UPDATE: I must inform Mr. Hawking that he may be slowly catching up to me. Read about his theory here and then go ahead and find out why I have stated that time travel is not only possible, but is accomplished every microsecond of everyday.
Time travel has been the subject of a large number of discussions, books, movies and such. Unfortunately, they all portray time travel in an extremely unrealistic manner. I myself have previously been fooled by what seemed to be a superior depiction, of what time travel would be like, that I found in some movies. But with a little thought about it, I have come to realize what it would be like to actually travel through time. And now I will share it with you.
To the Future
Time travel is much less dramatic than you think. In fact, I do it everyday. Everyone does it everyday. That’s right, we are all traveling through time. With our time travel we are heading from point A (birth) to point B (death). This is very simple to understand and makes time travel much less fascinating than before. As we head from point A to point B we make observations and learn new things that help us to mark different moments in our time-line. To take Marty McFly from the year 1985 to the year 2015 (as in Back to the Future 2) it would take thirty years. That would make a very boring movie.
To the Past
For Marty to go back to 1955 from 1985 things get slightly more interesting. Marty would have to have been born in 1968 or 1969 for him to be in high school in 1985, which means that if he went back to 1955, he would not exist in human physical form. Meaning that he would be physically in many different places such as: in some dirt in a field on a farm or in the ocean floating around, waiting to evaporate and rain down in a lake near Hill Valley. If we change the story a little and only take Marty to 1975 he would be 6 or 7 years old and he would, of course, not be aware of Doc Brown or anything in 1985. He would also not be aware of his re-travel forward to 1985 as it would seem like he was just living his life as he makes observations and learns new things at different points in time.
The 4th Dimension
A couple of times in the Back to the Future series of movies Doc tells Marty that he is not thinking 4th dimensionally. This is funny to me, since Doc is apparently not thinking 4th dimensionally either. Doc tells Marty not to worry about hitting some painted American Indians below a drive in movie screen because the movie screen isn’t there in 1885. Doc overlooks the fact that in 1885 the particles of matter that made up Marty and the Delorean are not organized into the form of a person and a car.
I used to think that the Bruce Willis movie “12 Monkeys” was an accurate depiction of time travel since he goes back in time to try to change the future but finds out that he cannot change anything. The fact that you cannot change anything is certainly correct, but the fact that he traveled back in time and was fully grown and aware of observations he had made in the future is a huge mistake.
It is my belief that, on the time-line that is the 4th dimension, we can travel back and forth. Traveling forward is what we call living and we make the aforementioned observations and learn things. Traveling backward would take our particles to the older time and replay everything to the future. As time is “replayed” we are completely unaware of anything that we did not observe or learn before a certain point and we have absolutely no idea that we have traveled back. If you need a time machine for this to feel right in your head you can just consider your particles of matter to be the time machine.
I agree with your comments on time except I don’t think it would necessarily have to take 30 years to move ahead 30 years in time. You should also be able to fast-forward or skip ahead or behind to any chapter or time index and see things how they exist at any point in time. Where things get confusing is when you start thinking about sending objects, like humans, around in time. Are you really sending an object through time, or are you repositioning the components of an object as they existed in that time to be how they exist in some other time? But if that is the case, you wouldn’t have the situation where Marty meets up with Marty, because surely some of the components of one Marty are in use in the other Marty, and if you repositioned them to create the Marty from the distant time, the Marty in the present time would no longer be complete and functional.