joigus

You make a good point here, but there are other factors. I can imagine no epoch in human evolution in which planning for the future, interpreting other people's intentions, guessing the best solution to a domestic problem --all of which is achieved mainly through language-- did not play a major role in women's lives. It is generally assumed that high-brow intellectual activity was what led to developing big (energetically costly) brains in humans. But the big pressure, the day-to-day strain on the brain to be able to develop more sophisticated cognitive abilities, is social, not inventive. That's what most anthropologists say. I may be able to provide more info about it later. It's been estimated that the main focus, by and large, of human language throughout the day is gossip, not the realm of 'big ideas.' And that goes for women and men alike.

This is known to be false. https://www.nasa.gov/pdf/64249main_ffs_factsheets_hbp_atrophy.pdf https://aging.ufl.edu/files/2011/01/deconditioning_campbell.pdf

Exactly. A person with few glicolytic fibers, a person whose body cannot synthesize myoglobin properly, etc. But also a person who doesn't exercise properly. The women that you're showing in the video --I haven't watched it either-- both are genetically conditioned to be that way, and have exercised to be that way. So it's a combination of both factors. Having a certain genetic make-up favours you being more muscular, but it doesn't determine it.

You've read a tad too much into what I've said. Some conditions are necessary. Other conditions are sufficient. Still other are necessary and sufficient (those are the terms in which you seem to be thinking.) A further category is when conditions are neither necessary nor sufficient: They are statistically correlating conditions. You say genetics determines what you are. I say genetics is affects what you are. See the difference?

Probably. And probably comes from a very ancient obsession with fertility. Hunter-gatherer societies were thin on the ground. And they needed manpower as any other. In northern Spain there is a Solutrean cave in which lots of vulvas are depicted. And fertility statuettes all across Europe. I don't think the motivation for that was ancient pornography.

It's a snowball phenomenon. And well known. And all evidence contrary to OP's premise. This is a very interesting conversation, but it's spilling over into wider aspects of anthropology.

Well, nomads are a bit of an exception. They are more pastoralists than agriculturalists. But they depend on agricultural societies to obtain the grain. Or move for pastures new, which leads to waging war again, when there are pastoralist agricultural societies claiming the land. Whether these and other similar societies used the bow and arrow is secondary. Agriculture brings conflict on account of claiming the land for yourself, and thereby war, which was the point. Yes. Agriculture is known to result in larger families. That's part of the equation. So we don't have 10,000 years of less war. It's just the opposite.

By the way, all the Bactria-Margiana area is full with evidence that these societies were agricultural, and also were very military-minded. They had to move because their rivers changed their courses. And conquered new land, south-east of Andronovo. According to Viktor Sarianidi.

Of course they're found in Andronovo. They're found in the Sahara too. And they made their way to America through the Bering Strait. It's one of the oldest techniques that comes from hunting and has been used on and off in warfare. You don't think it's true that I mentioned bows and arrows in connection with hunter-gatherer societies? I did. I know what I've mentioned, and in connection to what.

That's very well known. The Tuthmose pharaohs brought it to Egypt. The Romans also copied Carthaginian ships. So what? What's the point? The point is military build up (resting on both professionals and part-time soldiers) seems to be a requirement of agricultural societies. Agriculture brings large-scale war and preparation for war for obvious reasons. Although this is lateral to your reasoning, it's one of your premises. That's why I'm dwelling on it.

No. It is a universal phenomenon: Hittites, Egyptians, the Mitanni, the Hycsos... Quite simply: agriculture implies warfare on a grand scale. Study some ancient history. Bows and arrows I mentioned in connection with hunter-gatherer societies. They sometimes are present in agricultural military societies, sometimes not. Moot point. The Luwians, the Spartans,... it goes on and on. The Spartans are an interesting case: They managed to enslave a whole population to do the agricultural job, while they indulged in their militaristic activity.

Here's your claim: Large-scale military activity came about because of agriculture, not in spite of it. Hunter-gatherer societies are involved in periodic squabbles, rather than military power build-up. In hunter-gatherer societies, the same bow and arrow, slingshot, etc. that are used for hunting are put to alternative use in those squabbles. Agricultural societies, on the contrary, nurture specialists: artisans, peasants, blacksmiths and potters, textile workers and administrators. Your premises are plain wrong. The famous fyrd that Harold Godwinson mobilised against Hardrada and William the Conqueror were peasants.

