explain xkcd - User contributions [en]

Talk:1515: Basketball Earth

2015-04-22T18:35:53Z

173.245.50.107:

Apologies to the first editor, who made a snappier version of what I wrote. For the record, whilst fighting a dodgy internet connection I eventually ended up replacing the following...
Cueball is seen trying to explain the relative sizes of the earth and moon by comparing the earth to a basketball and the moon to what looks like a golf ball. This explanation is constantly thwarted by passerby interacting with the basketball while Cueball is explaining it.
For the title text, the answer is zero, since it is against basketball rules.
...with what I tried to keep short during my own writing from scratch. I also ommited several other concepts of my own thought: The fact that Blackhat must have used a very light-touch to ''only'' generate a megatsunami (albeit already unimaginably large, at Earthball's scale); The possibility of recursion (including something like the Men In Black 'cat collar' allusion); and that in the universe of the comic strip there is only ''one'' actual basketball (the Earthball itsself), although I like how we ''both'' had the idea that the basketballs upon Earthball would not have counted in a game of basketball with an Earthball-scaled hoop, due to quite obvious interpretations of the sport's regulations. [[Special:Contributions/141.101.98.67|141.101.98.67]] 05:11, 22 April 2015 (UTC)
:Oh yeah, and reversion is invited, if deemed preferable. As is amalgamation, and refinement and re-replacement by something even better, of course. As per the standard Wiki creed. Much as I am cringing at having upset the original contributor, I'm quite happy to be gazumped in turn. [[Special:Contributions/141.101.98.67|141.101.98.67]] 05:14, 22 April 2015 (UTC)
If you look at the third frame of the Blackhat sequence and compare it to the frames underneath, you can see that he didn't just touch the Earth or an ocean--he actually rotated it 90 degrees.[[Special:Contributions/108.162.221.115|108.162.221.115]] 09:38, 22 April 2015 (UTC)
:Well spotted! Edit that in! (Do it quickly with a pre-prepared edit. I kept getting hit by edit-conflicts, which I set about to resolve amicably without reversing anybody else's input; only to get hit by further edit-conflicts by the next person to come along and improve overlapping pieces, whom I also strived not to disregard.) [[Special:Contributions/141.101.98.67|141.101.98.67]] 09:57, 22 April 2015 (UTC)
::No he didn't. the Earth always rotates from the first panel to the next. So that it is in a different position when Black Hat touches it, to where it was the panel before does not imply that he rotated the Earth. If anything he only rotated it a few degrees, as it had already rotated most of those 90 degree from panel 1 to panel 2 before Black Hat reaches the Earth. As far as I can see there has not been any change to include this yet. So that is good. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 10:41, 22 April 2015 (UTC)

I really love this comic. It is great fun. Thanks Randall, happy Earth day. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 10:42, 22 April 2015 (UTC)

... a tennis ball an average 7.2 metres away, while the Sun would be 26 metres across and 2.8 km away. [[Special:Contributions/108.162.250.165|108.162.250.165]] 13:25, 22 April 2015 (UTC)

It's 13:23 right now, but the clock of explainxkcd.com says it's 13:37. [[Special:Contributions/108.162.221.201|108.162.221.201]] 13:37, 22 April 2015 (UTC)

If we assume 9,000,000 basketballs sold every year ([http://bbs.clutchfans.net/showthread.php?t=82227 bbs.ClutchFans.net]), one basketball lasts about 10,000 bounces ([http://www.sotruefacts.com/rule/770 SoTrueFacts.com]), and there's between 2,500 and 3,000 bounces per game ([http://www.answers.com/Q/What_is_the_average_lifespan_of_a_basketball_in_bounces_in_National_Basketball_Association_play Answers.com]) we can extrapolate that on average a basketball doesn't live for more than a year, and the number of basketballs sold replace those which have lifed-out. Let's build in a 10% slush factor and say there 10m basketballs produced in the world last year. Let's further say that there's an extra 1m basketballs sold every year which don't get regular use and are in some kid's room and those have been accumulating for about ten years (different kids get basketballs every year which end up in their bedrooms). Dunking a basketball gives two points, and at 20 million basketballs, that gives 40 million points – and a safe bet you're going to make it to the playoffs that year. [[User:Jarod997|Jarod997]] ([[User talk:Jarod997|talk]]) 13:51, 22 April 2015 (UTC)

