explain xkcd - User contributions [en]

Talk:2201: Foucault Pendulum

2019-09-13T10:16:28Z

Torax:

I take it the pendulum is somewhere deep underground, which would shield Black Hat from the cataclysmic side effects?
Besides, they have several backup pendulums that while not enough to maintain rotation are sufficient to slow the half enough to preserve life.[[Special:Contributions/108.162.212.149|108.162.212.149]] 20:11, 11 September 2019 (UTC)
:I fear that the use of multiple pendulums to smooth out the catastrophy of stoping the Earth's rotation would probably just cause bits of the Earth to keep going and other bits to stop. Hey! That's plate techtonics! ''Obviously'' there are subtly dampened/purturbed pendula in secret (masonic?) temples all across the world, making all that happen! Someone likely pushed the one in Atlantis too far, one fateful day...
:(BTW, the unsaid catastrophe element reminds me of a classic [https://en.wikipedia.org/wiki/The_Man_Who_Could_Work_Miracles_(story) short story])[[Special:Contributions/162.158.154.31|162.158.154.31]] 15:29, 12 September 2019 (UTC)

If the pendulum could really affect Earth's rotation, Black Hat wouldn't need to stop the pendulum entirely; he'd only need to prevent its plane of oscillation from rotating. Another thought: if the pendulum and Earth's rotation were really bidirectionally linked somehow, there would probably be nothing Black Hat could do to alter the pendulum's plane of oscillation -- any more than he could alter the rotation of the Earth with just one human being's strength. That last thought doesn't seem to be the case within this story, though, or else the final frame's news report wouldn't have happened. [[User:Trueflint|Trueflint]] ([[User talk:Trueflint|talk]]) 20:46, 11 September 2019 (UTC)
:Who says it's the energy from Black Hat's grab specifically? Maybe the magic pendulum just tells a device in the Earth whether or not the planet should be spinning, based on the current state of the pendulum. [[Special:Contributions/172.68.46.167|172.68.46.167]] 08:15, 12 September 2019 (UTC)

Why does the description description Megan as a "professor?" She could just as easily be a teacher, a docent, a scientifically-interested parent, or just a random bystander. 11 September 2019

The sentence "It stays in a fixed plane while the Earth rotates under it." and the correspoding text in explanation are wrong. It would be true only if the pendulum was located on one of Earth's poles. Elsewhere, the plane in which the pendulum moves would still rotate with respect to its surrondings, but slower than on the pole. The rotation speed is proportional to the sine of latitude. At the equator, the plane would stay fixed with respect to its surroundings. See [https://en.wikipedia.org/wiki/Foucault_pendulum#Explanation_of_mechanics Wikipedia].--[[Special:Contributions/162.158.93.207|162.158.93.207]] 23:45, 11 September 2019 (UTC)
:As a Physics teacher, I strongly support this. The fact that a Foucault's pendulum is keeping its oscillation plane constant with respect to an absolute reference frame is a common misconception, it should be mentionned as frequently as possible.--[[Special:Contributions/108.162.229.48|108.162.229.48]] 09:17, 12 September 2019 (UTC)

The Foucault Pendulum in this comic strongly resembles the one in the Franklin Institute in Philadelphia (both in shape and the way it is knocking over the pegs). Perhaps this should also be noted in the trivia section?[[Special:Contributions/162.158.126.46|162.158.126.46]] 05:16, 12 September 2019 (UTC)
:Then list *all* the ones it strongly resembles. Do you think Philadelphia’s is the only one with pegs? I think that is the usual presentation. [[Special:Contributions/172.69.70.107|172.69.70.107]] 10:01, 12 September 2019 (UTC)
:A Google search reveals that nearly all of them have a weight that looks like the one in this comic, and many of them have some sort of pegs to demonstrate the circular motion over the course of a day. To put the location of any of them in the explanation (as it is now) is probably not appropriate. If there is a significant one somewhere in the world (largest, oldest, etc), then maybe we could mention that specific one. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 14:56, 12 September 2019 (UTC)

