explain xkcd - User contributions [en]

1234: Douglas Engelbart (1925-2013)

2019-08-10T19:06:36Z

162.158.154.37: /* Transcript */ - typo fix

{{comic
| number = 1234
| date = July 5, 2013
| title = Douglas Engelbart (1925-2013)
| image = douglas engelbart 1925 2013.png
| titletext = Actual quote from The Demo: '... an advantage of being online is that it keeps track of who you are and what you're doing all the time...'
}}

==Explanation==
The comic describes and references ''{{w|The Mother of All Demos}}'' in honor of {{w|Douglas Engelbart}}, who died on July 2, 2013.

The demo is renowned for the numerous technologies Douglas' team introduced, which the comic references before sliding into apocryphal claims. In the first panel he presents various inventions, including the {{w|Computer Mouse}}. The second panel contains the opening lyrics of Leonard Cohen's song {{w|Hallelujah (Leonard Cohen song)|Hallelujah}}. The "Secret Chord" is a reference to the "Chord Key Set" that he presented at this demo. This relatively obscure device, essentially a piano with five keys, was meant as an alternative to the well-known keyboard. The way he introduces the song is also a reference to musical [https://en.wikipedia.org/wiki/Demo_(music) demo tapes], in which an artist presents a new piece of original music, tying it back to the ''Mother of All Demos'' title. The third is a reference to contemporary internet memes, specifically [http://knowyourmeme.com/memes/subcultures/cats cat pictures] and [http://knowyourmeme.com/memes/yolo YOLO].

The title text is a reference to recent revelations about spying by the United States {{w|National Security Agency}}, which was making headlines when this comic was published. While it might have seemed like an advantage at the time, in a modern context this aspect of the internet appears disturbing.

===The inventions in detail===
Several of the inventions presented by Douglas in 1968 were years ahead of their time, and many would prove to be very influential in the development of personal computing. Some of the technologies demonstrated found success in the following decades, while others did not.

'''Cathode ray tube'''
:The German physicist {{w|Ferdinand Braun}} invented the {{w|Cathode ray tube}}, or CRT, in 1897. The Russian scientist {{w|Boris Rosing}} was the first to use the CRT to receive a video signal. CRT was the most common technology used for television screens and computer monitors in the last century, but has since been succeeded by modern devices such as {{w|OLED}}, {{w|plasma display}}, or the ubiquitous {{w|LCD}}. In the demo, Douglas used CRT monitors to demonstrate video conferencing, as well as collaborative real-time editing.
'''Computer mouse'''
:Douglas did refer to this device as a "mouse", but officially it was named the "X-Y Position Indicator for a Display System". He filed a [http://www.google.com/patents/US3541541?printsec=drawing#v=onepage&q&f=false patent] for this device on June 21, 1967 and received the patent on November 17, 1970. Douglas stated: "I don't know why we call it a mouse. It started that way and we never changed it."
'''Text movement/cloning'''
:This is well known today as "cut, copy and paste". On some early text-based systems, the user moved the cursor to the beginning of the text to be copied, typed <CTRL>+K+B , and then moved the cursor to the end of the copied text and typed <CTRL>+K+E. At the demo, Douglas demonstrated that the same task could be accomplished with the mouse. Today, many people do not use keyboard commands for cut, copy and paste, and instead use the mouse exclusively.
'''Joint file editing'''
:Text editors were in the nascent stage of their development in 1968. Douglas demonstrated the first text editor capable of "joint file editing". The first successful system to implement joint file editing came 15 years later, when {{w|Concurrent Versions System|CVS}} was made available in the middle of the 1980's.
'''E-mail'''
:Although not referred to as e-mail, Douglas demonstrated the exchange of "direct messages", which fulfills a similar role to modern e-mail.
'''File sharing'''
:The demo also demonstrated the exchange of files between users, paving the way for modern file sharing, and the associated legal and ethical debate.
'''Audio codec'''
:Douglas demonstrated a "masking codec" capable of coding and decoding an audio stream. This would eventually lead to the development of the wide variety of modern audio codecs, including the MP3 codec, which was produced by the {{w|Fraunhofer Society}}.

