Okay. So, fundamentally, I am correct to say that if I have a permanent magnet (an iron magnet for example), and I constantly accelerate it very, very quickly (for example, I throw it into a black hole), it will emit EM radiation all the way down? Is that correct? Could I (theoretically) detect a magnet falling into a black hole by observing the radio waves it emits, and infer that a magnet must be falling into the black hole?

What happens to a black hole that's rotating if it has charge? Does it emit EM radiation? Intuitively, I think the answer is "no" because a black hole can't emit anything. So I think I'm misunderstanding things. Where am I going wrong?

As highlighted in most the papers I linked to (1) in comparing it to natural flux you have to consider not just the total mass but also the composition, i.e., for the natural flux of meteorites only about 5% are metal rich whereas most are silicates and (2) within the metal meteorite comparison to satellite comparison, we're talking primarily iron/nickel (for metallic meteorites) vs aluminum compounds (for satellites). The concentration and chemistry both matter for potential effects.

No real answers, but some thoughts...
Metal in the atmosphere is normal of course, because a lot (most) meteors that are burning up in the atmosphere are metallic. From this newspaper article it is estimated that about a ton falls to Earth every day. Using another "source" this page from Smithsonian magazine estimates it to be about 50 tons.

Either way, we're talking about a significant increase. But would there be an effect, and what would is be?

Obviously, the amount of dust that is swept up from the Earth by wind is higher by several orders of magnitude, but won't reach that high an altitude.

Potentially more important though... the question is about metal in the atmosphere, but what percentage of said satellites are actually metal? OP makes the implication of 100%, obviously this will be way lower (10%?), but if true, what constitutes the other 90% and what are the implication of that? A nice piece of iron burning up in the atmosphere after all, is not the same as some Lithium Ion battery encased in plastics...

Suppose the following:

I throw a permanent magnet (a chunk of iron or something) into a rotating black hole. The black hole has enormous mass, and it has to conserve angular momentum. So, as the chunk of iron falls into it, it should rotate. And if the magnet is very small, it should rotate very quickly (again, to conserve angular momentum).

My questions are:

1. As the magnet rotates, does it emits EM radiation?

2. If the magnet is emitting EM radiation, is it an antenna? Is it more-or-less a broadcast antenna that's powered by the black hole?

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The variables at play are (1) the mass of material added, (2) the level of the atmosphere to which the material is added, (3) the specific chemistry of the material added, and (4) the potential effects (e.g., change in albedo, etc) of those materials as a function of time and concentration. The type and magnitude of effect will scale with the mass and whatever the particular material does, but points 2 and 3 are also important as they control the residence time (i.e., the duration). We could consider something like sulfate aerosols that are injected into the atmosphere during things like large impacts or large volcanic eruptions. Residence time for these depend a lot on the level of the atmosphere the particles are in, e.g., Junium et al., 2022 consider residence times for sulfate related to the Chicxulub impact and highlight that particles injected into the troposphere might last a few days to weeks, whereas those in the stratosphere would linger for months to years. The specific chemistry also matters though, so behavior of one type of particle is not representative for all, i.e., if the particle in question readily reacts with something, the residence time might change. All of this is to highlight the uncertainty, i.e., without dedicated experiments we don't know exactly what the effect will be and it's not necessarily safe to just assume that it will be negligible.

>the wave analogy stop being relevant at this point?

It doesn't stop being relevant, you just have an incorrect picture of what is happening. You likely are basing this image on your intuition of waves of water.

Actually, a useful image is more like sound waves. A sound wave consists of oscillating pressure in some medium, such as air or even water. When you hear sound, do you just hear the "high" pressure peaks? Or the low pressure valleys? Or, do you hear the full range of changes over some period of time?

It's the latter.

In fact, if you were only hearing the "peaks" or the top half or the bottom half of a sound wave, you would hear something that is distorted. This is actually how sound distortion in music works, such as for guitar amps or synthesizers. When we speak, or a piano hammers a tuned string, the sound created is relatively smooth, like a sine wave (speaking has more complicated wave patterns but the patterns consist of a combination of relatively smooth waves). A distorted sound appears more like a square wave or something with more corners on it, when plotted visually. So instead of your ear sensing the smooth undulations of pressure changes, it experiences sustained pressure (such as the top of a square wave) followed by (or preceding) a much more abrupt and instantaneous change (the vertical part of a square wave). This is more jarring and unexpected, which is why it sounds "unnatural."

