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The "artist's rendering" is always my favorite part. Astronomer: We want something sort of like Jupiter, but purple. Artist: Can I do that big red storm thing
by sramsay 13y ago
The "artist's rendering" is always my favorite part.
Astronomer: We want something sort of like Jupiter, but purple.
Artist: Can I do that big red storm thing?
Astronomer: No, no. Don't do that. We don't know if there's a storm. We used blackbody radiation to find it.
Artist: So wait, it's supposed to be black?
Astronomer: No! It's gotta be PURPLE.
Artist: But you said . . .
Astronomer: Never mind. Just make it look lonely. And don't put any stars around it.
- hyperbovine 13y agoHey, whatever keeps the grant money flowing is A-ok in my book.
- aortega 13y ago>We used blackbody radiation to find it. Pardon my pedantry but that's another way to say "we used regular light to find it". If I remember my physics right, stars, like a candle or an incandescent light bulb emit light as blackbody radiation.
- raverbashing 13y agoYes, but the peak is not necessarily in the visible range The things on your desk are glowing in the same way, can you see? No, because it's mainly on infrared
- guard-of-terra 13y agoLight bulbs don't emit black body radiation. They don't nearly have enough black body temperature for bright yellow light. I guess tungsten has different emission pattern.
- aortega 13y agoEverything emits black body radiation even yourself.
- eitland 13y agoIsn't "black body" in physics just something that absorb all incoming radiation meaning that the radiation coming out from it is all originating from said object? The radiation from a black perfectly body is then a function of its temperature. (Disclaimer: many years since I studied :-)
- gus_massa 13y agoI measured the emission spectrum of a tungsten lamp in the laboratory a few years ago. I don’t remember all the details, but in the visible spectrum the tungsten the amount or radiation that the tungsten lamp emits is roughly 0.3-0.4 times the radiation that a black body would emit. I googled a little and found these two articles: 1) http://articles.adsabs.harvard.edu/full/seri/ApJ../0061//0000146.000.html http://articles.adsabs.harvard.edu/full/seri/ApJ../0061//000... : * In page 151 it has a graph of the emissivity of tungsten for different colors and temperatures. More emissivity for blue (A) than for red (C). * In page 156 it has a greph of the difference between the color temperature and the true temperature. For 3000K, the difference is only ~100K. I think that it’s changes the color only slightly. 2) http://physicsed.buffalostate.edu/pubs/TPT/TPTDec99Filament.pdf http://physicsed.buffalostate.edu/pubs/TPT/TPTDec99Filament.... * More friendly version, with an experiments with actual lamps. * In page 525 it explains that the emissivity if tungsten at that temperature in ~0.42 but you must introduce a correction because the glass of the lamp absorbs a 8% of the light.
- drjesusphd 13y agoYou're wrong. The very word "incandescent" means "glowing because it's hot". The fillamant and the gas inside the bulb reach temperatures of up to around 3000 K. The surface of the sun might be about 6000 K, but it glows white-hot, not yellow as many believe.
- sramsay 13y agoJust for the record: I'm an English professor. I know less about blackbody radition than the person who created the picture. I just read someone saying that in the thread and decided to make a joke out of it. But please, do continue pedanting.