===Concepts that Douglas did not invent===
The third panel exaggerates Douglas's claims to a hilarious and ridiculous level.

'''"Hallelujah"'''
:This song was first released by {{w|Leonard Cohen}} in 1984, sixteen years after Douglas's demo.
'''{{w|Image macro}}s'''
:A form of image with large text, typically in the font "Impact", superimposed over a photograph, typically for humorous effect.
'''{{w|LOLcats}}'''
:The most famous of the image macros, featuring cats.
'''YOLO'''
:As the fictional Douglas states, this is an acronym for "you only live once". It has been around for at least a century, but in 2011 it saw a huge boost in popularity in both youth culture and internet memes mocking youth culture.

==Transcript==
:San Francisco, December 9th, 1968:
:[We see a figure talking into a headset. It's a fair assumption that it's Douglas Engelbart.]
:Douglas: ...We generated video signals with a cathode ray tube... We have a pointing device we call a "mouse"... I can "copy" text... ... and we have powerful joint file editing... underneath the file here we can exchange "direct messages"...
:[Douglas continues to narrate. Some music is playing.]
:Douglas: ...Users can share files... ... files which can encode audio samples, using our "masking codecs"... The file you're hearing now is one of my own compositions...
:Music: I heard there was a secret chord
:[Douglas continues to narrate.]
:Douglas: ...And you can superimpose text on the picture of the cat, like so... This cat is saying "YOLO", which stands for "You Only Live Once"... ...Just a little acronym we thought up...

==Trivia==
*The full original video of the demo from December 9, 1968 is available at the [http://sloan.stanford.edu/MouseSite/1968Demo.html Stanford] website. The "Chord Key Set" can be found at Clip 13.

{{comic discussion}}
[[Category:Comics featuring real people]]
[[Category:Internet]]
[[Category:Tribute]]
[[Category:Version Control]]

2186: Dark Matter

2019-08-07T15:00:07Z

162.158.154.37: /* Explanation */

{{comic
| number = 2186
| date = August 7, 2019
| title = Dark Matter
| image = dark_matter.png
| titletext = To detect dark matter, we just need to build a bird feeder that spins two squirrels around the rim in opposite directions at relativistic speeds and collides them together.
}}

==Explanation==
{{incomplete|Created by a DARK MATTER SQUIRREL ON A SPINNING BIRD FEEDER. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
In this comic, [[Megan]] and [[Cueball]] are talking about {{w|Dark matter|dark matter}}. Megan states that dark matter's density is 0.3 GeV/cm3. Since Cueball likely does not have a science background, he does not understand what this means, so, to clarify, Megan explains that 0.3 GeV/cm3 equates to one squirrel's worth of dark matter on the Earth. For the last two panels, Cueball conflates this with dark matter actually ''being'' a squirrel for comedic effect, enraging Megan.

The giga-electron-volt (GeV) is a unit of energy that can be converted to a mass using Einstein's formula E=mc^2. It is typically used for subatomic particles, for example the mass of a proton is 0.938 GeV/c^2. However it is frequent to omit the c^2 factor and to represent masses in GeV (or MeV).

This implies a {{w|Squirrel|squirrel}} weighs 580 g [https://www.wolframalpha.com/input/?i=(0.3+(GeV%2Fc%5E2)%2Fcm%5E3)+*+(volume+of+earth)+in+grams], which is a typical mass for individuals among several species of common squirrels.

Here is a reference to a paper that comes up with the dark-matter density of 0.3 GeV/cm3: [https://arxiv.org/abs/1205.4033 On the local dark matter density].

==Transcript==
:[Megan walks with Cueball. She is holding a hand out while telling Cueball something.]
:Megan: Dark matter density in the solar system is around 0.3 GeV/cm3
:Cueball: Is... that a lot?

:[As they continue to walk and talk she spreads her arms out.]
:Megan: In terms of mass, it means the Earth contains one squirrel worth of dark matter at any given time.
:Cueball: Wow.

