B What is time? How can we see it?

[russ_watters]

To define "clock" we need something which allow us to distinguish it from other Instruments, or we could use a ruler to measure durations.

Please elaborate. I see no difference between the statements:
"Clocks measure time"
and
"Rulers measure distance"

Both are recursive definitions that apply only to their chosen dimension. IE, since by definition a ruler measures distance it is obviously incorrect to say that a ruler measures durations.

We need a better definition of "clock", a one which of course doesn't use the concept of time.

I agree with WW: a definition that does not make reference to/use of the concept it is defining is useless. The whole point of a definition is to explain the concept it is defining.

 

[William White]

lightarrow no, I shall not stop to ponder pseudo philosophical twaddle. Lifes too short - there are bigger problems.

Clocks measure time.

if you have an issue with that, you are the one in need to stop and think a bit

 

[William White]

use a ruler to measure durations?

so, the train leaves at 12 : 00 clock train from Euston to go to Glasgow; I want to know how long it takes; let me find that ruler...

 

[lightarrow]

Please elaborate. I see no difference between the statements:
"Clocks measure time"
and
"Rulers measure distance"

Both are recursive definitions that apply them only to their chosen dimension. IE, since by definition a ruler measures distance it is obviously incorrect to say that a ruler measures durations.

What you haven't grasped is that I'm not talking of logic or of syntax here. I'm talking of physics.
Someone asked what is time and someone else answered that "time is what a clock measures". Very good. Just to avoid ambiguity, this is the same answer I would give (and that I've really given, many times, in the past).
But then I need a clock. Would I choose a device at chance and I would stick the label "clock" to it? Of course not. We are advantaged, nowadays, because we already have clocks. But, if we wouldn't have any, which devices or other would we construct and why, which we could call a "clock"? It's not an easy answer at all.
It has to do with the physical fact that exists phenomena, perceptibly associated to "duration" and "repetition", of which we can verify the synchrony. The physical concept of "clock" starts from here.

--
lightarrow

 

[Dale]

Thanks to you, this thread is in danger, like most of the previous thread on this topic, of being shut down.

Yup.

Thread closed.

Everyone, please try to avoid the philosophical navel gazing.

PS clocks can be defined by instructions to build them. Similarly with rulers, and scales.