explain xkcd - User contributions [en]

Talk:2404: First Thing

2021-01-08T03:52:26Z

Jezzaaaa:

Note that Ponytail expects to get one of the mRNA or viral-carrier DNA vaccines, e. g. the Pfizer/BioNTech vaccine or Sputnik 5. Her description would not make sense if she receives the Novavax vaccine (NVX-CoV2373), which contains spike proteins and does not recruit the patient's cells to make them. [[Special:Contributions/162.158.78.12|162.158.78.12]] 04:14, 29 December 2020 (UTC)
:for a more detailed explanation of the differences between vaccines read this article: https://qz.com/1950365/what-is-the-novavax-vaccine-and-how-does-it-work/ [[Special:Contributions/162.158.62.221|162.158.62.221]] 05:07, 29 December 2020 (UTC)

How quickly does the immune system start responding to the vaccine? Maybe the actual first thing she'll do is produce a flood of neurotransmitters that represent happiness and relief. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 05:20, 29 December 2020 (UTC)

In the immediate post-Christmas TV adverts (here in the UK) it was notable that there were ''many'' suggesting people book foreign holidays(/vacations), clearly the surviving bits of the hard-hit travel-sector desperately trying to get summer (or earlier?) bookings and deposits to kick-start their return to normal. One ad (eventually, after a day of such saturation) started with "Hooray, the vaccine is here!" before 'seemlessly' flipping to reveal its main message of huge discounts on flights or whatever it was... Whether people ''are'' practically thinking of it as 'jab and go' (doubtless many are), firms are certainly relying upon them to do so. (Without even outwardly adressing the fallout from Brexit which will add a little extra frisson of uncertainty to much of the business model.) Such fun(!) to watch unfold... [[Special:Contributions/162.158.159.50|162.158.159.50]] 13:55, 29 December 2020 (UTC)
:On one hand, summer holiday is far enough for people not just getting vaccinated but also starting generating antibodies, yet not so far to not make sense to start ordering them. On the other, I suspect the travel-sector is desperate and there will likely be bankrupts, so they might really prefer people being irresponsible ... -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 00:16, 30 December 2020 (UTC)
::The initial priorities set down for UK vaccinations are skewed towards the older age groups and others with health vulnerabilities (mixing in carers and healthcare professionals) where the ''ninth''/least priority level is "all those 50 years of age and over" (...not already included earlier) and is aimed reducing the risks of the top 99% of the mortality-susceptible as quickly as possible. The archetypal "18-30" group (except those healthcarers at priorities 1&2 and ones with underlying conditions that put them in group #6, minorities and neither likely to be big spenders on foreign travel) and most members of any family setting off for sun/sea/beach will have to wait until after this comprehensive first set of phases are (effectively) complete to get in on the bonus. This could be as early as springtime if it all goes well, but easily could be so disorganised as to be up to half a year later than that. [[Special:Contributions/141.101.99.63|141.101.99.63]] 02:59, 30 December 2020 (UTC)

I think the explanation about maintaining other mitigation measures misses an important point: some (perhaps all) vaccines have not yet been shown to reduce transmission, as the primary outcome of studies was to reduce the COVID19 disease (symptoms), and was not to reduce either infection or transmission. In other words, the vaccine will help me from getting sick, but won't prevent me from being infected or passing it on. (https://theconversation.com/a-covid-19-vaccine-that-prevents-both-the-disease-and-viral-transmission-is-the-aim-until-then-heres-what-we-need-to-do-151839) [[User:Jezzaaaa|Jezzaaaa]] ([[User talk:Jezzaaaa|talk]]) 03:52, 8 January 2021 (UTC)

2118: Normal Distribution

2019-03-01T21:49:15Z

Jezzaaaa: /* Explanation */

{{comic
| number = 2118
| date = March 1, 2019
| title = Normal Distribution
| image = normal_distribution.png
| titletext = It's the NORMAL distribution, not the TANGENT distribution.
}}

==Explanation==
{{incomplete|Created by an ANNOYED STATISTICIAN. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
In statistics, a {{w|Probability distribution|distribution}} is a representation that can be understood in terms of how much of a sample is expected to fall into discrete bins. For example, if you wanted to represent an age distribution using bins of ten years (0-9, 10-19, etc.), you could produce a bar chart, one bar for each bin, where the height of each bar represents a count of the portion of the sample matching that bin. To turn that bar chart into a distribution, you'd get an infinite number of people, put them into age bins that are infinitely narrow, and then divide each bin count by the total count so that the whole thing added up to 1. It is common to ask how much of the distribution lies between two vertical lines; that would correspond to asking what percent of people are expected to fall between two ages.

