- #1
aditya ver.2.0
- 67
- 4
Is the change in frequency an actual change or is it like the Doppler effect?
Does the speed of light also change in a g-field?
Does the speed of light also change in a g-field?
What is an "actual change", and why isn't Doppler one?aditya ver.2.0 said:Is the change in frequency an actual change or is it like the Doppler effect?
Depends on how you measure it.aditya ver.2.0 said:Does the speed of light also change in a g-field?
This is the wrong sub forum for your questions... and as noticed, your questions are fuzzy -but that's quite normal if you don't understand it. :) I'll thus try to answer what you may be asking.aditya ver.2.0 said:Is the change in frequency an actual change or is it like the Doppler effect?
Does the speed of light also change in a g-field?
Doppler effect is an apparent change in the frequency of the sound source due to relative motion between it and the observer.Vanadium 50 said:The Doppler effect is an actual change in frequency.
jartsa said:The reason for extra real buns is real extra swiftness of the staff.
jartsa said:Then the bakery is moved to the top of a mountain.
aditya ver.2.0 said:Doppler effect is an apparent change in the frequency of the sound source due to relative motion between it and the observer.
Of course, in some specific cases it is difficult or even impossible to say with certainty what "really" changed. However, unwittingly you just explained (although perhaps not elaborately enough) how one can often in general distinguish changes in observed objects from changes in the used systems of observation. In physics experiments it's a rather standard operating procedure to induce changes at will at specified instances so that other influences can be filtered out. Such discovered laws of physics can give the kind of generic answers that the OP may be looking for.PeterDonis said:Relative to the people who are buying the buns. Move all the valley people who buy buns to the top of the mountain, and they will buy 101 buns a day instead of 100 because their metabolism is faster.
And even then, the reason the number of buns per day changes is that the "day" is determined by something external to the whole system (the Sun), so it can be viewed as staying the same while the swiftness and metabolism of the people changes. If the bakery and the people buying buns were inside a rocket that was hovering deep in the gravity well of a black hole, their "day", as judged by their own clocks, would not change at all relative to their bun production and consumption; they would be baking and consuming 100 buns a day, according to their own clocks, and would have no knowledge that, to someone far outside the gravity well, they were only producing and consuming a fraction of a bun per year, or decade, or whatever (unless they communicated with the person far outside the gravity well).
The point of all this is that getting fixated on what changes are "real" and what changes are only "apparent" is, IMO, a rabbit hole with no bottom. [..]
The reason for the extra buns is there is less gravitational 'drag' at higher elevation. The swiftness is due to less drag. Yes?jartsa said:Here's a little story:
There's a bakery in a valley making 100 buns a day. Valley people buy 100 buns a day.
Then the bakery is moved to the top of a mountain. Now bakery makes 101 buns a day. After million days bakery has million unsold buns.
The point of the story is that the extra buns are real buns. The reason for extra real buns is real extra swiftness of the staff.
Don't you really need a third observer to arbitrate between two other measurers. E.g. Fr A and Fr B are arguing results from each's perspective. Obtain a result from the 3rd observer as to the exact differences between those two frames. I advocate a Universal Reference Point to be the arbitrator. A space station at a fixed place between 3 nearby galaxies. That would be the "local" arbitrator. Of course, there is no absolute answer. All is interpretation as Nietzsche said. gdcPeterDonis said:Relative to the people who are buying the buns. Move all the valley people who buy buns to the top of the mountain, and they will buy 101 buns a day instead of 100 because their metabolism is faster.
And even then, the reason the number of buns per day changes is that the "day" is determined by something external to the whole system (the Sun), so it can be viewed as staying the same while the swiftness and metabolism of the people changes. If the bakery and the people buying buns were inside a rocket that was hovering deep in the gravity well of a black hole, their "day", as judged by their own clocks, would not change at all relative to their bun production and consumption; they would be baking and consuming 100 buns a day, according to their own clocks, and would have no knowledge that, to someone far outside the gravity well, they were only producing and consuming a fraction of a bun per year, or decade, or whatever (unless they communicated with the person far outside the gravity well).
The point of all this is that getting fixated on what changes are "real" and what changes are only "apparent" is, IMO, a rabbit hole with no bottom. Different observers on different worldlines through spacetime observe different things. It's possible to construct a viewpoint in which the different observations are due to "real changes", and it's possible to construct a viewpoint in which the different observations are only due to "apparent changes", or "relative changes", and nothing "real" changed. Since both interpretations can be made consistent with the actual observable data, which one is "true" is not, IMO, a question of physics.
bligh said:Don't you really need a third observer to arbitrate between two other measurers.
bligh said:I advocate a Universal Reference Point to be the arbitrator.
bligh said:Of course, there is no absolute answer.
bligh said:The reason for the extra buns is there is less gravitational 'drag' at higher elevation.
jartsa said:Here's a little story:
There's a bakery in a valley making 100 buns a day. Valley people buy 100 buns a day.
Then the bakery is moved to the top of a mountain. Now bakery makes 101 buns a day. After million days bakery has million unsold buns.
The point of the story is that the extra buns are real buns. The reason for extra real buns is real extra swiftness of the staff.
Gravity is a field phenomenon as all other things are. Once mass is deposited in the field it has inertia. I guess that is drag. I use this view to get away from paradoxes in SRT and GRT. Gravity is not a pull or a push. It is the self attraction of mass due to field requirements. Matter and anti-matter are both in the same location in space. Both are field properties. These ideas do not change anything, but provide a better model for explaining physics.PeterDonis said:What is "gravitational drag"?
bligh said:Gravity is a field phenomenon as all other things are. Once mass is deposited in the field it has inertia. I guess that is drag.
I use the so-called universal reference to clarify concepts of the SOL. The third observer or the Universal observer would give a better estimate of the velocity of light as it is coming from another frame of reference or two. It would get rid of the paradoxes when just using two observers or space ships and the light signals they might send.PeterDonis said:Sometimes that works; but in general, the third observer is just as constrained by his own point of view as the first two.
But as you yourself note later in your post...
...there is no such thing.
bligh said:I use the so-called universal reference to clarify concepts of the SOL. The third observer or the Universal observer would give a better estimate of the velocity of light as it is coming from another frame of reference or two. It would get rid of the paradoxes when just using two observers or space ships and the light signals they might send.
What paradoxes? And why do you think that the speed of light matters for redshift?bligh said:I use the so-called universal reference to clarify concepts of the SOL. The third observer or the Universal observer would give a better estimate of the velocity of light as it is coming from another frame of reference or two. It would get rid of the paradoxes when just using two observers or space ships and the light signals they might send.
Gravitational redshift is a phenomenon in which light or any electromagnetic radiation loses energy as it moves out of a gravitational field, causing a decrease in frequency and an increase in wavelength.
Gravitational redshift occurs due to the warping of space-time by massive objects, such as planets, stars, or black holes. This warping causes a change in the frequency of light as it travels through the gravitational field.
Gravitational redshift is an important concept in understanding the effects of gravity on light and other forms of electromagnetic radiation. It has also been used to test Einstein's theory of general relativity.
Gravitational redshift can be measured by comparing the frequency of light emitted from a source outside a gravitational field to the frequency of light observed from the same source inside a gravitational field. The difference in frequency can be used to calculate the strength of the gravitational field.
Yes, gravitational redshift can be observed in everyday life. For example, the GPS system relies on correcting for the effects of gravitational redshift in order to accurately measure time and location on Earth.