482: Height

2014-03-12T23:12:50Z

Ianmathwiz7: /* Explanation */ Added space elevator explanation.

{{comic
| number = 482
| date = September 29, 2008
| title = Height
| image = height.png
| titletext = Interestingly, on a true vertical log plot, I think the Eiffel Tower's sides would really be straight lines.
}}

==Explanation==
{{Incomplete|Lots of the little references aren't even mentioned, e.g. Human Altitude record, the space elevator, and I just added an explanation for "All Hail Discordia!" This is nearly there, but not yet.}}
The comic is a companion piece to [[485: Depth]], which explores a {{w|logarithmic scale}} from Earth's atmosphere down to the interior of a single proton. ''Height'' begins this process by viewing logarithmically smaller scales showing several objects in the universe, both real and fictional, from farthest (top) to closest (bottom). The comic starts with [[Black Hat]] throwing a cat off the edge of the universe, probably a reference to {{w|Schrodinger's cat}} (as since it is outside the {{w|observable universe}} (for us), it exists in a super-position of both living and dead until we actually 'observe' it and force it to be in one of the states). It may also refer to the common myth that a cat will always land on its feet, a myth Black Hat appears to be testing to the extreme. The top of the universe is shown as the distance from which the oldest rays of light reach Earth.

Displaying height logarithmically while displaying width linearly noticeably distorts the shapes of the terrestrial objects. The title text notes that this distortion would approximately cancel out the curve of the Eiffel Tower's profile, and speculates that the cancellation might in fact be exact enough to convert its silhouette to a straight-edged triangle.

The {{w|age of the universe}} is currently stated as 13.8 billion years. But the {{w|Observable universe}} is about 14.0 billion {{w|parsecs}} or 46 billion {{w|light years}}, as shown on the top of the image.

===Fictional Objects===

*[http://knowyourmeme.com/memes/cat-on-a-keyboard-in-space Cat on a keyboard in space].
*{{w|Ford_Prefect (character)|Ford Prefect}}, character from {{w|The Hitchiker's Guide to the Galaxy (franchise)}}, shown near his home star; Betelgeuse.
*The [http://en.memory-alpha.org/wiki/Romulan_Neutral_Zone Romulan Neutral Zone], marking the edge of the {{w|Star Trek}} Federation.
*{{w|Federation Sector 0-0-1}}, the sector of space assigned to Earth in {{w|Star Trek}}.
*"missing WMDs", a reference to the controversy about {{w|Iraq and weapons of mass destruction}}.
*{{w|Bupkis}} is Yiddish for "nothing". Only a handful of objects are known to orbit between the outer edge of the Kuiper Belt and the inner edge of the Oort Cloud, hence "Bupkis".
*A comet scheduled to hit earth in 2063, to coincide with the latest date for a supposed [http://www.askelm.com/prophecy/p971105.htm Biblically prophesized end of the world].
*Life on the moons of Jupiter and Saturn, which may or may not exist.
**The arrows most likely points to the following moons:
**Jupiter’s moon {{W|Europa (moon)|Europa}} which may be covered by a deep ocean of water - which is again covered by layer of ice many kilometers thick. In such an ocean life could have formed.
**Saturn’s moon {{W|Titan (moon)|Titan}} is the only known moon to have an atmosphere - although nothing like the one on earth. There may be oceans on the moon, but not filled with water but with liquid methane and ethane. It is way too cold for liquid water. Still in such oceans life could also have formed.
**For either moon the oceans cannot be viewed from earth either due to thick ice or opaque atmosphere.
*The little spaceship from {{w|Asteroids (video game)}}.
*The {{w|Discovery One}} from {{w|2001: A Space Odyssey}}, referring to the quote "open the pod bay door, HAL."
*The spaceplane is most likely the Planet Express from {{w|Futurama}}, where Fry once discussed "a big heaping bowl of salt." However, it could conceivably refer to these instead:
**The Quasi-elemental plane of Salt from the {{w|Inner Plane}} in {{w|Dungeons and Dragons}}.
**The Great Salt Vampire from [http://en.memory-alpha.org/wiki/M-113_creature Star Trek TOS].
**A relative of {{w|Russell's teapot}}.
*A lunar lander with someone inside proclaming "In retrospect, they shouldn't have sent a poet. I have no idea how to land". The goal of {{w|Lunar Lander (arcade game)}} is to land the vehicle without crashing it. The quote is a reference to {{w|Contact (1997 film)}} where the main character Ellie Arroway after witnessing a celestial light show up close says "Poetry! They should've sent a poet.". The actual vehicle in the movie was round and not shaped like a lunar lander.
*{{w|Cory Doctorow}}'s balloon. (first referenced in [[239]].)
*[[Cueball]], who is apparently still using Python as shown in comic [[353]].
*A {{w|Space elevator}} is a proposed method of transporting cargo or people into orbit, consisting of a station in a geosynchronous orbit, a cable connecting it to the Earth, and a climber that can scale the cable. No space elevator has been built to date, but according to the comic, one will be deployed "one of these days, promise!"