:[In a frame-less panel Cueball stops while Megan walks past him. Megan is face-palming herself while looking down.]
:Cueball: Is there any way to find out which squirrel it is?
:Megan: No, it's not literally-

:[Cueball holds his hand with one finger up in front of Megan, while she has turned towards him and is holding both arms up, possible with balled fist, as she shouts back at him, shown both with large fat letters and with small lines emanating above her head.]
:Cueball: Oh, that explains why they weigh enough to set off those spinning bird feeders!
:Megan: <big>'''''Dark matter isn't squirrels!</big>

{{comic discussion}}

[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]
[[Category:Squirrels]]
[[Category:Astronomy]]

Talk:1273: Tall Infographics

2019-08-03T18:43:17Z

162.158.154.37:

From 2019 here! I just found this comic and I am shook!

Still nothing.

[[File:Example.jpg]]I'm not really sure how to transcribe an infographic... Sorry. Saibot84 04:17, 4 October 2013 (UTC)
:I tried to expand on it a bit, sorry if it's not the best. ollien 04:20, 4 October 2013 (UTC)
For anyone wondering if the "FORMAT" frequency graph is self-referential to the entire comic... no, or at least not on actual explicit instances of the letters (certainly nowhere near 26 Ts, and even proportionally the As are vastly the most frequent and Fs the ''actual'' least, the rest almost identical), but I wouldn't put it past Randall having taken into account cummulative font-size, or something like that. [[Special:Contributions/178.98.253.80|178.98.253.80]] 07:23, 4 October 2013 (UTC)
:It's by position in the alphabet (F=6, O=15, R=18, M=13, A=1, T=20). [[Special:Contributions/67.183.134.13|67.183.134.13]] 07:38, 4 October 2013 (UTC)
::Gah, I'm an idiot. The "26" should have clued me in. [[Special:Contributions/178.98.253.80|178.98.253.80]] 17:20, 4 October 2013 (UTC)
It's a reference to cellphone screen aspect ratios![[Special:Contributions/121.74.169.237|121.74.169.237]] 10:48, 4 October 2013 (UTC)

I think this comic might be inspired by [http://www.symantec.com/connect/sites/default/files/users/user-2935611/zeroaccess_blog_infographic.png that infographic] which was recently published regarding an attack against a botnet. (At least that was my first association - and I, too, found that graphic a little unsuitable when I saw it in the news) -- [[User:Xorg|Xorg]] ([[User talk:Xorg|talk]]) 12:42, 4 October 2013 (UTC)
:Search for "infographics" at google images and you will find thousands other examples.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 12:50, 4 October 2013 (UTC)

I think there is more to the explanation: Big Data mostly will be analyzed statistically, so we will get diverse diagrams and infographics as result. The trend will be an increase in the number of cases where informationen is presented in this way. Sebastian --[[Special:Contributions/178.26.98.211|178.26.98.211]] 14:23, 4 October 2013 (UTC)

: Note that Big Data is used nowadays as a ''buzzword'', even if you don't have that much data. Remember: if your data cannot be processed by Excel, [http://www.chrisstucchio.com/blog/2013/hadoop_hatred.html it isn't big]. --[[User:JakubNarebski|JakubNarebski]] ([[User talk:JakubNarebski|talk]]) 14:47, 4 October 2013 (UTC)
::More accurately: Just because your data cannot be processed by Excel, that doesn't make it big.--[[Special:Contributions/108.162.216.21|108.162.216.21]] 13:16, 13 December 2013 (UTC)

I read the Venn diagram to mean that data would be either clear OR concise, if you took it literally.[[Special:Contributions/75.120.198.118|75.120.198.118]] 08:38, 6 October 2013 (UTC)gonzo

:I don't think that's quite right. The Venn diagram is intended to be just as superfluously self evident as the other graphics. The set of all things "Clear" intersects with the set of all things "Concise" in the region "And".
[[Special:Contributions/111.69.237.202|111.69.237.202]] 09:06, 7 October 2013 (UTC)

:: it's a Venn diagram? D'Oh! Of course it's a Venn diagram. I thought it was the Mastercard logo! [[Special:Contributions/141.101.104.71|141.101.104.71]] 19:33, 5 November 2018 (UTC)

