explain xkcd - User contributions [en]

Talk:552: Correlation

2025-03-11T22:58:09Z

Az1950: Added two points.

It is stated that Cueball is doubting, due to his newly found sceptism, which I believe is incorrect.

By stating that "the class helped", Megan is inferring there is a causal relation between Cueball taking a statistics class and him no longer believing correlation implies causation. However, Cueball is replying "well maybe" to indicate there is only a correlation between them, showing he correctly understood the distinction.
[[Special:Contributions/173.245.53.104|173.245.53.104]] 15:29, 13 May 2014 (UTC)

Another interpretation that explains why the comic is funny is as follows. Cueball replies "well maybe" because he has learned not to infer causation from correlation. But it is also clear that the statistics class caused him to think this way. This pokes fun at a tendency to apply the principle that correlation does not imply causation even when there is direct evidence for causation.
[[Special:Contributions/173.245.52.127|173.245.52.127]]

The way I see it, it's a paradox. [[User:The Cat Lady|-- The Cat Lady]] ([[User talk:The Cat Lady|talk]]) 22:14, 16 August 2021 (UTC)

Technically, this comic, despite its title, isn't about correlation, but association. As Britannica states, "Although the terms correlation and association are often used interchangeably, correlation in a stricter sense refers to linear correlation, and association refers to any relationship between variables." https://www.britannica.com/topic/measure-of-association. (Also, the second comment should be stating that Megan is implying, not that she is inferring. She did infer, but in "stating," she is implying.)

3033: Origami Black Hole

2025-01-04T23:21:35Z

Az1950: The statement "15 orders of magnitude smaller than " would result in a negative number, hence the edit.

{{comic
| number = 3033
| date = January 3, 2025
| title = Origami Black Hole
| image = origami_black_hole_2x.png
| imagesize = 272x480px
| noexpand = true
| titletext = You may notice the first half of these instructions are similar to the instructions for a working nuclear fusion device. After the first few dozen steps, be sure to press down firmly and fold quickly to overcome fusion pressure.
}}

==Explanation==
{{incomplete|Created by a PLANET-SIZED SWARM OF SELF-REPLICATING NUCLEAR POWERED PAPER COMPRESSION ROBOTS - Please change this comment when editing this page. It needs an explanation for the title text. Do NOT delete this tag too soon.}}

This comic shows what at first appears to be an actual page of {{w|origami}} directions, like [https://origami.me/crane/ this one] or [https://origami.guide/origami-animals/origami-rabbits/origami-sleeping-rabbit/ this one], except labeled "How to fold a real origami black hole". The "real" part may be referring to a "fake" origami black hole which would be a piece of origami made to look like a black hole (whatever that means). It seems black-hole-like origami does exist, as created by [https://parchmentandallthingspaper.wordpress.com/2011/11/16/folding/ Richard Sweeney]. The implication is that while the linked origami only resembles a black hole, Randall's instructions indicate a method to physically create a {{w|black hole}} out of origami paper. However, it quickly devolves into nothing other than repeating folds in half. This wouldn't really create a black hole unless one somehow additionally compressed the paper commensurate with its decrease in width and length as alluded to in the title text. Ordinarily it would become impossible long before the 190 folds in half that the instructions require. In fact - assuming a thickness of around 0.1mm the sum of the lengths and width of the paper would need to be around 10^110 meters for it to be possible to fold it 190 times.

The {{w|mathematics of paper folding}} were augmented with [https://web.archive.org/web/20051102085038/http://pomonahistorical.org/12times.htm work by a California high school student in 2001] who wrote equations that [https://web.archive.org/web/20211116013626/http://teachersofindia.org/sites/default/files/folding_paper_in_half.pdf related the size of paper to the maximum number of folds it could make], which has not yet exceeded the low teens in human competition. This could be exceeded by scoring the paper to cut and flatten the outer layers of the folds, but its thickness would immediately surpass its length, and compressing it beyond the size of its fibers would require some way to hold it together.

