Questions tagged [time]
Time is defined operationally to be that which is measured by clocks. The SI unit of time is the second, which is defined to be
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Clarification regarding the meaning of Universal Time UT1
I've been reading the book "From Sundials to Atomic Clocks: Understanding Time and Frequency" by James Jespersen and Jane Fitz-Randolph which is available at https://www.nist.gov/system/...
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Northern lights / aurora borealis "pre-warning" - how does this work w.r.t timing and different particle / wave speeds?
There is an article in the newspaper today entitled "Northern lights predicted in US and UK on Monday night in wake of solar storms".
I assume that the reason that someone can make this ...
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Condition for synchronizing clocks in the special relativity paper
I'm reading Einstein's special relativity paper and couldn't understand the condition for synchronizing given in the following paragraph taken from the paper -
If at the point A of space there is a ...
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Time dilation rotating around the center of mass
If 2 objects connected by a massless rod or wire, rotate around the center of mass, do they experience time dilation ? I'm thinking that the smaller one will move faster so time will pass slowly, but ...
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Time taken for an object to fall [duplicate]
Time taken for an object to fall is generally given by $$t=\sqrt{\frac{2h}{g}}.$$ But this is only true under the assumption that gravitational acceleration is constant. With variable gravity what ...
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Was "flow of time" equally fast during the life of universe? Is Doppler Effect the only interpretation of "shift to red"? [duplicate]
I'm an IT developer and recently I created a project where I tried to send signals between two threads in a slowing down environment. I simulated two points with their own clocks and tried to send a ...
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How does the distribution of floor choices of your co-passengers affect your time of arrival in an elevator?
Note: This is a wiki post.
Suppose you are late for a meeting and you have to take an elevator. The floor choice of your fellow passengers influences how late you will reach your destination. If ...
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What is the problem with two time dimensions? [duplicate]
I am reading a book "General relativity: The theoretical minimum" by Leonard Suskind.
In page 168-169, the author explains the reason why we don't consider the case with two time dimensions ...
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Need help to clarify understanding example of time nature from Hawking's book "Briefer History of Time"
I'm reading Hawking's book "Briefer History of Time" both in Ukrainian and Russian languages and found a possible translation mistake in this paragraph (last page of "Chapter 6. CURVED ...
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Can a homogenous electric/magnetic field vary in time?
In either case I was thinking their curl is cero since they're homogenous. But that only leaves with
$- \frac{\partial B}{\partial t}=0$ for example, but then?
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An unusual calculation of our universe's age? [closed]
Does the following make sense? And has anyone else come
across this odd ~’cosmological coincidence’ before?…
…If we posit that our total universe mass is:
(1) $$M_{U}=\frac{{M_{pl}}^4}{{M_{p}}^...
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Symmetrical Time Dilation [duplicate]
I have lately been researching time dilation and relativity, and thought about this phenomenon:
Take two people, Observer A, and Observer B, who are both carrying clocks. Observer A travels through ...
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Does the speed of light determine how slow time can move?
Since moving faster makes time move slower. Does that mean that there is an absolute minimum rate at which time passes? If so. Is there also a maximum?
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How much time passes relative to the protons inside the LHC?
The time depends on the speed of movement. Protons in the LHC move at near-light speed. Therefore, they perceive a different time than the scientist who is observing them. My question is how much time ...
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Time direction ambiguity in stationary observer's 4-velocity
Working in the mostly + convention, for a timelike geodesic in Minkowski spacetime we have the requirement that (c=1):
$$u^\alpha u_\alpha=-1$$
and that it of course obeys the geodesic equation.
If we ...
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