Do we have anything about resonance transfer being proportional to the difference in mass? [[Special:Contributions/172.68.189.19|172.68.189.19]] 16:20, 12 September 2019 (UTC)

I don't think there's any indication that this comic takes place during a physics lecture. It's more likely that it takes place in a science museum, and this is a museum tour guide explaining the Foucault Pendulum to museum visitors. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 00:16, 13 September 2019 (UTC)

I don't know if it's still the case, but back in the 90s some Earth orientation work was very hush-hush military business. It turns out that really detailed models of how the Earth moves are important for targeting long-range missiles. [[User:Dfeuer|Dfeuer]] ([[User talk:Dfeuer|talk]]) 02:35, 13 September 2019 (UTC)
:Are you suggesting that has some relevance to this comic about the Foucault Pendulum? [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 03:07, 13 September 2019 (UTC)

You really do not want to mess with IERRSS (IRS for short). Also, the pendulum is in an inertial reference frame to what? Can it be used to detect earths rotation around the sun as well, and the solar systems rotation around the galactic core [[User:Torax|Torax]] ([[User talk:Torax|talk]]) 10:16, 13 September 2019 (UTC)

Talk:1950: Chicken Pox and Name Statistics

2018-02-05T16:12:42Z

Torax: /* What's the new disease? */

I think Randall missed an opportunity to do another “make you feel old” joke here, perhaps something like “if your age isn’t on the chart, your doctors probably still thought chicken pox was caused by imbalanced humors or angry gods” or something. [[User:PotatoGod|PotatoGod]] ([[User talk:PotatoGod|talk]]) 15:24, 2 February 2018 (UTC)

Shouldn't the vaccine note have been placed at age 23, not 28, if the vaccine was introduced in 1995? [[User:Rockcell|Rockcell]] ([[User talk:Rockcell|talk]]) 15:28, 2 February 2018 (UTC)
:When do children get their first smallpox vaccine? If that's around three that might be one explanation for the position of the note. Also the vaccine wasn't only used on children born after its introduction, kids that were already a few years old but never had smallpox could still have gotten their shots. [[Special:Contributions/108.162.229.220|108.162.229.220]] 15:52, 2 February 2018 (UTC)

This isn't *smallpox*. Smallpox was eliminated in the middle of the 20th century, so it's weird if anyone gets it. Also: my understanding is that most people who got smallpox died before they got to be old enough to be on any of those graphs.

I found the top graph very hard to interpret, so I've included my interpretation here for posterity: If you are 35 years old, then you were a young child before the vaccine was introduced and probably 100% of the people you knew as a child got chicken pox. If you are 20-25 years old, there's a 50-50 chance that you got the vaccine and, as a result, about 50% of the people you knew as a child got chicken pox. If you are 10 years old, then you more than likely got the vaccine and have a low probably of getting chicken pox. If you are under 5, you probably don't know many other kids. [[Special:Contributions/162.158.62.39|162.158.62.39]] 17:03, 2 February 2018 (UTC)

: We are so used to reading graphs from left to right that this graph, with the inverse time line (current age) and the introduction of vaccines marked, seems to indicate that everyone had chicken pox after the vaccine was introduced, but that it was fairly rare before that. So this might be a stab at the antivaxx movement as well, and their use of warped statistics. [[User:Torax|Torax]] ([[User talk:Torax|talk]]) 11:36, 3 February 2018 (UTC)

Wait, this has nothing to do with confusing correlation with causation, right? The assumption is simply that if most of the kids your age got chicken pox, which is likely if you have certain names, you will consider chicken pox to be normal and common, which seems like a reasonable claim. On the other hand, if the comic hadn't said that, the implication would be that people with certain names cause chicken pox, which would be confusing correlation with causation. -[[Special:Contributions/108.162.219.16|108.162.219.16]] 17:17, 2 February 2018 (UTC)

:I agree, that’s how I interpreted the comic as well [[User:PotatoGod|PotatoGod]] ([[User talk:PotatoGod|talk]]) 18:15, 2 February 2018 (UTC)

