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Calculating the total time dilation when there is a combination of differences in gravitational potential, as well as relative motion, is a standard exercise that’s done in most undergrad courses on GR. It’s not that hard so long as you can use the Schwarzschild metric, which is highly symmetric. Usually it’s done in the context of GPS satellites, because the software on your GPS receivers has to explicitly account for both these effects. At an orbital height of ~20000km and a relative speed of ~3.9km/s wrt to the ground observer, the gravitational contribution works out to about \(38 \mu s \), and the kinematic contribution is roughly \(7 \mu s \). Because of the symmetries of the Schwarzschild metric, you can just add these together to get total time dilation. That’s like saying we have never been on the surface of the sun, so we don’t really know it’s hot. It’s a silly argument. We have had a large number of crafts of different kinds both on the surface of the moon, and in orbit around it. We have also bounced lasers and radar signals off the moon’s surface. All of these things explicitly take into account time dilation - it affects orbital mechanics, it affects light travel times, and it affects frequency shifts. No discrepancies with expected physics have ever been observed in that regard. True, we haven’t done that specific experiment you are suggesting - but we have done many, many others where time dilation plays a role too, so if anything unexpected was going on, we would have seen it long ago. Why is the movement of a planet/star/moon different from the movement of a satellite? Then why do you insist that this experiment must be conducted on the moon? It’s not the total amount that’s the problem, but the cost/benefit ratio. All the above were designed to observe specific phenomena, which our models indicated should be there, so these are direct tests of specific predictions. On the other hand, what you are suggesting is a wild goose chase - there is nothing whatsoever to suggest that anything out of the ordinary will happen if we perform that experiment of yours, because motion and gravity isn’t any different on the moon than it is in Earth orbit. Research funding in fundamental physics is a very limited resource, so we are careful where we invest it. Like I said, if you want to test time dilation on the moon’s surface with respect to an Earth observer, then bounce a laser or a radar echo off it, and compare propagation times and frequency shifts to what our models say they should be. It’s a much easier test that addresses the same issue of time dilation, and it’s been done many times since 1946 - Earth-Moon-Earth communications is in fact an entire sub-discipline of aeronautical engineering. Sure. I’m not opposed to performing such ann experiment, if anyone wants to provide the necessary funds. The more tests of GR/SR the better, so far as I am concerned. I just think it would be a waste of money, since there are much easier ways to test the physics in question here. Wrong, see above. The radar echo “Moon bounce” is a direct test of this (radar echo goes Earth-Moon-Earth), because any discrepancies in predicted time dilations would show up as anomalous frequency shifts in the reflected signals. Needless to say, no such thing as ever been observed. Yes, I’m denying that, because it’s a pop-sci misconception. Look at Newtonian gravity - there are any number of experiments that are in direct contradiction to what this model predicts. And yet, we are still using it very successfully, and we are even teaching it to our kids in school. The point here is that all models have a domain of applicability - a set of circumstances which they are able to model very well. So long as you stay within that domain, the model will continue to work for your purposes, just as Newtonian gravity continues to work for us within its domain of applicability, even though it’s been experimentally “disproven” in many different ways. And so it is with GR - we have already know for a long time that its domain of applicability is limited; we’re just not entirely sure precisely where those limits are. So if some experiment comes along that contradicts GR, then in the first instance we will tighten those limits. But it won’t ever be abandoned - that’s never going to happen, because it has already proven far too accurate and useful. That’s true. But it’s also dangerous to become obsessed with a single tree, and forgetting the rest of the forest - which is what you seem to be doing here.

! Moderator Note I think it is time for everyone to step back and take a breath. From skimming the topic it seems to me that a lot of the back and forth can be rather easily addressed. Since OP has a functional system, how about a short summary on its setup and function, including critical parameters (such as overall setup with details on filtration system, regular maintenance and so on) on this site would be beneficial, as opposed to referring to another forum. This would ground the discussion on something more concrete and would reduce the likelihood of getting personal.

