https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&user=108.162.246.135&feedformat=atomexplain xkcd - User contributions [en]2022-12-01T22:42:50ZUser contributionsMediaWiki 1.30.0https://www.explainxkcd.com/wiki/index.php?title=2062:_Barnard%27s_Star&diff=1962392062: Barnard's Star2020-08-20T23:18:02Z<p>108.162.246.135: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 2062<br />
| date = October 22, 2018<br />
| title = Barnard's Star<br />
| image = barnards_star.png<br />
| titletext = "Ok, team. We have a little under 10,000 years before closest approach to figure out how to destroy Barnard's Star." "Why, does it pose a threat to the Solar System?" "No. It's just an asshole."<br />
}}<br />
<br />
==Explanation==<br />
[[File:Near-stars-past-future-en.svg|thumb|300px|Distances to the nearest stars from 20,000 years ago until 80,000 years in the future]]<br />
{{w|Barnard's Star}} is a very-low-mass {{w|Red dwarf|red dwarf}} about 6 light-years away from Earth in the constellation of {{w|Ophiuchus}}. It is the fourth-nearest known individual star to the {{w|Sun}} after the three components of the Alpha Centauri system; it is the closest star to Earth in the Northern Hemisphere. It is a red dwarf with a mass of 0.144 Solar masses, a diameter one fifth that of the Sun, and it is 7–12 billion years old. Because of this low mass the gravitational pressure in the core is much lower and thus the fusion rate is far smaller than in the core of the Sun. In fact this star is so dim that, even though it's one of the nearest, it can't be seen by the naked eye. The low fusion rate also means that the lifespan of small stars is much longer. While huge stars might last a few hundred million years, and the Sun about 10 billion years, a small red dwarf has a lifespan of about a trillion years.<br />
<br />
Barnard's Star is the star with the greatest proper motion in the sky. Proper motion is motion in the sky other than that caused by Earth's rotation or orbit. Barnard's star is both very close to the sun (as these things go) and moving now at a speed of more than 140 km/s toward the Sun. It will make its closest approach to the Sun in approximately 10,000 years, at a distance of about 3.75 light-years.<br />
<br />
The image on the right shows different stars near the Sun over 100,000 years and it can be seen that none of them are getting closer than 3 light-years. This is a safe distance to our Solar System and the stars will not influence the orbits of the planets or smaller bodies. It's also obvious that much closer approaches never have happened since the Solar System formed 4.5 billion years ago because otherwise the nearly circular orbits of the planets in the same plane wouldn't be possible. Closer encounters have happened in the past by mostly small stars like {{w|Scholz's Star}} which actually passed through the {{w|Oort cloud}} at a distance of 0.82 light-years about 70,000 years ago, and at least one estimate suggests that a star is expected to pass through the Oort Cloud every 100,000 years or so. This distance is still too far away to influence the orbits of the planets, but those encounters cause {{w|Comet|comets}} perturbed from the Oort cloud to the inner Solar System roughly 2 million years later.<br />
<br />
The comic shows the sizes and the distances not in a proper scale. If the Sun was 1.4 cm (1.4 Mio km in real) in diameter, Barnard's Star would be less than 3 mm at a distance of 356 km. Even Jupiter wouldn't fit into this picture -- at ten times smaller than the Sun, it would be a few pixels, but at a distance of 7.8 m to the Sun and all the other planets would fit into a circle less than 100 meters in diameter. The distances to others stars are far beyond human imagination and at its closest distance a message still takes 3.75 years from Barnard's Star to the Sun.<br />
<br />
In regards to "20,000-year-long high-speed flyby", the joke here is suggesting Barnard's Star would need to scream out the maleficent, trolling statement as quickly as possible due to 20,000 years being such a small segment of time relative to the lifespan of the star (and our Sun, for that matter).<br />
<br />
The title text emphasizes that this close approach will not be any hazard to the Solar System, but someone is envious of the long lifetime of Barnard's Star or annoyed by its unpleasant behavior (yelling at the sun for 20,000 years would be a minuscule amount of time for the stars, but for humans it would be a vast length of time, and would get annoying very quickly).<br />
<br />
==Transcript==<br />
:[A black sky is shown with a yellow spot near the bottom, left of the center. Three smaller red spots at the diagonal from top left to bottom right indicate a moving star over time. Above these red spots lines are connected to a text that starts and ends with many ''A''s, first growing, and at the end getting smaller:]<br />
:...AAAAHHi Sun! I was here billions of years before you formed and will shine for trillions of years after you dieEEEEEEAAA...<br />
<br />
:[Caption below the frame:]<br />
:Sometimes, I wonder what Barnard's Star is saying to the Sun as it performs its 20,000-year-long high-speed flyby.<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics with color]]<br />
[[Category:Comics with inverted brightness]]<br />
[[Category:Astronomy]]</div>108.162.246.135https://www.explainxkcd.com/wiki/index.php?title=2343:_Mathematical_Symbol_Fight&diff=1957812343: Mathematical Symbol Fight2020-08-08T18:39:50Z<p>108.162.246.135: /* Explanation */ move assides about flatland to below table</p>
<hr />
<div>{{comic<br />
| number = 2343<br />
| date = August 7, 2020<br />
| title = Mathematical Symbol Fight<br />
| image = mathematical_symbol_fight.png<br />
| titletext = Oh no, a musician just burst in through the door confidently twirling a treble clef.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a SQUARE ROOT SCYTHE. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}<br />
<br />
This panel imagines which {{w|List of mathematical symbols|mathematical symbols}} would be good in a fight if they were made corporeal in two (or three) dimensions. Generally, objects with longer reach and pointier ends wind up on the right ("more useful") side of the scale, and symbols with less reach and more curves tend towards the left ("less useful") side. <br />
<br />
The comic invokes [[wikipedia:surreal humour|surreal humour]] by suggesting that mathematical symbols could be handled as physical objects in the real world. Another component of the humor is the implication that it is useful to prepare to use mathematical symbols in a fight, even though mathematicians, who use mathematical symbols, usually do not conduct their debates violently {{Citation needed}} (though some stories suggest that {{w|Hippasus}} was killed by his fellow Pythagoreans for his proof that irrational numbers exist), and even if they did, they wouldn't use large reproductions of their symbols as weapons.{{Citation needed}}<br />
<br />
{| class="wikitable"<br />
! Symbol<br />
! Meaning<br />
! Notes on using in a fight<br />
|-<br />
|ℝ<br />
|The set of [[wikipedia:real number|real number]]s<br />
|Megan seems to be struggling with a giant version of this symbol.<br />
|-<br />
|θ<br />
|[[wikipedia:Theta#Mathematics_and_science|Theta]]<br />
|This symbol is not very sharp, and [[White Hat]] is unable to use it in combat. It would not work as a good shield due to the hole in the symbol, but it possibly could be thrown. (The later version of Xena's chakram had a bar in the middle.)<br />
|-<br />
|∅<br />
|[[wikipedia:Empty set|Empty set]]<br />
|Similarly shaped to theta, but identified as being slightly more useful, presumably because the parts of the bar that extend beyond the circle can be used as thrusting weapons.<br />
|-<br />
|∞<br />
|infinity<br />
|-<br />
|><br />
|Greater than<br />
|-<br />
|∝<br />
|[[wikipedia:Proportionality_(mathematics)#Direct_proportionality|Direct Proportionality]]<br />
|-<br />
|∪<br />
|{{w|union (set theory)}}<br />
|-<br />
|∈/ϵ<br />
|{{w|Element (mathematics)|member of}} (set theory) or the "lunate" lowercase {{w|Epsilon#Symbol|epsilon}}<br />
|Cueball is holding this in the manner of a Klingon "{{w|Bat'leth}}" from the ''Star Trek'' franchise. The Bat'leth is [https://youtu.be/VsElSDXPgSA infamous] among swordfighters for being rather impractical, and that the Klingon warrior race would have been better suited using swords like humans. It seems Randall agrees, as the ∈ is quite far on the left of the chart.<br />
|-<br />
|π<br />
|[[wikipedia:Pi|pi]]<br />
|-<br />
|∀<br />
|"{{w|Universal quantification|for all}}"<br />
|Could be held by the crossbar clenched in a fist, and then used as a {{w|push dagger}}, with the legs acting as a guard. Or could be held by the legs.<br />
Compared to the similar Δ (delta) the point is sharper, the grip is closer to the point so it would be easier control (keep the weapon from twisting). Unclear why it is listed as much less effective than the delta. Perhaps the guard legs are too long?<br />
|-<br />
|∂<br />
|{{w|∂}} ([[wikipedia:Partial derivative|partial derivative]] or [[wikipedia:Boundary_(topology)|boundary operator]])<br />
|It's not clear why Randall ranks this symbol as so much less effective than the similarly-shaped 𝜌, but the curl in the "tail" of the ∂ would give it a shorter lever arm when swung and would disrupt the balance.<br />
|-<br />
| +<br />
|[[wikipedia:Plus_and_minus_signs#Plus_sign|Plus]]<br />
|Maybe thrown like a {{w|shuriken}}?<br />
|-<br />
|Ψ<br />
|[[wikipedia:Psi#Mathematics|Psi]]<br />
|It could be used as a slightly-less-functional trident or pitchfork, with a shorter handle. More particularly, it resembles a {{w|sai}} (which, funnily enough, is how "Psi" is pronounced).<br />
|-<br />
|≠<br />
|not equal sign<br />
|-<br />
|~<br />
|[[wikipedia:Tilde#Mathematics|tilde]], meaning "approximately", equivalent, or several transforms of a function<br />
|A potentially dangerous throwing weapon. Could also be similar to a dagger ({{w|Kris}}) or a sword ({{w|Flame-bladed sword}}), with a wavy blade.<br />
|-<br />
|#<br />