:I also agree, if anything this is doing the opposite and assuming no underlying causality between names and chickenpox likelihood, so that the people who get chickenpox at any given time should be distributed randomly amongst all names at prevalent at that time.[[Special:Contributions/162.158.78.184|162.158.78.184]] 19:06, 2 February 2018 (UTC)

:Basically, what he's describing is a two-step correlation (of which only the second one seems causal to me, but this is debatable). First, your first name and its popularity in particular eras leads to an estimation of your age/year of birth. Second, your year of birth and the prevalence of chicken pox shortly after this year will influence whether you think chicken pox is normal. --[[User:IByte|IByte]] ([[User talk:IByte|talk]]) 23:14, 2 February 2018 (UTC)

People with all six of those names probably think "Why do I have no less than six names?" --[[User:IByte|IByte]] ([[User talk:IByte|talk]]) 23:17, 2 February 2018 (UTC)

It would be considerably weirder if we didn't have teeth. [[Special:Contributions/172.68.25.106|172.68.25.106]] 11:39, 3 February 2018 (UTC)

: I disagree. [[User:Trevor|Trevor]] ([[User talk:Trevor|talk]]) 00:37, 4 February 2018 (UTC)

I thought the joke was that fewer people who have a rare name get chicken pox than those with a common name, therefore people with said rare name must be resistant. --[[Special:Contributions/172.69.33.167|172.69.33.167]] 12:41, 3 February 2018 (UTC)

I'm 30 and looking at my high school yearbook there was 1 Logan, 2 Brians, and 5 Sarahs. None of the other names appear. That makes the 2nd graph pretty accurate. However, I managed to avoid the chicken pox, so I got the vaccine when I was 12.[[Special:Contributions/108.162.237.40|108.162.237.40]] 15:41, 3 February 2018 (UTC)

== Logan ==

Logan becomes less popular at age 30. Coincidence? --[[Special:Contributions/162.158.126.10|162.158.126.10]] 19:09, 2 February 2018 (UTC)
: That just means that Logan started getting popular as a name about 30 years ago. So maybe their parents grew up watching X-Men cartoons on TV in the late 1970's through the 1980's? [[User:Nutster|Nutster]] ([[User talk:Nutster|talk]]) 20:40, 2 February 2018 (UTC)
:: I’m pretty sure the above was referencing the “Logan’s Run” and “Logan’s World” TV series and books, not X-men. It was meant as a joke.[[Special:Contributions/162.158.78.16|162.158.78.16]] 04:54, 3 February 2018 (UTC)

== Grammar ==

OK. Grammar check now. How many people actually have all six of these names? Can't be too many of them.
And is it only men who have this issue?
:Statistically... None. So there's your unique new baby name! [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 22:42, 3 February 2018 (UTC)

If you were to compare the top 1000 'male' and 'female' given (first) names in the USA, you'd see a number of cross-overs (such as Mary on the male list, Robert on the female list). [http://names.mongabay.com Most Common First Names and Last Names in the U.S.] [[User:These Are Not The Comments You Are Looking For|These Are Not The Comments You Are Looking For]] ([[User talk:These Are Not The Comments You Are Looking For|talk]]) 02:32, 4 February 2018 (UTC)

Another grammar check: I'm struggling to understand "fraction of kids my age". My age is 41; there are no kids my age, only adults.
: But those people age 41 now where kids around 40 years ago. [[User:LordHorst|LordHorst]] ([[User talk:LordHorst|talk]]) 08:20, 5 February 2018 (UTC)
: Isn't everybody someone's kid? Or is there a distinction between "kid" and "child" in such kind that the former addresses small humans of young age whereas the latter describes people who are descendants from someone else? I always assumed "kid" was just informal (or maybe an American English thing?). I don't know - I'm no native speaker and in German language both is "Kind" [[User:Elektrizikekswerk|Elektrizikekswerk]] ([[User talk:Elektrizikekswerk|talk]]) 11:56, 5 February 2018 (UTC)

