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anantchowdhary
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Does speed of light Change with respect to accelerating frames
It shouldn't be as gravitational time dilation exists
It shouldn't be as gravitational time dilation exists
This is not true, the photon is simply red shifted to zero frequency.quantum123 said:No, the speed of light slows down to = 0 at the Schwarzschild radius of the black hole, to the frame of the external observer.
anantchowdhary said:Does speed of light Change with respect to accelerating frames
It shouldn't be as gravitational time dilation exists
Hootenanny said:No, the speed of light is constant when viewed from any reference frame.
quantum123 said:No, the speed of light slows down to = 0 at the Schwarzschild radius of the black hole, to the frame of the external observer.
quantum123 said:If you look at the Schwarzschild solution, you just let ds=0 (light-like), you will obtain
dr/dt = 1 - 2GM/r , which proves what I said.
quantum123 said:Well it is bad to you but good to me. It is relative.
To the observer, the light photon will approach the event horizon, both its speed(dr/dt) and vibration slowing down, virtually stopping at the horizon. The same goes for any mass>0 object.
In terms of local inertial coordinate systems (defined in terms of measurements made by freely-moving observers in a small region of space and time) the speed of light is always c. But in terms of nonlocal coordinate systems in curved spacetime it doesn't have to be, and likewise, if you use a non-inertial (accelerating) coordinate system in flat spacetime it also may not be c.anantchowdhary said:please gimme a definite answer.yes or no?And how do u visulaize curvature of space-time when there is nothing to curve
Thrice said:SR vs GR again?
Ruian said:Recent Studies shows that speed of light might change...
http://www.sciencedaily.com/releases/2001/02/010212075309.htm
Ruian said:tnx for the reply maybe the studies are wrong or right... but speed of light might change then it will be a small speed diff. but we are not yet sure of this...
rbj said:the question you have to ask yourself is: how would we ever know that c has changed in a context where absolutely nothing else did (particularly the dimensionless constants of nature)? we measure (or perceive) only dimensionless quantities, and if you think you measured a change in c, you measured a change in some ratio of c against some other like-dimensioned quantity (perhaps [itex] e^2/(4 \pi \epsilon_0 \hbar) [/itex]) and that changing dimensionless quantity is the only salient measure.
I think rbj's point is that the notion of a dimensionful constant changing is inherently meaningless, because the only constants that actually have physical meaning are dimensionless ones...this article explains the idea pretty well:Ruian said:I am not saying that I FOUND c to be changing. What i am only saying is that we still must consider what some studies are presented. like speed of light might change. It is maybe its right or wrong. We still don't know. Currently we are considering c to be constant because
it was supported by experiments and used by some theories... Remember that Nicolaus Copernicus was once not beleived that the sun is the center of the universe...
lightarrow said:Maybe it's not c which varies, but the speed of light (which could be not exactly equal to c, depending on the frequency); c could be a limit for EM speed.
When we say that light's speed is equal to c, to which frequency do we refer? This is not specified, but, however, we have never used extremely high or extremely low frequencies, for example, so, how can we know it can't vary with frequency?
I'm sure about that evidence and I'm not claiming a variation of light's speed with frequency, I'm just saying that the statement: "light's speed cannot vary with frequency because c is a dimensionful constant" is wrong. Do you agree?ZapperZ said:But there's at least evidence that it doesn't change with frequency within the range that we know of already. There's zero evidence to the contrary. So we go by what we can verify, not what we can speculate. That's how physics works, and that's why you depend on things to work when you wake up every morning.
Zz.
lightarrow said:I'm sure about that evidence and I'm not claiming a variation of light's speed with frequency, I'm just saying that the statement: "light's speed cannot vary with frequency because c is a dimensionful constant" is wrong. Do you agree?
The speed of light is a fundamental constant in physics, denoted by the symbol "c". It is approximately 299,792,458 meters per second in a vacuum and is considered to be the fastest possible speed in the universe.
The speed of light was first accurately measured in 1676 by Danish astronomer Ole Rømer using astronomical observations of the moons of Jupiter. He noticed that the times between eclipses of the moons varied depending on the position of Earth in its orbit, which allowed him to calculate the speed of light.
According to Einstein's theory of relativity, it is not possible for anything to move faster than the speed of light. As an object approaches the speed of light, its mass increases and it requires an infinite amount of energy to reach the speed of light.
An accelerating frame is a reference frame in which the observer is accelerating or moving at a non-uniform rate. This can cause apparent changes in the speed of light, known as the Sagnac effect, which is important for understanding the behavior of light in rotating frames.
In an accelerating frame, the speed of light remains constant at c, but the observed frequency and wavelength of light can change due to the effects of acceleration on time and space. This is known as the principle of equivalence and is a key concept in understanding the behavior of light in accelerating frames.