explain xkcd - User contributions [en]

1591: Bell's Theorem

2015-10-16T18:58:44Z

173.245.54.151: /* Transcript */

{{comic
| number = 1591
| date = October 16, 2015
| title = Bell's Theorem
| image = bells_theorem.png
| titletext = The no-communication theorem states that no communication about the no-communication theorem can clear up the misunderstanding quickly enough to allow faster-than-light signaling.
}}

==Explanation==
{{incomplete|No explaination of the Title Text, and links should e in explanation, not transcript.}}

{{w|Bell's Theorem|Bell's Theorem}} states "No physical theory of (finitely many) local hidden variables can ever reproduce all of the predictions of quantum mechanics." It says that a theoretical treatment that divides the universe up into separate ("local") systems like this will always discard something about those systems' intercorrelations.

'Global hidden variables' are another story: if there is classical information shared across systems (perhaps by superliminal communication) even up to superdeterminism where the universe is just reading off a script, any correlations can be explained away. But this is unsatisfying.

The prefered resolution of the paradox is to not insist (as early physicists did) that the universe's state is a collection of bits (classical information), but treat it as a collection of qubits (quantum information).

Ponytail begins reading Bell's theorem to Cueball, who is standing 5 meters away. Cueball responds with a misunderstanding of Bell's Theorem in 1 nanosecond. The speed of light in a vacuum is 299,792,458 meters per second. In one nanosecond, the light from Ponytail would only have traveled 0.299 meters, thus Cueball misunderstands Bell's Theorem faster than the light from Ponytail reading the Theorem can reach him, which implies that faster-than-light communication occurred to set up the misunderstanding.

===More===
In quantum mechanics (QM), 'measurement' is the process of allowing a small system to interact with its environment in a controlled way. The interaction allows information about the system's state to escape to the environment, producing an 'observation'. If the measurement apparatus is governed by classical mechanics (impossible in reality, but a very common simplification for the purposes of calculation), then the observation can be thought of as classical information, a bit (yes/no answer) in the simplest case. While the system may have been in any one of infinitely many states before the measurement (each a superposition of classical states), the fact that the measurement must leave it consistent with the classical result means that it can end up in only finitely many states afterwards. This is the 'wave-function collapse' of early QM, popularized by Schrodinger's cat, but unrelated to the Heisenberg uncertainty principle, which lay audiences often confuse it with.

Modern quantum mechanics acknowledges that the environment is not classical, and that wave-function collapse happens by a (comparatively) gradual process called 'decoherence', where information leaving the system is made up for by information coming from the environment that drives the system closer and closer to one of the finitely many state predicted by the simplified model above. (I.e., if a "Schrodinger's cat" is in a half-and-half superposition of the states "dead" and "alive", when its liveness is measured, the ratios of "dead" and "alive" will shift rapidly towards (though not quite reach) 0 and 100% or 100 and 0%. For all but the shortest time scales, the cat's post-measurement state might as well be classical.)

Entanglement is a situation where the future outcomes of two or more measurements that would be independent in a classical world are nonetheless correlated. For example, two widely separated electrons could be in a state where, considered individually, each is in a superimposed spin-up/spin-down state, but if one is measured as spin-up, the others will necessarily be measured as spin-down. This is untroubling if the two electrons are modeled as a single system, but strange-seeming if we think of them as separate: how did the measurement of the first electron allow information from the environment around it affect the far-away second electron? It seems like the electron's are communicating, potentially at superliminal speeds, which would violate either relativity or causality. (In actuality, there's a fairly simple proof[citation needed] that correlations from entanglement can't be used to communicate, and causality and relativity are safe. But that doesn't make the seemingly faster-than-light effects much less of a surprise.)

One can try to address these concerns by considering 'local hidden variables', classical properties of a local system (like a single electron) that could have been observed but were not. For example, perhaps a classical part of the electrons' state lets them "agree" on a future classical state at the moment the are entangled, and then they just reveal that state in the future. But this becomes unwieldy: there are infinitely many possible future observations the electrons would have to agree on, and it seems difficult to do this without infinitely many local hidden variables.

===Title Text===
The title text, with 4 negatives, tries to be as confusing as possible. The real No-Communication Theorem states that although determination of the state of one half of an entangled pair immediately determines that of the other half, however far away it may be, there's no way for the observer of the other half to see if he's the first to find out the state or whether it'd already been determined by the first observer. Thus, no information travels from one observer to the other. Randall's version is recursive. It hypothesises a method of communication whereby somebody misunderstanding the no-communication theorem (which also happens faster than the speed of light) could function as the reception of a faster-than-light signal. However, it goes on to point out that turning the signal off requires clearing up the confusion which takes much, much longer, thus neatly restoring the normality of slower than light communication.

==Transcript==
[First frame captioned: t = 0 nanoseconds] 
Ponytail, holding a piece of paper and facing to the right: This is called Bell's Theorem. It was first–

[A double-headed arrow links the characters in the two frames. The arrow is labelled "5 meters".]

[Second frame captioned: t = 1 nanosecond] 
Cueball, facing to the left towards Ponytail: Wow, faster-than-light communication is possible!

Caption: Bell's Second Theorem: Misunderstandings of Bell's Theorem happen so fast that they violate locality.

{{comic discussion}}

[[Category:Physics]]
[[Category:Science]]

1568: Synonym Movies 2

2015-08-24T20:44:34Z

173.245.54.151: /* Table of the titles */

{{comic
| number = 1568
| date = August 24, 2015
| title = Synonym Movies 2
| image = synonym_movies_2.png
| titletext = There's also the TV show based on the hit Hot and Cold Music books: Fun With Chairs, Royal Rumble, Knife Blizzard, Breakfast for Birds, and Samba Serpents.
}}

==Explanation==
[[File:synonym_movies_2_rotated.jpg|right|A flipped version of the comic]]

This comic is a continuation of [[1563: Synonym Movies]] with a new set of movie series. As with the previous comic, the titles aren't always synonymous with the original (''Indiana Jones as Professor Whip'').

This set includes ''Wandboy'' (''Harry Potter''), ''Puncher'' (''Rocky''), ''Tropical Boaters'' (''Pirates of the Caribbean''), and ''Professor Whip'' (''Indiana Jones'').

