1517: Spectroscopy

2015-04-27T13:14:21Z

108.162.219.158: Fix typo

{{comic
| number = 1517
| date = April 27, 2015
| title = Spectroscopy
| image = spectroscopy.png
| titletext = 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==
{{incomplete|Just the basics. More info needed and links etc.}}
This comic mixes the method of using ''{{w|spectroscopy}}'' to detect {{w|oxygen}} on {{w|exoplanets}} (planets outside our {{w|Solar system}}) with [http://www.azlyrics.com/lyrics/faithhill/breathe.html the lyrics] for the {{w|Faith Hill}} song "{{w|Breathe (Faith Hill song)|Breathe}}" (listen to [https://www.youtube.com/watch?v=yCmsZUN4r_s "Breathe" on YouTube]).

From the lyrics:
:''I watch the sunlight''
:''dance across your face''
:''I can '''feel''' you breathe''
In the comic the word '''feel''' have been changed to '''see'''. The two first lines are one line in the song. The last line is from the chorus and is repeated five times during the song, although not right after the first two lines.

In the first and second panel the "I" examine the spectra of a remote planet "you" by ''watching the sunlight'' during the transition of the planet as this sunlight ''dances across the planets face''. Finally we determining that breathable oxygen exists. Since we cannot (as Faith can) ''feel'' the planet we have to ''see'' it. And by doing this ''I can see you breathe''.

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. When a planet, as pictured, moves between the star and the observer, then by looking at the spectrum received, the viewer is able to determine the contents of the planets atmosphere from the specific wavelengths of light that are {{w|Absorption spectroscopy|absorbed}} in this. If it turns out that the atmosphere absorbs the lines corresponding to molecular oxygen (O<sub>2</sub>) this is a clear indication that the planet has large quantities of breathable oxygen (but {{w|Exoplanet#Abiotic_oxygen|not necessarily life}}). But for life to exist (and breathe) as we know it, the there must be oxygen in large amounts in the atmosphere. So it is clear why [[Randall]] would be interested in exoplanets with oxygen

This comic came out four days after this article about [http://www.huffingtonpost.com/2015/04/23/nasa-nexss-search-for-life_n_7123788.html NASA's New NExSS Initiative]. {{w|NASA}} will search for signs of life on other planets, for instance by using "the light passing through the atmospheres of these exoplanets". And they "will study chemicals that have been detected on other worlds, such as oxygen and methane, to see if they were produced by biology".

The title text refers to determining {{w|radial velocity}} in the {{w|ESPRESSO}} program (Echelle SPectrograph for Rocky Exoplanet- and Stable Spectroscopic Observations). 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 the masses of planets as they are moving towards the Earth in their orbit around their distant stars. It is so precise that is should be able to detect {{w|Terrestrial planet|planets as small as Earth}} and the other of the Solar systems inner planets.

Randall is now even more excited about ESPRESSO, than he is about the oxygen levels, because it is now possible to detect these "very" small planets. So he is no longer listeling to "Breathe", but to another Faith Hill song: "{{w|This Kiss (Faith Hill song)|This Kiss}}".

==Transcript==
:[A dark panel with a bright star in the center. To the left a planet (drawn as a new moon) approaches the star. Text is written above in white with two musical notes, one on each side of the text.]
:I watch the sunlight

:[Same image but now the planet eclipses the star. Small lines around the planet indicate the atmosphere, as seen from the light from the star passing through it. Text is again written above in white with two different musical notes, one on each side of the text.]
:Dance across your face

:[A white frame with a black line. It Is the spectrum of the planets atmosphere. Two distinct absorbtion peaks are visible. The first one is labeled with an arrow. Text is again written above, now in black, with two, again, different musical notes, one on each side of the text.]
:I can see you breathe
:Label: O<sub>2</sub>

:[Below the panels is the following caption:]
:'''Faith Hill on exoplanet spectroscopy'''

{{comic discussion}}

[[Category:Science]]
[[Category:Exoplanets]]

1412: Teenage Mutant Ninja Turtles

2014-08-25T11:20:19Z

108.162.219.158: /* Explanation */

{{comic
| number = 1412
| date = August 25, 2014
| title = Teenage Mutant Ninja Turtles
| image = teenage_mutant_ninja_turtles.png
| titletext = My upcoming alubm, 'Linked List', has covers of 'The Purple People Eater', the Ninja Turtles theme, 'Itsy Bitsy Teenie Weenie Yellow Polka Dot Bikini', and the Power Rangers theme, with every song played to the tune of the next.
}}

==Explanation==
{{incomplete|Very early draft.}}
In reference to the recently released ''Teenage Mutant Ninja Turtles'' movie, Randall has compiled a list of Wikipedia article titles that, when stressed on the correct syllables, sound similar to theme song of the {{w|Teenage Mutant Ninja Turtles (1987 TV series)|1987 cartoon series}}. Some of the items on this list (e.g. {{w|Ace Ventura: Pet Detective|''Ace Ventura: Pet Detective''}}) are drawn in the same style as the logo from that series.

See also [[856: Trochee Fixation]], another comic dealing with a similar concept.

==Trivia==
Randall mistyped the word "album" as "alubm" in the title text

==Transcript==
{{incomplete transcript}}

{{comic discussion}}

[[Category: Comics with color]]
[[Category:Ninja Turtles]]
[[Category: Wikipedia]]

Talk:636: Brontosaurus

2014-08-15T15:14:46Z

108.162.219.158:

Title text might also be a retort from Megan for what he said. [[Special:Contributions/108.162.250.223|108.162.250.223]] 06:18, 16 April 2014 (UTC)

Agreed, I think the title text is a retort from Megan (based on the "Well," start to it).

explain xkcd - User contributions [en]

1517: Spectroscopy

1412: Teenage Mutant Ninja Turtles

Talk:636: Brontosaurus