One is painted red, the other is painted blue.
Which one has higher temperature?
(assume that they perfectly reflect outside of visible spectrum)
2007-02-07 10:00:50 · 7 answers · asked by Alexander 6 in Science & Mathematics ➔ Physics
"By the way: why orbiting around the sun? Why not just a blue and red ball on Earth?"
So that you try to figure out where the
absorbed energy goes.
2007-02-07 10:13:44 · update #1
Bekki:
The red ball reflects red.
It absorbs blue and green.
It radiates blue and green.
It does not radiate red, because it does not absorb it.
2007-02-08 05:10:03 · update #2
It depends on the tint, but all things being equal, I'll say the red one.
Solar irradiance peaks at about 500nm (on the bluer side). The red ball absorbs the blue light more (and emits at a lower energy frequency), so it will get be hotter at equilibreum.
Edit--yeah I mispoke. The red ball absorbs and emits the bluer frequencies. The blue ball absorbs and emits the redder frequencies. There's slightly more energy on the blue side (based on my reading of the solar irradiance graph, but it depends on the exact hue), so I say the red ball is hotter at equilibreum.
That's how I meant to explain it.
Edit2--this is an interesting thermodynamics question--I polled a bunch of PhD physics students and profs at the dept colloquium. Red got a lot of votes (based on the reasoning above), same got a few, blue got only a couple initial votes and they changed their minds once they thought about it. If I can't think of an answer I'm positive is correct, I'm asking the baby universe cosmology prof. If anyone would know, he would.
2007-02-07 11:03:41 · answer #1 · answered by Anonymous · 1⤊ 3⤋
Blue. It's darker, so it should retain more light.
(By the way: why orbiting around the sun? Why not just a blue and red ball on Earth?)
2007-02-07 10:04:39 · answer #2 · answered by siegfriedbalmung 2 · 0⤊ 2⤋
if they are perfectly the same distance from the sun its still not perfect because of solar flares and sunspots but id say the red one because its darker and therfore absorbs more light.
2007-02-07 10:06:49 · answer #3 · answered by Brandon S 1 · 0⤊ 3⤋
They would have the same temperature because they are the same distance from black on the color spectrum.
2007-02-07 10:08:01 · answer #4 · answered by Eric W 2 · 0⤊ 4⤋
blue
2007-02-07 10:05:31 · answer #5 · answered by Haven17 5 · 0⤊ 2⤋
depends what shade but i would say red
2007-02-07 10:08:22 · answer #6 · answered by Hayden W 2 · 0⤊ 1⤋
Eric W. is right.
2007-02-07 11:06:30 · answer #7 · answered by Greg V 2 · 0⤊ 2⤋