glurth t1_jd4n4io wrote on March 21, 2023 at 8:19 PM

Reply to comment by KarlSethMoran in Can a single atom be determined to be in any particular phase of matter? by Zalack

"You need internal degrees of freedom to define temperature."

This sounds inaccurate. Wouldn't the excitement states of a single atom's electrons be an internal degree of freedom?

glurth t1_itqjd1c wrote on October 25, 2022 at 3:57 PM

Reply to comment by PlaidBastard in If you lived on a planet in the center of the Milky Way would the nighttime be significantly brighter compared to Earth’s nighttime due to the larger concentration of stars? by bad_take_

Lemme riff some math off this data:

Luminosity Of Star / distance from star squared = apparent brightness of star

Let's pick a star with Luminosity: L

apparent brightness at avg EARTH star distance = Eb = L / (30k AU^2)

apparent brightness at avg galactic center star distance = GCb = L / (850 AU^2)

solve both for L

L= Eb/(30k AU^2)

L=GCb / (850 AU^2)

two terms for L: set expressions to equal each other

Eb/(30k AU^2) = GCb / (850 AU^2)

Gcb/Eb = Ratio of apparent brightness between star seen from earth and from the galactic center

Gcb/Eb = 30k^2/850^2 = 722.5K

So that one star will be 722k brighter at avg galactic center star distances, than at earth avg star distance.

(For comparison- our sun is 1AU from earth, using the same formula, it is 900 million times brighter than an avg earth distance star (of the same luminosity), and .... 722.5K times brighter than an avg galactic center distance star (of the same luminosity): the same number we computed earlier - what an odd coincidence- somebody better check my math!)