:: I think you mean "if your data ''can'' be processed by Excel, it isn't big". [[Special:Contributions/121.74.169.237|121.74.169.237]] 00:07, 5 October 2013 (UTC)

:: Or maybe "if your data cannot be processed by Excel, it isn't necessarily big." Because it might really ''be'' big - you wouldn't know. [[Special:Contributions/121.74.169.237|121.74.169.237]] 00:21, 5 October 2013 (UTC)

Another take on infographics: http://www.jwz.org/blog/2011/05/how-to-make-a-shitty-infographic/ --[[User:JakubNarebski|JakubNarebski]] ([[User talk:JakubNarebski|talk]]) 15:40, 4 October 2013 (UTC)

"In the pie chart, the areas represent the proportion of letters in each word." - this isn't right; the area for "will" is three times the size of the area for "be". It could be comparing the number of consonants in each word. {{unsigned ip|86.128.6.174}}
: "will" and "be" are both forms of the verb "to be". "Be" is therefore merely the infinitive, while "will" is both a conjugated form (3rd person singular) and in the future tense. Therefore "will" has three levels of meaning to "be"'s one... ;) [[Special:Contributions/108.162.229.122|108.162.229.122]] 12:49, 22 August 2014 (UTC)

Could the part where Megan is saying "Communicated" to Hairy and Hairy responds with an enthusiastic "Yes!" possibly be a reference to some other infographics about preventing sexual assault by making sure to have consent first? I remember seeing a lot of those around my high school and college, so I could just be assuming this based off my surroundings and whatnot. [[Special:Contributions/173.245.54.45|173.245.54.45]] 07:14, 5 February 2016 (UTC)

I make infographics, myself, and recently have given up and switched from using square, 4:3, or 16:9 to using 3:4 (making the image taller than wide) to deal with the fact that a snowballing proportion of my hypothetical audience is viewing the image on their phone, and can't even easily resize a wide graphic to see the whole thing comfortably...and that the ones who see it on the computer have far greater ability to view an image regardless of its aspect ratio. 
/me sighs — [[User:Kazvorpal|Kazvorpal]] ([[User talk:Kazvorpal|talk]]) 15:30, 16 December 2016 (UTC)

Fortunately, this, like that whole weird thing with the Mayans, is another doomsday prophecy that did not come to pass. [[Special:Contributions/162.158.75.178|162.158.75.178]] 02:09, 18 January 2019 (UTC)
:This is a travesty, we must change wiki to be infographic only [[User:Netherin5|Netherin5]] ([[User talk:Netherin5|talk]]) 18:05, 13 March 2019 (UTC)

Its 2019...--[[User:Realqwerty64|Realqwerty64]] ([[User talk:Realqwerty64|talk]]) 17:32, 13 March 2019 (UTC)
:Comments at the bottom. [[User:Netherin5|Netherin5]] ([[User talk:Netherin5|talk]]) 18:05, 13 March 2019 (UTC)

Talk:2172: Lunar Cycles

2019-07-08T12:33:17Z

162.158.154.37: /* Astrology */

Is it possible that the size of the Earth and the moon are supposed to be comparisons of how big the Earth looks from the moon vs. how big the moon looks from the Earth? {{unsigned ip|172.69.170.88}}
:Why would that have a cycle different from the distance cycle?[[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 20:20, 5 July 2019 (UTC)

Where is the total eclipse of the heart?
Actually, why do we not have a total eclipse of the hart - when all deer are hidden?

A very quick and dirty (probably flawed, until I can plug things into a suitable visualiser to check and/or improve my initial idea) attempt to describe the nature of the square/circle oscilations of the Moon might well be smething like ''|r.cos(θ)−r.sin(θ)|.|sin(t/λ)| + |r.cos(θ)+r.sin(θ)|.|sin(t/λ)| + |r.√(2/π)|.|cos(t/λ)|=k'' ...only then you'd also want to make k a quantity also multiplied by the relative Earth/Moon size cycle. Either way, YMoonMV. [[Special:Contributions/141.101.98.88|141.101.98.88]] 00:41, 6 July 2019 (UTC)
:Isn't the square/circle a reference to rounded corner rectangles. If you increase the corner radius of a square, enough, you get a circle. [[User:SDSpivey|SDSpivey]] ([[User talk:SDSpivey|talk]]) 05:37, 6 July 2019 (UTC)