The ''is in Another Movie'' title in the ''Professor Whip'' series differs from the other titles in that it does not reference the plot of the movie. The more dismissive reference may be due to ''Indiana Jones and the Kingdom of the Crystal Skull'' being poorly received by fans of the series.

The title text is a reference to the TV series ''A Game of Thrones'', based on the book series ''A Song of Ice and Fire''.

==Table of the titles==
'''SPOILER ALERT!''' Many of these explanations contain information revealed during the movie.

{| class="wikitable"
|-
! width="12em" | Synonym
! width="13em" | Real Title
! Explanation
|-
| ''Wandboy and the Magic Rock''
| ''{{w|Harry Potter and the Philosopher's Stone (film)|Harry Potter and the Philosopher's Stone}}''
| In this series, wizards and witches use wands to perform magic. The first installment of the series is also known as ''Harry Potter and the Sorcerer's Stone'' in the US.
|-
| ''Wandboy and the Hidden Room''
| ''{{w|Harry Potter and the Chamber of Secrets (film)|Harry Potter and the Chamber of Secrets}}''
| The {{w|Hogwarts#Chamber_of_Secrets|Chamber of Secrets}} is a very well hidden room that is central to the plot of the second book.
|-
| ''Wandboy and the Fugitive''
| ''{{w|Harry Potter and the Prisoner of Azkaban (film)|Harry Potter and the Prisoner of Azkaban}}''
| A central character in Harry Potter and the Prisoner of Azkaban, Sirius Black, is a fugitive.
|-
| ''Wandboy and the Burning Cup''
| ''{{w|Harry Potter and the Goblet of Fire (film)|Harry Potter and the Goblet of Fire}}''
| The goblet of fire is a wooden cup with blue magical fire burning at the rim.
|-
| ''Wandboy and the Firebird Club''
| ''{{w|Harry Potter and the Order of the Phoenix (film)|Harry Potter and the Order of the Phoenix}}''
| The {{w|Phoenix (mythology)|Phoenix}} is a bird that is strongly connected to fire. Dying phoenixes go up in flames, only to be reborn out of the ashes shortly afterwards. The Order of the Phoenix is an association of wizards founded by Albus Dumbledore, whose distinctive pet is a phoenix.
|-
| ''Wandboy and the Book Owner''
| ''{{w|Harry Potter and the Half-Blood Prince (film)|Harry Potter and the Half-Blood Prince}}''
| In ''Harry Potter and the Half-Blood Prince'', Harry's Potions textbook was previously owned by a "Half-Blood Prince." Therefore, "Half-Blood Prince" is replaced with "book owner."
|-
| ''Wandboy and the Magic Stuff (1/2)''
| ''{{w|Harry Potter and the Deathly Hallows – Part 1}}''
| rowspan="2" | The ''Deathly Hallows'' are three magical items which play an important part in the plot of the final books. See also {{w|The Tales of Beedle the Bard#"The Tale of the Three Brothers"}}.
|-
| ''Wandboy and the Magic Stuff (2/2)''
| ''{{w|Harry Potter and the Deathly Hallows - Part 2}}''
|-
|colspan=3| 
|-
| ''Puncher''
| ''{{w|Rocky}}''
| rowspan="5" | Rocky is a boxer. In {{w|boxing}} boxers attempt to punch their opponent until they are knocked out.
|-
| ''Puncher II''
| ''{{w|Rocky II}}''
|-
| ''Puncher III''
| ''{{w|Rocky III}}''
|-
| ''Puncher IV''
| ''{{w|Rocky IV}}''
|-
| ''Puncher V''
| ''{{w|Rocky V}}''
|-
| ''Puncher Lastname''
| ''{{w|Rocky Balboa (film)|Rocky Balboa}}''
| Balboa is Rocky's last name.
|-
|colspan=3| 
|-
| ''Tropical Boaters: Spooky Boat''
| ''{{w|Pirates of the Caribbean: The Curse of the Black Pearl}}''
| The Black Pearl is a ship crewed by "spooky" ghost pirates.
|-
| ''Tropical Boaters: Angry Wormface''
| ''{{w|Pirates of the Caribbean: Dead Man's Chest}}''
| This film's villain has (worm-like) octopus tentacles growing on his face.
|-
| ''Tropical Boaters: Boats Everywhere''
| ''{{w|Pirates of the Caribbean: At World's End}}''
| This film includes a huge fleet of ships.
|-
| ''Tropical Boaters: Vitamin Water''
| ''{{w|Pirates of the Caribbean: On Stranger Tides}}''
| "Vitamin Water" describes the Fountain of Youth.
|-
|colspan=3| 
|-
| ''Professor Whip and the Box of God''
| ''{{w|Raiders of the Lost Ark}}''
| Later marketed as Indiana Jones and the Raiders of the Lost Ark. The "Lost Ark" of the title is the Ark of the Covenant, a mythical box containing the contract between the Jewish people and Yahweh.
|-
| ''Professor Whip and the Scary Church''
| ''{{w|Indiana Jones and the Temple of Doom}}''
| A direct synonym for the title.
|-
| ''Professor Whip Looks for a Cup''
| ''{{w|Indiana Jones and the Last Crusade}}''
| Central to this film's plot is the search for the {{w|Holy Grail}}, which is supposedly a cup from which Jesus drank shortly before his death.
|-
| ''Professor Whip is in Another Movie''
| ''{{w|Indiana Jones and the Kingdom of the Crystal Skull}}''
| ''Indiana Jones and the Kingdom of the Crystal Skull'' is widely regarded as the worst in the series. Therefore, the "synonym" is simply called "another movie" to imply that it shouldn't have been made.
|-
|colspan=3| 
|-
| ''Hot and Cold Music books''
| ''{{w|A Song of Ice and Fire}}''
| A series of fantasy books written George R. R. Martin, detailing the toils and troubles in an imaginary realms, where the fight against the so-called 'Others' - cold, otherworldly creatures from beyond the Wall at the Northern borders (Ice) and against the fire-breathing dragons (Fire) plays an important role.
|-
| ''Fun With Chairs''
| ''{{w|A Game of Thrones}}''
|Book one of the cycle "A Song of Ice and Fire." and the main title of the television adaptation. The title refers to the machinations to obtain the Iron Throne after the old king Robert dies.
|-
| ''Royal Rumble''
| ''{{w|A Clash of Kings}}''
|Book two of the cycle "A Song of Ice and Fire." The title refers to the Battle of the Five Kings, a war involving five different kings, each reigning over one of the seven kingdoms of Westeros.
|-
| ''Knife Blizzard''
| ''{{w|A Storm of Swords}}''
|Book three of the cycle "A Song of ice and Fire." The title may refer to the continuation of the Battle of the Five kings, to which are added fights involving the Wildlings from the North, and Daenerys Targaryen and her Dragons.
|-
| ''Breakfast for Birds''
| ''{{w|A Feast for Crows}}''
|Book four of the cycle "A Song of Ice and Fire." The title probably refers to the fact that now, with the Battle of the Five Kings drawing to a close, many have died and are therefore in effect (even if not always literally) crow fodder.
|-
| ''Samba Serpents''
| ''{{w|A Dance with Dragons}}''
|Book five of the cycle "A Song of Ice and Fire." The title refers to the one of the story lines, in which Daenerys Targaryen has to deal with a lot of delicate situations, several involving her dragons.
|}

