[David Cooper]

If you have a gravity well with changing length contraction on it due to the source(s) making rapid changes in direction of travel, then you effectively have gravity being turned up and down, and the change can be rapid and near-instantaneous along a long length of the path the signal's travelling along (perpendicular to the gravitational source).

I read that about 6 times and could not figure out what you're trying to describe.

Picture a spherical gravity well. Draw a circle to represent it on paper, and the line will represent a contour of equal gravitational pull. Now take the central object which generates the gravity well and move it at 86.6c across the page, or imagine the page moving at that speed so that you don't have to move the object. The gravity well must contract to half its rest length in the direction of travel, so if the object's moving upwards, you should imagine the page moving down instead and the circle should be contracted into an ellipse with its shortest diameter half the size of its longest diameter (if diameter's the right word to use when dealing with an ellipse).

Now, there could be two black holes of equal mass forming our object, and they're orbiting each other, but both of them will always be moving in opposite directions and will have length contraction applying on them in the same direction. A quarter of an orbit further on, the length contraction will be applying perpendicular to the way it was applying before. What you'd actually get would be like an ellipse rotating.

Now, draw a dot somewhere inside the original circle, but outside of the original ellipse. Then rotate the ellipse and visualise the line crossing the dot. Zoom in on the dot and observe how the line that crosses it looks more and more straight. For the dot and the space to either side of it, gravity is effectively being turned up and down just as if someone was controlling it with a slider switch. If you do this with the dot far enough away from the black holes, the changes in the speed of functionality of the dot's light detector will be masked by the changes in the speed of the laser light, making the frequency appear constant.

[Light] has a wave nature with crests and troughs. A measurement of frequency is (at the lowest level) a measurement of how many crests arrive in a given length of time. The distance between two crests doesn't change as the gravity well changes shape.

This seems like conjecture, and in this example, it might not turn out to work the way you're describing it.

If light is a wave, each photon must be spread out over a distance with a frequency which manifests itself as a side-to-side movement of the wave. If you try to turn all of that into nothing more than point particles, the frequency is going to be lost, and so will the ability to red or blue shift it.

Surely light coming from a star at color X is not all in phase, and measurement of the wavelength of it isn't done by counting crests over time.  Twice as much green is still green.  I suspect they measure the energy of each photon and extrapolate the wavelength from that.  That's how eyes do it.

To detect sound of a specific frequency, you can do it by having something that resonates at a particular frequency so that the crests and troughs (which are the same thing if we aren't dealing with surface waves) cause it to move to and fro in response to the wave passing. Have lots of these things, like hairs in the ear which are tuned to different frequencies, and you are effectively identifying frequency by "counting" crests. If two lots of the same frequency of sound arrive simultaneously, they can cancel each other out and not be detected, but they can also add together and make a stronger signal. In the same way, two photons can be less easy to detect than one if they happen to cancel each other out at the detector - all the energy is still present, but it can be made incapable of interacting usefully with the detector in such a case, so the only energy that can be counted up is the energy transferred to the detector, making something in the detector move differently (i.e. an electron). Send ten photons in at once and there's very little chance of them all being cancelled out entirely, but most of the signal will still be missed due to it being cancelled out. Crucially though, the more photons that are involved, the bigger the component of uncancelled energy there will be able to drive the detector. If the energy absorbed has to be single photons, then you need to have some kind of quantum system which allows the photons to be provisionally captured and not captured at the same time, and then you have a simplification where the state is simplified, meaning that some of the photons in two states lose their captured form (and continue on unaffected by the provisional interactions with the detector) while others lose the uncaptured form (and become fully captured).

[David Cooper]

Orbiting black holes are a lousy example since each one deforms the ring of equal potential of the other, so it isn't a circle anymore.

If you're close to the black holes, that would be messier, but they may only be a few tens of miles apart while the observer could be a million miles away.

OK, I get that, but what does the dot represent?