Is it possible that the megatsunami is actually caused by the gravity of the scale Moon (it being way too close to the scale Earth)? This is a major problem that most children's books (or adult's books or websites) have. They scale the planets/moons/stars but not the distance. As the comment above, to get normal tides, the tennis ball should be 7.2m away at this scale. --[[User:Gravitron|Gravitron]] ([[User talk:Gravitron|talk]]) 14:06, 22 April 2015 (UTC)

I find it interesting that Randall makes the same mistake a lot of people make reguarding the distance between the earth and moon at that scale. I was watching Veritasium (https://www.youtube.com/watch?v=Bz9D6xba9Og) on Youtube a while back and the guy there was asking people how far away a tennis ball sized moon would be from a basketball sized Earth. Most people made the distance way too small, very similar to how far away they appear in the comic. In reality they would be something like 10 times that distance. Usually Randall is more accurate than this. [[Special:Contributions/108.162.221.171|108.162.221.171]] 14:09, 22 April 2015 (UTC)Agent0013
:Unless he was simply trying to compare the relative sizes. It's possible after that he would get in to the relative distance between the two - but good point. [[User:Jarod997|Jarod997]] ([[User talk:Jarod997|talk]]) 14:12, 22 April 2015 (UTC)
::It seemingly got lost when trying to resolve edits, but I'd calculated and intended to add that (for the size of a baseball, so a tennis ball would slightly different) 110 Moonball diameters separation between the two. Of course no human has (personally) seen that from a proper perspective, i.e. far enough away to get both bodies in the same convenient vision at the same time whilst off to the side. (Even the Apollo astronauts only got to look at one over the top of the other, at various times, or by panning between the two whilst in the midst of their trans-lunar trajectories.) But there's surely been a space probe or two with a suitable imager been tasked towards such a shot whilst off mostly perpendicular to the Earth-Moon and a decent distance away to get both in the same shot without distortion... [[Special:Contributions/141.101.98.67|141.101.98.67]] 17:52, 22 April 2015 (UTC)

I don't agree with the claim (at a couple points in the article) that *all* life would be extinguished by any of these manipulations. 2-4 may kill off most or all macroscopic life, but microbes would survive all of them (unless Megan has bleach in that sports bottle). If 3 or 4 shattered the earth, that might extinguish all microbes, but even that I doubt. The only case I can imagine would be if 3 or 4 caused it to spiral into the sun. [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 14:10, 22 April 2015 (UTC)

Title text might be reference to HHGTG: “
Ford Prefect: I read of one planet in the seventh dimension got used as a ball in a game of intergalactic bar billiards. Got potted straight into a black hole, killed ten billion people.
Arthur Dent: Madness. Total madness.
Ford Prefect: Yeah. Only scored thirty points too. ”[[Special:Contributions/198.41.241.91|198.41.241.91]] 14:23, 22 April 2015 (UTC)

-----

I admit that I'm super-confused by the structure of the comic. The explanation here describes possible consequences for the actions, but as depicted, only the first has any "real world" effect. I too would expect the water bottle to cause a deluge, but it doesn't seem to. What's going on? [[User:Mattdm|Mattdm]] ([[User talk:Mattdm|talk]]) 15:40, 22 April 2015 (UTC)

-----

The hoop in panel 16 seems too high, unless both Cueball and Megan are under 5 feet tall. --[[User:PsyMar|PsyMar]] ([[User talk:PsyMar|talk]]) 17:11, 22 April 2015 (UTC)

Happy Earth Day everyone. Today is the day we regret everything we do to the earth, and the next is the day we forget all that. [[User:YourLifeisaLie|The Goyim speaks]] ([[User talk:YourLifeisaLie|talk]]) 17:59, 22 April 2015 (UTC)

Why the whole paragraph about it being a baseball? We have no indication of what it is, so why not just say "if it's a tennis ball..." [[Special:Contributions/173.245.50.107|173.245.50.107]] 18:35, 22 April 2015 (UTC)