==Transcript==
:[22 DVDs on a shelf in four groups. All DVDs are labeled in black on light grey. Text written so it is supposed to be read when the DVD is lying down.]
:[First group of 8 DVDs. All standing straight]
:Wandboy and the Magic Rock
:Wandboy and the Hidden Room
:Wandboy and the Fugitive
:Wandboy and the Burning Cup
:Wandboy and the Firebird Club
:Wandboy and the Book Owner
:Wandboy and the Magic Stuff (1/2)
:Wandboy and the Magic Stuff (2/2)

:[Second group of six DVDs. Five standing straight, last on the right leaning against the rest]
:Puncher
:Puncher II
:Puncher III
:Puncher IV
:Puncher V
:Puncher Lastname

:[Third group of four DVDs. First and last standing straight, others leaning on first]
:Tropical Boaters: Spooky Boat
:Tropical Boaters: Angry Wormface
:Tropical Boaters: Boats Everywhere
:Tropical Boaters: Vitamin Water

:[Fourth group of four DVDs. Three standing straight, second from left leaning on first]
:Professor Whip and the Box of God
:Professor Whip and the Scary Church
:Professor Whip Looks for a Cup
:Professor Whip is in Another Movie

{{comic discussion}}

1468: Worrying

2015-05-11T15:07:12Z

173.245.54.151: /* Explanation */ refined statement about movie nosebleeds

{{comic
| number = 1468
| date = January 2, 2015
| title = Worrying
| image = worrying.png
| titletext = If the breaking news is about an event at a hospital or a lab, move it all the way over to the right.
}}

==Explanation==
This chart is a visual representation of how worried people should be by various events in real life compared to the same events in movies, based on the the likelihood of the event causing serious harm. In effect it's poking fun at various cliches and the emphasis on dramatic flair, regardless of realism. The chart's Y-axis indicates how worrying an event is in real life (from "not very worried" to "very worried"), while its X-axis shows how worrying the event is in movies. Nine events are shown in the chart, all of them cliches in the medium of film:

*'''Spilling a drink on your shirt''': In both real life and in movies, this just causes a stain and maybe a little embarrassment.
*'''Nosebleed''': Nosebleeds are common in real life and almost never are serious...almost. [https://allthetropes.orain.org/wiki/Deadly_Nosebleed Nosebleeds in movies] are almost always a sign that something ''is'' seriously wrong - the common, mundane nosebleeds almost never come up (The comedy movie {{w|Strange Brew}} derives humor by treating a nosebleed with an appropriate amount of concern, i.e. as a minor distraction). In ''Firefly'', the blue hand men use a device that causes a nosebleed followed by massive haemorrhaging and death. Even "mundane" nosebleeds brought on by fisticuffs are a sign that either someone has just lost, [https://allthetropes.orain.org/wiki/Heroic_Second_Wind or someone is about to have an adrenaline rush]. This does not always apply to boxing movies where the hero can easily have a massive nosebleed and still win the fight.
*'''Breaking news''': People in real life commonly don't pay much attention to the news at all, so many breaking stories go unnoticed until much later. Most breaking news stories are also about non-threatening events (eg. presidential addresses) or events that are far removed from the viewer. However, in movies, seeing the news station switch to a "breaking news" broadcast is usually a means to introduce a significant plot element that the characters find worrying, and large numbers of people are often shown watching and being emotionally affected by the news while it's breaking. XKCD has referenced [[1387|news reports as foreshadowing before]].
*'''Parking ticket''': Tickets in movies are almost always ignored, but in real life they are moderately worrying because they cost money and can tarnish your driving record.
*'''Persistent cough''': In real life, coughing fits can be a sign of serious illness, but usually aren't. If you have a persistent cough, you should check with a doctor. In movies, just like with nosebleeds, a person with a [https://allthetropes.orain.org/wiki/Incurable_Cough_of_Death persistent cough] is almost always extremely ill or infectious.
*'''"We need to talk."''': This phrase is a common, stereotypical lead-in to a serious conversation, usually about a couple's relationship status, that often causes a high level of worry in the recipient. According to this chart, this phrase is equally worrisome both in movies and in real life.
*'''Getting knocked out by a punch''': In movies, a character who is [https://allthetropes.orain.org/wiki/Tap_on_the_Head knocked out by a punch] always wakes up sometime later with no lasting effects, making it less cause for concern than a spilt drink. In real life, however, a person knocked out by a punch can suffer serious brain injuries or even die from the punch itself, or can sustain further injuries from their head hitting the ground.
*'''Chest wounds''': The chart mentions wounds on both your right and left sides. In real life, a chest wound to either side is extremely worrying. But in movies, getting wounded on the right side of the chest will rarely deal lasting damage to the hero or primary villain, to show how badass they are. Wounds on the ''left'' side of the chest signify swift death. This can be explained by the common misconception that the heart is on the left side of the chest - it is actually in the centre, with a slight tendency to the left. However, even left-side chest wounds are apparently still less worrisome than nosebleeds. It must also be noted that the term "chest wound" is more broad than what the author of the comic appears to mean. More narrow terms of "thoracic gunshot wound", "gunshot chest wound", "thoracic ballistic trauma" or "penetrating chest wound" (the latter is slightly broader and includes the damage inflicted by blades and other impaled objects) would be more appropriate, because just a "chest wound" includes such insignificant events as minor skin cuts in the chest area.