I’ve seen this claim before, but it’s actually erroneous. It’s true that if the GPS clocks were not adjusted they would accumulate a time difference of ~38 microseconds a day as compared to ground clocks (and ct would be around 10 km), but this would not show up as a positioning error in GPS, since the GPS clocks nominally run at the same rate, and the trilateration uses timing differences between signals from the GPS clocks. These clocks would random walk away from each other, and accumulate differences from orbital variations, if not synched up. But this would be on the scale of nanoseconds, not microseconds, per day. One of the reasons the clocks are adjusted is so that you can do clock corrections from the ground station, which uses time from the USNO master clock. If you didn’t do that, you would be forced to have clocks synchronize within the constellation (whose clocks are less stable than the master clock) which would be less efficient and less precise, so you’d potentially end up with a larger positioning error. But measured in meters, not kilometers

My tank is larger than your tank.

They are mutualistic symbionts, aren't they? Zooxanthellae are the photosynthetic algae which team up with the polyps, paying rent with sugar and aminos. Then parrotfish come along, eat the coral, and poop white sand. I love that I can type that sentence and be completely factual. Do larger scale reef aquariums introduce parrotfish and generate their own sand?

Even though this was years ago, it is interesting so I wanted to take a stab at it. My interpretation, and the most “science” way, it would be designed would be a 3 stage thermonuclear bomb. The (very) basics of how thermonuclear bombs work. A first stage (primary) fission bomb, a core of plutonium-239 or uranium-235 surrounded by a heavy metal tamper, is compressed through high explosives. Core reaches critical mass and fissions (started by a precisely timed neutron emitter). As the primary fissions, it releases a massive amount of x-rays. These x-rays fill the space (radiation channel) between the primary and the secondary, which is a sphere or cylinder of a heavy metal tamper filled with hydrogen fuel (lithium deuteride) and a spark plug of U-235 or P-239 in the center. The outer weapons case, also a heavy metal, absorbs and reemits the x-rays. The weapons are designed so that the x-rays hit the secondary equally all around it, which causes it to compress, much like the high explosives did to the primary but with much more force. This causes the sparkplug to fission and bombards the hydrogen fuel, compressed between the expanding sparkplug and the compressing tamper, with neutrons, causing it to fusion (which is actually a complex series of fusions and fissions of lithium deuteride, where the lithium fissions from being hit by a neutron, creating helium, tritium, and energy. The created tritium then fusions with the deuterium, producing helium, a neutron, and energy, with the escaping neutron fissioning another lithium. Repeat). These things happen very fast. All chain reactions happen in 0.0000005 seconds (half a microsecond), but 99.9% of the energy released comes from the last 7 out of 50-55 successive fission generations, which is about 0.00000007 seconds (0.07 microseconds). Being able to hold the compressed stage together infinitesimally longer will up the yield considerably. That is one of the reasons for the thick heavy metal tampers. Finally, the secondary tamper and outer casing can add to the yield. If they are made from U-238, they will be induced to fission by the high-energy neutrons produced by the deuterium-tritium fusion reactions. About 50% of tested nuclear weapons final yield comes from this but it adds and insane amount of fallout. The Tsar Bomba was tested with the “clean” version, which replaced the U-238 with lead and had a yield of 50 megatons. The Soviets decided not to test the 100 megaton dirty version because it would have covered a significant portion of the Soviet Union if radioactive fallout. You can up the yield even more (possibly as much as 70% of total yield) by replacing U-238 with U-235 (the same as is used in the core of the primary). The NOVA bomb is “nine fusion warheads encased in lithium triteride armor. When detonated, it compresses its fissionable material to neutron-star density, boosting the thermonuclear yield a hundredfold”. A fusion bomb is really a two stage thermonuclear bomb, where a fission primary is used to compress a mix of fusion/fission fuel enough to get largescale fusion. And we know that in modern weapons, as much as 70% of total yield can come from the final fission of U-235 tampers/case just by fusion neutron release (without compression). So, I would arrange 9 two-stage thermonuclear weapons around a massive central “fusion” third-stage of U-235 and lithium deuteride. All 9 primaries would go off simultaneously (within a few billionths of a second), compressing and fusioning all 9 secondaries and simultaneously opening a radiation channel from each to the tertiary stage. Not only would the absolutely massive pressure be able to compress an absolutely massive tertiary, but neutron release would further fission everything as the weapon disassembled. If we were using 25 megaton secondaries, that is 225 megatons, meaning we could probably have a 250-300 megaton tertiary and a yield of over half a gigaton. Ok. Now we can get into the fiction. The “lithium triteride armor” could be a fusionable case material made of lithium and tritium, like the fusion fuel lithium deuteride is made of lithium and deuterium. Maybe it is ultra-dense, ultra-strong, and fusions, which would boost each stage of this fictional weapon.

