explain xkcd - User contributions [en]

Talk:1531: The BDLPSWDKS Effect

2015-06-03T00:06:22Z

199.27.128.106:

Doesn't the reference to the "Doppler" effect refer to the fact that the Doppler effect may distort the meaning of words in a tonal language, thus making it harder to perceive the word being shouted out of the firetruck? [[User:A-jay|A-jay]] ([[User talk:A-jay|talk]]) 07:52, 29 May 2015 (UTC)

: I thought this too - tonal languages will inevitably suffer more from Doppler distortion than non-tonal ones, so it's going to take the listener longer to react to it. Obviously, that's not the sole cause for the delay with the BDLPSWDKS effect, but it's surely a contributing factor. [[User:Bish|Bish]] ([[User talk:Bish|talk]]) 11:22, 29 May 2015 (UTC)

I think it is a bit more complex than effect mentioned having an individual referent. It becomes complex because the language level, for example, interacts with the physics level. (I think this is the joke, that such random effects from different fields can actually interrelate in some bizarre scenario) A tonal language would be much more susceptible loss of meaning due to blue shift from the doppler effect than a nontonal language. Shouting red is also probably a reference to the 'red-shift' in the doppler effect, which, depending on the speed of the truck may distort the sound the shout or make it unintelligible. At sufficient speed, this would also distort the actual color of the firetruck, which is a topic Randall discussed in one of the What-If's about traffic lights and should probably be linked here. --[[User:MareCrisium|MareCrisium]] ([[User talk:MareCrisium|talk]]) 08:15, 29 May 2015 (UTC)

: I thought of the red being a redshift as well, but what the heck is "GREEN" then (rather than "BLUE")? [[User:Odysseus654|Odysseus654]] ([[User talk:Odysseus654|talk]]) 09:05, 29 May 2015 (UTC)

: Colors undergoing a red-shift move through the whole spectrum in sequence. Green is in the middle. Red-shifts happen when something is moving away from you, and blue-shifts happen when something is moving toward you, (although sometimes the more common term red-shift is used to describe both effects in casual context) but neither means that they thing turns red or blue. They mean that the color moves toward the red or blue side of the spectrum, from the (somewhat arbitrary) "middle" which is usually depicted as green. If the firetruck is coming toward the observer, they would be experiencing a blue-shift. If the fire truck is red, and moving very fast toward the observer, the apparent color would move toward the other end of the spectrum, but it may not be moving fast enough to get all the way to blue. Randall already did the calculations for a what if about the speeds necessary to change from red to green in an question about stoplights. --[[User:MareCrisium|MareCrisium]] ([[User talk:MareCrisium|talk]]) 00:06, 2 June 2015 (UTC)

I wonder if the reference to whether the language has a word for "firetruck" is a Sapir Whorf reference? If there's no word for firetruck, the listener (victim?) is likely to be more confused by the situation than a listener who can at least recognize what kind of vehicle is about to kill him/her (Curses! There's no sexless personal pronoun in this language!) So the reaction time of the first person is likely to be longer than that of the second person.
:"They/them/etc." has been the accepted sexless personal pronoun for a long time (in the order of centuries), even in the singular. The only people who say you shouldn't use it for such a purpose are the same ones who say you shouldn't split an infinitive despite it having been acceptable for centuries, simply because it's impossible to split infinitives in Latin. --[[Special:Contributions/141.101.99.109|141.101.99.109]] 19:42, 29 May 2015 (UTC)
::"...simply because it's impossible to -- in Latin -- split infinitives."[[Special:Contributions/108.162.219.165|108.162.219.165]] 19:10, 2 June 2015 (UTC)larK

There's a whole class of psychology experiments (with both human and animal subjects) that uses reaction-time as a measure of degree of understanding in various situations. Is this effect named after a famous experimental psychologist? If so, Randall may have to issue an update to this cartoon... {{unsigned|Ribbit}}