The title text expands on the aforementioned breaking news reports. While already overly worrying whenever they occur in movies compared to real life, should the movie's news report cover an event at a hospital (usually an outbreak of some major disease) or a laboratory (a monster escaping, a toxic gas released, an explosion, etc.), these events are universally much more worrisome than any other type of news story since they are guaranteed to be important for the protagonists in short order.

==Table==
The comic shows an X-Y plot of events, showing how worried you should be ''in real life'' on the vertical axis and ''in movies'' on the horizontal axis. The axis goes from "not very worried" to "very worried".

Below is a table listing the coordinate for each event according to how worrying it is. The coordinates have been found by measuring each dot to the two axises and then assuming that the extremes are at 100%.
*Note that this gives two possible ways to interpret the Y-axis "In real life" coordinate.
**Either chest wound is at 100% - this is the first Y-axis coordinate given below under "In real life".
**But alternatively it could be the most worrisome event over all that should be set to 100% including also the most worrisome event on the X-axis for "In movies". In this case the nosebleed event sets the 100% bar higher, thus lowering the percentage for the "In real life" events. Either way could be argued, and thus this other coordinate is given as In Real Life vs. Nose Bleed ('''IRL vs. NB''').
*For the "In movies" coordinate nosebleed is at 100%. However since nosebleed is located past the end of the x-axis arrow it could be argued that it is this event that is off the chart in the movies. But this table will assume this as the 100% mark either over all or at least for the X-axis for "In Movies".

{| class="wikitable sortable"
! In real life !! IRL vs. NB !! In movies !! Event
|-
| 100% || 73% || 30% || Chest wound on your right side
|-
| 100% || 73% || 80% || Chest wound on your left side
|-
| 81% || 59% || 9% || Getting knocked out by a punch
|-
| 75% || 55% || 62% || "We need to talk."
|-
| 51% || 37% || 90% || Persistent cough
|-
| 28% || 20% || 8% || Parking ticket
|-
| 24% || 18% || 74% || Breaking news
|-
| 12% || 8% || 11% || Spilling a drink on your shirt
|-
| 11% || 8% || 100% || Nosebleed
|}

==Transcript==
:'''How worried should you be when various things happen to you:'''
:[A chart with a scatter plot on which 9 dots are labeled. Each axis have a title and a scale. Reading from the top to the bottom and then left to right along the axis are:]
:Very worried
:'''...In Real Life'''
:Not very worried

:Not very worried
:'''...In Movies'''
:Very worried

:[The labels in the chart from the top:]
:[This first entry is standing in the middle of a square bracket that points to the two next entires both of which are at the same level:]
:Chest wound
:...on your right side
:...on your left side
:Getting knocked out by a punch
:"We need to talk."
:Persistent cough
:Parking ticket
:Breaking news
:Spilling a drink on your shirt
:Nosebleed

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

1490: Atoms

2015-05-08T13:48:54Z

173.245.54.151: /* Explanation */ Another possibility

{{comic
| number = 1490
| date = February 23, 2015
| title = Atoms
| image = atoms.png
| titletext = When I was little I had trouble telling my dad apart from the dog. I always recognized my mom because she had a bunch of extra plutoniums in her middle. I never did ask her why...
}}

==Explanation==
In this comic, [[Megan]] is preparing a sample of what appears to be some mineral for {{w|elemental analysis}}. It seems to be some kind of {{w|silicate}} containing a small amount of {{w|iron}} (a common example of this would be {{w|red sandstone}}), and she is running a test to see if it contains {{w|beryllium}} (a rarer element whose best-known natural form is as a component of {{w|emerald}}).

[[Beret Guy]] seems to be able to tell what elements the substance is composed of just by eyeballing it, making him perhaps the perfect elemental analysis instrument. To confirm this, Megan asks Beret Guy what he sees when he looks at her face, expecting that a normal person would describe the arrangement of colors that they see. Since Beret Guy only sees the atoms Megan is composed of (mostly {{w|Composition_of_the_human_body|oxygen, carbon and hydrogen}}) he only notices the unusual atoms. In this case he sees the metal atoms her {{w|Dental_restoration#Materials_used|dental fillings}} are composed of. This shows his "atomic vision" extends beyond the surface of the substances. Megan finds this bizarre and asks Beret Guy what is wrong with him. He states that he suspects people think he is weird because he contains too much {{w|zinc}}, missing Megan’s point: what is weird is not Beret guy’s zinc content, but his ability to apparently see everything as clouds of atoms.

High zinc intake ({{w|Zinc toxicity|zinc toxicity}}) can cause nausea, vomiting, pain, cramps and diarrhea. It also reduces copper absorption, which affects the immune system.

The comic continues the theme of Beret Guy’s naive misunderstandings of scientific terminology turning to be literally true: in a previous [[1486: Vacuum|comic]] his ill-informed misinterpretation of the notion of energy in the vacuum resulted in him gaining significant superpowers.

In the title text, the concept is taken even further: Beret Guy found his dad indistinguishable from a dog: likely because skin and fur are mostly made of {{w|keratin}}, which is an organic mix primarily made up of carbon, hydrogen, nitrogen, and sulfur that would make all mammals look similar.

He could, however, apparently distinguish his mother because she contained {{w|plutonium}}. This is a very unusual occurrence that cannot possibly occur naturally in humans. Several possible explanations have been proposed:

1) She had an {{w|Radioisotope thermoelectric generator|RTG}}-powered pacemaker (a few hundred were made in the 1970s).

2) She lived near Los Alamos during the second world war and was a member of the [http://pills52.com/2014/2837153/ UPPU club (translated as “You pee Pu!”)]. Alternatively, she could have been exposed to another source such as {{w|radioactive contamination from the Rocky Flats Plant}}.