The dot is the observer, sitting in the gravity well(s) of the black holes. A signal comes to the dot from a great distance, perhaps directly overhead (perpendicular to the page). The dot can either hover in position, or it can slowly orbit the pair of black holes.

I think you're picturing two black holes, but there is no aiming a beam of light at the dot, which is not a fixed location.  You aim it near one of the singularities or not.  Nothing is changing a perspective.

Our observer is ignoring the black holes and is looking at the signal source instead. As the gravity wells change shape, the observer's functionality speeds up and slows down. The signal, which could be a laser beam, operates at a constant frequency (and the frequency of the light is always the same in proportion to the frequency of pulses, so you could monitor the pulse rate instead of the light frequency if you want - this allows you to determine the frequency by counting pulses directly.

By the way, now that I'm picturing a rotating elliptical gravity well, I realise that the straight line (a contour line of depth in the well) crossing the dot will be at a different angle for when the dot is going deeper and when it's going shallower, so anything approaching perfect masking of the effect is impossible.

Light has a wave-like nature in some ways.  I don't think anybody says light is a wave.  Waves are not things, they're effects of multiple things.

How does it work with radio waves? What does an aerial do, and what does an antenna do when transmitting? We get movement of electrons, and something makes them move to and fro at a frequency. A wave is produced by moving the electrons in this way, and a wave being absorbed causes electrons to move in this way too. The manner of movement of the electrons sends out sine waves. Some kinds of radio pick out radio waves with a specific orientation, just like using a polarising filter with light.

]Light isn't point particles either, despite it having particle-like nature at times.  You seem to be attributing classical properties to a very non-classic entity.

Then you have a distribution of the particle which has the frequency built into that distribution, just like a wave.

Ears (a 0-D matrix) resonate at thousands of frequencies, which do a mechanical Fourier transform on the waves and send that result to the signal processor.

I'd call it an mechanical alternative to a Fourier transform. I wrote a program to analyse sound which works more like the ear instead of using the usual FFT method, and it produces good results (unsurprisingly, given that we know the ear does a good job). I simply do a lot of additions and subtractions with the results going into buckets which record the amount of resonance for the frequency they're tuned to.

I agree sort of, but then why does focused light from a random source (the sun say, which hardly puts out synced laser light) not just cancel itself to almost nothing?  No, it fries the ant.  Most of the signal does not in fact go missing.  Where would the energy go if it canceled?  Seems to violate conservation.

The unbalanced component will always be bigger (on average) for a given amount of energy in the signal, just as happens with a choir singing - they don't cancel each other out entirely, although to a large extent the signal is cancelled out at any given location, the energy passing without its full power being detected by the ear. A person standing behind you will hear a different signal from you, some of what you heard being cancelled out while some of the stuff you missed is audible to them. I clearly don't understand this stuff well enough though, because in the light case, if the uncancelled component is absorbed by the atoms nearest the surface of the ant, the rest would continue to cancel each other out all the way through it and then go deep into the ground beneath it too, so that might be a good topic for a new thread.

[Bogie_smiles]

My own model of the universe is one that is infinite, eternal, and on a large scale, the same every where (homogeneous and isotropic). The “sameness doctrine” that I invoke describes the universe as a multiple big bang landscape, and says that no matter where you are in this infinite expanse of space and time we call the universe, the  process of big bang arena action will be playing out around you. You will be in an active big bang arena like we observe in our Hubble view, or somewhere that is involved in the early stages that we would call the preconditions to a big bang.

That is why I picked up on the “What happened before the Big Bang” thread over in the Physics, Astronomy & Cosmology sub-forum, started by “guest48150” who seems to have left TNS all together (leaving his thread with the classic title adrift). I saw it as an opportunity to discuss preconditions in a hard science sub-forum, and so I brought up the cold spot.
https://www.thenakedscientists.com/forum/index.php?topic=75868.msg565389#msg565389