Talk:1473: Location Sharing

2015-02-28T04:35:52Z

173.245.50.107:

It's a reference to the Uncertainty Principle, a property of quantum mechanics that states that position and momentum cannot be known at the same time.
[[Special:Contributions/199.27.133.98|199.27.133.98]] 05:20, 14 January 2015 (UTC)

I may be thinking too much into this, but couldn't she also not want the website to know her mass? Momentum is Mass*Velocity, and Velocity can be derived from change in position [[Special:Contributions/173.245.56.159|173.245.56.159]] 05:34, 14 January 2015 (UTC)
:That was my understanding, too. Moreover, I don't see any humor in applying the uncertainity principle to macroscopic objects. [[Special:Contributions/108.162.254.57|108.162.254.57]] 08:53, 14 January 2015 (UTC)
::You're such a Bohr. --[[Special:Contributions/108.162.216.30|108.162.216.30]] 11:54, 18 January 2015 (UTC)
:::I genuinely cannot believe you made that joke.[[Special:Contributions/173.245.50.107|173.245.50.107]] 04:35, 28 February 2015 (UTC)

Angular momentum sensors - a.k.a. gyros, not accelerometers. {{unsigned ip|141.101.80.109}}

She does not want the website to calculate her mass and therefore her weight. It has nothing to do with the uncertainty principle {{unsigned|Saints22}}
:I disagree. Of course it is funny idea that she says nice try as if the website had interest in her weight. But since you cannot calculate mass from position and momentum your ideas makes no sense. You need the velocity and the momentum to calculate the mass. So even though they could have both position and momentum they would still not know her mass. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 10:33, 14 January 2015 (UTC)
::Unless, of course, the permission given by Megan to determine her location is persistent and lasts for at least two consecutive polls for location, which would enable the recipient to compute the velocity out of two locations and time between the polls. [[User:Nyq|Nyq]] ([[User talk:Nyq|talk]]) 13:12, 14 January 2015 (UTC)

I do not not think that Megan allows the website to access her location. The website wants her to, that's why the button is highlighted and blinking. In the beat panel, Megan presumably denies. The website then asks for momentum and wants Megan to deny the request (by highlighting "Deny"), so that, according to the uncertainty principle, they can still get her location (which is what they wanted all along). However, Megan sees through this trick and acknowledges its cleverness with a "Nice try". --[[Special:Contributions/108.162.254.134|108.162.254.134]] 10:27, 14 January 2015 (UTC)
:No I disagree. Of course the highlighted button is the one Megan pushes. And just because you do not know the momentum does not automatically give you the location. You just can't know both without a given uncertainty. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 10:33, 14 January 2015 (UTC)
::No, the highlighted buttons are definitely meant to be preselected. Megan pushes a button on the second panel, and then the website shows the page where denying the momentum is preselected.{{unsigned ip|108.162.254.47}}
:True! Thats exactly how I understand this comic. The website wants to know her location. She denies. Then the website tries to trick her in wanting to be forced not to know her exact momentum - so in turn to be able to know her exact location anyway.{{unsigned ip|108.162.254.47}}
:I think you're right. Her thumb is definitely only extended in panel 2, and, going back, it looks like the highlight is supposed to be [http://www.javascriptworkshop.com/wp-content/uploads/geolocation.png this] sort of window, although I have no idea what it looks like on mobile. Also, the "beat" panel makes more sense with this explanation, since it's actually an action panel instead of suggesting a weird gap between the two requests. It certainly makes more sense than the article asking for her momentum after already having her position, since measuring momentum would decrease their certainty of subatomic Megan's position. And it's definitely about the uncertainty principle, given: 1. This is Randall; he's way more likely to do a comic about a principle of particle physics than one about women not wanting people to know their weight, and 2. The alt text is about the uncertainty principle. [[Special:Contributions/199.27.128.237|199.27.128.237]] 05:31, 16 January 2015 (UTC)
What's with the persistent "females"? Would make sense in biology talk, but it's really weird when what you mean is "women"[[Special:Contributions/141.101.104.185|141.101.104.185]] 13:14, 14 January 2015 (UTC)
:: I'd suggest that it is just about avoidance: some might take 'women' as having negative derogative connotations in this context, whereas females is unarguably accurate. [[Special:Contributions/173.245.54.204|173.245.54.204]] 13:29, 14 January 2015 (UTC)
:::"Females" is shorter than "women and girls". [[Special:Contributions/108.162.221.201|108.162.221.201]] 14:54, 14 January 2015 (UTC)
::: Yes, some people are determined to be offended. Unfortunate. [[Special:Contributions/173.245.54.152|173.245.54.152]] 19:52, 14 January 2015 (UTC)
::: For the sake of accuracy, I move that we should really say something more along the lines of "living female homo sapiens organisms" - so that we can exclude the countless other female eukaryotes we know so little about socialogically, and/or the otherwise dead or nonexistent homo sapiens or their representations? I mean, come on! "Females" is sooooo nonspecific...-- [[User:Brettpeirce|Brettpeirce]] ([[User talk:Brettpeirce|talk]]) 19:57, 14 January 2015 (UTC)
::: A "woman" is a person; "female" is a sex. "Females" in this context is as rude as calling grown women "girls." [[Special:Contributions/108.162.216.36|108.162.216.36]] 03:45, 16 January 2015 (UTC)
:: The name of the academic field of the study of women's perspectives in most public universities is, "Gender, Sexuality, and Women's Studies." "Women" is the correct academic term for the discussion of women. [[User:ChristGoldman|ChristGoldman]] ([[User talk:ChristGoldman|talk]]) 20:36, 14 January 2015 (UTC)