If you think English has no sexless personal pronoun you *clearly* haven't read comic 145. Ahem... --[[User:MareCrisium|MareCrisium]] ([[User talk:MareCrisium|talk]]) 08:49, 29 May 2015 (UTC)

: Off topic, but I agree 'them' is a sufficient pronoun in this case, since you've already specified the singular 'listener'. [[User:Bish|Bish]] ([[User talk:Bish|talk]]) 11:22, 29 May 2015 (UTC)

Might the comic also involve the game Red Light, Green Light. In the firetruck version of the game, firetrucks don't stop for red lights. There's more to it than that, but you can google around for it because I don't want to post about that... [[Special:Contributions/199.27.128.106|199.27.128.106]] 00:06, 3 June 2015 (UTC)

To the best of my knowledge, the Bernoulli effect is, in fact, responsible to the aerodynamic lift. While it is correct that most people trying to explain aerodynamic lift use an incorrect explanation, the incorrect part has nothing to do with Bernoulli, as implied by the explanation. [[User:Shachar|Shachar]] ([[User talk:Shachar|talk]]) 09:53, 29 May 2015 (UTC)

The Bernoulli effect describes how pressure distribution changes with speed, and needs to be understood if you want to fully grasp all the science behind it. That being said, there isn't an intuitive way to grasp how airspeed varies across a wing's surface which ultimately means that any accurate explanation dependent on the Bernoulli effect goes well beyond the scope of a layperson's understanding. It's better to note that wings are tilted to push the airflow downward and for every action their's an equal and opposite reaction.([[User talk:Some Guytalk]]) --[[Special:Contributions/108.162.238.182|108.162.238.182]] 11:36, 29 May 2015 (UTC)
:Um, I'll give you half points – it depends on what type of wing you're talking about. You can have a "high lift" type wing fly straight and level and still provide plenty of lift. But a low chord wing (eg "fighter jet style") more greatly depends on forward speed and angle of attack to stay up than the lift provided by the wings. Needless to say, airplanes make people think - and too often the more people think about them, the more confused they get. [[User:Jarod997|Jarod997]] ([[User talk:Jarod997|talk]]) 13:10, 29 May 2015 (UTC)

There's a difference between saying this is how wings generate lift and this is the only factor in the equation. On top of which angle of attack is not defined by the zero lift angle. that being said, every scrap of airfoil data I've ever seen shows a proportional relationship between (angle of attack - zero lift angle of attack) and CL (and by extension lift). Is that everything a professional needs to know about aerodynamics? Far from it. Is it an adequate explanation for laypeople? As far as I'm concerned, yes.--Someguy[[Special:Contributions/173.245.54.156|173.245.54.156]] 20:57, 29 May 2015 (UTC)

"The Peltzman effect refers to how regulations intended to increase safety are ineffective or counterproductive. This is likely referenced by the observer responding to a dangerous situation more slowly if the language he is warned in has a word describing the object he's in danger from ("firefighter") than if the language didn't." The comic states that the person reacts more *quickly* if the language has a word for firefighter... {{unsigned ip|173.245.48.150}}

: I think it's actually about how the firefighter has gotten himself into a dangerous situation due to the feeling of safety he has from being in a modern firetruck, since a major case of the Peltzman effect is that increased car safety leads us to drive at higher speeds. The innocent pedestrian is less safe because the firefighter is driving more recklessly. [[User:Not-my-username|Not-my-username]] ([[User talk:Not-my-username|talk]]) 16:10, 29 May 2015 (UTC)

He totally could've added the McGurk effect in there. Just saying. [[Special:Contributions/108.162.237.181|108.162.237.181]] 15:37, 30 May 2015 (UTC)

Isn't part of the Doppler joke the fact that it is a fire truck, as emergency vehicle sirens are very often used as an example of the Doppler effect?
[[Special:Contributions/141.101.98.159|141.101.98.159]] 13:18, 30 May 2015 (UTC)

