Talk:1318: Actually

2014-01-19T11:27:23Z

Tc18021188:

I started reading the comic from the topmost line "Actually, measurements suggest it's flat." It seemed that he was talking about the planet, but it's also a response to the curved-space line from before. Upon further reading, I can't tell if the discussion is about a planet or a universe, and it looks like you can go around the circle twice and assume both. [[Special:Contributions/173.245.50.72|173.245.50.72]] 05:13, 17 January 2014 (UTC)

: It is about the shape of the Earth. The Earth exists in a curved universe. The alt text is referring to the fact that by being more and more specific you can always get the last word in but it may alienate you from your peers. [[Special:Contributions/108.162.246.117|108.162.246.117]] 05:14, 17 January 2014 (UTC)

: "Actually, measurements suggest it's flat." could mean two different things: the first would be in the physical sense, the second in the economic sense, if he is referring to the book "The World is Flat" from 2005.

The transcript needs some way to show that Cueball is talking to the second Hairy in the end. [[Special:Contributions/108.162.216.71|108.162.216.71]] 08:25, 17 January 2014 (UTC)

: "show that Cueball is talking to the second Hairy in the end" -> Do you consider it done ? [[User:MGitsfullofsheep|MGitsfullofsheep]] ([[User talk:MGitsfullofsheep|talk]]) 08:50, 17 January 2014 (UTC)

Fixed factual error about sum of angles of a triangle in a closed geometry. An example of closed geometry is spherical geometry, where sum of angles of a triangle is π < A + B + C<3π http://en.wikipedia.org/wiki/Spherical_trigonometry . Previous text wrongly stated that A+B+C would be smaller than π in closed geometry and greater in open geometry. [[User:MGitsfullofsheep|MGitsfullofsheep]] ([[User talk:MGitsfullofsheep|talk]]) 08:50, 17 January 2014 (UTC)

About the oblate configuration: why attribute it to centripetal force? Because centrifugal force is an "apparent" force? Well centripetal force from gravitational pull is actually balancing the centrifugal force caused by rotation of the earth. The whole "centrifugal force does not exist" thing is a misconception. It's an inertial force and writing the equilibrium equations for an object in the rotating reference frame (the one we experience everyday) at latitude phi you see: gravitational pull toward the center of the planet + centrifugal force away from the axis of rotation= mass*g(phi). This g(phi) is not the same in every spot of the earth, it changes in value and direction (does not always point exactly to the center of the earth) with latitude.{{unsigned ip|108.162.229.65}}
: I second this. The centripetal force would actually be the gravity of earth. Attributing the oblate shape of earth to this is just plain wrong, since it pulls inwards, not outwards. Actually all forces could be called "apparent" forces, since they're really just constructs to help you calculate the acceleration of a body. There's always a (local) reference frame where a particular force doesn't "exist". {{unsigned ip|173.245.53.131}}
:: Sure, there is always such frame, but gravitation is real force anyway because we can measure the higgs field by detecting higgs bosons. At least I think we can. Failing that, electromagnetic forces are real because we can measure electromagnetic field by detecting photons, this I'm sure of :-). -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 10:23, 17 January 2014 (UTC)
:::Come now. Do you really expect me to do coordinate substitution in my head while strapped to a centrifuge? [[User:Diszy|Diszy]] ([[User talk:Diszy|talk]]) 15:44, 17 January 2014 (UTC)
::::No, Mister Diszy, I expect you to die. [[Special:Contributions/108.162.238.117|108.162.238.117]] 20:14, 17 January 2014 (UTC)

I don't see why the explanation assumes the top claim is at the start and end. I think that part of the explanation is a stretch and that the "flat" claim is not meant to be given twice. [[Special:Contributions/108.162.246.117|108.162.246.117]] 17:38, 17 January 2014 (UTC)
:It's a loop. Technically there is no "start". Each line is a direct "more specific" response to the previous remark. [[Special:Contributions/108.162.238.117|108.162.238.117]] 20:17, 17 January 2014 (UTC)

I always suspected Freddie Mercury was a closet planetoligist. {{unsigned ip|127.0.0.1|20:26, 17 January 2014 (UTC)}}

I highly doubt this pun is intentional, but this could be seen as a case of circular logic. [[Special:Contributions/108.162.238.117|108.162.238.117]] 20:35, 17 January 2014 (UTC)

Any significance to where they are standing along the circle? If we start with flat, the first three are right in a row, but then the rest are spread out further.[[Special:Contributions/108.162.216.57|108.162.216.57]] 21:20, 17 January 2014 (UTC)
:Yes. They are standing close to the center of where their sentence is. [[Special:Contributions/108.162.238.117|108.162.238.117]] 03:17, 18 January 2014 (UTC)

