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It’s a postulate. The resulting theory is testable, and passes the tests.

! Moderator Note The topic here is a light clock.

Einstein's postulate on the invariance of the one-way speed of light is untestable as well. The speed of light is invariant only over a round trip to all observers, making it impossible to decide between Einstein's and Lorentz's theories experimentally on this point.

Walking droplets are mainstream physics. Lorentz transformations are classical wave mechanics and it's mainstream physics.

A postulate based on electrodynamics, which has an invariant speed of light. And given the success of relativity, and its experimental confirmation, it is a physical reality. I am reminded of a certain Sidney Harris cartoon Nope. So the Doppler effect somehow know about some prior acceleration? even if the signal isn't sent until after the object starts moving at constant velocity? That's magic, not science. You've made this error a number of times. Changing velocity does not produce the Doppler shift. Repeating the assertion does not make it true. None of which are present in the twins paradox. No. Your conclusion does not follow.

Here is the thing modern physics and research states c is invariant to all observers. The modern tests make the Michelson and Morley experiments look like child's play. It has always been a heavily researched topic. It is far too critical in all major theories for any potential error.

And here you admit that there’s no way to test Lorentz’s theory, rendering it unscientific.

! Moderator Note Responses to posts must be mainstream physics. Keep your own views in your thread in speculations It’s wrong. Perhaps that’s more simple, but since it’s wrong it’s not useful. You’ve not incorporated length contraction.

The term is not from me, the person responsible for the UN on these issues has called it a pandemic. That's the news. https://news.un.org/en/story/2024/04/1148696 It seems that what happened is that you did not read the news, but I am sharing the quote with you this CharonY. From the initial comment I have recognized that it does not directly affect humans, although it could indirectly affect animal production. But, according to the news, there is some risk that it will end up directly affecting humans (Like a pandemic).

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The study adjusted for weight, so that variable being the same from Shaun and Pontzer's point of view, I simply discarded it and was left only to check the fat-muscle ratio and its impact on energy expenditure, which is where Shaun differs. with Pontzer who conducted the study adjusted for fat-free mass. The TEE would depend on fat just like the BMR, since one is total energy expenditure and the other energy expenditure at rest. The thing is, Pontzer was limited only to energy expenditure adjusted for fat-free mass, and that's what Shaun says was wrong in his study.

AI-generated content must be clearly marked. Failing to do so will be considered to be plagiarism and posting in bad faith. IOW, you can’t use a chatbot to generate content that we expect a human to have made Since LLMs do not generally check for veracity, AI content can only be discussed in Speculations. It can’t be used to support an argument in discussions. Owing to the propensity for AI to fabricate citations, we strongly encourage links to citations be included as a best practice. Mods and experts might demand these if there are questions about their legitimacy. A fabricated citation is bad-faith posting. Posters are responsible for any rules violations stemming from posting AI-generated content ___ Discussion of policy is at https://www.scienceforums.net/topic/133849-aillm-policy-discussion/

No, because your math is gibberish. Yes. And you don't even need math to see it. You are missing the point. Top half of image: In the rest frame of the light clock (i.e. anything at rest with it: in the same train - in your unattributed image) the pulse of light is bouncing between A and B, travelling L back and forth. This is not about seeing the pulse of light, it's just doing what the pulse is doing. Bottom half of image: Considered from a different inertial frame, one where the train and the light clock are moving from left to right, the pulse of light makes a different path, travelling D back and forth. D is longer than L. But the speed of light was earlier shown to be invariant. For the same pulses of light to travel from A to B at the same speed, over different distances: it must be that time is relative.

This is impossible, the one-way speed of light cannot be measured: https://en.wikipedia.org/wiki/One-way_speed_of_light Lorentz's theory is based on a speed of light varying in one direction but = c on the average of the round trip.

The TEE is dependent on fat-free body mass and Hadza adults are not only leaner, but are also smaller. Specifically the component relating to fat-free body mass is the BMR. In the cited study TEE was measured, but BMR was calculated based on equation given by a paper by Henry (2007), which include age, body weight, height and sex. Physical activity was estimated as TEE/ calculated BMR. So body fat is not measured or otherwise included, from what I can tell.

