acceleration) in the first quadrant of the graph.

Since time would move at the same rate for the body (its own timeline), it would experience no change in the distance traveled on the graph (five seconds for the moving body would be like the distance a body at rest would travel in five seconds, though at a different angle to the y axis). Relative to the rest of the universe, though, time would be traveling slower (on the graph, a body at rest would be higher on the y axis than the body moving at an extreme velocity, showing that it has traveled through less time). This is why the fourth dimension is often referred to as time, since it is another dimension of motion independent of our perceived three-dimensional universe. This is a strange concept, though explains some of the basis of the clock example.


... So in conclusion, HeadHunter is correct since any movement at all would cause angular displacement through spacetime. Regular travel in cars, planes, boats, bikes, or anything else which is common will not cause visible change in the passage of time. Anyone launched into space, however, will have slightly measurable differences in time (this has been tested by sending a deadly accurate clock into space which lost time in comparison to another clock on Earth of which is was synchronized previously). If you have any questions about this feel free to ask me.

[Crescens]

Geez...you almost topped my old FFC posts with that...(snore)...

[Goto]

The most amazing part of that is that I read it and understood almost all of it... (and didn't fall asleep in the process )

You're good at explaining that kind of thing Cspace, good job. Oh and it's good to see Crescens get something wrong for once .

[Kowboy]

I dont have time to read a novel right now (jk, I think its great you can supply that much information) but I will read all of it again and again lol. If you can explain Einsteins theory of revolution, then that would be great.

[Crescens]

[Neraphym]

The one thing I've always been confused about is this: Length, height, and width are the first three dimensions. We can move through them freely goin up, right, and forward. On the same note, we can move down, left, and backward. Time, the forth dimension, doesn't seem to be so. How come we can only move in a positive direction? If it truely is such, then we should be able to go in a negative direction, right?

[Cspace]

[Crescens]

Nyeh, so I wasn't wrong after all...

[Cspace]

[Neraphym]

They way interprited it was that time would be slowed down, not reversed. They are two different things. Pehaps that graph is needed for me to understand.