===Real Objects===

*{{w|Hubble Deep Field}}, a long-exposure photograph of extremely distant galaxies.
*{{w|Great Attractor}}, an unusual concentration of intergalactic mass.
*{{w|Antennae Galaxies}}, a pair of colliding galaxies.
*{{w|Andromeda Galaxy}}, a sibling to our Milky Way.
*{{w|Magellanic Clouds}}, a pair of nearby dwarf galaxies.
*{{w|Crab Nebula}}, {{w|Orion Nebula}}, and {{w|Horsehead Nebula}}, supernova remnants.
*{{w|Pleiades}}, {{w|Rigel}}, and {{w|Betelgeuse}}, stars. The Pleiades also have a derogatory remark, as per [[66: Abusive Astronomy]]
*The distance that human radio transmissions have traveled so far. See {{w|Contact (1997 film)}} for a depiction of this. This is also referenced in [[1212]].
*{{w|Pollux}}, {{w|Arcturus}}, {{w|Sirius}}, {{w|Alpha Centauri}}, and {{w|Barnard's Star}}, nearby stars.
*{{w|Oort cloud}}, a halo of ice balls surrounding our solar system.
*{{w|Pioneer 10}} and {{w|Voyager 1}}, two early probes headed out of the solar system.
*{{w|Eris (dwarf planet)|Eris}} and {{w|Pluto}}, a pair of {{w|Trans-Neptunian object|TNOs}} now classified as {{w|dwarf planet}}s. The "All hail Discordia!" after Eris is a reference to {{w|Discordianism}}, a somewhat tongue-in-cheek religion based around the goddess Eris.
*{{w|Neptune}}, {{w|Uranus}}, {{w|Saturn}}, and {{w|Jupiter}}, giant gas planets at our {{w|Solar System|solar system}}.
*The {{w|Asteroid|Asteroid belt}} between Mars and Jupiter.
*{{w|Mars}}, {{w|Venus}}, and {{w|Mercury}}, our neighboring inner planets. Note that Venus and Mars are shown with looping paths, reflecting the fact that their distances from Earth vary as the planets move in their orbits (this is true for all planets, but more noticeable for these two because the ratio of smallest to greatest distance is particularly large).
*The {{w|Sun}} and the {{w|Moon}}.

