A couple years ago, I saw a photo of Jupiter and Uranus, magnified the same, juxtaposed next to each other. Uranus was a dot down at the bottom next to Jupiter, pretty much a comparison of their view through the same telescope.
Until recently, Wikipedia's page on isotopes of hydrogen described an exotic atom called "hydrogen-4.1". The entry has since been moved to https://en.wikipedia.org/wiki/Exotic_atom.
Hydrogen-4.1 is helium with one electron replaced with a massive electron (over 200 times the electron's mass). The massiveness leads to its orbital radius being less than 1/200 the electron's orbital radius. With only one regular electron, this thing is chemically hydrogen -- really -- except that it lasts only a couple microseconds. The big circle is the electron orbital, and the dot at the center is the massive-electron orbital.
On the other hand, if the massive electron's orbital is the big circle, the helium nucleus is that dot in the center.
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Limescale
One of the wonders of studying physics is the realization that on average the universe is empty. Both at large scale and at small scale. But that does not mean I can ignore the calcium buildup in my toilet bowl.
Here is an old video called "Powers of Ten": https://www.youtube.com/watch?v=0fKBhvDjuy0
Your friend
Crash
I've seen this.
I saw this before, at least once. I didn't know it was made in the late 70s. I thought it was earlier. Ah, Philip Morrison, the narrator. Elmer Bernstein, the composer.
The picture of the Milky Way Galaxy even back then gives a hint of the bar since discovered in our galaxy.
That carbon nucleus was way too big.
-- Daphne Xu
Love Philip Morrison; I have
Love Philip Morrison; I have the volume of his selected book reviews from Scientific American, his series "The Ring of Truth", and I watch "Powers of Ten" at least once a year. (Of course, that set in Chicago, so it's got THAT going for it, too.)
He has such a great voice.
Also very fond of James Burke...
And aren't barred spiral
And aren't barred spiral galaxies just really *neat*?