|[[wikipedia:Cardinality|Cardinality]], [[wikipedia:Connected_sum|connected sum]] (knot theory), or [[wikipedia:Primorial|primorial]].<br />
|Blondie uses this symbol.<br />
|-<br />
|Δ<br />
|[[wikipedia:Delta_(letter)|Delta]]<br />
|Could be held with one bar clenched in a fist, and then used as a {{w|push dagger}}. Unclear why listed as much more effective than ∀.<br />
|-<br />
|⇒<br />
|[[wikipedia:Material_conditional|Material consequence]] or [[wikipedia:Logical_consequence|Logical consequence]], meaning "implies"<br />
|The point is nice, but having two poles (or one board-like thick handle) would be difficult to wield. A collection of them might make a nice defensive pike line.<br />
|-<br />
|⋅<br />
|multiplication sign<br />
|If thrown, this could be a dangerous projectile weapon, or it could be scattered on the ground as a trip hazard. Three of them stacked together would make a "{{w|therefore sign}}", which might at least conclude the ''mathematical'' portion of the fight in the user's favor.<br />
|-<br />
|ζ<br />
|{{w|Zeta#Mathematics_and_science|Zeta}}<br />
|Could be sharpened into a scythe or curved saber, depending on the curvature and length of the 'tail' at the bottom.<br />
|-<br />
|ℵ<br />
|[[wikipedia:Aleph_number|Aleph number]]<br />
|Could be brandished or thrown in the manner of a shuriken.<br />
|-<br />
|Γ<br />
|uppercase Greek letter {{w|Gamma#Uppercase|Gamma}}<br />
|If this letter is formed with {{w|serif}}s, it could be used as an axe or hook, and if it is made {{w|sans-serif}}, it would make a powerful pick or war hammer.<br />
|-<br />
|√<br />
|{{w|square root}} sign<br />
|Randall has drawn this sign with a long overbar, which makes it useful like a {{w|Pole weapon|pole arm}}. Black Hat has chosen this symbol.<br />
|-<br />
|''ρ''<br />
|{{w|Prime_constant|italic rho}}<br />
|Ponytail is brandishing this symbol against Danish, apparently using it like a club or hammer and striking with the curve.<br />
|-<br />
|∮<br />
|{{w|contour integral}}<br />
|This symbol is drawn with a very tight center, giving it an almost identical figure to the regular integral symbol. Presumably, the added bulk for marginal additional use earns it a rating of 'less effective'.<br />
|-<br />
|∫<br />
|{{w|integral}}<br />
|Could be used in the manner of a shepherd's crook, or as a {{w|Bill (weapon)|billhook}}. Could be used as a {{w|spear thrower}}, combined with ⋅ or ⇀.<br />
|-<br />
|→<br />
|Implies; X→Y means that if X is true, then Y is also true<br />
|Danish is brandishing this symbol against Ponytail, apparently using it like a spear or other polearm.<br />
|-<br />
|⊥<br />
|{{w|up tack}} or falsum, indicating a false proposition in logic or the bottom element in a partial order<br />
|Used as a {{w|war hammer}} (held by the long stem), the opponent would be struck with either leg of the top of the T. Held by the short legs (like a wishbone), could be used as a two handed sword.<br />
(If tipped with a knapped stone head, it could become a {{w|Folsom point|falsum point}}.)<br />
|-<br />
|⇀<br />
|{{w|Vector notation}}<br />
|A single-barbed spear.<br />
|-<br />
|⎯⎯<br />
|{{w|Fraction#Vocabulary|Fraction bar}} (division) or {{w|Overline#Math_and_science|overline}} (complex conjugate or mean).<br />
|Hairy is brandishing this symbol against Black Hat. The single shaft would allow it to be used in the manner of a {{w|quarterstaff}}, {{w|bō}}, or other {{w|stick-fighting}} weapon. Of the symbols shown in the comic, Randall considers this one the most useful in a fight, presumably because of its greater reach than the vector arrow and its simplicity compared to the square root symbol.<br />
|-<br />
|𝄞<br />
|{{w|Treble clef}}<br />
|Mentioned in the title text; this is not a mathematical symbol, but a musical symbol. The treble clef is a much more complicated symbol than those used in mathematics, hence the musician's "confidence" in his weapon. The curve at the bottom could be used as a hook, the upper curl could be used as a blunt weapon, and the tight curl of the center would serve as a better defensive shield than theta.<br />
|}<br />
<br />
A straight line is farthest to the "more dangerous" side, which could possibly be a reference to the dangers posed by lines in "Flatland", because their infinitely-sharp endpoints could be difficult to see (particularly their rear end, which does not contain a gleaming eye as their front end does) and would fatally pierce whoever they chose to stab. However, taking a more literal view of the drawings, the straight line does not appear to be any thicker or thinner, or pointier, than any of the other lines. <br />
<br />
The title text refers to a {{w|clef}}, which is not a mathematical symbol but rather a {{w|List of musical symbols|musical symbol}}. The note of concern in the text suggests musical symbols may be viewed in such fights as exotic or especially dangerous.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
[Heading]<br />
<br />
Mathematical Symbols<br />
<br />
[Subheading]<br />
<br />
by how useful they would be in a fight<br />
<br />
<br />
more useful<br />
<br />
⟶<br />
<br />
ℝ ∅ > ∝ π + Ψ ~ ⇒ ⋅ Γ √ ∮ ∫ ⇀<br />
θ ∞ ∪ ∈ ∀ ∂ ≠ # Δ ζ ℵ ''ρ'' → ⊥ ⎯<br />
<br />
[Below the (number?) line, eight characters fight each other, using some of the symbols mentioned above as weapons.]<br />
<br />
[The characters hold more "useful" weapons from left to right, correlating with the chart.]<br />
<br />
<br />
<br />
[Megan is awkwardly handling a giant "ℝ".]<br />
<br />
[White Hat is holding a "θ" with both hands, as a shield.]<br />
<br />
[Cueball is holding an "∈" in both hands, with its "tines" pointed towards Blondie, who is swatting at him with a "#".]<br />
<br />
[Ponytail is leaping at Danish, swinging a "''ρ''" like an axe, while Danish is leaning back and thrusting a "→" back at her.]<br />
<br />
[Black Hat is swinging a long "√" like a polearm at Hairy, who is holding a long "⎯" defensively.]<br />
<br />
<br />
-<br />
List of symbols from left to right (by rightmost edge): <br />
<br />
ℝ θ ∅ ∞ > ∪ ∝ ∈ ∀ π ∂ + ≠ Ψ # ~ △ ζ ⇒ ⋅ ℵ Γ ''ρ'' √ → ∮ ∫ ⊥ ⇀ ⎯<br />
<br />
<br />
Note: Where two symbols had similar right-most edges, the overlay grid on an ASUS pro-art display was used to decide which one went further right. <br />
<br />
{{comic discussion}}<br />
[[Category:Math]]<br />
[[Category:Music]]<br />
[[Category:Charts]]<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Danish]]<br />
[[Category:Comics featuring White Hat]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Blondie]]<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Comics featuring Black Hat]]<br />
[[Category:Comics featuring Hairy]]</div>108.162.246.135https://www.explainxkcd.com/wiki/index.php?title=2343:_Mathematical_Symbol_Fight&diff=1957802343: Mathematical Symbol Fight2020-08-08T18:34:59Z<p>108.162.246.135: /* Explanation */ square root wikilink pole weapon</p>
<hr />
<div>{{comic<br />
| number = 2343<br />
| date = August 7, 2020<br />
| title = Mathematical Symbol Fight<br />
| image = mathematical_symbol_fight.png<br />
| titletext = Oh no, a musician just burst in through the door confidently twirling a treble clef.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a SQUARE ROOT SCYTHE. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}<br />
<br />
This panel imagines which {{w|List of mathematical symbols|mathematical symbols}} would be good in a fight if they were made corporeal in two (or three) dimensions. Generally, objects with longer reach and pointier ends wind up on the right ("more useful") side of the scale, and symbols with less reach and more curves tend towards the left ("less useful") side. <br />
<br />
The comic invokes [[wikipedia:surreal humour|surreal humour]] by suggesting that mathematical symbols could be handled as physical objects in the real world. Another component of the humor is the implication that it is useful to prepare to use mathematical symbols in a fight, even though mathematicians, who use mathematical symbols, usually do not conduct their debates violently {{Citation needed}} (though some stories suggest that {{w|Hippasus}} was killed by his fellow Pythagoreans for his proof that irrational numbers exist), and even if they did, they wouldn't use large reproductions of their symbols as weapons.{{Citation needed}}<br />
<br />
A straight line is farthest to the "more dangerous" side, which could possibly be a reference to the dangers posed by lines in "Flatland", because their infinitely-sharp endpoints could be difficult to see (particularly their rear end, which does not contain a gleaming eye as their front end does) and would fatally pierce whoever they chose to stab. However, taking a more literal view of the drawings, the straight line does not appear to be any thicker or thinner, or pointier, than any of the other lines. <br />
<br />
The title text refers to a {{w|clef}}, which is not a mathematical symbol but rather a {{w|List of musical symbols|musical symbol}}. The note of concern in the text suggests musical symbols may be viewed in such fights as exotic or especially dangerous.<br />
<br />
{| class="wikitable"<br />
! Symbol<br />
! Meaning<br />
! Notes on using in a fight<br />
|-<br />
|ℝ<br />
|The set of [[wikipedia:real number|real number]]s<br />
|Megan seems to be struggling with a giant version of this symbol.<br />
|-<br />
|θ<br />
|[[wikipedia:Theta#Mathematics_and_science|Theta]]<br />
|This symbol is not very sharp, and [[White Hat]] is unable to use it in combat. It would not work as a good shield due to the hole in the symbol, but it possibly could be thrown. (The later version of Xena's chakram had a bar in the middle.)<br />
|-<br />
|∅<br />
|[[wikipedia:Empty set|Empty set]]<br />
|Similarly shaped to theta, but identified as being slightly more useful, presumably because the parts of the bar that extend beyond the circle can be used as thrusting weapons.<br />
|-<br />
|∞<br />
|infinity<br />
|-<br />
|><br />
|Greater than<br />
|-<br />
|∝<br />
|[[wikipedia:Proportionality_(mathematics)#Direct_proportionality|Direct Proportionality]]<br />
|-<br />
|∪<br />
|{{w|union (set theory)}}<br />