==Transcript==
:[Map of the universe from observable universe to Earth. Each area of item is labelled.]
:[Labels left to right, up to down:]
:[Black Hat is standing on top, throwing a black kitty down.]
:Black Cat: mrowl!
::Top of Observable Universe
::46 Billion Light Years Up
::Hubble Deep Field Objects
:-One Billion Light Years-
::Great Attractor
:Antennae Galaxies (Colliding)
:Andromeda
:::Holy Crap Lots of Space
::-One Million Light Years-
::Magellanic Clouds
::Edge of Galaxy
::Galactic Center
::Crab Nebula
::Orion Nebula
::Horsehead Nebula
::Romulan Neutral Zone
:::The PLEIADES, Duh.
::Rigel
::Betelgeuse
::Ford Prefect
::-Expanding Shell of Radio Transmissions [Arrows are pointing up.]-
::Edge of Federation Sector 0-0-1
::Pollux
::Arcturus
::Missing WMDs
::Alpha Centauri
::Sirius
::Barnard's Star
:-One Parsec-
::-One Light Year-
::Oort Cloud (?)
::Bupkis
::Comet which will destroy Earth in late 2063
::Pioneer 10
::Eris (All hail Discordia!)
::Voyager I
::Pluto (Not a planet. Neener neener.)
::Neptune
::Uranus
:Saturn
::Asteroids
:::<~life~>
::Jupiter
::Venus
::Mars
::Sun
::Mercury
::Aircraft: Hey a heaping bowl of salt!
::"Open the fridge door, Hal."
::Moon
::Human Altitude Record (Apollo 13)
::2nd Place: Snoop Dogg
::Space Elevator - One of these days, promise!
::-Geosynchronous Orbit-
::GPS Satellites
::Lunar lander: In retrospect, they shouldn't have sent a poet. I have no idea how to land
::International Space Station
::Space Junk
::-Official Edge of Space (100 km)-
::Meteors
::-1/10 ATM-
::High Altitude Balloons
::Airliners
::-1/2 ATM-
::Cory Doctrow
::Shuttle Columbia Lost
::Everest
::Helicoptors
::Cueball: Woo Python!
::-800 m-
::-1 km-
::[Height progressivly gets smaller and smaller.]
::Burj Dubai (~800 m)
::Eiffel Tower (325 m)
::Kites
::Great Pyramid (140 m)
::Redwood (115 m)
::Pop Fly
::Oak (20 m)
::"Hey Squirrels!"
::Tallest Stilts
::Brachiosaur (13 m)
::Giraffe (8 m)
::[Megan and Cueball.] Folks
:The Observable Universe, from Top to Bottom ~On a log scale~
:Sizes are not to scale, but heights above the Earth's surface are accurate on a log scale (that is, each step up is double the height.)

{{comic discussion}}
[[Category:Charts]]
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Cory Doctorow]]
[[Category:Large drawings]]

881: Probability

2014-01-20T15:50:54Z

Ianmathwiz7: /* Explanation */ Added interpretation of "normal approach" in terms of Normal distribution

{{comic
| number = 881
| date = April 4, 2011
| title = Probability
| image = probability.png
| titletext = My normal approach is useless here, too.
}}

==Explanation==
{{incomplete|The difference between the two lines have to be explained.}}

[[Cueball]] and [[Megan]] are sitting on a hospital bed, reading a piece of paper with the statistics for {{w|breast cancer}} survival. It looks like Megan has just been diagnosed with breast cancer. The thick line represents the survival rate distribution (probability to be alive after X years, unconditioned): 81% are alive at 5 years, while 77% survive to 10 years. The dashed line represents the {{w|hazard function}} (in very loose terms, the risk of failing/dying at time t+delta after having survived until time t), which is the rate between the density of the failure distribution and the survival function.

[[Randall]] wrote this comic after his fiancee was diagnosed with breast cancer. Two months after posting this strip, he posted [http://blog.xkcd.com/2011/06/30/family-illness/ this blog post] explaining the cancer strips.

The title text references [[55: Useless|comic #55]]. Cueball's (and Randall's) normal approach -- math -- isn't much help in dealing with ''this'' emotional situation, either. The phrase "normal approach" may also in this case be a pun on the {{w|Normal distribution}}, which is another probability distribution that is commonly used in statistics. Interpreted this way, the title text states that the Normal distribution is not used as a hazard function.

==Transcript==
:[A plot of years vs. percent, with a solid and a dashed line. The solid line starts at 100%, and drops constantly. The dashed line starts around 85%, rises to 95% after 5 years, then drops.]

:[A simple table.]
:{| class="wikitable"
|-
|  5 years
| 81%
|-
| 10 years
| 77%
|}

:[Cueball and Megan are sitting on a bench, next to an IV drip hanging from a rack. Cueball is holding a paper.]
:Cueball: You know, probability used to be my favorite branch of math
:Cueball: Because it had so many real-life applications.

:[They embrace, faces together.]

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Romance]]
[[Category:Cancer]]
[[Category:Charts]]
[[Category:Math]]
[[Category:Statistics]]

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482: Height

881: Probability