Einstein discovered that time is compliant; the time given by a clock may be modified at will; the time given by a clock depends on that clock's motion
, a phenomenon called "time dilation".
Einstein's prediction made in the early 20th century has been verified experimentally by Hafele and Keating in 1971
and confirmed over and over since.
The experiments consisted of extremely precise atomic clocks, one flying in a plane around the globe and a reference clock kept on the ground; the time differences coincided precisely to Einstein's calculations.
The physical experiments are as follows:
- A clock on the ground is used as reference for time.
- The time given by a clock within a plane in motion with respect to the reference clock, differs from the time given by that reference clock.
In the following I am using the expressions clock inner motion
, rather than "time given by a clock", and clock overall motion
for the motion of the plane.
- Within a plane flying eastward the clock inner motion is slower than at rest on the ground.
- And the faster the clock overall motion (the faster the plane) the slower the clock inner motion mechanism (the slower the time).
- At the limit, should the plane reach speed of light, Einstein's time dilation predicts that time would stop.
Because nothing can exceed the speed of ligh the clock's inner motion mechanism has to stall physically while its overall motion is getting closer to speed of light!
One might argue...
One might argue that no matter its design a clockwork mechanism, which provides time, is always made of one or more cyclic motions that are repetitive back and forth motions; the pendulum, the hands of the clock, the electrons circling motions in the cesium atom are all back and forth motions.
As such one might argue that, in the "time dilation" experiments, the overall motion of the clock should alter the backward motions of the clockwork in the same amount but in the opposite direction than it does the clockwork forth motions; that would cancel on average any change occurring on the clockwork motion mechanism; which contradicts "time dilation" physical experiments.
And that would refute the postulation made in this page that the overall motion of the clock alters the clockwork mechanism rather than time.
But that is not the case; the alteration due to an added motion toward light speed is greater than the alteration due to the same motion subtracted in the opposite direction or away from light speed.
In the end, whether one considers the pendulum, the hands of the clock, or the circling electrons, the part of that cyclic motion which is accelerated toward speed of light is slowed more than the other part of that cyclic motion is quickened.
And the postulation made in this page that the closer to light speed the clockwork overall motion, the slower the inner clockwork motion mechanism, remains valid.
The clock's inner motion mechanism
, rather than time, is physically altered in accordance with Einstein's time dilation.