|-<br />
|∈/ϵ<br />
|{{w|Element (mathematics)|member of}} (set theory) or the "lunate" lowercase {{w|Epsilon#Symbol|epsilon}}<br />
|Cueball is holding this in the manner of a Klingon "{{w|Bat'leth}}" from the ''Star Trek'' franchise. The Bat'leth is [https://youtu.be/VsElSDXPgSA infamous] among swordfighters for being rather impractical, and that the Klingon warrior race would have been better suited using swords like humans. It seems Randall agrees, as the ∈ is quite far on the left of the chart.<br />
|-<br />
|π<br />
|[[wikipedia:Pi|pi]]<br />
|-<br />
|∀<br />
|"{{w|Universal quantification|for all}}"<br />
|Could be held by the crossbar clenched in a fist, and then used as a {{w|push dagger}}, with the legs acting as a guard. Or could be held by the legs.<br />
Compared to the similar Δ (delta) the point is sharper, the grip is closer to the point so it would be easier control (keep the weapon from twisting). Unclear why it is listed as much less effective than the delta. Perhaps the guard legs are too long?<br />
|-<br />
|∂<br />
|{{w|∂}} ([[wikipedia:Partial derivative|partial derivative]] or [[wikipedia:Boundary_(topology)|boundary operator]])<br />
|It's not clear why Randall ranks this symbol as so much less effective than the similarly-shaped 𝜌, but the curl in the "tail" of the ∂ would give it a shorter lever arm when swung and would disrupt the balance.<br />
|-<br />
| +<br />
|[[wikipedia:Plus_and_minus_signs#Plus_sign|Plus]]<br />
|Maybe thrown like a {{w|shuriken}}?<br />
|-<br />
|Ψ<br />
|[[wikipedia:Psi#Mathematics|Psi]]<br />
|It could be used as a slightly-less-functional trident or pitchfork, with a shorter handle. More particularly, it resembles a {{w|sai}} (which, funnily enough, is how "Psi" is pronounced).<br />
|-<br />
|≠<br />
|not equal sign<br />
|-<br />
|~<br />
|[[wikipedia:Tilde#Mathematics|tilde]], meaning "approximately", equivalent, or several transforms of a function<br />
|A potentially dangerous throwing weapon. Could also be similar to a dagger ({{w|Kris}}) or a sword ({{w|Flame-bladed sword}}), with a wavy blade.<br />
|-<br />
|#<br />
|[[wikipedia:Cardinality|Cardinality]], [[wikipedia:Connected_sum|connected sum]] (knot theory), or [[wikipedia:Primorial|primorial]].<br />
|Blondie uses this symbol.<br />
|-<br />
|Δ<br />
|[[wikipedia:Delta_(letter)|Delta]]<br />
|Could be held with one bar clenched in a fist, and then used as a {{w|push dagger}}. Unclear why listed as much more effective than ∀.<br />
|-<br />
|⇒<br />
|[[wikipedia:Material_conditional|Material consequence]] or [[wikipedia:Logical_consequence|Logical consequence]], meaning "implies"<br />
|The point is nice, but having two poles (or one board-like thick handle) would be difficult to wield. A collection of them might make a nice defensive pike line.<br />
|-<br />
|⋅<br />
|multiplication sign<br />
|If thrown, this could be a dangerous projectile weapon, or it could be scattered on the ground as a trip hazard. Three of them stacked together would make a "{{w|therefore sign}}", which might at least conclude the ''mathematical'' portion of the fight in the user's favor.<br />
|-<br />
|ζ<br />
|{{w|Zeta#Mathematics_and_science|Zeta}}<br />
|Could be sharpened into a scythe or curved saber, depending on the curvature and length of the 'tail' at the bottom.<br />
|-<br />
|ℵ<br />
|[[wikipedia:Aleph_number|Aleph number]]<br />
|Could be brandished or thrown in the manner of a shuriken.<br />
|-<br />
|Γ<br />
|uppercase Greek letter {{w|Gamma#Uppercase|Gamma}}<br />
|If this letter is formed with {{w|serif}}s, it could be used as an axe or hook, and if it is made {{w|sans-serif}}, it would make a powerful pick or war hammer.<br />
|-<br />
|√<br />
|{{w|square root}} sign<br />
|Randall has drawn this sign with a long overbar, which makes it useful like a {{w|Pole weapon|pole arm}}. Black Hat has chosen this symbol.<br />
|-<br />
|''ρ''<br />
|{{w|Prime_constant|italic rho}}<br />
|Ponytail is brandishing this symbol against Danish, apparently using it like a club or hammer and striking with the curve.<br />
|-<br />
|∮<br />
|{{w|contour integral}}<br />
|This symbol is drawn with a very tight center, giving it an almost identical figure to the regular integral symbol. Presumably, the added bulk for marginal additional use earns it a rating of 'less effective'.<br />
|-<br />
|∫<br />
|{{w|integral}}<br />
|Could be used in the manner of a shepherd's crook, or as a {{w|Bill (weapon)|billhook}}. Could be used as a {{w|spear thrower}}, combined with ⋅ or ⇀.<br />
|-<br />
|→<br />
|Implies; X→Y means that if X is true, then Y is also true<br />
|Danish is brandishing this symbol against Ponytail, apparently using it like a spear or other polearm.<br />
|-<br />
|⊥<br />
|{{w|up tack}} or falsum, indicating a false proposition in logic or the bottom element in a partial order<br />
|Used as a {{w|war hammer}} (held by the long stem), the opponent would be struck with either leg of the top of the T. Held by the short legs (like a wishbone), could be used as a two handed sword.<br />
(If tipped with a knapped stone head, it could become a {{w|Folsom point|falsum point}}.)<br />
|-<br />
|⇀<br />
|{{w|Vector notation}}<br />
|A single-barbed spear.<br />
|-<br />
|⎯⎯<br />
|{{w|Fraction#Vocabulary|Fraction bar}} (division) or {{w|Overline#Math_and_science|overline}} (complex conjugate or mean).<br />
|Hairy is brandishing this symbol against Black Hat. The single shaft would allow it to be used in the manner of a {{w|quarterstaff}}, {{w|bō}}, or other {{w|stick-fighting}} weapon. Of the symbols shown in the comic, Randall considers this one the most useful in a fight, presumably because of its greater reach than the vector arrow and its simplicity compared to the square root symbol.<br />
|-<br />
|𝄞<br />
|{{w|Treble clef}}<br />
|Mentioned in the title text; this is not a mathematical symbol, but a musical symbol. The treble clef is a much more complicated symbol than those used in mathematics, hence the musician's "confidence" in his weapon. The curve at the bottom could be used as a hook, the upper curl could be used as a blunt weapon, and the tight curl of the center would serve as a better defensive shield than theta.<br />
|}<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
[Heading]<br />
<br />
Mathematical Symbols<br />
<br />
[Subheading]<br />
<br />
by how useful they would be in a fight<br />
<br />
<br />
more useful<br />
<br />
⟶<br />
<br />
ℝ ∅ > ∝ π + Ψ ~ ⇒ ⋅ Γ √ ∮ ∫ ⇀<br />
θ ∞ ∪ ∈ ∀ ∂ ≠ # Δ ζ ℵ ''ρ'' → ⊥ ⎯<br />
<br />
[Below the (number?) line, eight characters fight each other, using some of the symbols mentioned above as weapons.]<br />
<br />
[The characters hold more "useful" weapons from left to right, correlating with the chart.]<br />
<br />
<br />
<br />
[Megan is awkwardly handling a giant "ℝ".]<br />
<br />
[White Hat is holding a "θ" with both hands, as a shield.]<br />
<br />
[Cueball is holding an "∈" in both hands, with its "tines" pointed towards Blondie, who is swatting at him with a "#".]<br />
<br />
[Ponytail is leaping at Danish, swinging a "''ρ''" like an axe, while Danish is leaning back and thrusting a "→" back at her.]<br />
<br />
[Black Hat is swinging a long "√" like a polearm at Hairy, who is holding a long "⎯" defensively.]<br />
<br />
<br />
-<br />
List of symbols from left to right (by rightmost edge): <br />
<br />
ℝ θ ∅ ∞ > ∪ ∝ ∈ ∀ π ∂ + ≠ Ψ # ~ △ ζ ⇒ ⋅ ℵ Γ ''ρ'' √ → ∮ ∫ ⊥ ⇀ ⎯<br />
<br />
<br />
Note: Where two symbols had similar right-most edges, the overlay grid on an ASUS pro-art display was used to decide which one went further right. <br />
<br />
{{comic discussion}}<br />
[[Category:Math]]<br />
[[Category:Music]]<br />
[[Category:Charts]]<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Danish]]<br />
[[Category:Comics featuring White Hat]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Blondie]]<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Comics featuring Black Hat]]<br />
[[Category:Comics featuring Hairy]]</div>108.162.246.135https://www.explainxkcd.com/wiki/index.php?title=2343:_Mathematical_Symbol_Fight&diff=1957772343: Mathematical Symbol Fight2020-08-08T18:20:29Z<p>108.162.246.135: /* Explanation */ typo</p>
<hr />
<div>{{comic<br />
| number = 2343<br />
| date = August 7, 2020<br />
| title = Mathematical Symbol Fight<br />
| image = mathematical_symbol_fight.png<br />
| titletext = Oh no, a musician just burst in through the door confidently twirling a treble clef.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a SQUARE ROOT SCYTHE. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}<br />
<br />
This panel imagines which {{w|List of mathematical symbols|mathematical symbols}} would be good in a fight if they were made corporeal in two (or three) dimensions. Generally, objects with longer reach and pointier ends wind up on the right ("more useful") side of the scale, and symbols with less reach and more curves tend towards the left ("less useful") side. <br />
<br />
The comic invokes [[wikipedia:surreal humour|surreal humour]] by suggesting that mathematical symbols could be handled as physical objects in the real world. Another component of the humor is the implication that it is useful to prepare to use mathematical symbols in a fight, even though mathematicians, who use mathematical symbols, usually do not conduct their debates violently {{Citation needed}} (though some stories suggest that {{w|Hippasus}} was killed by his fellow Pythagoreans for his proof that irrational numbers exist), and even if they did, they wouldn't use large reproductions of their symbols as weapons.{{Citation needed}}<br />
<br />
A straight line is farthest to the "more dangerous" side, which could possibly be a reference to the dangers posed by lines in "Flatland", because their infinitely-sharp endpoints could be difficult to see (particularly their rear end, which does not contain a gleaming eye as their front end does) and would fatally pierce whoever they chose to stab. However, taking a more literal view of the drawings, the straight line does not appear to be any thicker or thinner, or pointier, than any of the other lines. <br />
