Looping Through Time
With the release of the movie Looper, LiveScience has posted its obligatory "Is time travel really possible?" article. It seems to be some sort of constant in the universe that any time a new book or movie dealing with time travel comes out, this kind of article is required in all science publications.
The article itself mostly rehashes old ground and also gets concepts confused, so it's not particularly interesting, but some of the discussions in the comments section are worth reading.
I've always thought that one of the biggest embarrassments of modern physics is its failure to discover some kind of physical or mathematical principle that makes time travel impossible. To be sure, many of the greatest minds in science have tried to find some sort of "Chronology Protection Principle", but such a thing has so far eluded us.
Quantum mechanics is bizarre enough, but a universe that allows time travel results in so many logical paradoxes that it practically destroys any notion of a predictable universe that can be studied and understood through observation and experiment. If we ever somehow got proof that time travel is in fact possible, we would have to rethink all of our most basic notions of logic, philosophy, and science -- it would shake the very basis of human understanding to the core.
I want to be clear on one point where the Livescience article isn't. By "time travel", I'm not talking about the notion of time passing slower as we move faster. Popular science articles, for some reason, have an annoying habit of calling this a form of time travel. That isn't a form of time travel -- it's merely a straightforward consequence of Einstein's discovery that time doesn't pass at the same rate everywhere as we had previously thought.
Although somewhat counter-intuitive at first, the principles behind the relativity of time can be grasped and understood within a logical framework of the universe with a little study. It doesn't even require much knowledge of mathematics. It results in no logical paradoxes. Einstein's ideas flow seamlessly from one conclusion to the next in an elegant fashion that can only be admired once you take the time to understand it.
By "time travel", I'm talking about the classical sci-fi plot device of being able to move at will back and forth along the timeline from one given point to another -- whether this is accomplished by accelerating a Delorean to 88 miles per hour or aiming your stolen rickety Klingon cruiser at the sun and swinging around to the other side on just the right path or some other method.
That type of time travel clearly has to be impossible, although let me be clear in saying that science has not proved that yet. Admittedly time travel is one of my favorite science-fiction plot devices. I love a good time travel story because a well-written one can be a lot of fun. I count the Back to the Future trilogy among my all-time favorite sci-fi movies.
But if we're to maintain any notion of a universe that makes any kind of sense at all, jumping back and forth through time must remain in the realm of science fiction.
And besides . . . the Vulcan Science Academy clearly states that time travel is impossible.
The article itself mostly rehashes old ground and also gets concepts confused, so it's not particularly interesting, but some of the discussions in the comments section are worth reading.
I've always thought that one of the biggest embarrassments of modern physics is its failure to discover some kind of physical or mathematical principle that makes time travel impossible. To be sure, many of the greatest minds in science have tried to find some sort of "Chronology Protection Principle", but such a thing has so far eluded us.
Quantum mechanics is bizarre enough, but a universe that allows time travel results in so many logical paradoxes that it practically destroys any notion of a predictable universe that can be studied and understood through observation and experiment. If we ever somehow got proof that time travel is in fact possible, we would have to rethink all of our most basic notions of logic, philosophy, and science -- it would shake the very basis of human understanding to the core.
I want to be clear on one point where the Livescience article isn't. By "time travel", I'm not talking about the notion of time passing slower as we move faster. Popular science articles, for some reason, have an annoying habit of calling this a form of time travel. That isn't a form of time travel -- it's merely a straightforward consequence of Einstein's discovery that time doesn't pass at the same rate everywhere as we had previously thought.
Although somewhat counter-intuitive at first, the principles behind the relativity of time can be grasped and understood within a logical framework of the universe with a little study. It doesn't even require much knowledge of mathematics. It results in no logical paradoxes. Einstein's ideas flow seamlessly from one conclusion to the next in an elegant fashion that can only be admired once you take the time to understand it.
By "time travel", I'm talking about the classical sci-fi plot device of being able to move at will back and forth along the timeline from one given point to another -- whether this is accomplished by accelerating a Delorean to 88 miles per hour or aiming your stolen rickety Klingon cruiser at the sun and swinging around to the other side on just the right path or some other method.
That type of time travel clearly has to be impossible, although let me be clear in saying that science has not proved that yet. Admittedly time travel is one of my favorite science-fiction plot devices. I love a good time travel story because a well-written one can be a lot of fun. I count the Back to the Future trilogy among my all-time favorite sci-fi movies.
But if we're to maintain any notion of a universe that makes any kind of sense at all, jumping back and forth through time must remain in the realm of science fiction.
And besides . . . the Vulcan Science Academy clearly states that time travel is impossible.