IF you took college physics, celestial physics, or quantum mechanics, take some time to correct a guy that doesn't major in physics but dabbled in the courses.
I'm not sure about traveling back in time. I do have a belief about traveling foward though. According to Einstein's theory of Relativity, if you could move at the speed of light for a period of time and somehow get back to earth, you would return in a time that to you may have been minutes or even seconds. However, from the viewpoint of everyone that is on earth during your journey, it may have been a period of months or even years.
I believe that there was a movie or two that might have made use of this theory of time travel. Does anybody know of any?
It sounds as ridiculous as any other theory about time travel. However, I'm not sure that it's really a "theory" at all as the common misconception about theories is that they are not proven but are actually ideas or hypothesis. This is wrong; theories typically have an overwhelming amount of evidence to support them. In essence, there are no theories (outside the bound of the theory of Relativity) that can even be considered as theories about time travel.
So if you're looking for proof or an actual theory on time travel. Look into Einstein's work on quantum mechanics and celestial physics. If you want instant gratification or some kind of explanation that might help you believe that some sort of time travel actually exists, I'll take a stab at it.
Einstein actually recorded and witnessed this (apparently as a boy, although I can't be sure). Imagine a train passing by as you watch it at a perfect 90 degree angle. At noontime, light from the sun will pass directly downwards through the top of a cattle car through cracks in the roof. You would think that the light, which travels at 2.998 x 10^8 m/s (about 186,000 mps), would simply pass straight down and hit the point on the floor of the car DIRECTLY below the point that it touched on the roof. But it doesn't. The light actually BENDS; it hits a point farther back from the point that you would think it would hit (in the opposite direction that the train is traveling). Now I don't believe that Einstein actually saw this as a boy, but I know that he proved it to be true. If you want to really understand what the hell this has to do with Einstein's theory and the possibility of time travel, I suggest you check out some of his work AND a little experiment that was performed with a certain jetplane and an atomic clock.
Oh yeah, Andy. I wanted to ask you...I didn't quite understand your connection between a time machine and the Heisenberg Uncertainty Principle. I don't see how the relationship between momentum and position (if you know your exact position, you cannot know your exact momentum and vice versa) has anything to do with how a time machine might change the course of history. Maybe I'm missing something. Fill me in.
In case anyone missed my question...Does anyone know of any movies that include the use of Einstein's theory to (if you haven't figured it out yet, everything the equation E=mc^2 is based upon) explain the possible existence of time travel?
LATE
see response in other thread...I don't want to repost it.
Time is the measure of movement of all matter relative to itself. If all matter stops, time cannot be measured. This is the essence of "time travel". Can all movement of matter be reversed like running a movie backward? No. Therefore, traveling back in time is impossible. Travel forward in time is possible per Einstein. Similar to old Rip Van (whats his name). Go to sleep and wake up in the future. Or move faster than your relatives while in space and come back to see there grave markers. However, you cannot go back to where you started. If we can ever go faster than the speed of light, we might be able to get ahead of the light leaving the earth and look "back in time". This would be like watching a movie. You could "see" what happened at a given time in the past but you could not insert yourself anymore than you could insert yourself into a movie and converse with the actors within.
Required Sci-Fi Reading:
The Light Of Other Days, Arthur C. Clarke
Rip Van Winkle.
And you don't need to go at the speed of light (indeed, according to relativity, that is impossible as all matter has to be converted into energy). Basically, the faster you go, the more time slows down. But you need to be going really, really, really fast for there to be any noticeable effect.
There is the Martin Sheen movie the Final Countdown about a modern aircraft carrier that travels back in time to before Pearl Harbor...
Martin Sheen quotes Einstein and says that time travel is possible. Although, by the context, it must have been based on some of Einstein's unpublished works...
Time travelling into the future is not what it is termed. It is termed as time dilation. Einstein came up with this theory (which is a bad word because he is proved right millions of times daily through navigation and scientific experiments using high speed paricles that would be impossible without Einsteins observations) in his early twenties at the Bern Patent office. A theory that supposes light is constant in all reference frames and therefore uniform time and space must be given up. I.e. Time and space do not arrive together. This means one is able to dilute time if they travel at high speeds relative to another. Travelling at the speed of light is not neccessary and is an absurd suggestion that deserves no further comment. For matter to travel at the speed of light requires infinite energy but no doubt hollywood will find a way around it and chuck in some time travel too.