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We used to, and we wiped them out and/or mated them out of existence.

Somebody may correct me if I’m wrong, but it helps that the stars that go supernovae have comparatively short life spans, so there have been several more “generations” of them. If I recall, the life span of those stars is measured in the millions of years, versus our sun which is projected to have a 10 billion total life span (and is about 4.5 billion years into it).

Edit: and versus the estimated ~14 billion year age of the universe.

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Thank you! It's fascinating that we have any kind of nontrivial amounts of those elements at all in our grasp, considering their sources.

Yes! The creation of those elements take energy instead of releasing it.

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Yes. I didn’t want to get into “there is no such thing as a vacuum” because of quantum. While true it probably doesn’t affect dielectric constants.

IIRC quasars and supernovae are where you get the heavier elements, right?

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What matters is how stars fuse them. Iron, nickel, neon, are more common than chlorine.

So the most common element is hydrogen, followed by helium and so on. Stars are basically fusion reactors that fuse element up untill iron on the periodic table. The Wikipedia page of " Abundance of the chemical elements " will show you how little of the universe is not hydrogen helium. So by mass I'd say it's quite rare for sure, but compared to things like gold or uranium it's far less rare. Most we can do are estimates since it's really hard to find direct evidence on far away planets.

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If there is an electric field then it's not an ideal vacuum.

A field in that range is strong enough to produce electron/positron pairs from the energy in the electric field. It has some similarity to pair production from photons.

c=1/√(ε0μ0) shows the speed of light is related to the electric and magnetic field spontaneously generated by photons in a vacuum. I've probably mixed relativity with quantum theory there though...

Look into calorimetry and nutritional analysis. It may very well be that you could with the right equipment and to a useful extent, develop some math around this. I’m sure others have!

For me, I’ve noticed the higher the volume of raw fruits and veggies I eat, the fitter I am, regardless of calories consumed. Haven’t tried it with raw meat tho 😅

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Yeah, bill gates and Mark Zuckerberg both dropped out of college and are a billionaires, so you should too.

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The mechanism of rabies induced-agressive behavior involves viral infection of the limbic system in the brain, wich is responsible for our most primitive behaviors and responses. Rabies virus affects the limbic system while mantaining more superior cerebral cortical centers practically intact, so you most primitive behaviors are affected first and you still remains conscious.

In particular, a study of 1992 inoculated skunks with different strains of rabies virus; one caused agressive behavior, hydrophobia and convulsions, while the other caused paralysis but not behavioral disturbances. When they analysed the brain of these animals, they found that the ones who displayed agressivity, all had viral infection concentrated in the brain-stem, at the base of the brain, a structure vital to control our most automatic and primitive functions. In particular, there are strong viral infection at an area of the brain-stem called midbrain raphe nuclei. The raphe nuclei sends serotonin to all the brain, so it can control the function of various brain areas. Animals with don't showed agressive behavior with rabies had low or none viral infection at these raphe nuclei.

It is supposed that, when rabies virus changes neurons at these raphe nuclei, serotonin control over the brain is changed and this impinge on circuits involved with emotional and motor functions resulting in impulsive behaviors. It's like the defensive responses of the brain to threats is being turned-on in a exagerated way and this results in agressive behavior wich includes bitting others.

Smart NL, Charlton KM (1992) The distribution of challenge virus stan- dard rabies virus versus skunk street rabies virus in the brains of experimentally infected rabid skunks. Acta Neuropathol 84:501– 508

Jackson AC. Diabolical effects of rabies encephalitis. J Neurovirol. 2016 Feb;22(1):8-13.

when you get to cortex, spatial tuning is rather precise, and binocular neurons are generally tuned for the same retinal position (this suggests another question of "what is retinal position anyway?" but I don't think that's actually too problematic). I'm sure if you looked at a large number of such neurons, you'd find that (like everything else) it's actually a random distribution, albeit very narrowly distributed.

the precision of this common input is the real basis of retinal correspondence (apart from the matter of the parenthetical question above). the more precise it is (the narrower that distribution), the more informative differences in input can be, and so the better for stereopsis.