Linked Questions
14 questions linked to/from Why do clocks measure arc-length?
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How to measure time in presence of a strong gravitational field? [duplicate]
I need an operative definition of "measuring time in general relativity" that takes in consideration also the presence of strong gravitational fields between me and clock, able to deviate the light ...
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"Measure of time in general relativity" [duplicate]
Suppose to be in an arbitrary gravitational field and you are moving in it arbitrarily with a clock in your hand.
In this general situation I ask: if I read the positions of the hands of the clock, ...
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Do clocks really measure time?
Each time I listen to this quote from The man from Earth, I'm absolutely intrigued:
Dan: Time... you can't see it, you can't hear it, you can't weigh it, you can't... measure it in a laboratory. It ...
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Traveling between two planets at rest to one another [duplicate]
If I travel at relativistic speed from planet A to planet B which are at rest relative to one another, I will be younger than people on A or B when I arrive. However how does this mesh with the fact ...
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Why should we believe in clock hypothesis? [closed]
It is often assumed in special relativity that the rate of a clock in a non inertial frame does not depend on the proper acceleration of the observer. The point is, Rindler's observer shows us that ...
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Can we derive the relation between proper time and the spacetime interval?
In GR, it's usually taken for granted - or as a definition - that the time measured by an observer's clock is related to the geometry in a very simple way, $d\tau^2 = |ds^2|$. This is easy enough to ...
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Twin Paradox Without Acceleration [duplicate]
So I've been doing a lot of reading about the twin paradox and have encountered several different explanations that strive to resolve it. First off let me start by saying general relativity is not an ...
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How can we measure time?
If we cannot define a proper time (or synchronize clocks in different positions) in an inertial frame (independent with the theory of relativity), there seems to be no direct way to confirm the 2 ...
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Do clocks measure conformal time (new argument)?
Assuming the spatially flat FRW metric for simplicity:
$$ds^2=c^2dt^2-a(t)^2(dx^2+dy^2+dz^2)$$
where $t$ is cosmological time, $a(t)$ is the scaling factor and $x,y,z$ are co-moving spatial Cartesian ...
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Do bad clocks measure proper time?
It has been claimed several times e.g. here, and here, also here, or (outside PSE) there that
Clocks measure proper time.
Or equivalenty:
proper time is just the time that would be measured ...
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Why is a world line's proper time the age of an observer moving along this world line?
We define "world line" in Minkowski Space to be a curve whose velocity is time-like. Then we define "proper time" to be its arc length (with respect to the metric). The given question is
"why is ...
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What's a good reference for a revolving clock in relativity?
I'm searching for a book or journal article that supports what seems to be a very elegant proof of how a central stationary clock "measures" the proper time $T$ of a revolving clock, and most ...
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When do we say that a given clock could be further corrected?
In a recent report on experiments with a sample of ultracold ${\rm {}^{87} Sr}$ atoms, T. Bothwell et al. (physics.atom-ph:2109.12238), the abstract ends and culminates in the following punchline:
&...
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Difference between Gullstrand-Painlevé (GP) time coordinate and proper time $\tau$
The GP coordinates version of Sch. metric uses a new time coordinate, t', which is the time read from a free-falling clock that was dropped from rest at large r and falls past the event we're ...
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