# Thread: If Time is not physically part of the fabric of the Universe are clocks really just counting events?

1. If Time is not physically part of the fabric of the Universe are clocks really just counting events?

When we carry out an experiment with 2 atomic clocks as follows we notice that Clock A displays a lower reading than Clock B.

1. Synchronise clock A and Clock B in a given location at rest
2. Set clock A in motion
3. Move clock A back to the location of Clock B and no longer in motion relative to Clock B
4. Read the displays of both clocks

According to SR the lower reading on Clock A is due to time running more slowly in its inertial frame of reference. This is based on the assumption that time is something that is actually part of the fabric of the universe.

We can alternatively state from the observations without any explicit or implicit reference to time that due to its relative motion the number of transitions between the two hyperfine ground states of caesium-133 atoms registered by Clock A was less than Clock B. This is based on the assumption that time is solely a human notion and not something that is actually part of the fabric of the universe.

2.

3. Originally Posted by james fairclear
If Time is not physically part of the fabric of the Universe are clocks really just counting events?

When we carry out an experiment with 2 atomic clocks as follows we notice that Clock A displays a lower reading than Clock B.

1. Synchronise clock A and Clock B in a given location at rest
2. Set clock A in motion
3. Move clock A back to the location of Clock B and no longer in motion relative to Clock B
4. Read the displays of both clocks

According to SR the lower reading on Clock A is due to time running more slowly in its inertial frame of reference. This is based on the assumption that time is something that is actually part of the fabric of the universe.

We can alternatively state from the observations without any explicit or implicit reference to time that due to its relative motion the number of transitions between the two hyperfine ground states of caesium-133 atoms registered by Clock A was less than Clock B. This is based on the assumption that time is solely a human notion and not something that is actually part of the fabric of the universe.
Trying to determine whether or not time is part something termed "the fabric of the universe" seems pretty meaningless. Do you think length is part of "the fabric of the universe" and if so what do you mean by that? Length, breadth, height and time are axes forming a coordinate system to locate objects and events in relation to one another.

There is nothing special about atomic clocks, by the way. A pair of wristwatches would do equally well.

4. Originally Posted by james fairclear
If Time is not physically part of the fabric of the Universe are clocks really just counting events?

When we carry out an experiment with 2 atomic clocks as follows we notice that Clock A displays a lower reading than Clock B.

1. Synchronise clock A and Clock B in a given location at rest
2. Set clock A in motion
3. Move clock A back to the location of Clock B and no longer in motion relative to Clock B
4. Read the displays of both clocks

According to SR the lower reading on Clock A is due to time running more slowly in its inertial frame of reference. This is based on the assumption that time is something that is actually part of the fabric of the universe.
I don't think your understanding of SR is quite complete.
There is no absolute answer as to why clock A reads less than Clock B when they meet up. Someone at rest with respect to B would say that it was because clock A ran slow. However, that is just a consequence of choosing that inertial reference frame from which to make your determination, and it is not the only valid inertial reference frame you can use.
You could also choose to use the inertial frame that Clock A was at rest with respect to when the clocks were coming back together. In this frame, it is clock B that ticks slow. However, in this frame, the two clocks are never synchronized to each other. Thus when A starts its trip back to clock B, clock B already reads later than Clock A, and this more than makes up for the fact that it ticks slower while the clocks approach. In other words, while this frame agrees that B reads later than A when they meet, and by how much, it doesn't agree with clock B as to how this came about. In addition, this frame's perception of events is just as valid as clock B's.