<br />
The title text refers to a {{w|clef}}, which is not a mathematical symbol but rather a {{w|List of musical symbols|musical symbol}}. The note of concern in the text suggests musical symbols may be viewed in such fights as exotic or especially dangerous.<br />
<br />
{| class="wikitable"<br />
! Symbol<br />
! Meaning<br />
! Notes on using in a fight<br />
|-<br />
|ℝ<br />
|The set of [[wikipedia:real number|real number]]s<br />
|Megan seems to be struggling with a giant version of this symbol.<br />
|-<br />
|θ<br />
|[[wikipedia:Theta#Mathematics_and_science|Theta]]<br />
|This symbol is not very sharp, and [[White Hat]] is unable to use it in combat. It would not work as a good shield due to the hole in the symbol, but it possibly could be thrown. (The later version of Xena's chakram had a bar in the middle.)<br />
|-<br />
|∅<br />
|[[wikipedia:Empty set|Empty set]]<br />
|Similarly shaped to theta, but identified as being slightly more useful, presumably because the parts of the bar that extend beyond the circle can be used as thrusting weapons.<br />
|-<br />
|∞<br />
|infinity<br />
|-<br />
|><br />
|Greater than<br />
|-<br />
|∝<br />
|[[wikipedia:Proportionality_(mathematics)#Direct_proportionality|Direct Proportionality]]<br />
|-<br />
|∪<br />
|{{w|union (set theory)}}<br />
|-<br />
|∈/ϵ<br />
|{{w|Element (mathematics)|member of}} (set theory) or the "lunate" lowercase {{w|Epsilon#Symbol|epsilon}}<br />
|Cueball is holding this in the manner of a Klingon "{{w|Bat'leth}}" from the ''Star Trek'' franchise. The Bat'leth is [https://youtu.be/VsElSDXPgSA infamous] among swordfighters for being rather impractical, and that the Klingon warrior race would have been better suited using swords like humans. It seems Randall agrees, as the ∈ is quite far on the left of the chart.<br />
|-<br />
|π<br />
|[[wikipedia:Pi|pi]]<br />
|-<br />
|∀<br />
|"{{w|Universal quantification|for all}}"<br />
|Could be held by the crossbar clenched in a fist, and then used as a {{w|push dagger}}, with the legs acting as a guard. Or could be held by the legs.<br />
Compared to the similar Δ (delta) the point is sharper, the grip is closer to the point so it would be easier control (keep the weapon from twisting). Unclear why it is listed as much less effective than the delta. Perhaps the guard legs are too long?<br />
|-<br />
|∂<br />
|{{w|∂}} ([[wikipedia:Partial derivative|partial derivative]] or [[wikipedia:Boundary_(topology)|boundary operator]])<br />
|It's not clear why Randall ranks this symbol as so much less effective than the similarly-shaped 𝜌, but the curl in the "tail" of the ∂ would give it a shorter lever arm when swung and would disrupt the balance.<br />
|-<br />
| +<br />
|[[wikipedia:Plus_and_minus_signs#Plus_sign|Plus]]<br />
|Maybe thrown like a {{w|shuriken}}?<br />
|-<br />
|Ψ<br />
|[[wikipedia:Psi#Mathematics|Psi]]<br />
|It could be used as a slightly-less-functional trident or pitchfork, with a shorter handle. More particularly, it resembles a {{w|sai}} (which, funnily enough, is how "Psi" is pronounced).<br />
|-<br />
|≠<br />
|not equal sign<br />
|-<br />
|~<br />
|[[wikipedia:Tilde#Mathematics|tilde]], meaning "approximately", equivalent, or several transforms of a function<br />
|A potentially dangerous throwing weapon. Could also be similar to a dagger ({{w|Kris}}) or a sword ({{w|Flame-bladed sword}}), with a wavy blade.<br />
|-<br />
|#<br />
|[[wikipedia:Cardinality|Cardinality]], [[wikipedia:Connected_sum|connected sum]] (knot theory), or [[wikipedia:Primorial|primorial]].<br />
|Blondie uses this symbol.<br />
|-<br />
|Δ<br />
|[[wikipedia:Delta_(letter)|Delta]]<br />
|Could be held with one bar clenched in a fist, and then used as a {{w|push dagger}}. Unclear why listed as much more effective than ∀.<br />
|-<br />
|⇒<br />
|[[wikipedia:Material_conditional|Material consequence]] or [[wikipedia:Logical_consequence|Logical consequence]], meaning "implies"<br />
|The point is nice, but having two poles (or one board-like thick handle) would be difficult to wield. A collection of them might make a nice defensive pike line.<br />
|-<br />
|⋅<br />
|multiplication sign<br />
|If thrown, this could be a dangerous projectile weapon, or it could be scattered on the ground as a trip hazard. Three of them stacked together would make a "{{w|therefore sign}}", which might at least conclude the ''mathematical'' portion of the fight in the user's favor.<br />
|-<br />
|ζ<br />
|{{w|Zeta#Mathematics_and_science|Zeta}}<br />
|Could be sharpened into a scythe or curved saber, depending on the curvature and length of the 'tail' at the bottom.<br />
|-<br />
|ℵ<br />
|[[wikipedia:Aleph_number|Aleph number]]<br />
|Could be brandished or thrown in the manner of a shuriken.<br />
|-<br />
|Γ<br />
|uppercase Greek letter {{w|Gamma#Uppercase|Gamma}}<br />
|If this letter is formed with {{w|serif}}s, it could be used as an axe or hook, and if it is made {{w|sans-serif}}, it would make a powerful pick or war hammer.<br />
|-<br />
|√<br />
|{{w|square root}} sign<br />
|Randall has drawn this sign with a long overbar, which makes it useful like a polearm, something like a {{w|shepherd's crook}}. Black Hat has chosen this symbol.<br />
|-<br />
|𝜌<br />
|italic {{w|Rho#Mathematics_and_science|rho}}<br />
|Ponytail is brandishing this symbol against Danish, apparently using it like a club or hammer and striking with the curve.<br />
|-<br />
|∮<br />
|{{w|contour integral}}<br />
|This symbol is drawn with a very tight center, giving it an almost identical figure to the regular integral symbol. Presumably, the added bulk for marginal additional use earns it a rating of 'less effective'.<br />
|-<br />
|∫<br />
|{{w|integral}}<br />
|Could be used in the manner of a shepherd's crook, or as a {{w|Bill (weapon)|billhook}}. Could be used as a {{w|spear thrower}}, combined with ⋅ or ⇀.<br />
|-<br />
|→<br />
|Implies; X→Y means that if X is true, then Y is also true<br />
|Danish is brandishing this symbol against Ponytail, apparently using it like a spear or other polearm.<br />
|-<br />
|⊥<br />
|{{w|up tack}} or falsum, indicating a false proposition in logic or the bottom element in a partial order<br />
|Used as a {{w|war hammer}} (held by the long stem), the opponent would be struck with either leg of the top of the T. Held by the short legs (like a wishbone), could be used as a two handed sword.<br />
(If tipped with a knapped stone head, it could become a {{w|Folsom point|falsum point}}.)<br />
|-<br />
|⇀<br />
|{{w|Vector notation}}<br />
|A single-barbed spear.<br />
|-<br />
|⎯⎯<br />
|{{w|Fraction#Vocabulary|Fraction bar}} (division) or {{w|Overline#Math_and_science|overline}} (complex conjugate or mean).<br />
|Hairy is brandishing this symbol against Black Hat. The single shaft would allow it to be used in the manner of a {{w|quarterstaff}}, {{w|bō}}, or other {{w|stick-fighting}} weapon. Of the symbols shown in the comic, Randall considers this one the most useful in a fight, presumably because of its greater reach than the vector arrow and its simplicity compared to the square root symbol.<br />
|-<br />
|𝄞<br />
|{{w|Treble clef}}<br />
|Mentioned in the title text; this is not a mathematical symbol, but a musical symbol. The treble clef is a much more complicated symbol than those used in mathematics, hence the musician's "confidence" in his weapon. The curve at the bottom could be used as a hook, the upper curl could be used as a blunt weapon, and the tight curl of the center would serve as a better defensive shield than theta.<br />
|}<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
[Heading]<br />
<br />
Mathematical Symbols<br />
<br />
[Subheading]<br />
<br />
by how useful they would be in a fight<br />
<br />
<br />
more useful<br />
<br />
⟶<br />
<br />
ℝ ∅ > ∝ π + Ψ ~ ⇒ ⋅ Γ √ ∮ ∫ ⇀<br />
θ ∞ ∪ ∈ ∀ ∂ ≠ # Δ ζ ℵ 𝜌 → ⊥ ⎯<br />
<br />
[Below the (number?) line, eight characters fight each other, using some of the symbols mentioned above as weapons.]<br />
<br />
[The characters hold more "useful" weapons from left to right, correlating with the chart.]<br />
<br />
<br />
<br />
[Megan is awkwardly handling a giant "ℝ".]<br />
<br />
[White Hat is holding a "θ" with both hands, as a shield.]<br />
<br />
[Cueball is holding an "∈" in both hands, with its "tines" pointed towards Blondie, who is swatting at him with a "#".]<br />
<br />
[Ponytail is leaping at Danish, swinging a "ρ" like an axe, while Danish is leaning back and thrusting a "→" back at her.]<br />
<br />
[Black Hat is swinging a long "√" like a polearm at Hairy, who is holding a long "⎯" defensively.]<br />
<br />
<br />
-<br />
List of symbols from left to right (by rightmost edge): <br />
<br />
ℝ θ ∅ ∞ > ∪ ∝ ∈ ∀ π ∂ + ≠ Ψ # ~ △ ζ ⇒ ⋅ ℵ Γ 𝜌 √ → ∮ ∫ ⊥ ⇀ ⎯<br />
<br />
<br />
Note: Where two symbols had similar right-most edges, the overlay grid on an ASUS pro-art display was used to decide which one went further right. <br />
<br />
{{comic discussion}}<br />
[[Category:Math]]<br />
[[Category:Music]]<br />
[[Category:Charts]]<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Danish]]<br />
[[Category:Comics featuring White Hat]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Blondie]]<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Comics featuring Black Hat]]<br />
[[Category:Comics featuring Hairy]]</div>108.162.246.135https://www.explainxkcd.com/wiki/index.php?title=2343:_Mathematical_Symbol_Fight&diff=1957762343: Mathematical Symbol Fight2020-08-08T18:19:20Z<p>108.162.246.135: /* Explanation */ falsum/folsom point</p>
<hr />
<div>{{comic<br />
| number = 2343<br />
| date = August 7, 2020<br />
| title = Mathematical Symbol Fight<br />
| image = mathematical_symbol_fight.png<br />
| titletext = Oh no, a musician just burst in through the door confidently twirling a treble clef.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a SQUARE ROOT SCYTHE. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}<br />
<br />