This comic is likely a reference to the {{w|Schwarzschild radius}} of a piece of paper. The Schwarzchild radius is a characteristic of every object that depends on the object's mass. If an object is compressed into the volume of a sphere with its characteristic Schwarzschild radius, then that object will become a black hole. (More specifically, it will become a {{w|Schwarzschild metric|Schwarzschild black hole}}.) As such, if a piece of paper were folded sufficiently many times so as to fit within its own Schwarzschild radius, it would become a black hole. However, this would require compressing the paper into a flat sheet at every step, otherwise the paper would have a thickness greatly exceeding its Schwarzschild radius.

If we assume standard {{w|origami paper#Kami|kami origami paper}} with a side length of 15cm and a weight of 70 grams per square meter, we get a Schwarzschild radius of 2.339×10^-30 meters corresponding to a mass of 1.575 grams. It follows that, ignoring the paper's thickness, we would need to halve each side length -log2((2×2.339×10-30)/0.15)=94.69 times to fit each side length within the "Schwarzschild diameter" of the paper. Using the square folding technique in the comic, this would take approximately 95*2=190 steps to complete, the exact number given in the comic.
Note that the radius of the resulting black hole is 10 to the negative 15th the size of the {{w|Proton#Charge_radius|charge radius of a proton}}. {{w|Micro black holes|Black holes this small}}, if they can be created at all, are believed to quickly disintegrate by losing energy by {{w|Hawking radiation}}, but this has yet to be proved.

In actual fact, it's not possible to fold a piece of paper this many times, because the amount of paper 'wasted' in each fold [https://web.archive.org/web/20211116013626/http://teachersofindia.org/sites/default/files/folding_paper_in_half.pdf will quickly surpass the length and width of the paper]. For an ordinary letter-sized sheet (A4 or 8.5x11) the maximum number of folds is 7. The [https://www.guinnessworldrecords.com/world-records/494571-most-times-to-fold-a-piece-of-paper world record] for the total number of folds is 12, done with a length of tissue paper 3/4 mile (4000ft, 1219m) long. A group of MIT students demonstrated 13 folds using multiple miles of paper, but had to lay separate pieces together as it made them too thick to tape them. Materials other than paper, such as thin foil, can be folded more times. Not only that but, as the title text alludes to, prior to reaching any creation of a black hole, the pressures generated by the resulting {{w|Nuclear fusion#Confinement in thermonuclear fusion|fusion of its atoms}} must be overcome. Electron and neutron degeneracy pressure would also have to be overcome.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:How to fold a '''''real''''' origami black hole:

:Step 1.
:[A square sheet of paper shown folded in half, with a dashed line going across the middle, and an arrow pointing from one half to the other.]

:[In each step from Step 2. to Step 9., the paper is shown folded in half again and depicted in the same manner as Step 1. The aspect ratio of the sides alternates between 2:1 and 1:1.]
:Step 2.
:Step 3.
:Step 4.
:Step 5.
:Step 6.
:Step 7.
:Step 8.
:Step 9.

:Steps 10-189.
:[Text shown between tall square brackets:]
:Fold paper in half another 180 or so times.

:Step 190.
:[A labeled arrow points to a dot]
:Black hole!

{{comic discussion}}

[[Category:Physics]]

2383: Electoral Precedent 2020

2020-11-12T03:16:09Z

Az1950: /* Explanation */ She's not the first of Indian descent. https://en.wikipedia.org/wiki/Charles_Curtis

{{comic
| number = 2383
| date = November 9, 2020
| title = Electoral Precedent 2020
| image = electoral_precedent_2020-new.png
| titletext = He also broke the streak that incumbents with websites are unbeatable and Delawareans can't win, creating a new precedent: Only someone from Delaware can defeat an incumbent with a website.
}}

==Explanation==
{{incomplete|Created by an UNBEATABLE DELAWAREAN WITH A WEBSITE. Please explain how. Do NOT delete this tag too soon.}}

This comic is an update to [[1122: Electoral Precedent]], adding "broken precedents" for the US presidential elections in 2016 and 2020. The majority of the comic's panels are duplicates from 1122, with the exception of the 2012 panel (modified to show that Obama did in fact break the streak), the 2016 panel (added to reflect the election of Donald Trump), and the two 2020 panels.

