explain xkcd - User contributions [en]

1702: Home Itch Remedies

2016-07-05T02:32:01Z

108.162.215.103: /* Explanation */ mosquitoes need water

{{comic
| number = 1702
| date = July 4, 2016
| title = Home Itch Remedies
| image = home_itch_remedies.png
| titletext = In my experience, mosquitos and poison ivy are bad, but the very worst itch comes from bites from chiggers (Trombicula alfreddugesi). They're found across the American south and great plains, so the best home remedy is to move to Iceland.
}}

==Explanation==
{{incomplete|Basic transcript. Please improve on it.}}

Bug bites, such as mosquito bites, are itchy. Home remedies are often ineffective, and in some cases very complicated -- think of the number of suggestions you have got on how to cure hiccups. In this case [[Cueball]]'s suggesting turns out to be insanely complicated, involving finding rare French orchids. In this case [[Megan]] is not actually interested in trying out a complex home remedy, but really just wants sympathy.

The suggested remedy is a mix of many popular home remedies such as :
* Taking a hot shower: supposedly to stimulate nerve endings, it can also destroy some toxins
* Applying vinegar: supposedly effective on mosquito bites
* Applying ice: numbs the pain, more commonly used on bruises
* Using aspirin: as a anti-inflammatory drug, aspirin may have an effect on itches, although it may cause more itches rather than provide relief.
* Tea and "rare French orchid": Orchids, like many other plants, are commonly used in traditional medicine to cure various ailments, and tea is a common route of administration.

Megan's answer is a {{w|sarcastic}} comment stating that her own family home remedy is to keep scratching until the skin falls off -- which is a natural tendency to do, although not until the skin literally falls off, and hence it is not a home remedy but a natural reaction.

The title text refers to {{w|chigger|chiggers}} or {{w|Trombicula alfreddugesi}} as the worst source for itches. But in fact only at larval stages this mites are parasitic. A move to the northern region of this world like Iceland would be a perfect cure because those parasites exist only in warmer southern regions (similarly, since mosquitoes lay their eggs in water, moving to a dry place with no water usable by mosquitoes would be a "cure" for mosquito bites). Chigger refers also to the chigoe flea or "jigger", {{w|Tunga penetrans}}, a parasitic flea which also leads to bad itching. But [[Randall]] explicitly mentions the mites ''Trombicula alfreddugesi''.

==Transcript==
:[Megan and Cueball stand together while Megan scratches her itches.]
:Megan: Argh, bug bites are the ''worst''. I shouldn't scratch, but... so itchy.
:Cueball: Oh, you know what's great for that?

:[Zoom-in to Megan's head. Cueball is off-panel.]
:Megan: No, don't tell me. Everyone always has weird home remedies that never work. I just want sympathy.
:Cueball: No, this one isn't weird, I promise. It really helps!

:[Zoom-out to Megan and Cueball. Megan is still scratching.]
:Cueball: First, take a hot shower. Then dip some ice cubes in vinegar and use them to crush one baby aspirin. Then make some tea, and...

:[Megan walks away while Cueball looks at her.]
:Cueball: ...then, you need a rare French orchid-
:Megan: I'm going to try a different home remedy where I complain a lot and scratch until my skin comes off.
:Cueball: Sounds effective.
:Megan: It's an old family trick.

{{comic discussion}}

1701: Speed and Danger

2016-07-05T02:14:52Z

108.162.215.103: /* Explanation */ File:speed and dangerFIXED.png link is bad

{{comic
| number = 1701
| date = July 1, 2016
| title = Speed and Danger
| image = speed_and_danger.png
| titletext = NASCAR removed the passenger seats because drivers hated how astronauts kept riding along with them and loudly announcing "Ahh, what a nice and relaxing drive."
}}

==Explanation==
{{incomplete|More on the speed of sport cars and the race cars. How much faster does it feel for a human to see a regular sports car on a high way and then a formula one car. More on why a rocket seems slow?

Also, the File:speed and dangerFIXED.png link doesn't work.}}

In this {{w|scatter plot}} [[Randall]] plots the speed of several vehicles (including people on foot for "normal sports") and how disastrous a crash would be. The punchline is that space {{w|rocket}}s travel so dangerously fast, and crashes are so utterly catastrophic, that it pushes literally every other kind of crash to the "slow and safe" corner by comparison. (A similar punchline was used in the title text of [[388: Fuck Grapefruit]].)

