Dr. Mercola July 09 2005 1,047 views
While time travel may seem like a phenomenon found only in movies like Back to the Future and The Terminator, science reveals this may not be the case.
According to physicists, real-life time travel can occur within a kind of feedback loop where backward movement is possible, but only in a way that is "complementary" to the present. In other words, people can only go back in time and look around but cannot do anything that would alter the present they left behind.
Debunking the Time Travel Paradox
One of the biggest myths surrounding time travel is the idea that if one goes back in time they could, theoretically, do something to change the present. The new model, which uses the laws of quantum mechanics, tosses that famous paradox out the window.
Clearly the present has never been changed by roguish time-travelers, simply due to the fact that people don't suddenly fade out of existence because a rerun of events has prevented their births. Therefore, time travel is either:
While the former option may seem the most logical, Einstein's general theory of relativity has led physicists to suspect the latter.
Using Einstein's Theory of Relativity
According to Einstein, space-time can curve back on itself, allowing time-travelers to double back and meet the younger versions of themselves. A team of physicists from the United States and Australia claim this situation can only be the case if there are physical restrictions protecting the present from changes in the past.
These restrictions exist because of the weird laws of quantum mechanics, though (traditionally) they don't account for a backward movement in time. Quantum behavior is ruled by probabilities:
Before something has actually been observed, there are many other possibilities regarding its state; however, once its state has been measured, those possibilities are cut down to only one, eliminating all uncertainty.
To put it plainly, quantum mechanics discerns between something that might happen and something that did happen. For example, if someone doesn't know if their father is alive--if there is only a 90 percent chance he is alive--then there is a possibility one can go back in time and kill him. But, if one's father is alive in present time, then there is no chance he can be killed in the past.
Ahh, the mysteries of quantum mechanics ...
BBC News June 17, 2005
Like me, many of you may be interested in the possibility of time travel. I have always been fascinated with this topic and science fiction films about it are some of my favorite ones.
Of course, as someone who already works 80-100 hours a week, and is trying to cut down, I know that if time travel ever did become possible, my "to-do list" would get completely out of control.
As with most things not totally quantifiable or measureable by science, I find this attempt to explain time relatively lacking in depth or understanding. Scientists fatally insist that everything go under laws already in existence - at least laws in existence according to them. This blinds them to so many other possibilities. In my opinion, unless they can at one point look outside of the physical for answers, most things with elude them.
it may be feasible at the sub-atomic level, because space-time itself appears quantized to sub-atomic particles. However, it may not be feasible for a large object such as a human being, unless all the quantum states in the body were simultaneously to follow the same exact space-time path. As we are talking about a googleplex of states, maybe, this is bordering on the impossible. Then, even if you could go back in time, all your physiological needs must also be kept on track. You have to breathe air, for instance, that has not been converted already into carbon dioxide. It is not clear that bending space-time would be so convenient. But never declare something to be impossible ! In 2000 years' time we are quite likely to have a view of ourselves and the universe that will make our current science look childishly misguided.