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Denton
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Sources of great mass slow time down relative to an outside observer, so why is it that light itself is not slowed down, not in velocity but simply due to the fact that time has slowed down near the mass?
It is!Denton said:Sources of great mass slow time down relative to an outside observer, so why is it that light itself is not slowed down,
Exactly like this. The distant observer will measure the light near the mass to travel at less than c, using his own fast clock. It will appear "slowed down" to him. But the local observer near the mass with a slow clock will measure the light passing him at c.Denton said:not in velocity but simply due to the fact that time has slowed down near the mass?
Is that right? I thought one of the core ideas behind relativity was the constancy of the speed of light, meaning that no matter where you are at in the universe, you would always measure the speed of light (in a vacuum) to be 3x10^8 meters/second. Is there something I've misunderstood?A.T. said:It is!
Exactly like this. The distant observer will measure the light near the mass to travel at less than c, using his own fast clock. It will appear "slowed down" to him. But the local observer near the mass with a slow clock will measure the light passing him at c.
That's correct for light near you. But the OP is asking about an outside observer measuring the speed of light in a gravity well.LucasJ said:Is that right? I thought one of the core ideas behind relativity was the constancy of the speed of light, meaning that no matter where you are at in the universe, you would always measure the speed of light (in a vacuum) to be 3x10^8 meters/second
Not only frequency is affected. If you send a light signal from outer space to a mirror stationary to you in a gravity well, it will return with the same frequency. But it still will need longer then if there was no gravity. So it will appear to you, that it was slowed down.atyy said:Anything wrong with this handwaving?
c=f.l (speed = frequency.wavelength)
Time is related to frequency. If time slows, frequency decreases, but if wavelength also increases, speed can stay the same.
Anything wrong with this handwaving?
c=f.l (speed = frequency.wavelength)
Time is related to frequency. If time slows, frequency decreases, but if wavelength also increases, speed can stay the same.
Then comes to the other question. What is so special about the velocity of light that it must remain constant, and that its frequencies and wavelengths are but insignificant.
Time dilation is a phenomenon in which time appears to pass at different rates for objects in motion relative to each other. This is due to the effects of special relativity, which states that time and space are not absolute and can be influenced by an object's speed and gravity.
The theory of special relativity states that the mass of an object increases as its velocity approaches the speed of light. This increase in mass causes time to slow down for the object, leading to time dilation.
Light sources, specifically the speed of light, play a crucial role in time dilation. According to special relativity, the speed of light is the same for all observers, regardless of their relative motion. This means that time dilation occurs to maintain the constant speed of light for all observers.
Time dilation can be observed and measured through experiments, such as the famous Hafele-Keating experiment, which used atomic clocks to demonstrate the effects of time dilation on objects in motion. Additionally, time dilation has been observed through astronomical observations, such as the decay rate of particles traveling at high speeds.
Understanding time dilation has practical applications in various fields, such as GPS technology, where precise timekeeping is crucial for accurate location tracking. It also plays a role in particle accelerators, where time dilation allows particles to reach high speeds and energies. Additionally, time dilation has been used in science fiction as a plot device for time travel and exploring the concept of time perception.