With the plot Randall makes the observation that the danger of a crash is greatly influenced by its speed and highlights the concept of relativity between what we perceive as "fast," normal sports and two different types of racing cars, vs. a much faster vehicle, a rocket during launch. A rocket may appear to ascend slowly (and of course it begins its ascent slowly), but on the way to orbit it ends up moving very fast. But before it reaches the more extreme speed regime it will be far away from the ground (and the casual observer), where there is nothing to compare this speed to as opposed to a race car speeding by a spectator during a race. (Of course rockets are slow compared to the speed of light.)

Apart from the high speed, there is also the altitude to take into account for a rocket launch, and the vast amount of fuel needed to get into orbit, and any sort of catastrophic failure is almost certainly fatal.

Racing cars are often involved in crashes, but at that speed it is possible to construct them so even serious crashes may not be fatal. Although rockets are also made as safe as possible, it is a completely different regime of ''speed and danger'', and the risk of something going wrong during a take off is much higher, and it is impossible to prevent a lethal disaster if the launch fails during the ascent. This results in a much higher mortality rate for each crashed rocket (probably 100%) vs. crashed sports/race cars.

Rocket launches are compared to "normal {{w|sports}}" (presumably meaning people running approximately 25 km/h, and possibly also {{w|polo}} {{w|horse}}s galloping approximately 40 km/h), {{w|NASCAR}} (which reaches speed of 320 km/h), and {{w|Formula One}} (F1), where the fastest race cars go 380 km/h. Although peak speed for an F1 car is higher than NASCAR, the average lap speed is much lower as F1 tracks have slow corners while NASCAR ovals can be negotiated with much less speed variation. It is also arguable whether F1 is more dangerous than NASCAR - there have been fewer fatalities in F1 this millennium, though fewer cars compete and races are of shorter duration.

A rocket launched to reach the {{w|International Space Station|ISS}} needs to match the speed of the space station which moves at 27,600 km/h. A rocket that needs to {{w|Escape velocity|escape}} from Earth needs to reach 40,270 km/h, but so far no humans have escaped. However, the astronauts going to the Moon came close, with {{w|Apollo 10}} setting the {{w|List_of_spaceflight_records#Fastest|speed record}} for manned flights with 39,896 km/h. (It was only about [https://www.quora.com/Why-was-Apollo-10-the-fastest-of-all-the-Apollo-missions 0.4% faster] than the next 7 missions that, in contrast to Apollo 10, were supposed to land on the Moon). The lowest of the rocket speeds mentioned above is still more than 70 times as fast as the highest speed for race cars.

The title text serves to emphasize the point further, as an astronaut (used to the several G's of acceleration during takeoff and overall much higher speeds) would likely find a NASCAR car moving at ~300 km/h paltry compared to what they're acclimated and has supposedly aggravated NASCAR drivers by making a point of saying so. And thus this is used to explain why there are no passenger seats in NASCAR cars, to prevent astronauts from joining the drivers for a nice, slow ride.

Of the many [[:Category:Charts|charts in xkcd]] this one is notable for containing the fewest sample points of any [[:Category:Scatter plots|scatter plots]] in xkcd.

The comic is also (deliberately?) imprecise. Speed and danger do not extend infinitely in both directions. For instance, another way to show the dat would be:
[[File:speed_and_dangerFIXED.png]]

==Transcript==
:[A two-axis diagram with two double headed arrows centered in the middle of the panel. Each arrow is labeled. There are four large dots in the diagram, three close together in the top left corner and one in the bottom right corner. Each dot is labeled.]

:[Y axis:]
:Top: Crashes are safe
:Bottom: Crashes are dangerous

:[X axis:]
:Left: Slow
:Right: Fast

:[Dots from top left to bottom right:]
:Normal sports
:NASCAR
:Formula One
:Rocket launches

{{comic discussion}}

[[Category:Scatter plots]]
[[Category:Sport]]
[[Category:Space]]

113: Riemann-Zeta

2015-06-05T10:13:27Z

108.162.215.103: /* Explanation */

{{comic
| number = 113
| date = June 9, 2006
| title = Riemann-Zeta
| image = riemann-zeta.jpg
| titletext = The graph is of the magnitude of the function with the real value between 0 and 2 and the imaginary between about 35 and 40. I've misplaced the exact parameters I used.
}}

