swansont

Seems to me the time reversal of a photon absorption would be an excited atom emitting a photon. Not stimulated emission.

Then you could get stimulated emission, but there’s no need to apply CPT to get it, and you’re changing the conditions of the experiment, so you’ve removed the existing symmetry - it’s a different experiment. Basic examples of CPT I’ve seen don’t do this. It’s possible an issue here is that AFAIK time-reversal symmetry is not the same thing as the thermodynamic arrow of time; an entropy increase does not violate CPT, even though such a process is not reversible.

There’s nothing to put the target in an excited state. How does stimulated emission happen?

The stimulated de-excitation can happen with the laser causing the excitation. It’s why a two-level system can’t have more than 50% of the atoms in an excited state. And since de-excitation requires that the atom be in an excited state, the situations aren’t the same.

How is this tied to minimum wage being increased?

Color blind doesn’t mean grayscale. “In all animals, including humans, the perception of colour is determined by the presence of cells in the eye called cone photoreceptors. Cats and dogs have two kinds of cones, which are sensitive to blue and green light. This means they have a useful level of colour vision. The level of colour vision in other animals depends on the presence and types of the cones.” https://www.vetwest.com.au/pet-library/can-animals-see-colour/#:~:text=Only one animal cannot see in colour&text=The only animal that has,no cones in its eyes. Also: “The only animal that has been confirmed to see only in black and white is a fish called a Skate. This is because it has no cones in its eyes.”

Opposite to the direction of motion 12 hours earlier. You are aware that the earth rotates, right? Or is that something else you contend? That’s a spectacular failure to understand what is meant by relative. There is, in physics literature, so you’re just making stuff up. Again. If one quantity doubles and the other is cut in half, what happens to their product? Or just increases/decreases by the same factor? (I know math, or using a calculator, is difficult for you, so I’ll tell you the answer: it stays constant. “No experiment is conclusive” is the battle cry of crackpots everywhere. Who never seem to be able to figure out how to properly use the quote function. You can, but of the two of us, only one has a PhD in physics and has been employed as a physicist. No, it’s me expressing how tedious you and your seemingly willful ignorance are. ! Moderator Note Seeing as you are not following the rules of the speculations forum, and the direction not to bring up a closed topic, this is closed. Just repeating your ignorant statements is not how science is conducted

! Moderator Note Your thread is still in Science News, with very little traffic. I’m not sure what you’re on about.

No? You can’t measure the speed of light in different frames of reference? Say, doing itat noon, and then 12 hours later, where the earth’s rotation has your lab moving in the opposite direction? And doing this at 6 month intervals, so the earth’s orbit is in the opposite direction? Surely something so basic has been done. Even if not systematically, it can’t be the case that all of the measurements of the speed of light have happened at the same time on the same day of the year. This would show up in the data, if it were true. You just asserted that mass and length are not frame dependent. You’re right about rest mass, but the mere assertion is contradicted by this claim. The least you can do is be consistent. c being invariant is proven by electrodynamics, as I have described. SR is shown to be correct by various experiments, perhaps most famously by the Hafele-Keating experiment You don’t get to judge others’ understanding of physics. They have, as I have described above. The concepts of physics are completely independent of your understanding of them Yeah, whatever.

Length and time are most definitely frame-dependent. Not understanding is not the same as being irrational And yet experimental physics shows this not to be the case. Who’s right? That’s a real puzzler.

Sorry to hear, but what does this have to do with the US minimum wage? My understanding is the UK’s economy is suffering right now, for reasons unrelated to this issue.

But we also see this with the muons, as Eise has explained, without a “contraption”

We agree on that now, but prior to 1905 or thereabouts, the ramifications of this were not known. No, this is not the case. Can you cite any experiment that shows a variable speed of light in inertial frames? Police radar uses the doppler effect - the change in the frequency of the signal. Not the speed. https://copradar.com/chapts/chapt3/ch3d1.html

Airplane folks (mostly) follow safety regulations. By many accounts, Oceangate did not.

You assertion suggests that these don’t occur at all, but my comment was associated with “variable” which was from a different quote. Or it indicates they started looking near the destination, i.e. the shipwreck, and the debris was found nearby (~1600 feet, according to the press conference that just concluded)

We’re not talking about a safety risk, though, and challenging for precision mapping implies that there is uncertainty in the location. “When you reach the bottom, you don’t really know where you are. The Titanic is somewhere at the bottom of the ocean, but it was so dark that the largest object was only 500 yards (1,500 feet) distant, and we spent 90 minutes searching for it.” So again, there is uncertainty in the location. “Rare occurrences known as benthic storms, which are typically associated with surface eddies, can also produce powerful, sporadic currents that can remove material from the seafloor.” “South of the bow section, the currents appear to be especially variable, shifting from northeast to northwest to southwest.” Variable is kinda the opposite of well-known These statements you missed were right before the bit you quoted.

Something that science neophytes often miss is that you can do “indirect” confirmations of scientific principles. In this case, you don’t have to measure the speed of light in different frames, since the invariance of c has implications. In the case Mordred has highlighted, it’s Lorentz invariance. Experimentalists can be quite clever in devising experiments where you can do a precision measurement, where you have this situation. e.g. you don’t have to directly measure the fine structure constant to place (rather stringent) limits on its variation in time.

“…Titan's estimated 96-hour oxygen supply, which includes oxygen tanks and equipment known as carbon dioxide scrubbers…” https://www.cbc.ca/news/canada/titan-submersible-search-questions-1.6883870 The Apollo 1 situation was from pure oxygen in the cabin. Presumably the submersible started out with a normal ~80/20 nitrogen/oxygen mix

The submersible doesn’t go straight down. It’s not an elevator. Do you have any evidence that we know the ocean currents will be known? Over a depth of almost 4 km?

! Moderator Note Similar(almost identical) topics merged

If you combine and rewrite the equations in the form of a wave equation, you find the relation between these terms and the speed, and that leads to the conclusion that c is invariant. Because light waves are still light waves even if there is motion of the source p\or detector (e.g. your radio works even when your car is moving), and that would not be the case if the speed of the waves varied. Yes. And in modern terminology, that is called invariance. In 1905 (and in German) the phrasing was somewhat different.

Something that’s the same in all frames is invariant. Something that’s the same everywhere (and over time) in one frame is a constant. A constant current (which could be from charges at constant velocity) can exert a force.

Air in the tube? I doubt they use hollow-core fiber.

No, this is patently untrue. A charge at rest will exert a force on any other charge, and with Newtonian gravity, the same holds true for a mass at rest exerting a force on other masses. Rope tension, normal forces, and static friction are other examples of forces that can be present at zero velocity.

! Moderator Note This is enough to tell me you are unserious about discussing physics. Either you don’t understand relativity well enough to know that this is a flawed test and thus is irrelevant, or you do, and this is an argument in bad faith. Either way, we’re finished here. You’re free to ask questions to fill in the significant gaps in your knowledge, but no more preaching.