Difference between revisions of "1517: Spectroscopy"

Explain xkcd: It's 'cause you're dumb.
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(Transcript: Starting on it)
(Explanation)
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"I can see you breathe" - determining that breathable oxygen exists.
 
"I can see you breathe" - determining that breathable oxygen exists.
  
The mouseover text refers to determining rotational velocity (based on emission line broadening) from another Faith Hill song, "This Kiss" referring to centrifugal motion.
+
The mouseover text refers to determining radial velocity in the http://en.wikipedia.org/wiki/ESPRESSO program. By noting that the radial velocity of the star changes slightly as the planet that orbits it moves around the star (centrifugal acceleration), the ESPRESSO program should be able to detect planets of masses approaching the Earth around distant stars.
  
 
==Transcript==
 
==Transcript==

Revision as of 12:13, 27 April 2015

Spectroscopy
Although right now I'm more excited about ESPRESSO's radial velocity measurements, so I'm listening to This Kiss, her song about measuring "centrifugal motion" on "a rooftop under the sky".
Title text: Although right now I'm more excited about ESPRESSO's radial velocity measurements, so I'm listening to This Kiss, her song about measuring "centrifugal motion" on "a rooftop under the sky".

Explanation

Ambox notice.png This explanation may be incomplete or incorrect: Just the basics. More info needed and links etc.
If you can address this issue, please edit the page! Thanks.

Measuring the light output of stars (spectra) we are able to determine a number of details of the star, including rotation, relative radial velocity, chemical composition, temperature and to some degree, distance and size. As the planet pictured transitions between the star and the observer, and looking at the spectrum received, the viewer is able to determine that the planet is absorbing the specific wavelengths that molecular oxygen absorbs; a clear indication that the planet has large quantities of breathable oxygen.

http://www.huffingtonpost.com/2015/04/23/nasa-nexss-search-for-life_n_7123788.html

This comic mixes this method of detection of oxygen on remote planets with the lyrics for the Faith Hill song "Breathe" "I see the sunlight" - examining the spectra of a remote star "I dance across your face" - examining the transition of the planet across the star "I can see you breathe" - determining that breathable oxygen exists.

The mouseover text refers to determining radial velocity in the http://en.wikipedia.org/wiki/ESPRESSO program. By noting that the radial velocity of the star changes slightly as the planet that orbits it moves around the star (centrifugal acceleration), the ESPRESSO program should be able to detect planets of masses approaching the Earth around distant stars.

Transcript

I watch the sunlight
Dance across your face
I can see you breathe
Faith Hill on exoplanet spectroscopy
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Discussion

Thanks, Kynde, for the nice explanation. 108.162.221.201 13:29, 27 April 2015 (UTC)

Your welcome, and Thanks. I think I was still working on it when you wrote this comment ;-).--Kynde (talk) 13:42, 27 April 2015 (UTC)

I was wondering how many people go to watch these two songs on YouTube today (and the next few days) solely because of Randall's comic. I have long time wondered about this. Now maybe a time to find out. Of course we never know in advance how many new hits the song he chooses received the days before. But now we have a chance of following it over the next few days. Of course the comic has been up several hours but it is still early across most of the US... Here are the counters for the two videos linked above in the comic as of right before this post was made: Breathe: 9.493.222 and This Kiss 4.079.410. Please feel free to add new counts a few times over the next week or so. :-) --Kynde (talk) 13:42, 27 April 2015 (UTC)


Links for your convenience: "Breathe", "This Kiss" and as control "Cry".

"Breathe" 9,493,334, "This Kiss" 4,079,458, "Cry" 3,182,592 108.162.221.201 13:54, 27 April 2015 (UTC)

Thanks. Here goes after 1 day and 2 hours:
9.500.026 (+6692/+,07%)
4.083.297 (+3839/+,09%)
3.184.334 (+1742/+,05%)
I'm nut sure we can learn anything from this yet...?--Kynde (talk) 13:55, 28 April 2015 (UTC)

Actually, if the star or region of space is anything similar to our own, O2 is definitively a sign of life. Not animal life, but at least plant life, to crack the O2 out of the CO2 with photosynthesis.Seebert (talk) 14:00, 27 April 2015 (UTC)