Nobody's saying you haven't. And stop playing straw-man, please. I can see right through it. And if you have, then you know, no doubt, that once an organism's genetic makeup is set in motion, so to speak, developmental biology takes charge to determine how it's going to develop, right? The environment interacting with this genetic conditioning does that. Right?

That's why I didn't do that. Apparently you need some help to read and understand simple sentences in English. Maybe repetition can do the trick:

Of course not. Many genetic conditions can affect your muscle composition. But the cases of women looking more muscular than in previous generations --that you brought up-- is easily explained by factors having to do with a person's lifestyle, not with evolution. IOW, you have not proven that we as a species are evolving towards sexual dimorphism. People are changing their muscular development because of the gym and the diet.

My emphasis. Be careful with what is 'generally accepted.' And we didn't even start talking about the effect of hormones.

You missed @Prometheus's excellent point about hippocampi. The answer to this is a similar argument applied to muscles. Although muscles can change more easily than nervous tissue. Even for hippocampus. In fact, the kind of muscular tissue you get depends very directly on the kind of exercise you do, or whether you exercise at all. Astronauts that spend a long time in outer space suffer a rapid deterioration of their muscular tissue if they don't exercise regularly. That has nothing to do with evolution, but with adaptation of your tissues to varying environmental conditions.

My interpretation of your question goes along the same lines as MigL's and Markus'. Just adding more raisins to the cake... The problem is in the scaling properties of the coupling constant (1 over mass squared). They make it blow up at large energies (short distances) in an uncontrollable way --> Non-renormalizability. Gravity cannot be 'tamed' with the techniques of QFT. In recent years it has been found that supersymmetric gravity can be quantum-mechanically tamed. But supersymmetry is proving very elusive. I sense a question within your question though: How come gravity is so special? What sets it apart from the other ones? Other interactions can be pictured as 'arrows' on the reference frame, signaling a distortion in it along internal directions; but gravity is a distortion of the reference frame itself. Maybe the re-phrasing of the question that MigL was asking for is here: Is that it?

I'd say 'door' is wrong. It's the most democratic thing I can think of. But minorities must be respected. All my respect for 'door'.

It is the right analogy as concerns the fact that it is as much of a helical motion as a nut: Not a helical motion at all. Your nut is a rigid body. Angular momentum cannot be converted into linear momentum. The list of inconsistencies in your thinking is almost impossible to keep in check. At least I know now that you know nothing about rigid body dynamics. It's been a lot of time down the drain for me. Thank you very much. You are right, we are wrong, is all that you can say. Your reasoning has changed at every step. I and others have always responded with standard physics. Different scope perhaps, but same good old reliable physics. You've taken none of it. The very same motto that you proudly bear in your profile speaks of your ignorance of physics: "circumventing Newton's 3rd law through Euler inertial forces." Newton's laws are only valid in an inertial frame. You don't even know that and you make a banner or your ignorance. Bye.

Good analogy.

Yes, feel free to, @Ghideon. I was including what I think are the relevant eqs. for completeness and conceptual clarification. I was trying to do a top-down derivation. The final equations are much simpler.

Wrong method, IMO. There are infinitely many action-reaction pairings in all the radial directions, resulting in no radial net force. Except the components along the axis. But I wouldn't care to do that sum. Too much work, I suppose, if I ever tried that. Much better to write 4 variables and start guessing constraints. Anyway... Later. Displaced you mean? The screw, of course. (In free space.) But now you seem to have a gravitational field. Anyway... Later.

Every bit of the body moves as a whole, following each other by means of a velocity field: \[\boldsymbol{V}_{i}=\boldsymbol{V}+\boldsymbol{\omega}\wedge\boldsymbol{r}_{i}\] V is the velocity of the body as a whole from an inertial system, and r_i is the position vector from the centre to the particular place where that part of the body is with respect to the common centre. Usually the "centre" is chosen to be the COM. IOW, every part of the body moves according to all other parts. It would be crazy to deal with this as a system of actions-reactions. Really? I think it's high time we talk some maths. Otherwise you have infinitely many points of action and reaction. Don't you?

I know of no treatment that deals with the motion of a rigid body, and a nut or a bolt, in terms of action and reaction. All the parts of the body are integrated into a whole that has 6 degrees of freedom.