3) She was one of {{w|The Stepford Wives}} robots.

4) She was the victim of some unidentified, unethical medical experimentation.

It is also possible that the presence of plutonium in his mother may be the source of his own differences: radioactive exposure (in this case, potentially in utero) is a common source of super powers in comic books and other fiction. However, there is not a clear link between maternal plutonium and Beret Guy's "too many zincs".

One explanation for Beret Guy having too much zinc could be that his mother's plutonium changed into zinc through the process of {{w|Radioactive Decay}}.

The English physicist {{w|Henry Moseley}} discovered the law relating the {{w|Atomic Number}} of elements with their {{w|Characteristic X-ray|Characteristic X-rays}} when bombarded by free electrons, providing physical evidence for the {{w|Periodic Table}}, the {{w|Bohr Model}} of the atom and the concept of {{w|Atomic Number}}. In doing so he developed a method of identifying elements in a substance by bombarding them in a vacuum with electrons and using {{w|X-Ray Diffraction}} methods to measure the resulting X-rays. A famous French chemist brought him a complicated mixture of {{w|Rare Earth element|Rare Earth elements}}, many of which had only recently been discovered, to test his method. Within a short time, Mosley amazed the chemist by identifying all the elements by number using his method and referring to his chart to name them. This comic may therefore be subtly alluding to this method by suggesting that Beret Buy's eyes can fire electrons at anything he looks at and "read" the resulting X-ray radiation, giving him the ability to identify the composite elements in a similar manner.

==Transcript==
:[Megan stands at a table and is preparing a sample for some kind of analysis in a device, when Beret Guy walks in.]
:Beret guy: What’re you doing?
:Megan: Testing a sample for beryllium.
:Beret guy: That? Yeah, there’s a bunch of berylliums.
:Megan: How do you know?

:[Megan turns to Beret Guy who takes the sample and looks at it.]
:Beret guy: Look at it! See? Tons of oxygens and silicons, a few irons but definitely some berylliums too! Can’t you see them?

:[They continue to talk.]
:Megan: No, I can’t see a list of the atoms in a thing by looking.
:Beret guy: How do you tell what things are?

:[Zoom in on Megan.]
:Megan: This is ridiculous. Look at me. What do you see?
:Beret guy (off-panel): You have tons of metal in your face. Lots of fillings, I guess?

:[Megan states at Beret Guy who takes a looks at his own arm.]
:Megan: What’s '''''wrong''''' with you?
:Beret guy: Too many zincs? I’ve always worried I had too much zinc and everyone thought I was weird.

==Trivia==
*In the original version of the comic there was a typo in the title text, ''form'' instead of ''from'':
**I had trouble telling my dad apart '''form''' the dog.

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

Talk:1522: Astronomy

2015-05-08T08:49:05Z

173.245.54.151:

For a telescope you can be far away, for a magnifying glass or microscope you need a ladder to be nearer to the stars. Microscopes are for biology, telescopes for astronomy.
They have got a similar purpose, but look and are applied differently. Sebastian --[[Special:Contributions/108.162.254.122|108.162.254.122]] 07:09, 8 May 2015 (UTC)

Seemed like another example of Beret guy contradicting how things work, like how he blows into the power cord and inflated a computer, or how he plugged a cord into a power outlet labeled "COFFEE" and coffee came out. [[Special:Contributions/108.162.238.168|108.162.238.168]] 07:19, 8 May 2015 (UTC)
:Yes obviously this approach works for Berret Guy because this is what he does. Explanation lacks this fact. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 07:44, 8 May 2015 (UTC)
:Soup, wasn't it? But yes, for some reason he can actually use a stepladder to get a closer look (and a better one, thanks t the magnifying glass) on the "curtain of the night", which for him ''is'' actually within reach. As if it is just like a stage back-cloth with some form of star-effect (holes and backlight or sewn-in LEDs) as far as he is concerned.
:But what I was actually coming here to say was regarding Astrobiology being a portmanteu (as currently in the explanation). I'm not sure I'd call it that. It's really a perfectly normal compound description of a study area, like many others in science, used to clarify what ''subset'' of biology it is (e.g. paleobiology being the biology of historic organisms, more or less, coming roughly from the greek for "old life study"). Although it does rather hint at it's "the biology of stars themselves", as opposed to the perhaps more accurate exobiology ("outside life study") when it comes to off-Earth life not in (or being) actual stars; or xenobiology ("strange life study"), although that does tend to include oddments of obscure Earth biology and artificial life as well and really doesn't mean the study of extra-terrestrial organisms... [[Special:Contributions/141.101.98.186|141.101.98.186]] 08:00, 8 May 2015 (UTC)
:: Astrobiology is a perfectly normal word. http://en.wikipedia.org/wiki/Astrobiology. [[Special:Contributions/173.245.54.151|173.245.54.151]] 08:49, 8 May 2015 (UTC)

A minor comment on the incorrect use of the word ''portmanteau'' in the explanation so far: it is defined as [http://www.thefreedictionary.com/portmanteau a word formed by merging the sounds and meanings of two different words], [[wikipedia:portmanteau]]; however, [http://dictionary.reference.com/browse/astro- astro-] is a combining form of the the greek word ''aster'' meaning ''star'', used to form compound words, such as ''astro-bio-logy'' (aster-bios-logos: star-life-word). See [[1485]] for an example of the correct use of ''portmanteau''. (someone beat me to it while i was editing this ;-))
[[Special:Contributions/141.101.104.161|141.101.104.161]] 08:07, 8 May 2015 (UTC)

You could view the comic as a theatrical production, Megan's telescope as a prop, and Beret guy is just inspecting the backdrop. The ladder is for comic and aesthetic effect {{unsigned ip|141.101.99.53}}

1521: Sword in the Stone

2015-05-07T13:23:29Z

173.245.54.151: /* Explanation */ Additional explanation of the title text

{{comic
| number = 1521
| date = May 6, 2015
| title = Sword in the Stone
| image = sword in the stone.png
| titletext = That seems like an awful lot of hassle when all I wanted was a cool sword.
}}

==Explanation==
In this comic, [[Megan]] pulls a sword out of a stone. A flash of light comes down and music plays, and a heavenly voice tells her she has ascended to the {{w|throne of England}}. Megan then pulls out her phone and searches on Wikipedia for {{w|England}} (proving the comic takes place in a time period with Wikipedia). After having read for a while she begins, while reading on, to replace the sword into the rock.