This panel imagines which {{w|List of mathematical symbols|mathematical symbols}} would be good in a fight if they were made corporeal in two (or three) dimensions. Generally, objects with longer reach and pointier ends wind up on the right ("more useful") side of the scale, and symbols with less reach and more curves tend towards the left ("less useful") side. <br />
<br />
The comic invokes [[wikipedia:surreal humour|surreal humour]] by suggesting that mathematical symbols could be handled as physical objects in the real world. Another component of the humor is the implication that it is useful to prepare to use mathematical symbols in a fight, even though mathematicians, who use mathematical symbols, usually do not conduct their debates violently {{Citation needed}} (though some stories suggest that {{w|Hippasus}} was killed by his fellow Pythagoreans for his proof that irrational numbers exist), and even if they did, they wouldn't use large reproductions of their symbols as weapons.{{Citation needed}}<br />
<br />
A straight line is farthest to the "more dangerous" side, which could possibly be a reference to the dangers posed by lines in "Flatland", because their infinitely-sharp endpoints could be difficult to see (particularly their rear end, which does not contain a gleaming eye as their front end does) and would fatally pierce whoever they chose to stab. However, taking a more literal view of the drawings, the straight line does not appear to be any thicker or thinner, or pointier, than any of the other lines. <br />
<br />
The title text refers to a {{w|clef}}, which is not a mathematical symbol but rather a {{w|List of musical symbols|musical symbol}}. The note of concern in the text suggests musical symbols may be viewed in such fights as exotic or especially dangerous.<br />
<br />
{| class="wikitable"<br />
! Symbol<br />
! Meaning<br />
! Notes on using in a fight<br />
|-<br />
|ℝ<br />
|The set of [[wikipedia:real number|real number]]s<br />
|Megan seems to be struggling with a giant version of this symbol.<br />
|-<br />
|θ<br />
|[[wikipedia:Theta#Mathematics_and_science|Theta]]<br />
|This symbol is not very sharp, and [[White Hat]] is unable to use it in combat. It would not work as a good shield due to the hole in the symbol, but it possibly could be thrown. (The later version of Xena's chakram had a bar in the middle.)<br />
|-<br />
|∅<br />
|[[wikipedia:Empty set|Empty set]]<br />
|Similarly shaped to theta, but identified as being slightly more useful, presumably because the parts of the bar that extend beyond the circle can be used as thrusting weapons.<br />
|-<br />
|∞<br />
|infinity<br />
|-<br />
|><br />
|Greater than<br />
|-<br />
|∝<br />
|[[wikipedia:Proportionality_(mathematics)#Direct_proportionality|Direct Proportionality]]<br />
|-<br />
|∪<br />
|{{w|union (set theory)}}<br />
|-<br />
|∈/ϵ<br />
|{{w|Element (mathematics)|member of}} (set theory) or the "lunate" lowercase {{w|Epsilon#Symbol|epsilon}}<br />
|Cueball is holding this in the manner of a Klingon "{{w|Bat'leth}}" from the ''Star Trek'' franchise. The Bat'leth is [https://youtu.be/VsElSDXPgSA infamous] among swordfighters for being rather impractical, and that the Klingon warrior race would have been better suited using swords like humans. It seems Randall agrees, as the ∈ is quite far on the left of the chart.<br />
|-<br />
|π<br />
|[[wikipedia:Pi|pi]]<br />
|-<br />
|∀<br />
|"{{w|Universal quantification|for all}}"<br />
|Could be held by the crossbar clenched in a fist, and then used as a {{w|push dagger}}, with the legs acting as a guard. Or could be held by the legs.<br />
Compared to the similar Δ (delta) the point is sharper, the grip is closer to the point so it would be easier control (keep the weapon from twisting). Unclear why it is listed as much less effective than the delta. Perhaps the guard legs are too long?<br />
|-<br />
|∂<br />
|{{w|∂}} ([[wikipedia:Partial derivative|partial derivative]] or [[wikipedia:Boundary_(topology)|boundary operator]])<br />
|It's not clear why Randall ranks this symbol as so much less effective than the similarly-shaped 𝜌, but the curl in the "tail" of the ∂ would give it a shorter lever arm when swung and would disrupt the balance.<br />
|-<br />
| +<br />
|[[wikipedia:Plus_and_minus_signs#Plus_sign|Plus]]<br />
|Maybe thrown like a {{w|shuriken}}?<br />
|-<br />
|Ψ<br />
|[[wikipedia:Psi#Mathematics|Psi]]<br />
|It could be used as a slightly-less-functional trident or pitchfork, with a shorter handle. More particularly, it resembles a {{w|sai}} (which, funnily enough, is how "Psi" is pronounced).<br />
|-<br />
|≠<br />
|not equal sign<br />
|-<br />
|~<br />
|[[wikipedia:Tilde#Mathematics|tilde]], meaning "approximately", equivalent, or several transforms of a function<br />
|A potentially dangerous throwing weapon. Could also be similar to a dagger ({{w|Kris}}) or a sword ({{w|Flame-bladed sword}}), with a wavy blade.<br />
|-<br />
|#<br />
|[[wikipedia:Cardinality|Cardinality]], [[wikipedia:Connected_sum|connected sum]] (knot theory), or [[wikipedia:Primorial|primorial]].<br />
|Blondie uses this symbol.<br />
|-<br />
|Δ<br />
|[[wikipedia:Delta_(letter)|Delta]]<br />
|Could be held with one bar clenched in a fist, and then used as a {{w|push dagger}}. Unclear why listed as much more effective than ∀.<br />
|-<br />
|⇒<br />
|[[wikipedia:Material_conditional|Material consequence]] or [[wikipedia:Logical_consequence|Logical consequence]], meaning "implies"<br />
|The point is nice, but having two poles (or one board-like thick handle) would be difficult to wield. A collection of them might make a nice defensive pike line.<br />
|-<br />
|⋅<br />
|multiplication sign<br />
|If thrown, this could be a dangerous projectile weapon, or it could be scattered on the ground as a trip hazard. Three of them stacked together would make a "{{w|therefore sign}}", which might at least conclude the ''mathematical'' portion of the fight in the user's favor.<br />
|-<br />
|ζ<br />
|{{w|Zeta#Mathematics_and_science|Zeta}}<br />
|Could be sharpened into a scythe or curved saber, depending on the curvature and length of the 'tail' at the bottom.<br />
|-<br />
|ℵ<br />
|[[wikipedia:Aleph_number|Aleph number]]<br />
|Could be brandished or thrown in the manner of a shuriken.<br />
|-<br />
|Γ<br />
|uppercase Greek letter {{w|Gamma#Uppercase|Gamma}}<br />
|If this letter is formed with {{w|serif}}s, it could be used as an axe or hook, and if it is made {{w|sans-serif}}, it would make a powerful pick or war hammer.<br />
|-<br />
|√<br />
|{{w|square root}} sign<br />
|Randall has drawn this sign with a long overbar, which makes it useful like a polearm, something like a {{w|shepherd's crook}}. Black Hat has chosen this symbol.<br />
|-<br />
|𝜌<br />
|italic {{w|Rho#Mathematics_and_science|rho}}<br />
|Ponytail is brandishing this symbol against Danish, apparently using it like a club or hammer and striking with the curve.<br />
|-<br />
|∮<br />
|{{w|contour integral}}<br />
|This symbol is drawn with a very tight center, giving it an almost identical figure to the regular integral symbol. Presumably, the added bulk for marginal additional use earns it a rating of 'less effective'.<br />
|-<br />
|∫<br />
|{{w|integral}}<br />
|Could be used in the manner of a shepherd's crook, or as a {{w|Bill (weapon)|billhook}}. Could be used as a {{w|spear thrower}}, combined with ⋅ or ⇀.<br />
|-<br />
|→<br />
|Implies; X→Y means that if X is true, then Y is also true<br />
|Danish is brandishing this symbol against Ponytail, apparently using it like a spear or other polearm.<br />
|-<br />
|⊥<br />
|{{w|up tack}} or falsum, indicating a false proposition in logic or the bottom element in a partial order<br />
|Used as a {{w|war hammer}} (held by the long stem), the opponent would be struck with either leg of the top of the T. Held by the short legs (like a wishbone), could be used as a two handed sword.<br />
(If tipped with a knapped stone head, it could become a {{w|Folsom point|falsum point).)<br />
|-<br />
|⇀<br />
|{{w|Vector notation}}<br />
|A single-barbed spear.<br />
|-<br />
|⎯⎯<br />
|{{w|Fraction#Vocabulary|Fraction bar}} (division) or {{w|Overline#Math_and_science|overline}} (complex conjugate or mean).<br />
|Hairy is brandishing this symbol against Black Hat. The single shaft would allow it to be used in the manner of a {{w|quarterstaff}}, {{w|bō}}, or other {{w|stick-fighting}} weapon. Of the symbols shown in the comic, Randall considers this one the most useful in a fight, presumably because of its greater reach than the vector arrow and its simplicity compared to the square root symbol.<br />
|-<br />
|𝄞<br />
|{{w|Treble clef}}<br />
|Mentioned in the title text; this is not a mathematical symbol, but a musical symbol. The treble clef is a much more complicated symbol than those used in mathematics, hence the musician's "confidence" in his weapon. The curve at the bottom could be used as a hook, the upper curl could be used as a blunt weapon, and the tight curl of the center would serve as a better defensive shield than theta.<br />
|}<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
[Heading]<br />
<br />
Mathematical Symbols<br />
<br />
[Subheading]<br />
<br />
by how useful they would be in a fight<br />
<br />
<br />
more useful<br />
<br />
⟶<br />
<br />
ℝ ∅ > ∝ π + Ψ ~ ⇒ ⋅ Γ √ ∮ ∫ ⇀<br />
θ ∞ ∪ ∈ ∀ ∂ ≠ # Δ ζ ℵ 𝜌 → ⊥ ⎯<br />
<br />
[Below the (number?) line, eight characters fight each other, using some of the symbols mentioned above as weapons.]<br />
<br />
[The characters hold more "useful" weapons from left to right, correlating with the chart.]<br />
<br />
<br />
<br />
[Megan is awkwardly handling a giant "ℝ".]<br />
<br />
[White Hat is holding a "θ" with both hands, as a shield.]<br />
<br />
[Cueball is holding an "∈" in both hands, with its "tines" pointed towards Blondie, who is swatting at him with a "#".]<br />
<br />
[Ponytail is leaping at Danish, swinging a "ρ" like an axe, while Danish is leaning back and thrusting a "→" back at her.]<br />
<br />
[Black Hat is swinging a long "√" like a polearm at Hairy, who is holding a long "⎯" defensively.]<br />
<br />
<br />
-<br />
List of symbols from left to right (by rightmost edge): <br />
<br />
ℝ θ ∅ ∞ > ∪ ∝ ∈ ∀ π ∂ + ≠ Ψ # ~ △ ζ ⇒ ⋅ ℵ Γ 𝜌 √ → ∮ ∫ ⊥ ⇀ ⎯<br />
<br />
<br />