Many statistical samplings form a pattern called a "{{w|normal distribution}}". A theoretically perfect normal distribution would have an infinite sample size and infinitely small bins. That would produce a bar chart matching the shape of the curve in the comic.

The area between two vertical lines of the distribution represents the probability that the value is between the x-values of the lines, and the total area is 1. Randall finds the area between two ''horizontal'' lines instead, which, while correct, is not meaningful. The items in one bin are thought of as being identical; there's no reason to put one above another, and the fact that two items happen to fall at the same height horizontally don't mean they have anything in common. The comic explores the humor of annoying people by deliberately misunderstanding their work.

The title text refers to the {{w|Normal (geometry)|normal line}}, which is perpendicular to the {{w|tangent}} line at a given point. The normal line is not at all related to the normal distribution, as the former is a geometry concept and the latter is probability/statistics one. Saying this to a statistician would only annoy the statistician further. This refers to the fact that the diagram attempts to divide the graph with horizontal lines when such a division would usually be done with vertical lines.

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

:[A bell curve of a normal distribution, with the area between two _horizontal_ lines shaded.]

:[The distance between the lines is marked offset from the center of the curve, with the label:]
:Midpoint - 52.7%

"Remember, 50% of the distribution falls between these two lines!"

:[Caption below the panel:]
:How to annoy a statistician

{{comic discussion}}
[[Category:Charts]]
[[Category:Statistics]]

Talk:1508: Operating Systems

2015-04-06T06:43:59Z

Jezzaaaa:

[something].js isn't that far off: https://github.com/runtimejs/runtime (Sometimes I feel like JavaScript is a cult...) :) [[User:Bb010g|Bb010g]] ([[User talk:Bb010g|talk]]) 06:07, 6 April 2015 (UTC)

Typo in title text: ''singed'' should be ''signed''.[[User:Jezzaaaa|Jezzaaaa]] ([[User talk:Jezzaaaa|talk]]) 06:43, 6 April 2015 (UTC)

1492: Dress Color

2015-03-01T05:46:05Z

Jezzaaaa: grammar/typos

{{comic
| number = 1492
| date = February 27, 2015
| title = Dress Color
| image = dress_color.png
| titletext = This white-balance illusion hit so hard because it felt like someone had been playing through the Monty Hall scenario and opened their chosen door, only to find there was unexpectedly disagreement over whether the thing they'd revealed was a goat or a car.
}}

==Explanation==
This comic shows two drawings of [[Megan]] wearing the same dress, but with different background colors. The two drawings are split with a narrow vertical portion of an image from the web.

The comic strip refers to a dress whose image went viral on [http://swiked.tumblr.com/post/112174461490/officialunitedstates-unclefather Tumblr] only hours before the strip was posted and soon showed up also on [http://www.reddit.com/r/explainlikeimfive/comments/2xaprc/eli5why_does_this_dress_appear_whitegold_to_some/ Reddit], [https://twitter.com/hashtag/thedress?src=hash Twitter], [http://www.wired.com/2015/02/science-one-agrees-color-dress/ Wired] and on [http://www.nytimes.com/2015/02/28/business/a-simple-question-about-a-dress-and-the-world-weighs-in.html The New York Times].

Due to the dress's particular color scheme and the exposure of the photo, it forms an {{w|optical illusion}} causing viewers to disagree on what color the dress actually seems to be. The xkcd strip sandwiches a cropped segment of the photographed dress between two drawings which use the colors from the image against different backgrounds, leading the eye to interpret the white balance differently, demonstrating how the dress can appear different colors depending on context and the viewer's previous experiences.

Both dresses have exactly the same colors actually:
* RGB 113, 94, 58 (orange) <div style="display:inline-block; height:1em; width:1em; background-color: #715E3A"></div>
* RGB 135, 154, 189 (blue) <div style="display:inline-block; height:1em; width:1em; background-color: #879ABD"></div>

Below is an illustration demonstrating that the "colors" of the dresses are the same by connecting them with two lines with the above mentioned colors (all the way!):
:[[File:dress.png|400px]]

Similar types of illusions can be seen at Wikipedia's {{w|Optical illusion#Color_and_brightness_constancies|optical illusion page}} and for instance here at [http://www.echalk.co.uk/amusements/OpticalIllusions/colourPerception/colourPerception.html echalk] (the latter page requires Flash®player).