Is there a name for the law that states "red ones go faster"? I believe that too was referenced, but possibly not by name. [[Special:Contributions/198.41.238.46|198.41.238.46]] 19:59, 1 June 2015 (UTC)

Saw a nice post on this before I actually saw the comic, and came here to create a reference to it: http://languagelog.ldc.upenn.edu/nll/?p=19252 ... for extra commentary. [[User:Jadawin|Jadawin]] ([[User talk:Jadawin|talk]]) 21:44, 2 June 2015 (UTC)

And then I read that link's comments to the end, and saw a link here! Circularity achieved! [[User:Jadawin|Jadawin]] ([[User talk:Jadawin|talk]]) 21:48, 2 June 2015 (UTC)

665: Prudence

2014-05-31T00:49:15Z

199.27.128.106: /* Explanation */

{{comic
| number = 665
| date = November 20, 2009
| title = Prudence
| image = prudence.png
| titletext = Moments later, the White Witch rolls up and, confused, tries to tempt the probe with a firmware upgrade.
}}

==Explanation==
This comic references the fantasy novel series "{{w|The Chronicles of Narnia}}" by {{w|C. S. Lewis}}. In the first book, four children discover the fictional world of Narnia which can be accessed through a wardrobe.

The comic mocks at the imprudent behaviour shown by the protagonists of the novel, who enter the world of Narnia without knowing anything about its dangers. In the comic, Megan discovers the magical wardrobe while playing {{w|hide-and-seek}}. Unlike the original characters, Megan does not precipitately set foot into Narnia. Instead, she fetches her technical equipment and sends a remote-controlled probe through the wardrobe door in order to sound the situation first. The probe can be seen in the last panel, encountering {{w|Mr. Tumnus}} the faun with an umbrella at a lamppost in a snowy wood. This picture is the first impression of Narnia in the novels and was apparently Lewis' original idea for the series.

The {{w|White Witch}} mentioned in the title text is the main antagonist in the novel. She originally lures one of the protagonists with a hot drink and Turkish Delight. In the scenario displayed in the comic, she tries to tempt the probe with a firmware update accordingly.

Megan takes a scientific approach to Narnia again in [[821: Five-Minute Comics: Part 3|a later comic]].

==Transcript==
:[Megan is running towards a closed wardrobe.]
:Someone off-panel: Everyone hide! 99... 98... 97...

:[Megan opens the wardrobe.]
:Wardrobe: click

:Megan, looking inside: !!!

:[Megan looks thoughtful.]

:[Megan walks away.]

:[Megan returns with an armful of electronics.]

:[Megan is kneeling, typing on a laptop, which has a cord extending into the wardrobe.]

:[A robotic probe is approaching Mr. Tumnus, the faun, under the lamppost in narnia.]

{{comic discussion}}
[[Category:Comics featuring Megan‏‎]]

Talk:1372: Smartwatches

2014-05-23T20:07:31Z

199.27.128.106: 2500 lives on

I like how much detail Randall put into the damage of the smartphone and smartwatches.<small>[[User:MrGameZone|0100011101100001011011010110010101011010011011110110111001100101]] ([[User talk:MrGameZone|talk page]])</small> 09:44, 23 May 2014 (UTC)

About the transcript, it seems that I added one at the same time someone else did. I like mine better, but I won't be offended if someone else changes it back to the first revision. Also, feel free to re-format.[[User:Jarod997|Jarod997]] ([[User talk:Jarod997|talk]]) 13:19, 23 May 2014 (UTC)

:I am reminded of this:
:http://thedoghousediaries.com/4974
:...even so, I still would like a Samsung SWatch Note III complete with a watch app (downloaded by the Play Store or F-Droid, of course)! [[User:Greyson|Greyson]] ([[User talk:Greyson|talk]]) 14:55, 23 May 2014 (UTC)

Maybe it's just me, but the explanation regarding the */# keys on Bell phone seems irrelevent. There's nothing inherent about those keys that make a comparison to cellular phones logical, at least not that I'm aware of.--[[Special:Contributions/108.162.216.61|108.162.216.61]] 16:35, 23 May 2014 (UTC)

I question the assumption that the smartwatches are working. The watch keeps displaying the time of 10:13. Even if it had just turned 10:13 I don't think the entire mod could be done in sub 60 seconds. That said, I love the reuse of the sawn screen protector to protect the screen on the smartwatches.