Note: Where two symbols had similar right-most edges, the overlay grid on an ASUS pro-art display was used to decide which one went further right. <br />
<br />
{{comic discussion}}<br />
[[Category:Math]]<br />
[[Category:Music]]<br />
[[Category:Charts]]<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Danish]]<br />
[[Category:Comics featuring White Hat]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Blondie]]<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Comics featuring Black Hat]]<br />
[[Category:Comics featuring Hairy]]</div>108.162.246.135https://www.explainxkcd.com/wiki/index.php?title=2343:_Mathematical_Symbol_Fight&diff=1957752343: Mathematical Symbol Fight2020-08-08T18:14:49Z<p>108.162.246.135: /* Explanation */ falsum hammer</p>
<hr />
<div>{{comic<br />
| number = 2343<br />
| date = August 7, 2020<br />
| title = Mathematical Symbol Fight<br />
| image = mathematical_symbol_fight.png<br />
| titletext = Oh no, a musician just burst in through the door confidently twirling a treble clef.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a SQUARE ROOT SCYTHE. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}<br />
<br />
This panel imagines which {{w|List of mathematical symbols|mathematical symbols}} would be good in a fight if they were made corporeal in two (or three) dimensions. Generally, objects with longer reach and pointier ends wind up on the right ("more useful") side of the scale, and symbols with less reach and more curves tend towards the left ("less useful") side. <br />
<br />
The comic invokes [[wikipedia:surreal humour|surreal humour]] by suggesting that mathematical symbols could be handled as physical objects in the real world. Another component of the humor is the implication that it is useful to prepare to use mathematical symbols in a fight, even though mathematicians, who use mathematical symbols, usually do not conduct their debates violently {{Citation needed}} (though some stories suggest that {{w|Hippasus}} was killed by his fellow Pythagoreans for his proof that irrational numbers exist), and even if they did, they wouldn't use large reproductions of their symbols as weapons.{{Citation needed}}<br />
<br />
A straight line is farthest to the "more dangerous" side, which could possibly be a reference to the dangers posed by lines in "Flatland", because their infinitely-sharp endpoints could be difficult to see (particularly their rear end, which does not contain a gleaming eye as their front end does) and would fatally pierce whoever they chose to stab. However, taking a more literal view of the drawings, the straight line does not appear to be any thicker or thinner, or pointier, than any of the other lines. <br />
<br />
The title text refers to a {{w|clef}}, which is not a mathematical symbol but rather a {{w|List of musical symbols|musical symbol}}. The note of concern in the text suggests musical symbols may be viewed in such fights as exotic or especially dangerous.<br />
<br />
{| class="wikitable"<br />
! Symbol<br />
! Meaning<br />
! Notes on using in a fight<br />
|-<br />
|ℝ<br />
|The set of [[wikipedia:real number|real number]]s<br />
|Megan seems to be struggling with a giant version of this symbol.<br />
|-<br />
|θ<br />
|[[wikipedia:Theta#Mathematics_and_science|Theta]]<br />
|This symbol is not very sharp, and [[White Hat]] is unable to use it in combat. It would not work as a good shield due to the hole in the symbol, but it possibly could be thrown. (The later version of Xena's chakram had a bar in the middle.)<br />
|-<br />
|∅<br />
|[[wikipedia:Empty set|Empty set]]<br />
|Similarly shaped to theta, but identified as being slightly more useful, presumably because the parts of the bar that extend beyond the circle can be used as thrusting weapons.<br />
|-<br />
|∞<br />
|infinity<br />
|-<br />
|><br />
|Greater than<br />
|-<br />
|∝<br />
|[[wikipedia:Proportionality_(mathematics)#Direct_proportionality|Direct Proportionality]]<br />
|-<br />
|∪<br />
|{{w|union (set theory)}}<br />
|-<br />
|∈/ϵ<br />
|{{w|Element (mathematics)|member of}} (set theory) or the "lunate" lowercase {{w|Epsilon#Symbol|epsilon}}<br />
|Cueball is holding this in the manner of a Klingon "{{w|Bat'leth}}" from the ''Star Trek'' franchise. The Bat'leth is [https://youtu.be/VsElSDXPgSA infamous] among swordfighters for being rather impractical, and that the Klingon warrior race would have been better suited using swords like humans. It seems Randall agrees, as the ∈ is quite far on the left of the chart.<br />
|-<br />
|π<br />
|[[wikipedia:Pi|pi]]<br />
|-<br />
|∀<br />
|"{{w|Universal quantification|for all}}"<br />
|Could be held by the crossbar clenched in a fist, and then used as a {{w|push dagger}}, with the legs acting as a guard. Or could be held by the legs.<br />
Compared to the similar Δ (delta) the point is sharper, the grip is closer to the point so it would be easier control (keep the weapon from twisting). Unclear why it is listed as much less effective than the delta. Perhaps the guard legs are too long?<br />
|-<br />
|∂<br />
|{{w|∂}} ([[wikipedia:Partial derivative|partial derivative]] or [[wikipedia:Boundary_(topology)|boundary operator]])<br />
|It's not clear why Randall ranks this symbol as so much less effective than the similarly-shaped 𝜌, but the curl in the "tail" of the ∂ would give it a shorter lever arm when swung and would disrupt the balance.<br />
|-<br />
| +<br />
|[[wikipedia:Plus_and_minus_signs#Plus_sign|Plus]]<br />
|Maybe thrown like a {{w|shuriken}}?<br />
|-<br />
|Ψ<br />
|[[wikipedia:Psi#Mathematics|Psi]]<br />
|It could be used as a slightly-less-functional trident or pitchfork, with a shorter handle. More particularly, it resembles a {{w|sai}} (which, funnily enough, is how "Psi" is pronounced).<br />
|-<br />
|≠<br />
|not equal sign<br />
|-<br />
|~<br />
|[[wikipedia:Tilde#Mathematics|tilde]], meaning "approximately", equivalent, or several transforms of a function<br />
|A potentially dangerous throwing weapon. Could also be similar to a dagger ({{w|Kris}}) or a sword ({{w|Flame-bladed sword}}), with a wavy blade.<br />
|-<br />
|#<br />
|[[wikipedia:Cardinality|Cardinality]], [[wikipedia:Connected_sum|connected sum]] (knot theory), or [[wikipedia:Primorial|primorial]].<br />
|Blondie uses this symbol.<br />
|-<br />
|Δ<br />
|[[wikipedia:Delta_(letter)|Delta]]<br />
|Could be held with one bar clenched in a fist, and then used as a {{w|push dagger}}. Unclear why listed as much more effective than ∀.<br />
|-<br />
|⇒<br />
|[[wikipedia:Material_conditional|Material consequence]] or [[wikipedia:Logical_consequence|Logical consequence]], meaning "implies"<br />
|The point is nice, but having two poles (or one board-like thick handle) would be difficult to wield. A collection of them might make a nice defensive pike line.<br />
|-<br />
|⋅<br />
|multiplication sign<br />
|If thrown, this could be a dangerous projectile weapon, or it could be scattered on the ground as a trip hazard. Three of them stacked together would make a "{{w|therefore sign}}", which might at least conclude the ''mathematical'' portion of the fight in the user's favor.<br />
|-<br />
|ζ<br />
|{{w|Zeta#Mathematics_and_science|Zeta}}<br />
|Could be sharpened into a scythe or curved saber, depending on the curvature and length of the 'tail' at the bottom.<br />
|-<br />
|ℵ<br />
|[[wikipedia:Aleph_number|Aleph number]]<br />
|Could be brandished or thrown in the manner of a shuriken.<br />
|-<br />
|Γ<br />
|uppercase Greek letter {{w|Gamma#Uppercase|Gamma}}<br />
|If this letter is formed with {{w|serif}}s, it could be used as an axe or hook, and if it is made {{w|sans-serif}}, it would make a powerful pick or war hammer.<br />
|-<br />
|√<br />
|{{w|square root}} sign<br />
|Randall has drawn this sign with a long overbar, which makes it useful like a polearm, something like a {{w|shepherd's crook}}. Black Hat has chosen this symbol.<br />
|-<br />
|𝜌<br />
|italic {{w|Rho#Mathematics_and_science|rho}}<br />
|Ponytail is brandishing this symbol against Danish, apparently using it like a club or hammer and striking with the curve.<br />
|-<br />
|∮<br />
|{{w|contour integral}}<br />
|This symbol is drawn with a very tight center, giving it an almost identical figure to the regular integral symbol. Presumably, the added bulk for marginal additional use earns it a rating of 'less effective'.<br />
|-<br />
|∫<br />
|{{w|integral}}<br />
|Could be used in the manner of a shepherd's crook, or as a {{w|Bill (weapon)|billhook}}. Could be used as a {{w|spear thrower}}, combined with ⋅ or ⇀.<br />
|-<br />
|→<br />
|Implies; X→Y means that if X is true, then Y is also true<br />
|Danish is brandishing this symbol against Ponytail, apparently using it like a spear or other polearm.<br />
|-<br />
|⊥<br />
|{{w|up tack}} or falsum, indicating a false proposition in logic or the bottom element in a partial order<br />
|Used as a {{w|war hammer}} (held by the long stem), the opponent would be struck with either leg of the top of the T. Held by the short legs (like a wishbone), could be used as a two handed sword.<br />
|-<br />
|⇀<br />
|{{w|Vector notation}}<br />
|A single-barbed spear.<br />
|-<br />
|⎯⎯<br />
|{{w|Fraction#Vocabulary|Fraction bar}} (division) or {{w|Overline#Math_and_science|overline}} (complex conjugate or mean).<br />
|Hairy is brandishing this symbol against Black Hat. The single shaft would allow it to be used in the manner of a {{w|quarterstaff}}, {{w|bō}}, or other {{w|stick-fighting}} weapon. Of the symbols shown in the comic, Randall considers this one the most useful in a fight, presumably because of its greater reach than the vector arrow and its simplicity compared to the square root symbol.<br />
|-<br />
|𝄞<br />
|{{w|Treble clef}}<br />
|Mentioned in the title text; this is not a mathematical symbol, but a musical symbol. The treble clef is a much more complicated symbol than those used in mathematics, hence the musician's "confidence" in his weapon. The curve at the bottom could be used as a hook, the upper curl could be used as a blunt weapon, and the tight curl of the center would serve as a better defensive shield than theta.<br />
