Time - II

Time – II.

Disclaimer: I am not a mathematician or a theoretical physicist. I aim primarily to establish, or rather to discuss (establish is way to arrogant) the way time is viewed in literature, mostly popular literature and some films.

Paraphrasing Newton, we have his views on ‘absolute time’: “Absolute, true, and mathematical time, from its own nature, passes equably without relation the anything external, and thus without reference to any change or way of measuring of time (e.g., the hour, day, month, or year).”

Later physicists, principally the authors of modern physics, ie, people like Poincare and Einstein have constructed theories according to which it is incorrect, or incomplete to view time as an independent parameter on a ‘timeline’. Rather, it makes sense to talk about events that are separated by both space and time.. or rather ‘spacetime’. Here time is now viewed as another parameter like length, breadth and height. Relative time, as recorded by a clock on a spaceship depends on how fast that spaceship is moving. The faster it moves, the slower the clock ticks. The upper limit to this appears to be the speed of light. So far we have gracefully pirouetted around the question of whether the clock can tick backwards. Let me rephrase that: can time be made to flow backwards? Hmmm.. tricky. In fact, we will not try to answer that question in a scientific form at all.

But before we start our journey into the speculative, let us talk of Alice and Bob. They happen to have been taking a coffee break while their graduate students were preparing two spin half particles in an entangled state. Alice then walks off with one of the entangled particles and Bob has the other. When Alice wants to send some information to Bob, she performs a basic unitary operation on her particle.. which is just a fancy mathematical term for something like rotating its spin by 180 degrees. Bob’s particle is immediately affected by whatever Alice has done to her particle: such is the nature of entangled states. So it appears that information transmission is instantaneous. This is interesting indeed.

Anyway, to get back to our discussion of time and its treatment in popular entertainment, there have been very erudite discussions and speculations on superluminal, or faster than light travel. Most of these discussions are motivated by the simple analogy of an ant walking on the surface of a rubber ball. To get to the diametrically opposite side, he must travel a minimum equatorial distance of pi*radius. If some one is so kind as to provide him with a radial channel passing through the centre of the ball, he will only have to travel a distance of 2*radius. This is “hyperspatial” travel. In fact, most theories of superluminal travel speculate that there are available such “wormholes” in space through we which we might be able to travel to reach far distant reaches. I remember a particularly cheesy movie ‘Event Horizon’ which had a spaceship that seemingly passed through a black hole. Yes, black holes, (which are collapsed stars) seem to always be good candidates for space wormholes. Well, the Event Horizon came back and apparently it had been to some truly evil place, for its crew had died quite gruesomely. Yes, a particularly cheesy film indeed, made only slightly tolerable by the presence of Laurence Fishburne. In the next, and concluding article in this series, I will explore the religious connotations associated with such flights of science fiction.

References:
1. http://plato.stanford.edu/entries/newton-stm/ (support this project!!!)
2. http://eve.physics.ox.ac.uk/NewWeb/Research/communication/communication.html (this is an excellent reference written by two of the most respected scientists in the field of quantum computation)
3. http://en.wikipedia.org/wiki/Time_in_physics
4. http://en.wikipedia.org/wiki/CPT_symmetry
5. http://en.wikipedia.org/wiki/Time#Time_in_physical_sciences
6. http://www.imdb.com/title/tt0119081/
7. http://math.ucr.edu/home/baez/physics/Relativity/SR/TwinParadox/twin_intro.html
8. http://www.vectorsite.net/tarokt_7.html
9. http://en.wikipedia.org/wiki/EPR_paradox
10. http://math.ucr.edu/home/baez/physics/Quantum/bells_inequality.html