The comic references the fables of {{w|King Arthur}} and the {{w|Knights of the Round Table}}. In Arthurian legend, whoever can remove {{w|Excalibur#Excalibur_and_the_Sword_in_the_Stone|The Sword in the Stone}} is the lawful king of England. Arthur is an orphan being raised in secret; he notices the sword, removes it, and is proclaimed king. The sword is sometimes identified as {{w|Excalibur}}, although in other versions Excalibur was acquired by King Arthur from the {{w|Lady of the Lake}}. The most familiar version of this story is {{w|The Sword in the Stone}} by {{w|T. H. White}} which is based on {{w|Le Morte d'Arthur}} by {{w|Sir Thomas Malory}}. The animated {{w|The_Sword_in_the_Stone_(film)|musical}} by Walt Disney is a well known version of this fairytale based on White's book.

A key element in the joke is that as Megan begins to read about England, especially information concerning being an English ruler, she quickly thinks better of this and begins to put the sword back in its place. The punchline that Megan puts the sword back after reading about England suggests that the "gift" of being the leader of England is not worth the risk and/or work associated. It is also likely intended to suggest some degree of antipathy towards England and/or English people on the part of the character or author.

English history is rife with monarchic strife, and a brief inquiry into their {{w|List of monarchs of the British Isles by cause of death|causes of death}} will show that almost one in three {{w|British rulers}} have died either in battle or from murder, etc. This would quickly lead most sane people to conclude that the risks associated with ruling England far outweigh the benefits.

The title text furthers this plot, having Megan comment on the hassle when the only thing she was interested in was the cool sword. Apparently Megan is not enthusiastic about power, and her choice is made when she sees how problematic it could be to reign over the country of England. There is also a subtle play on the fact that in the T. H. White version, Arthur likewise is unaware of the significance of pulling the sword from the stone; he is simply looking for a sword to replace the one the one belonging to his step-brother Kay that was stolen under his watch, to avoid embarrassment and reproach.

From the time of the {{w|Roman Empire}} all the way up to {{w|Charles II of England|Charles II's}} reclamation of the throne, England was one of the most contested and most difficult to hold chunks of real estate on Earth. Besides the constant threat of usurpation, as evidenced by the numerous wars for the crown, such as the {{w|Norman_conquest_of_England|Norman conquest}} and the {{w|War of the Roses}}, there were also constant difficulties in managing the frontier regions. This can be seen from {{w|Hadrian's Wall}}, a creation of the titular Roman Emperor designed to keep the ever difficult Scots out of the areas of Roman control (the Scots would be a {{w|Anglo-Scottish Wars|constant problem}} for England up until the reign of {{w|James VI and I|King James VI and I}}; think of the movie {{w|Braveheart}} for a good example of the regular headaches they caused, seen from the English point of view), as well as the {{w|List_of_Anglo-Welsh_Wars|Welsh uprisings}} that occurred with such consistency that you could set your watch by them.

It should be noted that in Arthurian Legend, it is stated that Arthur would return when England most needed him. It is possible that Megan in this comic is a 21st century version (reincarnation) of the old Arthur.

The timing of this comic might relate to the birth of princess {{w|Princess_Charlotte_of_Cambridge|Charlotte Elizabeth Diana}} on May 2nd, 2015 just four days before this comic, and the burden of a royal of having a whole life in public shaking hands of strangers. Since {{w|Succession to the Throne Act, 2013|2013}} the {{w|Line of succession to the British throne|line of succession}} was changed to {{w|Primogeniture#Absolute_primogeniture|absolute primogeniture}}, meaning that she will keep her current position in the line (4th after her {{w|Prince George of Cambridge|older brother}}) even if she later gets baby brothers. Before this year, that would not have been the case, as the male gender took rank over birth order.

It is also probably not a coincidence that this comic was published the day before the {{w|United Kingdom general election, 2015|UK General Election}}, occurring on May 7, 2015. This election decides the modern day leader of England and the rest of the UK. And the problems they face today, may even be more likely to cause Megan to give away the throne, than the risk of untimely death she would have faced in Arthur's days.

==Transcript==

:[Megan walks up to a sword in a stone.]

:[Megan attempts to pull the sword out of the stone.]

:[A beam of light and music plays as she removes the sword.]

:[While standing with the swords a voice from the sky speaks in gray shaky letters:]
:Celestial voice: ''The Throne of England is yours''

:[Megan takes out her smart phone and searches:]
:Wikipedia
:England

:[Megan reads on her phone.]

:[Megan starts to replace the sword back into the stone.]

{{comic discussion}}


[[Category:Comics featuring Megan]]
[[Category:Wikipedia]]

1145: Sky Color

2015-04-29T17:04:41Z

173.245.54.151: /* Explanation */ Some clarifications

{{comic
| number = 1145
| date = December 10, 2012
| title = Sky Color
| image = sky_color.png
| titletext = Feynman recounted another good one upperclassmen would use on freshmen physics students: When you look at words in a mirror, how come they're reversed left to right but not top to bottom? What's special about the horizontal axis?
}}

==Explanation==
The point of this comic is that often, curious children ask their parents simple questions about understanding how the world works. Often, although the question is simple, the answer is not. "Why is the sky blue?" is a common example, since most parents are not familiar with {{w|Rayleigh scattering}}, and thus are unable to answer the question.

[[Randall]]'s hobby is to make those questions even harder, in order to stump the (scientist) parents and make them uncomfortable.

Another point of this comic is that we often think that we understand a scientific phenomenon (e.g. why is the sky blue?); however, a certain simple question (e.g. why isn't the sky violet?) can often uncover large gaps in our actual understanding.