|}<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
[Heading]<br />
<br />
Mathematical Symbols<br />
<br />
[Subheading]<br />
<br />
by how useful they would be in a fight<br />
<br />
<br />
more useful<br />
<br />
⟶<br />
<br />
ℝ ∅ > ∝ π + Ψ ~ ⇒ ⋅ Γ √ ∮ ∫ ⇀<br />
θ ∞ ∪ ∈ ∀ ∂ ≠ # Δ ζ ℵ 𝜌 → ⊥ ⎯<br />
<br />
[Below the (number?) line, eight characters fight each other, using some of the symbols mentioned above as weapons.]<br />
<br />
[The characters hold more "useful" weapons from left to right, correlating with the chart.]<br />
<br />
<br />
<br />
[Megan is awkwardly handling a giant "ℝ".]<br />
<br />
[White Hat is holding a "θ" with both hands, as a shield.]<br />
<br />
[Cueball is holding an "∈" in both hands, with its "tines" pointed towards Blondie, who is swatting at him with a "#".]<br />
<br />
[Ponytail is leaping at Danish, swinging a "ρ" like an axe, while Danish is leaning back and thrusting a "→" back at her.]<br />
<br />
[Black Hat is swinging a long "√" like a polearm at Hairy, who is holding a long "⎯" defensively.]<br />
<br />
<br />
-<br />
List of symbols from left to right (by rightmost edge): <br />
<br />
ℝ θ ∅ ∞ > ∪ ∝ ∈ ∀ π ∂ + ≠ Ψ # ~ △ ζ ⇒ ⋅ ℵ Γ 𝜌 √ → ∮ ∫ ⊥ ⇀ ⎯<br />
<br />
<br />
Note: Where two symbols had similar right-most edges, the overlay grid on an ASUS pro-art display was used to decide which one went further right. <br />
<br />
{{comic discussion}}<br />
[[Category:Math]]<br />
[[Category:Music]]<br />
[[Category:Charts]]<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Danish]]<br />
[[Category:Comics featuring White Hat]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Blondie]]<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Comics featuring Black Hat]]<br />
[[Category:Comics featuring Hairy]]</div>108.162.246.135https://www.explainxkcd.com/wiki/index.php?title=2343:_Mathematical_Symbol_Fight&diff=1957672343: Mathematical Symbol Fight2020-08-08T18:01:29Z<p>108.162.246.135: /* Explanation */ integral - billhook or atlatl</p>
<hr />
<div>{{comic<br />
| number = 2343<br />
| date = August 7, 2020<br />
| title = Mathematical Symbol Fight<br />
| image = mathematical_symbol_fight.png<br />
| titletext = Oh no, a musician just burst in through the door confidently twirling a treble clef.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a SQUARE ROOT SCYTHE. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}<br />
<br />
This panel imagines which {{w|List of mathematical symbols|mathematical symbols}} would be good in a fight if they were made corporeal in two (or three) dimensions. Generally, objects with longer reach and pointier ends wind up on the right ("more useful") side of the scale, and symbols with less reach and more curves tend towards the left ("less useful") side. <br />
<br />
The comic invokes [[wikipedia:surreal humour|surreal humour]] by suggesting that mathematical symbols could be handled as physical objects in the real world. Another component of the humor is the implication that it is useful to prepare to use mathematical symbols in a fight, even though mathematicians, who use mathematical symbols, usually do not conduct their debates violently {{Citation needed}} (though some stories suggest that {{w|Hippasus}} was killed by his fellow Pythagoreans for his proof that irrational numbers exist), and even if they did, they wouldn't use large reproductions of their symbols as weapons.{{Citation needed}}<br />
<br />
A straight line is farthest to the "more dangerous" side, which could possibly be a reference to the dangers posed by lines in "Flatland", because their infinitely-sharp endpoints could be difficult to see (particularly their rear end, which does not contain a gleaming eye as their front end does) and would fatally pierce whoever they chose to stab. However, taking a more literal view of the drawings, the straight line does not appear to be any thicker or thinner, or pointier, than any of the other lines. <br />
<br />
The title text refers to a {{w|clef}}, which is not a mathematical symbol but rather a {{w|List of musical symbols|musical symbol}}. The note of concern in the text suggests musical symbols may be viewed in such fights as exotic or especially dangerous.<br />
<br />
{| class="wikitable"<br />
! Symbol<br />
! Meaning<br />
! Notes on using in a fight<br />
|-<br />
|ℝ<br />
|The set of [[wikipedia:real number|real number]]s<br />
|Megan seems to be struggling with a giant version of this symbol.<br />
|-<br />
|θ<br />
|[[wikipedia:Theta#Mathematics_and_science|Theta]]<br />
|This symbol is not very sharp, and [[White Hat]] is unable to use it in combat. It would not work as a good shield due to the hole in the symbol, but it possibly could be thrown. (The later version of Xena's chakram had a bar in the middle.)<br />
|-<br />
|∅<br />
|[[wikipedia:Empty set|Empty set]]<br />
|Similarly shaped to theta, but identified as being slightly more useful, presumably because the parts of the bar that extend beyond the circle can be used as thrusting weapons.<br />
|-<br />
|∞<br />
|infinity<br />
|-<br />
|><br />
|Greater than<br />
|-<br />
|α<br />
|[[wikipedia:Alpha_(disambiguation)#Mathematics_and_statistics|Alpha]]<br />
|-<br />
|∪<br />
|{{w|union (set theory)}}<br />
|-<br />
|∈/ϵ<br />
|{{w|Element (mathematics)|member of}} (set theory) or the "lunate" lowercase {{w|Epsilon#Symbol|epsilon}}<br />
|Cueball is holding this in the manner of a Klingon "{{w|Bat'leth}}" from the ''Star Trek'' franchise. The Bat'leth is [https://youtu.be/VsElSDXPgSA infamous] among swordfighters for being rather impractical, and that the Klingon warrior race would have been better suited using swords like humans. It seems Randall agrees, as the ∈ is quite far on the left of the chart.<br />
|-<br />
|π<br />
|[[wikipedia:Pi|pi]]<br />
|-<br />
|∀<br />
|"{{w|Universal quantification|for all}}"<br />
|Could be held by the crossbar clenched in a fist, and then used as a {{w|push dagger}}, with the legs acting as a guard. Or could be held by the legs.<br />
Compared to the similar Δ (delta) the point is sharper, the grip is closer to the point so it would be easier control (keep the weapon from twisting). Unclear why it is listed as much less effective than the delta. Perhaps the guard legs are too long?<br />
|-<br />
|∂<br />
|{{w|∂}} ([[wikipedia:Partial derivative|partial derivative]] or [[wikipedia:Boundary_(topology)|boundary operator]])<br />
|It's not clear why Randall ranks this symbol as so much less effective than the similarly-shaped 𝜌, but the curl in the "tail" of the ∂ would give it a shorter lever arm when swung and would disrupt the balance.<br />
|-<br />
| +<br />
|[[wikipedia:Plus_and_minus_signs#Plus_sign|Plus]]<br />
|Maybe thrown like a {{w|shuriken}}?<br />
|-<br />
|Ψ<br />
|[[wikipedia:Psi#Mathematics|Psi]]<br />
|It could be used as a slightly-less-functional trident or pitchfork, with a shorter handle. More particularly, it resembles a {{w|sai}} (which, funnily enough, is how "Psi" is pronounced).<br />
|-<br />
|≠<br />
|not equal sign<br />
|-<br />
|~<br />
|[[wikipedia:Tilde#Mathematics|tilde]], meaning "approximately", equivalent, or several transforms of a function<br />
|A potentially dangerous throwing weapon. Could also be similar to a dagger ({{w|Kris}}) or a sword ({{w|Flame-bladed sword}}), with a wavy blade.<br />
|-<br />
|#<br />
|[[wikipedia:Cardinality|Cardinality]], [[wikipedia:Connected_sum|connected sum]] (knot theory), or [[wikipedia:Primorial|primorial]].<br />
|Blondie uses this symbol.<br />
|-<br />
|Δ<br />
|[[wikipedia:Delta_(letter)|Delta]]<br />
|Could be held with one bar clenched in a fist, and then used as a {{w|push dagger}}. Unclear why listed as much more effective than ∀.<br />
|-<br />
|⇒<br />
|[[wikipedia:Material_conditional|Material consequence]] or [[wikipedia:Logical_consequence|Logical consequence]], meaning "implies"<br />
|The point is nice, but having two poles (or one board-like thick handle) would be difficult to wield. A collection of them might make a nice defensive pike line.<br />
|-<br />
|⋅<br />
|multiplication sign<br />
|If thrown, this could be a dangerous projectile weapon, or it could be scattered on the ground as a trip hazard. Three of them stacked together would make a "{{w|therefore sign}}", which might at least conclude the ''mathematical'' portion of the fight in the user's favor.<br />
|-<br />
|ζ<br />
|{{w|Zeta#Mathematics_and_science|Zeta}}<br />
|Could be sharpened into a scythe or curved saber, depending on the curvature and length of the 'tail' at the bottom.<br />
|-<br />
|ℵ<br />
|[[wikipedia:Aleph_number|Aleph number]]<br />
|Could be brandished or thrown in the manner of a shuriken.<br />
|-<br />
|Γ<br />
|uppercase Greek letter {{w|Gamma#Uppercase|Gamma}}<br />
|If this letter is formed with {{w|serif}}s, it could be used as an axe or hook, and if it is made {{w|sans-serif}}, it would make a powerful pick or war hammer.<br />
|-<br />
|√<br />
|{{w|square root}} sign<br />
|Randall has drawn this sign with a long overbar, which makes it useful like a polearm, something like a {{w|shepherd's crook}}. Black Hat has chosen this symbol.<br />
|-<br />
|𝜌<br />
|italic {{w|Rho#Mathematics_and_science|rho}}<br />
|Ponytail is brandishing this symbol against Danish, apparently using it like a club or hammer and striking with the curve.<br />
|-<br />
|∮<br />
|{{w|contour integral}}<br />
|This symbol is drawn with a very tight center, giving it an almost identical figure to the regular integral symbol. Presumably, the added bulk for marginal additional use earns it a rating of 'less effective'.<br />
|-<br />
|∫<br />
|{{w|integral}}<br />
|Could be used in the manner of a shepherd's crook, or as a {{w|Bill (weapon)|billhook}}. Could be used as a {{w|spear thrower}}, combined with ⋅ or ⇀.<br />
|-<br />
|→<br />
|Implies; X→Y means that if X is true, then Y is also true<br />
|Danish is brandishing this symbol against Ponytail, apparently using it like a spear or other polearm.<br />
|-<br />
|⊥<br />
|{{w|up tack}} or falsum, indicating a false proposition in logic or the bottom element in a partial order<br />