Does anyone know of a real chart similar to the format of the last panel? That might be a cool thing to link to.
[[Special:Contributions/162.158.75.166|162.158.75.166]] 16:38, 6 July 2019 (UTC)

Did anyone else expect to see "Total Eclipse of the Heart" right after "Total Eclipse of the Sea"? No? Ah, my coat, thank you.[[User:Daemonik|Daemonik]] ([[User talk:Daemonik|talk]]) 09:17, 8 July 2019 (UTC)

== Astrology ==
I think this is primarily an astrology joke. Astrologers often use astronomical cycles (both real and made up) to "predict" future events or explain historic events. By having enough cycles, they can usually come up with results like "skinny jeans are always popular whenever the happy moon is in Pices and wet Mars is in the same Chinese zodiac as Mercury".

There's also possibly an allusion to Fourier transforms. {{unsigned ip|162.158.92.160|03:14, July 6, 2019‎}}

I think this is unlikely - the jokes all hinge on cycles of the moon, and don't reference any dates or other celestial bodies in the way astrology does.
[[Special:Contributions/162.158.154.37|162.158.154.37]] 12:33, 8 July 2019 (UTC)

==Phase x distance and supermoons==
I've been absolutely nerd-sniped by the "Phase x distance" in the bottom diagram. As far as I can figure out, if you multiply phase and distance, you should end up with a new cycle with a period of (29.5 x 27.5) = 811.25 days, which is about 2 years. A supermoon is when a full moon occurs when the Moon is closest to the Earth, so this phase x distance figure is effectively a supermoon detector - that's why supermoons occur at the peaks in Randall's diagram.

But when I looked into supermoons a bit - specifically [https://en.wikipedia.org/wiki/Supermoon#/media/File:Moon_distance_with_full_&_new.png this diagram from Wikipedia] - other sources shows supermoons occurring on a ''yearly'' cycle - we supposedly get them every year. How can that be the case, if the two lunar cycles only synchronize every 2 years? It seems to me like there has to be at least one out of every two years where we get no supermoons at all - ie. the full moon is always coinciding with the moon being furthest away.

I feel like I must have made a mistake or wrong assumption, but I can't figure out what it is. [[User:Hawthorn|Hawthorn]] ([[User talk:Hawthorn|talk]]) 17:15, 6 July 2019 (UTC)
:I figured it out; it turns out that I was simply wrong about how to calculate the length of a combined cycle. This [https://www.desmos.com/calculator/vaj4vapdul graph] shows that the two cycles would coincide every 400 days or so. Still can't figure out what "phase x distance" is meant to represent, though. [[User:Hawthorn|Hawthorn]] ([[User talk:Hawthorn|talk]]) 17:54, 6 July 2019 (UTC)

Talk:1062: Budget News

2017-04-23T00:28:37Z

162.158.154.37:

Shame the hawk didn't go after a war hawk. Iran has been going on for faaar too long. '''[[User:Davidy22|Davidy22]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 13:43, 8 January 2013 (UTC)

This has now happened to Donald Trump http://www.independent.co.uk/news/world/americas/donald-trump-narrowly-escapes-being-attacked-by-a-bald-eagle-on-time-magazine-shoot-a6767501.html [[Special:Contributions/162.158.255.37|162.158.255.37]] 03:45, 14 December 2015 (UTC)
:Yeah but I wouldn't call Trump any kind of eagle. That scene is still hilarious and indicative though, especially since now Bernie Sanders can simply summon small birds to him -Pennpenn [[Special:Contributions/108.162.250.155|108.162.250.155]] 05:33, 30 March 2016 (UTC)
::Of course Trump is some kind of eagle: an ill eagle!

Has anyone else noticed that Black Hat is in the audience? Does anyone else think that that might be a hint as to what's going on? --[[User:XndrK|XndrK]] ([[User talk:XndrK|talk]]) 00:09, 3 June 2016 (UTC)