{{W|Rayleigh scattering}} is the phenomenon that explains the color of the sky, where light of every wavelength gets scattered in the air by the inverse quartic (fourth power) of its wavelength as given in the comic. In the {{w|visible spectrum}}, blue light has a wavelength of 450–495 nm while violet has a shorter wavelength of 380–450 nm. Violet light does indeed get scattered more than blue light, however the lower portion of the spectrum for sunlight consists of blue light and eyes are much more sensitive to blue light than violet light. This leaves the impression of a blue sky. A good explanation, including why blue and not violet, can be found in [http://math.ucr.edu/home/baez/physics/General/BlueSky/blue_sky.html Usenet Physics FAQ :: Why is the sky blue?], but note that human color perception [http://blog.asmartbear.com/color-wheels.html is more complicated] than described there.

The title text refers to a {{w|mirror image}}, and is discussed by the famous American theoretical physicist {{w|Richard Feynman}} in a famous BBC documentary [http://www.youtube.com/watch?v=6tuxLY94LXw], as one of the problems which he used to have fun with first years (British English for first year student or freshman).

A mirror image is a virtual image produced by the reflection of light on a mirror. In the mirror image, only front and back are switched around — like a printing press or a rubber stamp. Left and right are still left and right in an absolute reference frame — wave your left arm in front of the mirror and the "mirror person" also waves the arm on the left side. It is only when using "personal" reference frame —tied to the individual— that we can say that the "mirror person" is moving their right arm. The apparent inversion comes from the fact that the mind projects itself onto the person in the mirror.

To help understand why this effect happens, imagine that you are holding a sign which says "MIX" and facing a mirror. Initially, you face the sign towards you. The M is on the left and the X on the right. Now, you turn the sign around so that the sign faces the mirror. Now, even without paying any attention to the mirror, simply because you have turned it around, now the M is on the right and the X is on the left and if you could see through the back of the sign, it would say "XIM" from your perspective. When you look at it in the mirror, you are now able to see that orientation and it appears to read "XIM". If instead of turning the sign around horizontally to look at it in the mirror, you flipped it vertically and looked at it in the mirror, it would appear to say "WIX" in the mirror. Thus the mirror is only revealing how the text is oriented relative to your eyes. Or, to put it more succinctly: mirrors ''don't'' reverse left to right, ''turning around'' does. Mirrors reverse along whatever direction is perpendicular to the plane of the mirror. You can induce a mirror to reverse left and right only --- by standing next to it instead of in front of it, facing along the plane of the mirror itself. If you lift your right arm, you can clearly see your image's left arm raising, without having to adjust for frame of reference. Similarly, you can induce a mirror to reverse top and bottom only by holding it flat above your head or laying it flat on the ground and standing on it (or perhaps standing under a suitably equipped bedroom ceiling).

==Transcript==
:[Girl and her mother, Megan. Megan is at a desk and facing the girl.]
:Girl: Mommy, why is the sky blue?
:Megan: Rayleigh scattering! Short wavelengths get scattered ''way'' more (proportional to 1/''λ''4). Blue light dominates because it's so short.
:Girl: Oh.
:Girl: So why ''isn't'' the sky violet?
:Megan: Well, because, uh... ...hmm.

:My hobby: Teaching tricky questions to the children of my scientist friends.

{{comic discussion}}
[[Category:Comics featuring Megan]]
[[Category:Physics]]
[[Category:My Hobby]]

1145: Sky Color

2015-04-29T17:01:17Z

173.245.54.151: /* Explanation */ Added some useful scenarios to more fully understand the mirror paradox

{{comic
| number = 1145
| date = December 10, 2012
| title = Sky Color
| image = sky_color.png
| titletext = Feynman recounted another good one upperclassmen would use on freshmen physics students: When you look at words in a mirror, how come they're reversed left to right but not top to bottom? What's special about the horizontal axis?
}}

==Explanation==
The point of this comic is that often, curious children ask their parents simple questions about understanding how the world works. Often, although the question is simple, the answer is not. "Why is the sky blue?" is a common example, since most parents are not familiar with {{w|Rayleigh scattering}}, and thus are unable to answer the question.

[[Randall]]'s hobby is to make those questions even harder, in order to stump the (scientist) parents and make them uncomfortable.

Another point of this comic is that we often think that we understand a scientific phenomenon (e.g. why is the sky blue?); however, a certain simple question (e.g. why isn't the sky violet?) can often uncover large gaps in our actual understanding.

{{W|Rayleigh scattering}} is the phenomenon that explains the color of the sky, where light of every wavelength gets scattered in the air by the inverse quartic (fourth power) of its wavelength as given in the comic. In the {{w|visible spectrum}}, blue light has a wavelength of 450–495 nm while violet has a shorter wavelength of 380–450 nm. Violet light does indeed get scattered more than blue light, however the lower portion of the spectrum for sunlight consists of blue light and eyes are much more sensitive to blue light than violet light. This leaves the impression of a blue sky. A good explanation, including why blue and not violet, can be found in [http://math.ucr.edu/home/baez/physics/General/BlueSky/blue_sky.html Usenet Physics FAQ :: Why is the sky blue?], but note that human color perception [http://blog.asmartbear.com/color-wheels.html is more complicated] than described there.

The title text refers to a {{w|mirror image}}, and is discussed by the famous American theoretical physicist {{w|Richard Feynman}} in a famous BBC documentary [http://www.youtube.com/watch?v=6tuxLY94LXw], as one of the problems which he used to have fun with first years (British English for first year student or freshman).

A mirror image is a virtual image produced by the reflection of light on a mirror. In the mirror image, only front and back are switched around — like a printing press or a rubber stamp. Left and right are still left and right in an absolute reference frame — wave your left arm in front of the mirror and the "mirror person" also waves the arm on the left side. It is only when using "personal" reference frame —tied to the individual— that we can say that the "mirror person" is moving their right arm. The apparent inversion comes from the fact that the mind projects itself onto the person in the mirror.