==Explanation==
A prime number is any positive whole number greater than 1 that is only divisible by itself and 1. There are an infinite number of prime numbers, but they are somewhat elusive since there is no known function that yields all prime numbers and only prime numbers. The {{w|Riemann zeta function}} begins with the infinite series of 1/n^s where s is a complex number (i.e., s = x + iy where x>1 and y are real and i is imaginary) and is summed from n=1 to infinity. It is then extended to be defined for all complex numbers, except s=1, by some advanced techniques. As the image text indicates, the graph in the picture is of the Riemann-Zeta function in the complex plane. {{w|Leonhard Euler}} proved that there is a relationship between the Riemann-Zeta function and prime numbers, which explains Randall's statement of the deep ties between the two.

Here [[Randall]] appears to be talking to his significant other, comparing her to prime numbers and himself to the Riemann-Zeta function. It is mathematically correct and quite poetic, until he mentions that his relationship differs from the comparison because "The Riemann-Zeta function couldn't have given you {{w|herpes}}." This implies that he has infected his lover with an incurable venereal disease. The comic effect of an abrupt change in tone like this is known as {{w|bathos}}.

The title text explains that Randall has forgotten the value of the complex number "s" for which he plotted the Riemann zeta function, but the "real" part (the "x" when s is written x+iy) is between 0 (the square root of 0) and +2 (the positive square root of +4), and the "imaginary" part (the "iy" when s is written x+iy) is between about 35i (the square root of -1225) and 40i (the square root of -1600).

==Transcript==
:[A z=fn(x, y) plot, with pointy spikes on the back sloping to a relatively flat front.]

:You are like the prime numbers. Unpredictable turns, unconstrainable. Tantalizingly regular but never quite the same.
:I am like the Riemann-zeta function. A rippled curtain of the imagined and real. Deeply tied with you in ways incomprehensible.
::Although, strictly speaking, The Riemann-zeta function couldn't have given you herpes.

{{comic discussion}}
[[Category:Math]]

Talk:1530: Keyboard Mash

2015-05-28T03:11:30Z

108.162.215.103:

Disagree with the flag: I do not find the explanation "too chatty", nor do I think cutting it to 1/3 the size would be beneficial. (No, I had nothing to do with the writing of it, just thought I'd voice my support of the original author) [[Special:Contributions/108.162.219.165|108.162.219.165]] 21:01, 27 May 2015 (UTC)larK

Spiders. We knew this would happen someday.

So, the plot seems to be that he went outside to deal with his dog, and the spider got inside, perhaps lurking in his room and striking when he sat down at his computer, hence the keyboard smash.
It could be him being taken, or perhaps the spider getting adjusted to the keyboard rather clumsily, what would you see as more feasible?
And from then on, it's the spider typing? [[Special:Contributions/108.162.238.168|108.162.238.168]] 06:23, 27 May 2015 (UTC)

"All your hands" were on the home row? Surely he means *both* hands or all *fingers* - unless he's already aware of the spider? Plot hole? [[Special:Contributions/141.101.99.121|141.101.99.121]] 06:43, 27 May 2015 (UTC)

: Good catch. May be he always was aware he was talking with a spider. And the las comment from the spider is just sarcastic. [[User:Arturotena|Arturotena]] ([[User talk:Arturotena|talk]]) 07:46, 27 May 2015 (UTC)

: Yes, that had me wondering too. Perhaps the spider didn't realise she needed to turn the webcam off? [[Special:Contributions/108.162.250.159|108.162.250.159]] 09:20, 27 May 2015 (UTC)

The comment "I am a normal Human typing with my Human hands." seems like something Beret Guy would say. Perhaps his time with Beret Guy has desensitized Cueball to those kind of comments? [[Special:Contributions/108.162.219.9|108.162.219.9]] 09:08, 27 May 2015 (UTC)
:On the other hand, beret guy wouldn't accuse someone of being "weird" or "bizarre" [[User:Zeimusu|Zeimusu]] ([[User talk:Zeimusu|talk]]) 09:13, 27 May 2015 (UTC)

;Internal skeleton

In the title text, the spider invite to “CHAT ABOUT OUR INTERNAL SKELETONS.” Of course, the spiders, being arachnid, are invertebrate and don't have internal skeletons. Humans have. My guess is the spider is trying to fool the human. :-) [[User:Arturotena|Arturotena]] ([[User talk:Arturotena|talk]]) 07:34, 27 May 2015 (UTC)