The phone mentioned was one of the earliest ([http://xkcd.com/1368/ One of]) to present the # and * keys and the format has been unchanged since the implementation of cellular phones. It could be argued that the user has the same presented interface for dialing as on cellular phones so modding a 2500 should be completely reasonable.
[[Special:Contributions/199.27.128.106|199.27.128.106]] 20:07, 23 May 2014 (UTC)

1371: Brightness

2014-05-21T07:26:14Z

199.27.128.106: /* Explanation */

{{comic
| number = 1371
| date = May 21, 2014
| title = Brightness
| image = brightness.png
| titletext = Recently, some exoplanet astronomers have managed to use careful analysis of reflected light to discover Earth during the day.
}}

==Explanation==
[http://en.wikipedia.org/wiki/Exoplanet Exoplanets] are planets outside of our solar system, and exoplanet astronomers are astronomers who attempt to discover and study such planets.

In the comic, Megan is using a common exoplanet [http://en.wikipedia.org/wiki/Exoplanet#Indirect_methods discovery technique] to discover a planet (Earth) around a nearby star (the Sun). When a planet passes between an observing astronomer and a star the planet will block some of the light coming from that star causing it to appear dimmer for some amount of time. When the Earth does this, we call it [http://en.wikipedia.org/wiki/Night Night]. By observing that the the Sun's brightness at night has decreased (by 100%) compared to daytime, Megan correctly concludes that it is orbited by at least one planet (the Earth).

The title text alludes to using more complicated techniques to look observe light reflected off of small, dark planets like the Earth. For example, detecting [http://en.wikipedia.org/wiki/Methods_of_detecting_exoplanets#Polarimetry polarized light] reflected from the planet's atmosphere. Since these require light from the star to reflect off of the planet, it's easier for us to image the Earth directly during daylight hours. Observing the light that reflects off of the Earth is in fact how we see everything around us.

More details at: http://en.wikipedia.org/wiki/Methods_of_detecting_exoplanets

==Transcript==
:[Megan is standing on a black (night-time) background, staring at the ground.]
:Megan: Based on this decrease in the star's brightness, I believe it is orbited by at least one planet.

:Exoplanet Astronomers At Night

{{comic discussion}}

1371: Brightness

2014-05-21T07:18:35Z

199.27.128.106: /* Explanation */

{{comic
| number = 1371
| date = May 21, 2014
| title = Brightness
| image = brightness.png
| titletext = Recently, some exoplanet astronomers have managed to use careful analysis of reflected light to discover Earth during the day.
}}

==Explanation==
Exoplanets are planets outside of our solar system, and exoplanet astronomers are astronomers who attempt to discover and study such planets. One method of discovering exoplanets is detecting fluctuations in a star's brightness over time. Such fluctuations could be caused by a planet's orbit around the star, partially blocking the light that reaches an observer on Earth. In the comic, the exoplanet astronomer is trying to observe the sun through the ground at night, observing that it has decreased in brightness compared to daytime (which it has by 100%). She then rightfully concludes that the star is orbited by at least one planet (the Earth), which is of course true.

The title text refers to another method of discovering exoplanets by detecting light reflected off of them from nearby stars. Observing the light that reflects off of the Earth is in fact how was see everything around us, so one hardly needs to be an exoplanet astronomer to discover the Earth in this way.