The final two panels again show how the 'precedent' have side conditions that influenced these precedents:
* No sitting president who was impeached was even nominated for the office again... until Donald Trump. (Only two other presidents have been impeached. Bill Clinton was impeached, but he was not eligible for re-election due to term limits; before that, Andrew Johnson sought re-election but failed to be nominated at the 1868 Democratic Convention.)
* The last time a challenger beat an incumbent was in 1992 when websites weren't nearly as predominant as now, and Randall assumes the 1992 Clinton campaign did not have a website. By 1996 that had changed and both the incumbent [http://www.livingroomcandidate.org/websites/cg96/ Bill Clinton campaign] and the challenger [http://www.dolekemp96.org/main.htm Bob Dole campaign] had websites that look very simple by today's standards. There is no 'curse' on using websites. {{Citation needed}}

The 2020 election is also precedent-breaking in a few ways that Randall didn't mention:
* Biden received over 76 million votes, the highest ever, beating Obama 2008's previous record of just under 69.5 million votes. The second highest raw vote total was for Trump, with approximately 71.5 million votes, ''also'' beating Obama 2008. Turnout as a percentage of the eligible population was the highest in over a century. Consequently (especially as total population has also been rising), both major parties' raw vote totals smash previous precedents.
* At 78, Joe Biden will be the oldest president ever on the day of his inauguration.
* Biden's running mate Kamala Harris will be the first-ever female vice president, and first Black vice president. A Californian, she'll also be the first Democratic president or vice president from the West.

The title text continues the theme of websites, by stating that no incumbent with a website had ever lost. Also, Biden is the first president from the state of Delaware, thus he broke the "precedent" that Delawareans can't win. Randall then proceeds to combine these 2 facts to create a new precedent: Only Delawareans can defeat incumbents with a website.

==Table of New Broken Precedents==

All original options can be found at [[1122: Electoral Precedent]].

{| border =1 width=100% cellpadding=5 class="wikitable"
|-
! Year !! Broken Precedent !! Explanation !! Validity

|-
|2012
|Democratic incumbents never beat taller challengers. ... Until Obama did. (Updated)
|
|
|-
|2016
|No one has become president without government or military experience. ... Until Trump did.
|
|
|-
|2020?
|No one has won after being impeached. ✓
|None of the three prior presidents who were impeached even ran for re-election. This is the first time this specific condition has even been tested.
|Trump was impeached, did run and has  lost, so this test 'remains' true at this point in history.
|-
|2020?
|No challenger with a website has won. X
|The ''possibility'' of having a website only arose in the '90s and Bill Clinton seems to not have had one when he succeeded Bush Sr. Although websites became increasingly ubiquitous, no president since had ever been defeated by their respective challengers.
|"...until Biden"
(This may be the frame used in future updates.)
|}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:The problem with statements like
:"No <party> candidate has won the election without <state>"
:Or
:"No president has been reelected under <circumstances>"