There's some confusion over the sensors. GPS is used to determine the device's position on Earth, but not its orientation. An accelerometer may be used to determine a phone's orientation in terms of flat/portrait/landscape, but not in which direction in terms of north/south. The magnetometer can measure magnetic forces, but isn't enough to determine north (because of inclination). To measure magnetic north, you need to combine data from accelerometer and magnetometer, which gets a working, but quite unsteady compass. These sensors (GPS, accelerometer, magnetometer) are available on most current smart phones. Better devices also include a gyroscope, which measures angular momentum, but no absolute angle towards the horizon and/or north. A gyroscope may be used to improve the stability of the accelerometer/magnetometer compass (but requires a good algorithm which I'm still looking for). Knowing this, the title text is disputable, because devices without gyro aren't actually able to provide a steady compass, while those with gyro are (although there are apps which don't use the gyro even when available, so they won't get a fast, steady compass anyway). --[[User:SlashMe|SlashMe]] ([[User talk:SlashMe|talk]]) 15:24, 14 January 2015 (UTC)

It seems to me that the paragraph explaining mass and weight is too complicated and overly long, and the hypothesis that the app is trying to steal this information unrelated to the comic, or rather, wild speculative extrapolations of logic and meaning. Likewise, the sentences on how the accelerometer may be used to guess passwords seems to me to be unfounded in science. The uncertainty principle is the clear main theme of this comic. --[[User:Canned Soul|Canned Soul]] ([[User talk:Canned Soul|talk]]) 16:03, 14 January 2015 (UTC)

Added one word to make it "An example is a weather app which would need your location in order to '''automatically''' find the correct forecast." It's often trivial to manually get forecasts (or other services, like "nearest branch of a shop that has your desired item in stock") for a current location, just so as long as /you/ know where you are... (I don't turn on my GPS unless I'm actually wanting to use it for something, and don't like websites knowing these things just because they ask for them in the background. Go away, Google Location Services... and why does it grey-out the "Don't share information" hotspot when I've ticked the "Don't ask me again" and only lets me continually refuse ''manually''!? Which I do on principle!!) I keep a variety of common home/away locations on permalink in my favourite weather forecast app and know I can easily add another at a moment's notice when I ''want'' to. (And, the beauty is, I don't even need to be there at the time, just perhaps ''planning'' to go!)