Thanks, Mr. skeletal.
[[Special:Contributions/108.162.219.86|108.162.219.86]] 11:08, 27 May 2015 (UTC)

;Number of "Fingers"

It is 7 keys - "fingers" that are used for the smash on the home row. Spiders have 8 legs. Anybody else notice that? lg tier666 [[Special:Contributions/141.101.92.43|141.101.92.43]] 07:44, 27 May 2015 (UTC)

:I count 8 keys: 7 letters and the digit "7". Bit, since the letters are repeated, the spider couldn't press all of the with its legs at the same time. All of this make me think that a spider could be an awesome typist. [[User:Arturotena|Arturotena]] ([[User talk:Arturotena|talk]]) 07:51, 27 May 2015 (UTC)

;Turing test

The spider passed the Turing test. Of course, the test were for machines, not arachnids. [[User:Arturotena|Arturotena]] ([[User talk:Arturotena|talk]]) 07:54, 27 May 2015 (UTC)

;What if?

Coincidentally, or perhaps not, the current "What if?" at http://what-if.xkcd.com/136/ is also spider related. It comes with a health warning: "If you're a serious arachnophobe, you might want to skip this one." :-) . [[User:Gearoid|Gearoid]] ([[User talk:Gearoid|talk]]) 08:09, 27 May 2015 (UTC)

What should be the name of the picture of White Hat? White Hat/Spider or White Hat Chat Avatar or Spider with the acces of White Hats Avatar or spider who seems to be White Hat or Spider who replaced White Hat in the Interweb of better Names I couldn't think of yet. And how do we know, that Cueball is Cueball as well maybe this is the invasion of the spiders who come through the web!! [[User:ẞ qwertz|ẞ qwertz]] ([[User talk:ẞ qwertz|talk]]) 10:32, 27 May 2015 (UTC)

: https://www.pinterest.com/pin/310959549243301172/ That is all. - [[User:Frankie|Frankie]] ([[User talk:Frankie|talk]]) 11:51, 27 May 2015 (UTC)

;Possible reference by the title?
{{w|Monster_Mash|A keyboard '''mash''' by a '''monster'''ous spider...}} {{unsigned ip|141.101.99.110}}

; Where's your dog now?

Maybe the dog keeps barking because of the Spider. We should totally think of many different ways, how the spider got inside the house and when.
[[User:ẞ qwertz|ẞ qwertz]] ([[User talk:ẞ qwertz|talk]]) 10:12, 27 May 2015 (UTC)

The dog is probably a reference to Terminator 2 where a barking dog reveals the terminator identity. [[Special:Contributions/141.101.98.222|141.101.98.222]] 12:45, 27 May 2015 (UTC)

[[wikipedia:On_the_Internet,_nobody_knows_you%27re_a_dog|On the Internet, nobody knows you're a dog.]] [[Special:Contributions/108.162.254.131|108.162.254.131]] 16:29, 27 May 2015 (UTC)

;Keystroke Dynamics
I see a hint to keystroke dynamics in this comic, which is being increasingly used to assert someone's identity online. [[Special:Contributions/198.41.230.68|198.41.230.68]] 16:55, 27 May 2015 (UTC)xquestion

Back 30+ years ago I had an Apple II+ with a keyboard that did EXACTLY this. Every time you "keyboard mashed", there were odd "7"s and "5"s appearing where none should be. Aside from this comic now having creepy undertones for me, personally, this seems like a factoid about ancient keyboards that's worthy of a "Did You Know?" bullet. What do you guys think? [[Special:Contributions/108.162.250.193|108.162.250.193]] 02:36, 28 May 2015 (UTC)

;Spiders FTW![[Special:Contributions/141.101.104.154|141.101.104.154]]

I am so glad that spiders can only grow to about 5-8 inches before physics stop them. Though prehistoric times were awesome, they had dragonfly bodies the length of thighs with 26 inch wingspans and cockroaches half a meter long! I've let a 1/3rd foot Madagascar hissing roach walk on me in a museum and don't mind but I think I'd be scared to see the underside of that half meter cockroach!

Thrackerzod, is that you? [[Special:Contributions/108.162.215.103|108.162.215.103]] 03:11, 28 May 2015 (UTC)