This comic shows Megan using a common [http://en.wikipedia.org/wiki/Exoplanet exoplanet] discovery [http://en.wikipedia.org/wiki/Exoplanet#Indirect_methods technique] to discover a planet (Earth) around a nearby star (the Sun). When a planet passes between an observing astronomer and a star the planet will block some of the light coming from that star causing it to appear dimmer for some amount of time. When the Earth does this, we call it [http://en.wikipedia.org/wiki/Night Night]

The title text alludes to using more complicated techniques to look observe light reflected off of small, dark planets like the Earth. For example, detecting [http://en.wikipedia.org/wiki/Methods_of_detecting_exoplanets#Polarimetry polarized light] reflected from the planet's atmosphere. Since these require light from the star to reflect off of the planet, it's easier for us to image the Earth directly during daylight hours.

More details at: http://en.wikipedia.org/wiki/Methods_of_detecting_exoplanets

==Transcript==
:[Megan is standing on a black (night-time) background, staring at the ground.]
:Megan: Based on this decrease in the star's brightness, I believe it is orbited by at least one planet.

:Exoplanet Astronomers At Night

{{comic discussion}}

1371: Brightness

2014-05-21T06:59:37Z

199.27.128.106: /* Transcript */

{{comic
| number = 1371
| date = May 21, 2014
| title = Brightness
| image = brightness.png
| titletext = Recently, some exoplanet astronomers have managed to use careful analysis of reflected light to discover Earth during the day.
}}

==Explanation==
{{incomplete|Created by a BOT - Please change this comment when editing this page.}}

==Transcript==
:[Megan is standing on a black (night-time) background, staring at the ground.]
:Megan: Based on this decrease in the star's brightness, I believe it is orbited by at least one planet.

:Exoplanet Astronomers At Night

{{comic discussion}}

809: Los Alamos

2014-02-02T01:48:29Z

199.27.128.106: /* fixed misspelling */

{{comic
| number = 809
| date = October 22, 2010
| title = Los Alamos
| image = los_alamos.png
| titletext = The test didn't (spoiler alert) destroy the world, but the fact that they were even doing those calculations makes theirs the coolest jobs ever.
}}

==Explanation==
This comic refers to the {{w|Manhattan Project}} at {{w|Los Alamos, New Mexico}}, where in 1945 their development of the first nuclear weapon had progressed to the point that they were going explode "The Gadget" at {{w|Trinity Site}}. There was genuine concern that some unexpected result was possible, including the scenario about the atmosphere igniting. The scientists were almost certain that it would either work as expected, or just be a dud, but were unable to rule out several other scenarios. The test proceeded, and it worked as expected.

The joke part at the end is a reference to a common {{w|Mnemonic}} device for basic {{w|Trigonometric}} functions, namely identifying the relationships of ''sine'', ''cosine'', and ''tangent'' with respect to the lengths of a right triangle's edges: '''s'''in = '''o'''pposite over '''h'''ypotenuse, '''c'''os = '''a'''djacent over '''h'''ypotenuse, and '''t'''an = '''o'''pposite over '''a'''djacent (in other words, SOH CAH TOA.) "Steve" becomes concerned by the seriousness of the situation, and wants to make sure that he has not made a mistake on stuff that should be ''very'' elementary to a scientist in his position.

"Now I am become Death, destroyer of worlds." – {{w|Robert Oppenheimer}}, Lead scientist on bomb project, quoting Hindu scripture after the successful test.

==Transcript==
:[Three stick figures stand in front of a few graphs and scientific looking pictures. One of them has hair.]
:Los Alamos, 1945...
:Cueball: We have a decision. If we've done our math right, this test will unleash heaven's fire and make us as gods.
:Cueball: But it's possible we made a mistake, and the heat will ignite the atmosphere, destroying the planet in a cleansing conflagration.
:Steve: Wow. Um. Question: Just to double-check - although I'm 99% sure-
:Steve: Is it "SOH CAH TOA" or "COH SAH TOA"?
:Cueball: Oh, for the love of... can someone redo Steve's work?
:Right figure: I don't want to do the test anymore.
{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Math]]