Time in Philosophy and Physics
My apologies for the delayed response. My first effort was not posted.
Philosophies connecting time with change are numerous. Consider our use of the Earth's rotation to regulate our clocks. Julian Barbour's winning essay for the The Foundational Questions Institute is an appropriate reference for our discussion of time as movement as it is against his views that I am arguing.
General Relativity
Einstein Proposed that because acceleration compresses space/time, observers that have experience different accelerations (inertial reference frames) will experience different intervals. He reasoned that since time (Path through Space/time) will be different for each observer there can be no "real" time. An observer that has accelerated will move into the future of one that has not. On a microscope scale we are all moving at different velocities. Are we disconnected in time? The astronaut in orbit experiences faster time as a result of his lesser gravitational acceleration. Are we short cutting into his future? Another conundrum; could there be thousands of you's communicating with thousands of me's all at thousands of different points along the unmoving time continuum?
My position is that general relativity does not require discontinuity of Space/time. Along any time-line there are an infinite number of points that can be exactly mapped to the infinite number of points on a different space/time track. Your GPS unit easily correlates the effects of general relativity to give each location a position in space and time. There are Lorentz transformations that can unite all our time-lines into a connected continuum. The result is that time and the passing of time is a shared reality.
Friday, January 29, 2010
Tuesday, January 19, 2010
The Ultimate Clock
Some will assert that time is a purely human invention. However, there are several biological clocks that are used by organisms to measure time. Apparently the measurement of time elapsed is a critical function of many biological systems. But, no clocks, biological or human made, measure some absolute, universal time. Yet the universe may contain the absolute time measurement.
Many philosophers agree that time is measured in terms of change. If so, there may be an absolute clock. That clock would measure the one absolute, universal change; the velocity of light. That is the change in the position of a photon (regardless of the observer's inertial reference frame). Such a clock would indicate the change in photon position in terms of distance. The movement of photons is the upper limit at which at which energy and information can travel. If photons do not move time does not pass, nothing happens. Moreover, we cannot breathe, think, or perceive. From this perspective the idea of a timeless universe seems untenable.
(A more rigorous discussion would include Lorentz Transforms and common reference points to reconcile inertial reference frames. These point can be considered later.)
Many philosophers agree that time is measured in terms of change. If so, there may be an absolute clock. That clock would measure the one absolute, universal change; the velocity of light. That is the change in the position of a photon (regardless of the observer's inertial reference frame). Such a clock would indicate the change in photon position in terms of distance. The movement of photons is the upper limit at which at which energy and information can travel. If photons do not move time does not pass, nothing happens. Moreover, we cannot breathe, think, or perceive. From this perspective the idea of a timeless universe seems untenable.
(A more rigorous discussion would include Lorentz Transforms and common reference points to reconcile inertial reference frames. These point can be considered later.)
Monday, January 18, 2010
The Parsimony of Future Prediction
Organisms that waste energy are at a disadvantage to similarly equipped ones that do not. Under the stress of competition they will lose out. The human brain is costly in terms of energy consumption. An important brain function is partitioning energy use according to the value of a task. Avoiding life threats is a high value task that intensely engages a number of brain regions. Humans can afford this energy drain because it gives them a survival advantage over organisms that cannot anticipate threats or make plans to avoid them.
Many physicists, Julian Barbour in particular, assert organisms have no control over their futures because there is no "future" in the sense that the passage of time is an illusion. His book "The End of Time" and his recent winning essay for The Foundational Questions Institute,"The Nature of Time," assert that biologists and psychologists need to investigate the origins of this illusion.
Yet if organisms invest valuable energy on nervous systems that sense the environment in order to make behavioral adjustments; how could this investment payoff if time does not pass?
Next we will have to examine the "timeless" physicists' opinions on mechanisms of evolution!
Many physicists, Julian Barbour in particular, assert organisms have no control over their futures because there is no "future" in the sense that the passage of time is an illusion. His book "The End of Time" and his recent winning essay for The Foundational Questions Institute,"The Nature of Time," assert that biologists and psychologists need to investigate the origins of this illusion.
Yet if organisms invest valuable energy on nervous systems that sense the environment in order to make behavioral adjustments; how could this investment payoff if time does not pass?
Next we will have to examine the "timeless" physicists' opinions on mechanisms of evolution!
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