Quick suggestion. Under the (first) "[Actually,] measurements suggest it's flat." explanation title, just have the first point given. Then continue through the other "Actually"'s and ''then'' have (under a second "Actually, measurements suggest it's flat." header) the "Finally, the first speaker comments again," point and then the "The arguments could continue around the circle," one at the end. [[Special:Contributions/141.101.99.223|141.101.99.223]] 22:41, 17 January 2014 (UTC)

It was not the case that the middle age believd in a flat eart (some of the antic cultures did). See [https://en.wikipedia.org/wiki/Myth_of_the_Flat_Earth Wikipedia]. --[[User:DaB.|DaB.]] ([[User talk:DaB.|talk]]) 00:27, 18 January 2014 (UTC)

;not a recursive loop

"Further statements could now continue to be interpreted as referring to the universe rather than the Earth, thus forming a recursive loop.". This phrase is awful. As far as I understood this long hypothetical sentence does not even wrap 2 times. Adding 'recursive' is totally pointless here. Am I right? {{unsigned ip|141.101.98.222}}

''Actually,'' you can win every exchange just by being one level more precise than '''whom'''ever talked last. --[[User:Jesse|Jesse]] ([[User talk:Jesse|talk]]) 05:44, 19 January 2014 (UTC)

1318: Actually

2014-01-18T21:30:06Z

Tc18021188:

{{comic
| number = 1318
| date = January 17, 2014
| title = Actually
| image = actually.png
| titletext = Protip: You can win every exchange just by being one level more precise than whoever talked last. Eventually, you'll defeat all conversational opponents and stand alone.
}}

==Explanation==
The image shows a sphere, a simple model for the shape of the Earth. Six people stand on its surface, talking about ways to best describe it, starting with a flat surface, the first belief held, and ending with general relativity. As the statements form a circle, the very first statement can lead recursively off the last, as described below.

The statements in detail:

;Actually, measurements suggest it's flat.
* This statement is located at the top of the sphere in the comic, making it most likely to be read first. Given no other context, it will be interpreted as referring to the Earth; i.e. "The Earth is flat." This references the earliest view of our planet's surface.
;Actually, it's a sphere.
* This refers to the second earliest view of our planet's surface, as a ball with uniform radius everywhere.
;Actually, it's an oblate spheroid.
* This clarifies the previous statement; an {{w|oblate spheroid}} has a wider radius at the equator than through the poles. On Earth, this occurs because a rotating body tends to bulge at the equator, where the matter experiences greater centripetal forces (analogous to experiencing more force at the outside of a round-a-bout rather than at the center). This is known as the {{w|equatorial bulge}}.
;Actually, it's a shape defined by the EGM96 coefficients.
* This adds even more clarification to the previous statement; the {{w|EGM96|Earth Gravitational Model 1996}} is a detailed map of the Earth's gravitational field, which is not as uniform as a pure oblate spheroid would suggest.
;Actually, it's that plus local topography.
* This adds an almost unnecessary level of clarification to the previous; obviously the Earth's surface is not a smooth shape but rather contains numerous mountains, hills, valleys, etc. which constitute "local topography".
;Actually, it's embedded in a universe that's curved.
* This shifts the perspective from the actual shape of the Earth to the "shape" of the space around it. According to {{w|General relativity}}, our planet's gravity bends the space-time around it, making it curved. At the time General relativity was discovered, it was not conclusively known whether the {{w|Shape of the universe|whole universe was flat or curved}}.
;Actually, measurements suggest it's flat.
* Looping around to the first statement and given the context from the previous one, this can now be interpreted as "the universe is flat" rather than "the Earth is flat". Recent measurements of the universe's shape strongly suggest that it is more or less completely flat rather than curved.
* Further statements could now continue to be interpreted as referring to the universe rather than the Earth, thus forming a recursive loop.
* This could also refer to Thomas Friedman's 2005 book "The World is Flat" which discusses globalization and the idea of the world as a level playing field of equal opportunity for commerce.

The title text pulls the whole comic tegether, pointing out that each statement in the comic is more precise than the previous. Unlike the loop in the comic, someone who does this will likely eventually win any real-life debate. The phrase "stand alone" refers to driving away all conversation, resulting in no one wanting to speak to the person.

==Transcript==
:[Six people are standing upon a white circle as if it were a miniature planet. Each person is facing the reader and says something to the person on their right. All texts are displayed as a near-continuous stream over their heads to form one circle that encloses the whole picture.]
:[From topmost, going clockwise.]
::Cueball: '''''Actually,''''' measurements suggest it's flat.
::Ponytail: '''''Actually,''''' it's a sphere.
::White Hat: '''''Actually,''''' it's an oblate spheroid.
::Megan: '''''Actually,''''' it's a sphere defined by the EGM96 coefficients.
::Hairy 1: '''''Actually,''''' it's that plus local topography.
::Hairy 2: '''''Actually,''''' it's embedded in a universe that's curved.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring White Hat]]
[[Category:Comics featuring Hairy]]
[[Category:Physics]]
[[Category:Language]]

explain xkcd - User contributions [en]

Talk:1318: Actually

1318: Actually