No, that’s not the reason. The ratio for nuclei stable vs beta decay grows larger as Z increases. And that ratio is not the reason for stability, merely an indicator. As Z increases, the electrostatic repulsion increases, as it has an infinite range, but the nuclear attraction saturates, owing to its finite range. You need more neutrons in larger nuclei. What the nuclei are “trying to obtain” is being in the lowest energy state. If a beta decay gets them to a lower energy state, they will decay. Similar to a ball rolling downhill to minimize its potential energy. same as above - spontaneous decay will happen because the final state is lower in energy. The mass is lower.

I want to believe you but I know that you aren't addressing all the problems, evidently you don't even know all the parameters of a reef tank. You have dismissed surface skimming as though it doesn't matter, surface skimming was a big plus in the search for a viable reef tank. Your "coral" would seem to be glued to plugs inserted into the sides of the tank and it doesn't seem you actually have any hard coral in the tank. Only small beginning clusters of soft coral. If it had been set up as long as you say the polyps would have outgrown the "vase" by now. Your whole presentation is deceptive, I wonder what motives you have. If I ever decide to set up a tiny reef, I really don't have the money to spare at this time, it will include methods of dealing with things like surface organics and calcium ions. The way yours is set up you could replace the animals on an on going basis, in fact it seems to be set up that way. I keep going back to that photo shopped pic of the tank setting in a car seat. Oh BTW, I live near the ocean and can, if I want, collect animals for a tank. No pet stores required.

Wow, I had no idea aquariums were such a battleground. My question concerns chlorine. When I was a teen, I had a 55 with Oscars, a tropical cichlid. I was told to let tapwater stand for a couple days so chlorine could evaporate out of solution before adding to aquarium. Never was sure how important that was. Is that necessary with reef tanks? Anyway, interesting thread, at least where one can step around the blood puddles.

Pretty much all research into the neurological basis of consciousness finds it to be emergent rather than fundamental. One molecule of water isn't wet. A billion are, at sea level between 0 and 100 C. As for theories, those are generated by minds. It doesn't mean what the theory is about is also generated by minds.

I disagree. If one follows the development, one can see that all these grand cosmological theories come from experiment and observation processed by human mind.

Ok, that’s fair enough! I freely admit that I’m more versed in the physics of time dilation than I am in the engineering details of the GPS system. The salient point here is though that if you didn’t account for gravitational and kinematic time dilation at all, the system couldn’t work in the way it does now, or at least it would be a lot less accurate.

Don't let the door hit you in the ass on your way out. It's kind of sad, I have a 3 gallon glass sphere that just begs for live coral, I'd really have loved to have been able to repeat his results but he never did provide anything but anecdotal evidence.

My tank: Bonaire National Marine Park - Stinapa Bonaire

I do not do any other forums. Never did. I am not even sure what it means. I guess it relates to home aquariums. My aquarium is too big to keep at home. Fortunately, it takes care of itself pretty well. It has a lot of fish, naturally.

I found a link to the 2022 highlights from the Journal of experimental biology on Mastodon, so just sharing here as it may be of interest to anyone here. https://journals.biologists.com/jeb/pages/highlights-2022 This is a free download. Hope this is of interest, I am not connect to them in anyway, just followed them and am sharing. Paul

Without specifics all your videos and magazine quotes mean nothing, I do not believe you, I require specifics verified by something other than your claims. I can claim anything, in fact I have claimed I could grow coral in a shot glass and I could with a significant amount of technological and volumetric back up. You posted a picture that was obviously a photo shop and then you think we should believe everything you claim after that... not gonna happen. Proves nothing, we don't know how long it's been set up or how often you do a water change. How do you deal with coral aggression, what do you feed them and how often do you feed them? I could stuff all that stuff in vase and call it a pico reef, doesn't mean it's a long term stable environment. The bio-waste build up is the first but not the least of my concerns. The inserts that hold the organisms suggest it is a short term fake and how do you keep the plastic free of Coraline algae? The questions I have are not being answered by this display.