This image has sparked surprisingly heated debate in many internet communities. A select few individuals may have prior experience with optical illusions of this ilk, but because this particular image went viral -- it got heavy exposure over such a short amount of time -- it reached millions of people who aren't so familiar with these sorts of mind tricks. To the uninitiated, the color of the dress seems immediately obvious; when others cannot see it their way, it can be a surreal (even uncomfortable) experience.

The title text refers to the game show {{w|Let's Make a Deal}}, hosted by Monty Hall, which was famous for having contestants pick among several doors which either had a real prize (for example, a car) or a joke prize (for example, a goat). [[Randall]] states that people find the dress color issue just as baffling as if upon opening the chosen door no one can agree if the item behind the door is a car or a goat. This is a reference to what has become known as the "{{w|Monty Hall problem}}:" if there are two goats and a prize behind three doors, the contestant has chosen a door, and one of the unchosen doors is opened to reveal a goat, should the contestant change his/her choice? Statistically, the answer is yes, but many people find this counterintuitive; discussion of this problem in ''Parade'' magazine touched off public outrage similar to the viral dress image.

Randall is presumably pointing out how ridiculous it is for people who don't understand the underlying science to become so adamant in defending their beliefs. A spoof of the "Monty Hall problem" previously appeared in [[1282: Monty Hall]], where [[Beret Guy]] decides to take the goat.

==Transcript==
:[Two images of Megan in a dress on each side of an image of a close up of a real dress with the same colors. On the left, she is coloured blue on a dark blue background, while on the right, she is yellow against a buttercup background. Her dress is the same colour in each panel - the same as the real one in-between.]

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Comics featuring Megan]]

User talk:Jezzaaaa

2014-04-14T21:45:02Z

Jezzaaaa: Created page with "Torque"

Torque

Talk:1353: Heartbleed

2014-04-14T21:42:55Z

Jezzaaaa: /* == */

I added an explanation for the punchline. [[User:ImVeryAngryItsNotButter|ImVeryAngryItsNotButter]] ([[User talk:ImVeryAngryItsNotButter|talk]]) 16:13, 10 April 2014 (UTC)

I added a transcript, if I messed up on anything, I'm sorry! [[Special:Contributions/173.245.55.73|173.245.55.73]] 06:08, 9 April 2014 (UTC)
:Thanks for the transcript! (nothing seems messed up) [[Special:Contributions/141.101.88.206|141.101.88.206]] 06:41, 9 April 2014 (UTC)
::But wait! You forgot a comma! (It's okay, I fixed it :) ) [[Special:Contributions/108.162.216.67|108.162.216.67]] 06:47, 9 April 2014 (UTC)

The alt-text contains a reference to the scene "Tears in the rain" of Blade Runner [[Special:Contributions/173.245.49.90|173.245.49.90]] 06:19, 9 April 2014 (UTC)

Is Explainxkcd using Open SSL? [[User:Jonv4n|Jonv4n]] ([[User talk:Jonv4n|talk]]) 06:56, 9 April 2014 (UTC)

I'd just like to take this moment to say that even though you probably don't have anything of value stored here, Explain xkcd is good on the Heartbleed front. Not using any of the affected software because the data we handle isn't private at all probably helps with that. And yes, Mediawiki hashes your passwords before they're sent. '''[[User:Davidy22|<u>{{Color|#707|David}}<font color=#070 size=3>y</font></u><font color=#508 size=4>²²</font>]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 07:18, 9 April 2014 (UTC)

: Davidy22 - While your first point was correct (explainxkcd isn't vulnerable to heartbleed as explainxkcd doesn't any encryption -- everything starts being sent in plaintext over the net), your second point is wrong. As anyone with wireshark can verify (or using your web browsers' developer tools), when you login to explainxkcd from `http://www.explainxkcd.com/wiki/index.php?title=Special:UserLogin&returnto=Main+Page`, you make a POST request to `/wiki/index.php` that contains as a POST variable your user name (in the POST variable wpName), and your password (in the POST variable wpPassword), both sent in plaintext. Granted it probably is stored in the database hashed (hopefully with a unique salt and a good hash algorithm), it is readable by any network eavesdropper. Not really a problem though, if you don't reuse passwords or mind if your account here was compromised. [[User:Jimbob|Jimbob]] ([[User talk:Jimbob|talk]]) 22:38, 9 April 2014 (UTC)