To help understand why this effect happens, imagine that you are holding a sign which says "MIX" and facing a mirror. Initially, you face the sign towards you. The M is on the left and the X on the right. Now, you turn the sign around so that the sign faces the mirror. Now, even without paying any attention to the mirror, simply because you have turned it around, now the M is on the right and the X is on the left and if you could see through the back of the sign, it would say "XIM" from your perspective. When you look at it in the mirror, you are now able to see that orientation and it appears to read "XIM". If instead of turning the sign around horizontally to look at it in the mirror, you flipped it vertically and looked at it in the mirror, it would appear to say "WIX" in the mirror. Thus the mirror is only revealing how the text is oriented relative to your eyes. Or, to put it more succinctly: mirrors ''don't'' reverse left to right, ''turning around'' does. Mirrors don't reverse left to right but they reverse front to back. In fact, you can induce a mirror to reverse left and right only --- by standing next to it instead of in front of it, facing along the plane of the mirror itself. If you lift your right arm, you can clearly see your image's left arm raising, without having to adjust for frame of reference. Similarly, you can induce a mirror to reverse top and bottom and nothing else by holding it flat above your head or laying it flat on the ground and standing on it (or perhaps standing under a suitably equipped bedroom ceiling).

==Transcript==
:[Girl and her mother, Megan. Megan is at a desk and facing the girl.]
:Girl: Mommy, why is the sky blue?
:Megan: Rayleigh scattering! Short wavelengths get scattered ''way'' more (proportional to 1/''λ''4). Blue light dominates because it's so short.
:Girl: Oh.
:Girl: So why ''isn't'' the sky violet?
:Megan: Well, because, uh... ...hmm.

:My hobby: Teaching tricky questions to the children of my scientist friends.

{{comic discussion}}
[[Category:Comics featuring Megan]]
[[Category:Physics]]
[[Category:My Hobby]]

Talk:776: Still No Sleep

2015-04-02T03:20:42Z

173.245.54.151:

I think the squirrel did not mean not to worry about his hallucination. The squirrel's comment is a joke that cueball should not consider the possibility that he is totally sane. He is not sane and this is obvious even to the hallucinated squirrel.
[[Special:Contributions/141.101.97.225|141.101.97.225]] 11:46, 9 November 2014 (UTC)

What if the squirrel is the one hallucinating?

1409

2014-08-18T07:06:28Z

173.245.54.151: doesn't seem MySQL-specific

{{comic
| number = 1409
| date = August 17, 2014
| title = Query
| image = query.png
| titletext = SELECT * FROM GHOSTS
}}

==Explanation==
[[Megan]] picks up a strange device that mysteriously asks her to enter a query after stating "LOADED TABLE: PEOPLE ENTER QUERY." She looks around and sees people surrounding her. Upon entering a SQL-esque query into it (SELECT * FROM PEOPLE WHERE AGE > 30), the specified people are basked in a yellow light. She then tries other experimental queries, and sees it work every time.
Finally, she types "DROP TABLE PEOPLE" (delete the Table named People), and everybody, including herself, disappears.
It can be noted that the title text may be a joke stating that when the people died, they were moved to a table called "GHOSTS." The query would then, presumably, see all the people that were deleted.

==Transcript==
{{incomplete transcript}}

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Hairy]]
[[Category:Comics with color]]

Talk:1392: Dominant Players

2014-07-09T13:27:26Z

173.245.54.151:

This may be related to the recent MOBA segregation controversy: http://www.pcgamer.com/uk/2014/07/02/hearthstone-tournament/ {{unsigned ip|108.162.229.25}}

What is the significance of the line colors? {{unsigned ip|108.162.215.78}}
:I think the red lines are those players that were undisputed #1 for a significant period. [[Special:Contributions/103.22.201.239|103.22.201.239]] 08:02, 9 July 2014 (UTC)
: But Petrosian has no colored line, although he was world champion. Maybe he did not have the highest ELO rating despite being WC?[[User:Jkrstrt|Jkrstrt]] ([[User talk:Jkrstrt|talk]]) 09:23, 9 July 2014 (UTC)

Dashed lines are apparently for the period before ELO ratings existed, taking 1965 as a start point (midway between the point in time when ELO rating was adopted by USCF and FIDE, respectively. There seems to be an exception for Alekhine -or is that a very long dash? [[User:Jkrstrt|Jkrstrt]] ([[User talk:Jkrstrt|talk]]) 09:23, 9 July 2014 (UTC)

Naughty Randall, always label your axes! [[User:Kaa-ching|Kaa-ching]] ([[User talk:Kaa-ching|talk]]) 08:00, 9 July 2014 (UTC)

The comment in the women's rankings about Kira Zvorykina is a little odd. One would hope she continued playing in tournaments into the 20th century, given that the first 81 years of her life were in the 20th century. {{unsigned ip|108.162.250.220}}

While at the time, the V-1 was called a "Flying Bomb", wikipedia indeed calls it an early pulse-jet ancestor of the modern cruise missile: http://en.wikipedia.org/wiki/V-1_flying_bomb . I built a model of one in an 8th grade rocketry club, replacing the pulse jet with an Estes D-6-0. Mine took off, but sure enough, yes, the stubby wings stalled easily, the flight path was a weird s curve as the wings stalled out twice while under thrust.[[User:Seebert|Seebert]] ([[User talk:Seebert|talk]]) 09:03, 9 July 2014 (UTC)

Link to the game against Deep Blue, anybody? Also, shouldn't the title text be at least mentioned? [[Special:Contributions/199.27.128.71|199.27.128.71]] 09:13, 9 July 2014 (UTC)

Kasparov-Deep Blue Games: http://www.chessgames.com/perl/chesscollection?cid=1014770 {{unsigned ip|141.101.64.131}}

The explanation says in the first sentence that for chess there's an overall rating and a woman's rating in the comic. All I see is a men's rating and a woman's rating, no overall rating, however. {{unsigned ip|108.162.254.24}}
: As Judith Polgar is present in the first chart, it appears to be an overall, not specifically a men's chart.[[User:Jkrstrt|Jkrstrt]] ([[User talk:Jkrstrt|talk]]) 11:37, 9 July 2014 (UTC)

Anyone knows why Viswanathan Anand is not included (or am I blind?) Marty / [[Special:Contributions/141.101.104.43|141.101.104.43]]
I had the exact same question. It appears that this is a West and Russian centric view of the world [[User:Indianrediff|Indianrediff]] ([[User talk:Indianrediff|talk]]) 13:23, 9 July 2014 (UTC)

It's Julius Erving not Irving. [[Special:Contributions/173.245.54.151|173.245.54.151]] 13:27, 9 July 2014 (UTC)