The explanation currently covers links that show that not all oxygen will be created because of life, and not all life (even 'as we know it') will necessarily require/produce a significant oxygen signal. But there seems to be a missing middle-bit in that oxygen initially seems to have been a smothering 'industrial pollutant' by early (oxygen splitting) life-forms until other life-forms developed the machinary to use this oxygen as part of their own energy mechanisms (creating the eventual two-way dynamic of CO2 and O2 production/usage between the major groups of life) and thus making the unstable free oxygen both an indicator of life and an indicator of the capability of life (by mainstream terrestrial standards of biology, of course). 141.101.98.186 18:06, 27 April 2015 (UTC)
That is not necessarily true. There is now a theory that oxygen could be have been created without life involved here on Earth based on the snow ball earth scenario. In the ice H2O2 formed and when the ice melted this was released into the water where it then would release oxygen. See for instance here: Did snowball Earth's melting let oxygen fuel life?. --Kynde (talk) 14:09, 28 April 2015 (UTC)

I'm pretty sure the original lyric for "This Kiss" is "it's centripetal motion" (see: http://www.sweetslyrics.com/59372.Faith%20Hill%20-%20This%20Kiss.html). I assumed the joke Randall was making was that centrifugal really is a force, Mr. Bond, even if Faith Hill doesn't know about it. Djbrasier (talk) 00:25, 28 April 2015 (UTC)

I agree: I only recall hearing "centripetal motion", but Google tells me there are actually more hits for "centrifugal", and that there are some lyrics sites putting both phrases in the song. Mark Hurd (talk) 01:41, 28 April 2015 (UTC)
I think the song says "centrifical" which is not even a word, let alone a force, ficticious or not. Nonetheless, it seems to be a common misspelling since it has its own wiktionary entry (http://en.wiktionary.org/wiki/centrifical). 108.162.249.180 08:54, 28 April 2015 (UTC)
I agree that she doesn't sing centrifugal. I have changed the explain to say it is centripetal (I'm sure she is supposed to at least, maybe she doesn't know the word either ;-) But left in a comment on the fact that there are different versions on-line. But I'm sure that that is because people do not know the word centripetal and also that people who make lyrics pages cut and paste from each other. I have often seen the same mistake on several lyrics pages. --Kynde (talk) 13:50, 28 April 2015 (UTC)
Its not centripetal, she sings "centrifugal" but with pronounced wrong. Its a pop song, and centrifugal with a long u wouldn't fit, so the i is short but stressed, and the u is reduced to a schwa. Rightly or wrongly, "centrifugal" is the common word.141.101.70.43 18:37, 28 April 2015 (UTC)
How is it pronounced wrongly? There's two pronunciations for the word "centrifugal," and one of them is without a long-U sound. /sɛnˈtrɪf yə gəl, -ə gəl/ (see: http://dictionary.reference.com/browse/centrifugal?s=t) Maybe she's a bit harder on the G than might be proper, but most people I know pronounce it as she does, or close enough anyway. -- 108.162.237.188 03:20, 29 April 2015 (UTC)
I believe a close viewing of the linked official video of "This Kiss" makes it certain that Ms. Hill is singing "centrifugal". To see this, examine some frames near 0:33, when Ms. Hill is singing "centrifugal" for the first time. Although (so far as I can tell) YouTube does not support frame-by-frame advance, you can hit play and stop in rapid succession, and convince yourself quite thoroughly that Ms. Hill's top teeth are always visible, and that her lips never meet. Compare this to the very first frames of the cut at 1:19 when Ms. Hill is just beginning to sing "pivotal". You will very clearly see her lips touching and slightly pursed. (Is there a way to attach screenshots?) Given that it is impossible to pronounce a "p" phoneme without the lips coming together at some point, Ms. Hill is not singing a word with a "p" in it at 0:33, but rather one with an "f," pronounced with the top teeth touching the bottom lip -- "centrifugal," in fact. Conclusion: Randall is quoting the actual lyrics intended by the singer on the official video. 173.245.52.87 01:21, 30 April 2015 (UTC)