Have the following from [http://www.openssl.org/news/secadv_20140407.txt OpenSSL Bug Report]
Should this be incorperated into the main explanation, and how should it be formated
[[User:Jonv4n|Jonv4n]] ([[User talk:Jonv4n|talk]]) 08:07, 9 April 2014 (UTC)
----

OpenSSL Security Advisory [07 Apr 2014]
========================================

TLS heartbeat read overrun (CVE-2014-0160)
==========================================

A missing bounds check in the handling of the TLS heartbeat extension can be
used to reveal up to 64k of memory to a connected client or server.

Only 1.0.1 and 1.0.2-beta releases of OpenSSL are affected including
1.0.1f and 1.0.2-beta1.

Thanks for Neel Mehta of Google Security for discovering this bug and to
Adam Langley <agl@chromium.org> and Bodo Moeller <bmoeller@acm.org> for
preparing the fix.

Affected users should upgrade to OpenSSL 1.0.1g. Users unable to immediately
upgrade can alternatively recompile OpenSSL with -DOPENSSL_NO_HEARTBEATS.

1.0.2 will be fixed in 1.0.2-beta2.

----

:Actually, attack is limited to data in memory of the webserver PROCESS. Even on affected computers, other applications are safe and most of disk content is safe. Not speaking about the fact that in many cases, the public-facing webserver is just proxy cache before the real ones. The real problem is if someone immediately used the revealed data - either to impersonate the server or for example found the admin password and used it to copy the database ... which DOES leave traces. I agree with Cueball: there can be worse kind of bug. In fact, I'm sure that what Edward Snowden revealed is worse, although not technically bug. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 10:18, 9 April 2014 (UTC)

: Hkmaly -- Completely agree. Posted a [http://security.stackexchange.com/questions/55270/does-xkcd-com-1353-overstate-heartbleeds-capability similar discussion] at security.stackexchange.com and altered the text here to describe heartbleed in more detail. [[User:Jimbob|Jimbob]] ([[User talk:Jimbob|talk]]) 21:33, 9 April 2014 (UTC)

"
''If the certificate is registered the browser accepts it.'' This is incorrect. Server certificates aren't accepted because they're registered, they're accepted because they can prove a chain of trust up to a CA certificate which is explicitly trusted. Ironically, certificates only need to be registered when they're revoked (on a CRL - certificate revocation list). The whole idea of the digital certificate system we use is that of federated trust, which requires no online lookup to validate a certificate. [[User:Jezzaaaa|Jezzaaaa]] ([[User talk:Jezzaaaa|talk]]) 22:19, 10 April 2014 (UTC)
:Nope, you have to pay for it. The browser trusts that few sites and accepts the certificate silently. Otherwise you do get that popup to accept or deny. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 22:29, 10 April 2014 (UTC)
::You're talking about the CA certificate at the root of the trust chain. But the certificate in ''the server sends a certificate ... if the certificate is registered'' is the server's certificate, not the CA certificate. [[User:Jezzaaaa|Jezzaaaa]] ([[User talk:Jezzaaaa|talk]]) 00:40, 11 April 2014 (UTC)
:::Another attempt at explanation: server certificate is accepted because it's SIGNED by (private key of) AUTHORITY. The certificate (public key) of AUTHORITY is part of browser. So, the implicitly trusted certificates of authorities are registered/listed in browser, but no list of server certificates is needed. And yes, you need to pay for getting your certificate signed by one of those few (120?) authorities which are part of most browsers. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 10:53, 11 April 2014 (UTC)
::::Yep, and being signed does not require being registered. So, instead of "if the certificate is registered the browser accepts it", perhaps "if the certificate is ''signed by a trusted authority'' the browser accepts it".[[User:Jezzaaaa|Jezzaaaa]] ([[User talk:Jezzaaaa|talk]]) 21:42, 14 April 2014 (UTC)

Talk:1353: Heartbleed

2014-04-14T21:41:27Z

Jezzaaaa: /* == */

User:Jezzaaaa

2014-04-11T00:48:46Z

Jezzaaaa: Created page with "Hey, that's me!"

Hey, that's me!

Talk:1353: Heartbleed

2014-04-11T00:40:17Z

Jezzaaaa: /* == */

Talk:1353: Heartbleed

2014-04-10T22:19:26Z

Jezzaaaa: