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How Many Equations of Motion Describe a Moving Human?

arxiv.org

11–20 of 24 posts

Re: How Many Equations of Motion Describe a Moving Human?

#11
Counting equations is dubious. Is dx^2/dt^2 = c one or two equations?

The fact that this paper is written in Word doesn't help it.

I have never heard of applying Pearson-Coefficients for system identification like that.

This paper smells like someone applying insufficient math to a problem. The world is not linear. In fact the human body also requires Algebraic constraints.

This is just a bad paper.

Re: How Many Equations of Motion Describe a Moving Human?

#12
post #2

This is tangentially related. Do you know why we have hair in armpits but not on back of the knees or on inner side of the elbow (between biceps and forearm)? Both knee and elbow can move in a way that skin touches itself (just like armpit), but the knee and elbow have only 1 degree of freedom, no matter how you move them, the skin cannot rub on itself. Skin can only rub on itself in armpit (2 degrees of freedom), gr…

Because we have sweat glands for pheremones in our armpits. The main theory is that armpit hair serves to waft that. We don't have those types of glands on the backs of our knees or inner side of elbow, etc. So no extra hair there, and no need for antiperspirant there either.

And pubic and anal hair is meant to waft the pheromones from those regions too? :)

Re: How Many Equations of Motion Describe a Moving Human?

#13
post #10
post #3

Earlier quoted context omitted.

Not sure that holds up to strict scrutiny. It's a fine hypothesis for the armpit but makes no sense with the groin. There the hair is heaviest on skin that touches nothing else and almost indistinguishable from background on the actual sliding surfaces. Same for butt crack.

Hair act as mechanical lubricant.

Exactly, so why isn't there more hair on places that need mechanical lubrication other than the armpits?

Re: How Many Equations of Motion Describe a Moving Human?

#14

Earlier quoted context omitted.

Because we have sweat glands for pheremones in our armpits. The main theory is that armpit hair serves to waft that. We don't have those types of glands on the backs of our knees or inner side of elbow, etc. So no extra hair there, and no need for antiperspirant there either.

And pubic and anal hair is meant to waft the pheromones from those regions too? :)

Unironically yes: https://en.wikipedia.org/wiki/Skatole

However, it strikes me as more likely that pheromones are emitted in places already adapted for evaporative cooling, which in turn would be hairy places, which in turn could be lubricative.

Re: How Many Equations of Motion Describe a Moving Human?

#15

Counting equations is dubious. Is dx^2/dt^2 = c one or two equations? The fact that this paper is written in Word doesn't help it. I have never heard of applying Pearson-Coefficients for system identification like that. This paper smells like someone applying insufficient math to a problem. The world is not linear. In fact the human body also requires Algebraic constraints. This is just a bad paper.

No post body was provided.

Re: How Many Equations of Motion Describe a Moving Human?

#17
post #2

This is tangentially related. Do you know why we have hair in armpits but not on back of the knees or on inner side of the elbow (between biceps and forearm)? Both knee and elbow can move in a way that skin touches itself (just like armpit), but the knee and elbow have only 1 degree of freedom, no matter how you move them, the skin cannot rub on itself. Skin can only rub on itself in armpit (2 degrees of freedom), gr…

Because we have sweat glands for pheremones in our armpits. The main theory is that armpit hair serves to waft that. We don't have those types of glands on the backs of our knees or inner side of elbow, etc. So no extra hair there, and no need for antiperspirant there either.

OK but why are the pheromones in your armpit instead of your elbow?

You might be reversing cause and effect.

Re: How Many Equations of Motion Describe a Moving Human?

#18
post #17

Earlier quoted context omitted.

Because we have sweat glands for pheremones in our armpits. The main theory is that armpit hair serves to waft that. We don't have those types of glands on the backs of our knees or inner side of elbow, etc. So no extra hair there, and no need for antiperspirant there either.

OK but why are the pheromones in your armpit instead of your elbow? You might be reversing cause and effect.

Local maxima that can not be left anymore with the given mutation rate.

Better alternatives for so many functions that were never explored/reached by evolution.

Re: How Many Equations of Motion Describe a Moving Human?

#19
post #17

Earlier quoted context omitted.

Because we have sweat glands for pheremones in our armpits. The main theory is that armpit hair serves to waft that. We don't have those types of glands on the backs of our knees or inner side of elbow, etc. So no extra hair there, and no need for antiperspirant there either.

OK but why are the pheromones in your armpit instead of your elbow? You might be reversing cause and effect.

Evolution, though directed by natural selection, is a random process. So sometimes the answer's just because that's how it happened.
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