:<nowiki>★</nowiki> Updated for 2020 ★

:1788... No one has been elected president before. ...But Washington was.
:1792... No incumbent has ever been reelected. ...Until Washington.
:1796... No one without false teeth has become president. ...But Adams did.
:1800... No challenger has beaten an incumbent. ...But Jefferson did.
:1804... No incumbent has beaten a challenger. ...Until Jefferson.
:1808... No congressman has ever become president. ...Until Madison.
:1812... No one can win without New York. ...But Madison did.
:1816... No candidate who doesn't wear a wig can get elected. ...Until Monroe was.
:1820... No one who wears pants instead of breeches can be reelected. ...But Monroe was.
:1824... No one has ever won without a popular majority. ...J.Q. Adams did.
:1828... Only people from Massachusetts and Virginia can win. ...Until Jackson did.
:1832... The only presidents who get reelected are Virginians. ...Until Jackson.
:1836... New Yorkers always lose. ...Until Van Buren.
:1840... No one over 65 has won the presidency. ...Until Harrison did.
:1844... No one who's lost his home state has won. ...But Polk did.
:1848... As goes Mississippi, so goes the nation. ...Until 1848.
:1852... New England Democrats can't win. ...Until Pierce did.
:1856... No one can become president without getting married. ...Until Buchanan did.
:1860... No one over 6'3" can get elected. ...Until Lincoln.
:1864... No one with a beard has been reelected. ...But Lincoln was.
:1868... No one can be president if their parents are alive. ...Until Grant.
:1872... No one with a beard has been reelected in peacetime. ...Until Grant was.
:1876... No one can win a majority of the popular vote and still lose. ...Tilden did.
:1880... As goes California, so goes the nation. ...Until it went Hancock.
:1884... Candidates named "James" can't lose. ...Until James Blaine.
:1888... No sitting president has been beaten since the Civil War. ...Cleveland was.
:1892... No former president has been elected. ...Until Cleveland.
:1896... Tall midwesterners are unbeatable. ...Bryan wasn't.
:1900... No Republican shorter than 5'8" has been reelected. ...Until McKinley was.
:1904... No one under 45 has become president. ...Roosevelt did.
:1908... No Republican who hasn't served in the military has won. ...Until Taft.
:1912... After Lincoln beat the Democrats while sporting a beard with no mustache, the only Democrats who can win have a mustache with no beard. ...Wilson had neither.
:1916... No Democrat has won while losing West Virginia. ...Wilson did.
:1920... No incumbent senator has won. ...Until Harding.
:1924... No one with two Cs in their name has become president. ...Until Calvin Coolidge.
:1928... No one who got ten million votes has lost. ...Until Al Smith.
:1932... No Democrat has won since women secured the right to vote. ...Until FDR did.
:1936... No President's been reelected with double-digit unemployment. ...Until FDR was.
:1940... No one has won a third term. ...Until FDR did.
:1944... No Democrat has won during wartime. ...Until FDR did.
:1948... Democrats can't win without Alabama. ...Truman did.
:1952... No Republican has won without winning the House or Senate. ...Eisenhower did.
:1956... No Republican has won without Missouri. ...Until Eisenhower.
:1960... Republicans without facial hair are unbeatable. ...Kennedy beat Nixon.
:1964... No Democrat has won without Georgia. ...Johnson did.
:1968... No Republican vice president has risen to the Presidency through an election. ...Until Nixon.
:1972... Quakers can't win twice. ...Until Nixon did.
:1976... No one who lost New Mexico has won. ...But Carter did.
:1980... No one has been elected President after a divorce. ...Until Reagan was.
:1984... No left-handed president has been reelected. ...Until Reagan was.
:1988... No one with two middle names has become president. ...Until "Herbert Walker."
:1992... No Democrat has won without a majority of the Catholic vote. ...Until Clinton did.
:1996... No Dem. incumbent without combat experience has beaten someone whose first name is worth more in Scrabble. ...Until Bill beat Bob.
:2000... No Republican has won without Vermont. ...Until Bush did.
:2004... No Republican without combat experience has beaten someone two inches taller. ...Until Bush did.
:2008... No Democrat can win without Missouri. ...Until Obama did.
:2012... Democratic incumbents never beat taller challengers. ... Until Obama did.
:2016... No one has become president without government or military experience. ... Until Trump did.
:2020? No one has won after being impeached. <big>✓</big>
:2020? No challenger with a website has won. <big>X</big>

:[Caption below the comic]
:Congratulations to President-Elect Joe Biden for breaking the website curse!

==Errors==
*This comic seems to have used the same image as [[1122: Electoral Precedent]], and so the original version of this comic had a ghost image of the original 2012 2nd "streak": "No nominee whose first name contains a "K" has lost."

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Statistics]]
[[Category:Politics]]
[[Category:Elections]]
[[Category:Comics featuring politicians]]
[[Category:Comics featuring John F. Kennedy]]
[[Category:Comics with color]]