== Chickenpox Parties ==

As a parent with five children born between 1980 and 1988 before the chickenpox vaccine was available, I recall a phenomena called ''Chickenpox Parties''. If you had a preschooler and heard about a neighbor's child who had the chickenpox, you would arrange a playdate with sick child so that your child would catch the disease young and then be ''inoculated'' against catching it later when it was believed to have worse prognosis. Apparently this is no longer in fashion. See this article [https://www.parents.com/health/vaccines/chicken-pox/chickenpox-parties/] So the joke could be rewritten, "People named 'Sarah' and 'Brian' are more likely to have been invited to a chickenpox party than people named 'Logan' and 'Harper'." P.S. one of my 5 is named Sarah and none are named Logan or Harper. [[User:Rtanenbaum|Rtanenbaum]] ([[User talk:Rtanenbaum|talk]]) 13:44, 4 February 2018 (UTC)

== What's the new disease? ==

I'm 30, and absolutely everyone I knew eventually caught chickenpox (and then I even caught shingles, as a statistically improbable teenager). I even have a small scar/blemish from it on my torso. The idea that it's been practically eliminated is fantastic. What diseases do parents worry about these days? --[[Special:Contributions/172.68.141.196|172.68.141.196]] 21:32, 4 February 2018 (UTC)
: A.I.D.S., maybe? *wink* [[Special:Contributions/172.68.143.48|172.68.143.48]] 23:57, 4 February 2018 (UTC)
: Unfortunately too many parents worry about autism from vaccines, despite there being no indication of any risk what so ever. So in some areas these diseases are making a come back. [[User:Torax|Torax]] ([[User talk:Torax|talk]]) 16:12, 5 February 2018 (UTC)

Talk:1950: Chicken Pox and Name Statistics

2018-02-03T11:36:26Z

Torax:

1890: What to Bring

2017-09-15T09:24:01Z

Torax: Filled in one case that had been omitted.

{{comic
| number = 1890
| date = September 15, 2017
| title = What to Bring
| image = what_to_bring.png
| titletext = I always figured you should never bring a gun to a gun fight because then you'll be part of a gun fight.
}}

==Explanation==
{{incomplete|Bare necessities, could use elaboration. Do NOT delete this tag too soon.}}

A graph based on variations of the phrase "never bring a knife to a gun fight", an idiom usually attributed to either {{w|Elmer Keith}} or ''{{w|The Untouchables (film)|The Untouchables}}''.

The second part of the graph is based on reactions to an {{w|Class B fire|oil fire}}, which should be extinguished by removing the oxygen (such as by covering it with a lid). Attempting to apply water to an oil fire will result in a large, potentially dangerous flame.

* If you bring a knife to a knife fight, you will be evenly matched with your opponent.

* If you bring a knife to a gunfight, you will be at a perilous disadvantage.

* Attempting to fight a wood fire with a knife will lead to you being burned.

* Attempting to fight an oil fire will lead to you being burned, in addition to causing metallic scrapes.

* Bringing a gun to a knife fight will leave your opponent at a perilous disadvantage.

* Bringing a gun to a gunfight will leave you {{w|Mexican standoff|evenly matched with your opponent}}.

* Shooting either a wood or an oil fire is an ineffective way of extinguishing them.{{Citation needed}}

* Splashing either a knife-wielder or a gunman with water will serve only to agitate your opponent.

* Wood fires are best extinguished with a well-aimed splash of water.

* Pouring water on an oil fire is notorious for creating huge fireballs, aggravating the situation even more.

* Attempting to put a lid on the head of a knife-wielder or gunman will probably not help matters, as it may only serve to agitate said knife-wielder. There's a possibility that your attacker may be momentarily stunned by the surrealism of the situation, but even that will only buy you about a ten-foot running start.

* Trying to put out a wood fire with a lid would require a lid bigger than can possibly be considered 'brought with'.

* An oil fire is best extinguished by cutting it off from oxygen; stovetop oil fires generally spawn in cooking pans, which often come with lids suited to making an airtight seal.

The title text makes the observation that bringing a gun to a gunfight only raises your status from 'civilian' to 'combatant'.

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

{{comic discussion}}