# Time delation or clock malfunction

by R Power
Tags: clock, delation, malfunction, time
 P: 272 Using an example of light clock, it shows light takes more time now to reflect between reflectors due to elongated path as to moving observer, so 1 sec gets elongated. But this could also mean that the clock malfunctions as compared to observer. I mean one second is one second, how it can change???? light now takes more time to complete its one cycle doesn't mean 1 sec gets elongated. It's just the clock which now takes more than one second to show one second increment to the observer. That means clock malfunctions for the moving observer but it can't elongate 1 sec. Why will biological processes get slower? So why will aging occur?
 Math Emeritus Sci Advisor Thanks PF Gold P: 39,503 No, there doesn't have to be any clock involved. If A is moving at a high speed relativer to B, then B will observe everything about A is slower. It is NOT the case that the clock has "malfunctioned".
P: 3,187
 Quote by R Power Using an example of light clock, it shows light takes more time now to reflect between reflectors due to elongated path as to moving observer, so 1 sec gets elongated. But this could also mean that the clock malfunctions as compared to observer. I mean one second is one second, how it can change???? light now takes more time to complete its one cycle doesn't mean 1 sec gets elongated. It's just the clock which now takes more than one second to show one second increment to the observer. That means clock malfunctions for the moving observer but it can't elongate 1 sec. Why will biological processes get slower? So why will aging occur?
We call the count of progress of physical processes "time". According to SR, what is true for a light clock must be true for all physical processes, thus also for age. While one may philosophize about the existence of some kind of universal or "absolute" time, the only time that we can measure is that of physical processes. If according to our measurements all of them slow down, it is common to call this common slowdown "time dilation". A more conservative phrasing of the same is "clock retardation".
Perhaps you would still call that "clock malfunction", but as it is in the nature of the best clocks that we can make, few people would agree with calling it such.

 PF Gold P: 4,737 Time delation or clock malfunction R Power, if you have two clocks in relative motion, they each will observe the other one to be running slow, so how do you decide which one is malfunctioning?
P: 272
 R Power, if you have two clocks in relative motion, they each will observe the other one to be running slow, so how do you decide which one is malfunctioning?
Obviously for each them the other one will malfunction.
PF Gold
P: 4,737
 Quote by R Power Obviously for each them the other one will malfunction.
You said one second is one second. Which one is correctly measuring that one second?
P: 272
 You said one second is one second. Which one is correctly measuring that one second?
hmmm...... so you want to say that time is not some universal duration its just the duration between two successive events. For each of the moving observers the successive events occur slowly at the other one.
But for your question each clock measures one second correctly for its own observer but wrong for the other observer.
PF Gold
P: 4,737
 Quote by R Power hmmm...... so you want to say that time is not some universal duration its just the duration between two successive events. For each of the moving observers the successive events occur slowly at the other one. But for your question each clock measures one second correctly for its own observer but wrong for the other observer.
Well, that's not my idea, it's Einstein's. Before he came up with this idea, people thought that there was a universal time based on an absolute rest state and since the surface of the earth is constantly changing its motion through space, all our clocks must be suffering a slow-down. But Einstein said, "Time is what a clock measures", so if two identical clocks run at different rates only because they are moving with respect to each other, that must mean that time is relative and that makes it right for each clock. Neither clock is wrong, they just have a different definition of what a second is. This might seem to make no sense at all, in fact, Einstein pointed this out in his 1905 paper introducing Special Relativity, but he went on to show how you could create a concept of a Frame of Reference involving both space and time in such a way that it makes perfect sense.
 P: 272 So, now for both the clocks the other one is slow. What will happen in case these both clocks meet each other. Imagine the clocks reverse their path to meet each other.
 PF Gold P: 4,737 It depends on exactly what you have in mind. For example, if to begin with, both clocks passed each other so that they could set their clocks to the same time, and then some time later according to each clock, they both turned around in the same way and eventually met up again, then their clocks will display the same time when they pass each other the second time. However, if only one of them turned around and headed back to the other one, then that clock will display an earlier time when they pass.
Mentor
P: 17,220
 Quote by R Power Using an example of light clock, it shows light takes more time now to reflect between reflectors due to elongated path as to moving observer, so 1 sec gets elongated. ... Why will biological processes get slower? So why will aging occur?
Here is an answer that I gave previously to a similar question:
 Quote by DaleSpam So, from this comment it seems that you understand time dilation for light beam clocks. Remember that special relativity is founded on two postulates. 1) that all the laws of physics are the same in all inertial reference frames 2) that the speed of light is the same in all inertial reference frames So the part that you understand, the time dilation of a light clock, is primarily based on the second postulate. But to understand how we make the jump from light clocks to time in general you need to consider the first postulate: Imagine that we have a light clock, an atomic clock, a piezoelectric quartz clock, a windup spring clock, and a rat with a really steady heartbeat. All are clocks working on different physical principles. Because the laws of physics are the same in all inertial reference frames (first postulate) if they all beat at the same rate in one frame they must all beat at the same rate in any other frame. So, in an inertial frame where the clocks are moving at relativistic velocity, because the light clock slows down the other clocks must also slow down or the laws of physics would be different. Therefore, because any physics expression with a "t" in it must slow down, we say time slows down.

 Related Discussions Special & General Relativity 55 Special & General Relativity 7 Special & General Relativity 3 Special & General Relativity 204 Special & General Relativity 4