Vision and light share some of these characteristics of experience, in that when your eyes see, they are typically experiencing a smooth range of changes in the Electromagnetic spectrum over time as the photon passes the receptors in your eye. It's not simply the peaks or valleys of this wave, it is the frequency and the total energy ( simply: how many photons in the frequency range) that your eyes sense. You can't really experience an instant of a photon. You need the changes of the wave over time for your body and brain to sense and interpret these signals.

Most of the people here are wrong. It is possible to un-blur an image within reasonable fidelity, provided that you know how the blur was done (i.e. which method, what the parameters for the method were, etc).

The naive way of blurring an image basically averages the input pixels from its neighbors and outputs it on the output. This is a reversible process, provided you know how the averaging window was created.

The averaging window can also be estimated to potentially get a "good enough" reproduction of the image before it was blurred.

This really sounds like one of those "what goes up must come down" moments. Presumably it would be through precipitation, which means it would end up in our water. The effect of this would depend on the metal concentration when spread out. Is there anything that would prevent this and keep the metal afloat? Seems like this should be a pretty simple chemistry question, but I guess I'm not an expert.

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Say I had a beam of photons with a very specific wavelength and I was able to check the position of a particle, would that position be somewhere along a very well defined sine curve? Or is that just a simplification like the nebulous clouds of atomic electron shells were dumbed down to be circular orbits that look cool as sciency logos in the 50s and 60s?

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> The model of reality that treats all particles as excitation in fields is part of the single most accurate model humanity has ever come up with.

Isn't that just "ether theory" with extra steps?

It's a good question, but one that does not seem like it's answered yet (though it is theoretically addressable with global climate models, etc). There are a variety of papers in the last few years highlighting that both emissions from increasingly frequent rocket launches and material (like aluminum and other metals) added to the atmosphere via satellite deorbiting could have substantial impacts on a variety of things, but almost all of these are really calls for more attention and research as opposed to answers to the question itself (e.g., Ross & Toohey, 2019, Hobbs et al., 2020, Boley & Byers, 2021, Schulz & Glassmeier, 2021, Adilov et al., 2022, Ross & Jones, 2022, Shutler et al., 2022, Lawrence et al., 2022). There is at least one paper directly trying to answer this with modelling for the emissions from increasingly frequent rocket launches (e.g., Maloney et al., 2022), but I at least could not find a paper actually demonstrating what the impact of addition of significant amounts of metal to the upper atmosphere would be (beyond the generalizations in the previously linked papers that suggest it would likely do something). The closest is really the Hobbs et al., 2020, but sadly this is an abstract for a conference presentation and I couldn't find a follow up (might still be in the works, lag time between stuff presented at conferences and eventual publication can definitely be several years). It does seem like there is a fair bit of interest in this within pockets of the scientific community (as illustrated by all the "we should pay attention to this" papers cited above), so I wouldn't be surprised if there are studies in the works on this, but at least for me it's far enough outside my area that I don't know that for sure (maybe others more in this space can provide some details).

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Specifically, the syncytins are important because they keep the mother's immune cells from being able to reach "through" the placenta into the developing fetus.

There are certain immune cells that are able to slip between other epithelial cells. If the mother's immune cells were to slip past the cells of placenta, they would almost certainly attack the fetus. Placental mammals solve this by having a "boundary layer" between the placenta and the mother. The cells of the boundary layer use those viral syncytins to "fuse" together, becoming one giant solid mega-cell with lots of nuclei. Because there are no longer any individual cells to slip between, the mother's immune cells are unable to get past this boundary layer (the syncytiotrophoblast) and thus the rest of the placenta and fetus are protected from the mother's immune system.

Placental mammals (like us) basically start with 3 precursor tubes that fuse together early in development.

In marsupials, the ureters (which transport urine from kidneys to the bladder) pass in between the 3 vaginas, so it would be pretty much impossible for them to fuse without cutting off the transport of urine to the bladder. In placental mammals, the ureters develop differently and no longer pass between the tubes, which is why it's possible for us to fuse the 3 precursor tubes into one.

An antenna is one or more conductive elements electrically connected to a receiver or transmitter. What does a black hole have to do with anything?

When you hit an atom with a burst of energy, it causes electrons to move from an orbit close to the nucleus, to an orbit slightly further from the nucleus (excitation). When that induced energy is removed, the electron "sinks" back to the original orbit and emits a "particle" of light.

At least that's how I learned it quite a few years back!

This raised WAY more questions than it answered

I need to get up on my marsupial facts

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