482: Height

Explain xkcd: It's 'cause you're dumb.
(Difference between revisions)
Jump to: navigation, search
(Explanation: someone else can add the terrestrial objects)
Line 8: Line 8:
  
 
==Explanation==
 
==Explanation==
The comic contains a chart shows several objects in the universe, from farthest (top) to closest (bottom) on a logarithmic scale. 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 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). The top of the universe is shown as the distance from which the oldest rays of light reach Earth. Several celestial objects are shown for scale, and some fictional ones. The latter include, from top to bottom:
+
The comic contains a chart shows several objects in the universe, both real and fictional, from farthest (top) to closest (bottom) on a logarithmic scale. 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 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). The top of the universe is shown as the distance from which the oldest rays of light reach Earth.
 +
 
 +
===Fictional Objects===
 +
 
 +
*[http://knowyourmeme.com/memes/cat-on-a-keyboard-in-space Cat on a keyboard in space].
 
*{{w|Ford Prefect}}, character from {{w|The Hitchiker's Guide to the Galaxy (franchise)}}.
 
*{{w|Ford Prefect}}, character from {{w|The Hitchiker's Guide to the Galaxy (franchise)}}.
 
*The [http://en.memory-alpha.org/wiki/Romulan_Neutral_Zone Romulan Neutral Zone], marking the edge of the {{w|Star Trek}} Federation.
 
*The [http://en.memory-alpha.org/wiki/Romulan_Neutral_Zone Romulan Neutral Zone], marking the edge of the {{w|Star Trek}} Federation.
*[http://knowyourmeme.com/memes/cat-on-a-keyboard-in-space Catonakeyboardinspace].
+
*{{w|Federation Sector 0-0-1}}, the sector of space assigned to Earth in {{w|Star Trek}}.
*{{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}}.
*"missing WMDs", a reference to the controversy over the {{w|Presidency of George W. Bush|George W. Bush administration}}'s allegations that {{w|Iraq and weapons of mass destruction|Iraq possessed weapons of mass destruction}}
+
*{{w|Bupkis}} is Yiddish for "nothing".
*A comet scheduled to hit earth  in 2063, to coincide with the latest date for the Biblically prophesized end of the world. [http://www.askelm.com/prophecy/p971105.htm 1] (fictionality disputed; included here for legibility.)
+
*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 given that they seem to have all the necessary conditions to harbor it.
+
*Life on the moons of Jupiter and Saturn, which may or may not exist.
*The {{w|Discovery One}} from {{w|2001: A Space Odyssey}}.
+
*The little spaceship from {{w|Asteroids (video game)}}.
*A spaceplane finding a bowl of salt. (disputed, see below.)
+
*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://boards.straightdope.com/sdmb/archive/index.php/t-485523.html Star Trek TOS].
 +
**A relative of {{w|Russell's teapot}}.
 
*{{w|Cory Doctrow}}'s balloon. (first referenced in [[239]].)
 
*{{w|Cory Doctrow}}'s balloon. (first referenced in [[239]].)
 
*[[Cueball]], who is apparently still using Python as shown in comic [[353]].
 
*[[Cueball]], who is apparently still using Python as shown in comic [[353]].
  
Some theories about the spaceplane finding the bowl of salt:
+
===Real Objects===
*A bowl left behind by the Planet Express spaceplane in a {{w|Futurama}} episode which Fry refers to as "a big heaping bowl of salt."
+
*The Quasi-elemental plane of Salt from the {{w|Inner Plane}} in {{w|Dungeons and Dragons}}.
+
*The Great Salt Vampire from Star Trek TOS [http://boards.straightdope.com/sdmb/archive/index.php/t-485523.html 2].
+
  
Non-fictional points of note:
+
*{{w|Hubble Deep Field}}, a long-exposure photograph of extremely distant galaxies.
*{{w|Eris (dwarf planet)|Eris}}, a {{w|dwarf planet}} named after the {{w|Eris (mythology)|Greek goddess of discord}}.
+
*{{w|Great Attractor}}, an unusual concentration of intergalactic mass.
*{{w|Pluto}}, demoted from {{w|definition of planet|planet}} to {{w|dwarf planet}}.
+
*{{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 distance that human radio transmissions have traveled so far. See {{w|Contact (film)}} for a depiction of this.
 +
*{{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.
 +
*{{w|Neptune}}, {{w|Uranus}}, {{w|Saturn}}, and {{w|Jupiter}}, our gas giant planets.
 +
*The {{w|Asteroid|Asteroid belt}} between Mars and Jupiter.
 +
*{{w|Mars}}, {{w|Venus}}, and {{w|Mercury}}, our neighboring inner planets.
 +
*The {{w|Sun}} and the {{w|Moon}}.
  
 
==Transcript==
 
==Transcript==

Revision as of 23:07, 20 August 2013

Height
Interestingly, on a true vertical log plot, I think the Eiffel Tower's sides would really be straight lines.
Title text: Interestingly, on a true vertical log plot, I think the Eiffel Tower's sides would really be straight lines.

Explanation

The comic contains a chart shows several objects in the universe, both real and fictional, from farthest (top) to closest (bottom) on a logarithmic scale. The comic starts with Black Hat throwing a cat off the edge of the universe, probably a reference to Schrodinger's cat (as since it is outside the 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). The top of the universe is shown as the distance from which the oldest rays of light reach Earth.