Oh I certainly can show you 100's of professional peer reviewed literature showing light is invariant to all observers. The tests for lorentz invariance is literally up to 1 part in 10^18 for any possible variance. We literally test SR and GR every single day via particle accelerators etc the amount of research and tests involving the speed of light is astronomical

This is only true on a field that is of characteristic > 2. In discrete arithmetics it's not true that 1+1=2. In binary arithmetics 1+1=0 or 2=0 (mod2). The moral of my silly little story: Don't take anything for granted. Not even aether theory. Yes, I know what acceleration is. I wonder whether you do. As to your last statement, it went badly wrong the moment you wrote 'so if'. Because nothing you said after that follows from the antecedent. But don't mind me. Carry on with your enthralling conversation.

You are missing my point entirely. I am saying you keep mixing up terms and using them in a wrong way. What we have here are zoonotic outbreaks, not pandemics. I.e. if you changed the word in the above quote, you would be accurate. Calling it pandemic in this context is just wrong from a technical viewpoint. And every potential jump from animal influenza to humans is worrisome, regardless of scope. The reason is that it keeps mixing in animals, including farm animals and there is a chance of new variants that might be able to spread human to human. An important example was the 2009 swine flu pandemic, where H1N1 jumped to human (and pig-human is an expected route due to many similarities between these species) and spread from human to human.

Of course, it is a zoonotic pandemic that has no human-to-human transmission. But neither is the usual or routine, unless you suggest that the WHO is being alarmist.

What is a acceleration ? it's a change in velocity, so if time dilation is not relative during a change in velocity it cannot be relative after this change, it's the same level of understanding as 1+1 = 2 If time dilation is relative during inertial journeys, how does the twin come back younger knowing that the total journey is only the sum of two inertial journeys? We must add a sudden aging of the Earth during the U-turn, but nothing of the sort occurs in the signals received by the traveler, the Earth does not age suddenly, so there is no physical symetrical time dilation during inertial journeys. The traveler ages less throughout the journeys.

I insist, I can't edit. I summarize: My idea is to adjust the fat percentages that appear in Pontzer's study (13.5% Hadza, 22.5% Western, on average). The other fact is that a man with 20% body fat would burn 20% calories from muscle and 5% from fat. The goal was to determine how much of the 26% extra calories that Shaund says the Hadzas burn by adjusting for fat-to-muscle ratio instead of fat-free mass as Pontzer had done in the study. Please remember that these are all approximate figures. I calculated that of the 26%, only 8% of total caloric expenditure could not be explained by the greater percentage of muscle of the Hadza. But that 8% would be subject to determining what values were used to estimate 26% of Shaun's items. I hope that now I have made myself explain this. There is more, but the matter would be somewhat more extensive. Blessing.

You keep mixing up concepts (or using them in a bit sloppy manner) which confused matters a fair bit. To clarify things here are some rough definitions and relevant context. Zoonotic disease: infectious disease that can cross from non-humans to humans. They are very common and happen certainly more frequently than once a weekend. A very common infection is for example salmonellosis. Pandemic: generally refers to wide spread of an epidemic crossing international boundaries (especially spanning continents) and typically affecting large-ish number of people. It does not refer, for example, to severity. Using these definitions in OP refers to an animal pandemic (i.e. a large number of animals affected over a large area), but it is not a human pandemic, as there are only few jumps to humans. Any zoonotic infection can be a source of worry as mutations over time could lead to human to human infections (such as the case with swine flu and SARS-CoV-2 and ebola) but certainly it cannot be a human pandemic at the current state.

Will you just read what's answered to you??? Otherwise it's a monumental waste of time for everyone involved. (my emphasis.) The returning twin is subject to accelerations. Is it not? This is the major bone of contention with people who don't understand the twin's paradox. (Or should I say it just goes over their heads?) It is practically a socio-physical theorem that there will always be people who don't understand it. You are living proof of it.

If all spatial dimensions loop back on themselves seamlessly, so that whichever direction you travel in, after n light years you are back where you started, then what does 'centre' even mean? It's definitely finite with a volume oto (n light years)3. But there is no point more remote from the boundary than any other because there is no boundary. All points within the space are geometrically exactly equivalent.