|Held like an axe, the top of the T could be arced towards an opponent. Held like a wishbone, two hands could be used to try to drive the point into an opponent. <br />
|-<br />
|⇀<br />
|{{w|Vector notation}}<br />
|A single-barbed spear.<br />
|-<br />
|⎯⎯<br />
|{{w|Fraction#Vocabulary|Fraction bar}} (division) or {{w|Overline#Math_and_science|overline}} (complex conjugate or mean).<br />
|Hairy is brandishing this symbol against Black Hat. The single shaft would allow it to be used in the manner of a {{w|quarterstaff}}, {{w|bō}}, or other {{w|stick-fighting}} weapon. Of the symbols shown in the comic, Randall considers this one the most useful in a fight, presumably because of its greater reach than the vector arrow and its simplicity compared to the square root symbol.<br />
|-<br />
|𝄞<br />
|{{w|Treble clef}}<br />
|Mentioned in the title text; this is not a mathematical symbol, but a musical symbol. The treble clef is a much more complicated symbol than those used in mathematics, hence the musician's "confidence" in his weapon. The curve at the bottom could be used as a hook, the upper curl could be used as a blunt weapon, and the tight curl of the center would serve as a better defensive shield than theta.<br />
|}<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
[Heading]<br />
<br />
Mathematical Symbols<br />
<br />
[Subheading]<br />
<br />
by how useful they would be in a fight<br />
<br />
<br />
more useful<br />
<br />
⟶<br />
<br />
ℝ ∅ > α π + Ψ ~ ⇒ ⋅ Γ √ ∮ ∫ ⇀<br />
θ ∞ ∪ ∈ ∀ ∂ ≠ # Δ ζ ℵ 𝜌 → ⊥ ⎯<br />
<br />
[Below the (number?) line, eight characters fight each other, using some of the symbols mentioned above as weapons.]<br />
<br />
[The characters hold more "useful" weapons from left to right, correlating with the chart.]<br />
<br />
<br />
<br />
[Megan is awkwardly handling a giant "ℝ".]<br />
<br />
[White Hat is holding a "θ" with both hands, as a shield.]<br />
<br />
[Cueball is holding an "∈" in both hands, with its "tines" pointed towards Blondie, who is swatting at him with a "#".]<br />
<br />
[Ponytail is leaping at Danish, swinging a "ρ" like an axe, while Danish is leaning back and thrusting a "→" back at her.]<br />
<br />
[Black Hat is swinging a long "√" like a polearm at Hairy, who is holding a long "⎯" defensively.]<br />
<br />
<br />
-<br />
List of symbols from left to right (by rightmost edge): <br />
<br />
ℝ θ ∅ ∞ > ∪ α ∈ ∀ π ∂ + ≠ Ψ # ~ △ ζ ⇒ ⋅ ℵ Γ 𝜌 √ → ∮ ∫ ⊥ ⇀ ⎯<br />
<br />
<br />
Note: Where two symbols had similar right-most edges, the overlay grid on an ASUS pro-art display was used to decide which one went further right. <br />
<br />
{{comic discussion}}<br />
[[Category:Math]]<br />
[[Category:Music]]<br />
[[Category:Charts]]<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Danish]]<br />
[[Category:Comics featuring White Hat]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Blondie]]<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Comics featuring Black Hat]]<br />
[[Category:Comics featuring Hairy]]</div>108.162.246.135https://www.explainxkcd.com/wiki/index.php?title=2341:_Scientist_Tech_Help&diff=1955802341: Scientist Tech Help2020-08-06T00:09:16Z<p>108.162.246.135: </p>
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<div>{{comic<br />
| number = 2341<br />
| date = August 3, 2020<br />
| title = Scientist Tech Help<br />
| image = scientist_tech_help.png<br />
| titletext = I vaguely and irrationally resent how useful WebPlotDigitizer is.<br />
}}<br />
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==Explanation==<br />
{{incomplete|Created by our finest algorhitms. Do NOT delete this tag too soon.}}<br />
In this comic, Randall pokes fun at stereotypes of scientists that "tech people" hold.<br />
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In the first panel Randall, presents an idealized view of the tasks of tech people. A group of scientists have run their experiments and compiled their data, but find that the data is simply too complicated for humans, even advanced scientists such as themselves; the tech people resolve in heroic statements to decipher the data with their most advanced algorithms. Large portions of {{w|machine learning}} and {{w|data science}} hinge around finding a pattern (either regression or classification) in a given data set, but the more common, real-world problem is in {{w|data cleaning}} and preparation. For the most part, the rest can be done with preexisting implementations. These types of tasks are those that tech people both expect to perform, and hope to expand upon.<br />
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The second panel presents a different reality. The scientists are fully confident they can interpret the data on their own, provided they can access it, because the methods of ''recording'' their data are incredibly sub-par. Apparently wasps had infested the lab, and the scientists had to take photos of their equipment through the window. This created a much more fundamental problem of data format than normal (image vs spreadsheet, as opposed to something more normal like pixel-wise vs vertex-based segmentation). The joke is that the scientists' questions for their tech specialists are very mundane in nature; it presents not a chance to test and prove their machine learning systems, but a simple and tedious process of untangling digital paperwork. [https://old.reddit.com/r/talesfromtechsupport/comments/hxt0fw/my_whole_computer_went_black_what_did_you_do/ This is true in real life] &mdash; experts' expertise is usually deep, but not broad, and helping them with issues outside their comfort zone is rarely glamorous.<br />
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{{w|Polaroid Corporation|Polaroid}} is a brand of {{w|instant camera}}, though "Polaroid" is often used to refer to instant cameras in general. Excel is referring to {{w|Microsoft Excel}}, a spreadsheet management program.<br />
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The title text refers to [https://automeris.io/WebPlotDigitizer/ WebPlotDigitizer], a tool which may be used on visual displays of data such as graphs and charts in order to extract the underlying data. This tool would have the potential to solve the problem which the scientists have by extracting data from the images taken of the equipment. Randall acknowledges the usefulness of the tool, but also expresses some dislike that the tool was invented at all &mdash; someone must have had the original data to draw the graph, thus if they had made the data available then he wouldn't have to reverse engineer the plot. Other possibilities are that he simply feels that the tool is too powerful and leaving him less work to do, or that tools so trite and seemingly unnecessary prove so useful in the end.<br />
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[[2116: .NORM Normal File Format]] deals with nested file formats.<br />
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==Transcript==<br />
:What tech people think scientists need help with:<br />
:[Cueball, Ponytail, and Megan are facing a second Cueball and Hairbun. Ponytail is gesturing with her hand out. The second Cueball has his finger raised.]<br />
:Ponytail: Please&ndash;our data, it's too complex! Can your magical machine minds unearth the patterns that lie within?<br />
:Cueball 2: We shall marshal our finest algorithms!<br />
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:What scientists actually need:<br />
:[The two Cueballs, Ponytail, Megan, and Hairbun are in the same position as before. The second Cueball no longer has his finger raised.]<br />
:Ponytail: For a few weeks in June, the lab was infested by wasps, so we had to take pictures of the equipment through the window.<br />
:Ponytail: How do you get graphs from a Polaroid photo into Excel?<br />
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{{comic discussion}}<br />
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[[Category:Multiple Cueballs]]<br />
[[Category:Comics featuring Hairbun]]<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Science]]<br />
[[Category:Computers]]<br />
[[Category:Bees]]</div>108.162.246.135https://www.explainxkcd.com/wiki/index.php?title=Talk:2337:_Asterisk_Corrections&diff=195065Talk:2337: Asterisk Corrections2020-07-25T04:36:22Z<p>108.162.246.135: </p>
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<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
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I think the only spot of the title text quote into which "witchcraft" makes a decent sentence is to replace "next": "I'd love to meet up, maybe in a few days? Witchcraft week is looking pretty empty" [[Special:Contributions/173.245.54.161|173.245.54.161]] 01:02, 25 July 2020 (UTC) Me<br />
:I'd go with replacing "meet up". "I'd love to witchcraft, maybe in a few days? Next week is looking pretty empty." [[User:Orion205|Orion205]] ([[User talk:Orion205|talk]]) 01:14, 25 July 2020 (UTC)<br />
:: "I'd love to meet up, witchcraft in a few days? Next week is looking pretty empty." would be the third interpretation [[User:Multiverse42|Multiverse42]] ([[User talk:Multiverse42|talk]]) 01:39, 25 July 2020 (UTC)<br />
::Or it could be "I'd love to meet up, maybe witchcraft a few days?" Munroe really loves to mess with people. [[User:A|A]] ([[User talk:A|talk]]) 01:43, 25 July 2020 (UTC)<br />
: Alternatively, witchcraft replaces maybe: "I'd love to meet up, [how about we practice] witchcraft in a few days?" [[Special:Contributions/162.158.75.66|162.158.75.66]] 02:06, 25 July 2020 (UTC)<br />
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A splat? I didn't know that. IME it's just the messed up word resurrected to, summon a beech, auto corrected to the same wrong word. BTW the asterisk on an obsolete keyboard looked like a squished spider, thus 'splat.'<br />
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Asterisks can replace multiple words, right? Something like "I'd like to meet up, maybe witchcraft? Next week is looking pretty empty" could work, yeah? [[Special:Contributions/108.162.246.135|108.162.246.135]] 04:36, 25 July 2020 (UTC)</div>108.162.246.135