Fictional Objects

Real Objects

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 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
Antanne 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
Aircraft 2: I have no idea how to land
Aircraft 2: In retrospect, they shouldn't have sent a poet
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.)
comment.png add a comment! ⋅ Icons-mini-action refresh blue.gif refresh comments!

Discussion

Are you sure it reads "missing winds"? It looks like "missing WMDs" to me, which would suggest a political reference to the US engagement of 2003 in Iraq. 109.40.138.109 02:48, 22 May 2013 (UTC)

Yeah. Agreed. Changed. PinkAmpersand (talk) 11:23, 23 May 2013 (UTC)
"The comic starts with Black Hat throwing a cat off the edge of the universe, probably a reference to Schrodinger's cat" 
Has the editor here never heard of the "cats always land on their feet" myth? Black Hat would appear to be testing this from the extreme. Anonymous 01:43, 4 December 2013 (UTC) (and yes, that would be WMDs)
If I am not mistaken, this is a wiki; there is no set editor. If you have a suggestion for how to improve a page, it would be apt to edit it yourself. The discussion tends to be a forum for matters that may be tangentially related to the comic, or uncertain suggestions for improving the article. Davidy²²[talk] 03:18, 4 December 2013 (UTC)
Sorry, I wasn't aware of the proper terminology. I'll add my line shortly. Anonymous 05:13, 13 December 2013 (UTC)

Why is there a "(?)" in "Oort Cloud"? 108.162.212.196 02:10, 15 December 2013 (UTC)

Because it's not known if this cloud really does exist. Many objects are assumed to be there at that vast distance to the sun, but that distance is also the reason they could not be detected from earth. Voyager 1, the farthest humanmade object from Earth, will reach that region in many thousand years. --Dgbrt (talk) 21:37, 15 December 2013 (UTC)

Why is Snoop Dogg in space? 108.162.219.223 (talk) (please sign your comments with ~~~~)

Because he's high as shit, man--he's so high, he's the second-furthest any person's ever been from the earth. 108.162.216.76 10:12, 6 February 2014 (UTC)
Diameter of milky way: 100 - 120 kly (Lets call it 110 kly)
Suns distance to galactic centre: 27.2 kly
Distance to edge of galaxy: (0.5*110)-27.2 = 27.8 kly = 263E18

Is my understanding and maths right? --Pudder (talk) 08:08, 11 September 2014 (UTC)
Conversion of pixels to height

Because it is a log graph for the y axis

heightfinal = heightinitial * factor
pixels = Logbase(height)

Using identities to show that a vertical distance on this graph represents a multiplicative change in true distance from the starting point of measure, and that a vertical change (delta) in the same number of pixels represents a corresponding multiplicative factor on total height.

pixelsfinal = Logbase(heightinitial * factor) = Logbase(initial) + Logbase(factor)
pixelsfinal - pixelsinitial = Logbase(factor) = pixelsdelta

Solving for the factor and the base of the log function

factor = basepixelsdelta
base = factor1/pixelsdelta

From the diagram it appears that a change (delta) of 550 pixels represents a change of x*1000000 therefore we can determine the base and determine the multiplicative factor for any change in pixels in the original drawing.

base = 10000001/550 
factor = (10000001/550)pixelsdelta = 1000000pixelsdelta/550

Therefore:

heightfinal = heightinitial * 1000000pixelsdelta/550
The above can be used as an equation to estimate and validate the heights on the diagram, where heightinitial is the height of the reference point in meters, pixelsdelta is the vertical change in pixels on the diagram, and is positive if height increases and negative if height decreases.

108.162.216.149 12:40, 30 September 2014 (UTC)

We just need to be careful that the existing heights (which in most cases have been fairly thoroughly researched) are not replaced by heights determined by their 'pixel position'. --Pudder (talk) 11:16, 1 October 2014 (UTC)
Wrong, the explanation is intended to explain the comic not the real world. Before you get excited though let me explain, we may be on the same page.
Many height values can be determined from external research, and can be shown to be consistent with the graph (e.g. center of the galaxy). In these cases the researched number should be used in the height column, as clearly these numbers represent the authors intent.
There or other cases where the height is labeled. These should always be used as height, as these numbers represent the authors intent. If they are inconsistent with the scale of the graph this should be noted in the description.
There are other cases, such as where the space shuttle disintegrated, where we can research the numbers, but they are inconstant with the graph by more than an order of magnitude. Any large inconsistencies should be noted in the description, but in these cases the graph position, not the actual position should be in the height column, because this is the closest representation we can have to authors intent.

108.162.216.106 11:50, 1 October 2014 (UTC)

Completely agree with the basis that authors intent is priority, and with pretty much everything written above. What I was concerned about was the possibility of someone indiscriminately changing existing height values based solely on its pixel position, with no cross-checking against the real world height. I would venture that the heights of the real items on the graph are intended by Randall to be at their correct positions, but there may be exceptions. I have a personal bias here, in that I spent quite considerable time doing research on many of the heights. That said, I don't in any way expect the height entries I worked on to be taken as correct, simply that there is some degree of reasoning behind the existing heights, and to change them without checking any discrepancies would be reckless. --Pudder (talk) 12:48, 1 October 2014 (UTC)
Personal tools
Namespaces

Variants
Actions
Navigation
Tools

It seems you are using noscript, which is stopping our project wonderful ads from working. Explain xkcd uses ads to pay for bandwidth, and we manually approve all our advertisers, and our ads are restricted to unobtrusive images and slow animated GIFs. If you found this site helpful, please consider whitelisting us.

Want to advertise with us, or donate to us with Paypal or Bitcoin?