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- But, we can’t live without it. We live in our ordinary lives thinking the tick-tock of time to be a constant., a relentless march forward into the future.
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- The tick-tock of time is not a constant. It changes from your head to your toes. Light travels 1 foot a nanosecond and that is what is constant. Our brains are too slow to comprehend nanoseconds. The changes in time are so slight we won’t notice them.
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- The tick-tock of time is faster in lower gravity, at the tops of mountains, or in orbit. A satellite 250 miles above the surface of the Earth has it clocks running faster because gravity is weaker, the curvature of space-time caused by the mass of the Earth is less at that altitude.
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- But, the satellite is orbiting at 17,000 miles per hour. Time’s tick-tock is slower when it is in motion. The faster time travels the slower it gets. When it reaches 299,792,458 meters per second time slows to a stop. ( 670,616,629 mile per hour, or , 186,282 miles per second.).
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- In order for the Global Positioning System to work for us on the surface of the Earth we need to adjust our clocks faster for the elevation and slower for the relative velocity of transmitter-receivers in orbit. Without these corrections an offset of only a millionth of a second would cause an error of 1/5 of a mile on the surface. A satellites circular orbit is a 2 dimensional circle in space, but, it is a 3 dimensional spiral in space-time.
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- When Einstein’s thought experiment put the speed of light as a constant, not to be exceeded, he had to do something with speed that equals space divided by time, meters per second. In order to bring this ratio to a stop he had to make distance and time the variables. Space had to shrink to nothing and time had to stop.
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- Simultaneity had to be “ relative”. Two events that occur at the same moment observed from one reference frame will occur at a different moment viewed from another reference frame. For example, an instant for an event on Mars will be viewed as occurring 20 minutes later on Earth. We will always see the result after the event.
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- The same dilemma with time will occur with relative motion. An event that might be in the undecided future may have already occurred in the other observer’s past.
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- Time offers us a huge dilemma in describing future events turning into present events and then into past events. If time is flowing , if it is moving, how do we decide relative to what is it moving?
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- Time is better understood as simply what clocks measure. It is one dimension of space-time. We assume time to be continuous , but, in the smallest increments it might actually exist as discrete “ chronons”, like the frames in a movie.
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- The events in our lives undeniably form a unidirectional sequence. Physics has its 2nd law of thermodynamics that requires disorder, or Entropy, to always increase in one direction with time. A shattered egg has more Entropy than when it was an intact egg. The process is irreversible.
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- Physics has other laws that dictate the asymmetry of time. Closely related to Entropy involves the Information content of a system. Memory adds information and raises the Entropy. So, our brains see time as unidirectional.
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- Still a 3rd law adds to the mystery of time. The Heisenberg Uncertainty Principle requires that properties of a system remain undecided from one moment to the nest. Quantum indeterminism requires any quantum state to have an infinite alternative futures. All outcomes are the result of their relative probabilities. Only when the event is observed is one outcome obtained. Time does not tell us how nature transitions from many potential realities into a single actuality. The act of the observer appears to prompt nature to decide what actually happens.
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- Time is a mystery implying we take advantage of living in the present because the past, present, and future will be things of the past.
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- Other reviews about time available upon request: 1735, 1736, and 12 others listed in the footnotes of these two reviews.
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----- 707-536-3272 ---------------------- Wednesday, April 1, 2015 -----
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