Plus, to the "I don't see any humor in applying the uncertainity principle to macroscopic objects." person, above, please pass by your local XKCD offices at the first opportunity in order to hand back your XKCD Membership Card. You're obviously not one of us! ;) [[Special:Contributions/141.101.98.191|141.101.98.191]] 16:28, 14 January 2015 (UTC)
::My goodness, yes! What a lot of seriousness has found its way into this discussion! How could anyone miss the humo[u]r in the personification of a subatomic particle as a Megan?[[User:Taibhse|Taibhse]] ([[User talk:Taibhse|talk]]) 04:23, 15 January 2015 (UTC)
::No humor in it? Clearly, your [http://xkcd.com/1471/ macrobiome] is out of balance. {{unsigned ip|173.245.52.124}}
Per the explanation: "Randall suggests the poor accuracy of the compasses in mobile phones (measuring the angular position) is due to the gyroscopes being too good. (If both the gyroscope and the compasses were completely accurate, it would violate the uncertainty principle)."
The compass points in a particular direction but tells you nothing about location or momentum. How would it be involved in any violation of Uncertainty? The gyroscope and GPS I could see, maybe. But the compass? I don't see how it combined with anything could involve Uncertainty. - Equinox [[Special:Contributions/199.27.128.117|199.27.128.117]] 16:46, 14 January 2015 (UTC)
: The Uncertainty Principle extends to other pairs of conjugate variables besides the well-known pair of position and momentum. One of these pairs is orientation and angular momentum. [[Special:Contributions/173.245.52.142|173.245.52.142]] 17:45, 14 January 2015 (UTC)

The way I read this, by knowing her current location AND momentum (ignoring the uncertainty principle thing for the moment) it becomes possible to predict where whe'll be in the future, which would open up all sorts of ... 'interesting' marketing opportunities for the app maker. Megan doesn't mind the app knowing where she *is*, but doesn't want it to know where she's *going*, and so rejects the second seemingly innocent question. Maybe? {{unsigned ip|108.162.249.205}}
:I agree. It is not about the uncertainty principle, but about predicting future locations with the momentum, or future orientations with the angular speed from the gyroscope. It would NOT violate Heisenberg to measure two (not conjugating) physical parameters with bad accuracy (only the other way round). The argument goes: The phone can measure the orientation quite well despite of the bad compass. So its only option is using the gyroscope and integrating its angular speeds over time. The initial value can come from the GPS, the compass (offset error, if it is really so bad) or from an initialization in the factory (then the gyroscope has to function exceptionally well, but this could be the joke). Sebastian --[[Special:Contributions/108.162.254.56|108.162.254.56]] 14:15, 15 January 2015 (UTC)

+1 for this being about the uncertainty principle. Frankly, I'm surprised there's any controversy (many of the alternative explanations offered seem very unlikely, quite apart from anything else): if there's any ambiguity in the cartoon itself, surely the title text (by riffing on another pair of conjugate variables) clears that up?
[[Special:Contributions/141.101.98.169|141.101.98.169]] 10:47, 16 January 2015 (UTC)

Talk:1492: Dress Color

2015-02-28T02:15:07Z

173.245.50.107:

LOOK, Randall. Schrödinger was a crossdresser. This was Schrödinger's dress. My Schrödinger fanfics say so and you can't take away my dreams! [[Special:Contributions/173.245.50.107|173.245.50.107]] 02:15, 28 February 2015 (UTC)

To me, they both look blue/gold [[User:Mikemk|Mikemk]] ([[User talk:Mikemk|talk]]) 06:29, 27 February 2015 (UTC)
:To me as well. The one on the right, with a lighter background, appears more bluish and the collar is a darker brown. (The collar on the left, to my eyes, matches the face on the right.) But both definitely appear bluish with a dull yellow. - Equinox [[Special:Contributions/199.27.128.120|199.27.128.120]] 16:50, 27 February 2015 (UTC)

What is the illusion supposed to be? The colors of the dress look a bit darker with the light background, but not very much. Is that the illusion? --[[Special:Contributions/141.101.80.82|141.101.80.82]] 07:07, 27 February 2015 (UTC)
: Agree. To me, it looks like it's definitely light blue (maybe "cornflower"?) with pale olive stripes. "Gold" would really be a stretch. It looks like that in all lighting conditions and in both backgrounds of the strip. Did I pass some kind of color-blindness test? Or fail? [[Special:Contributions/108.162.254.133|108.162.254.133]] 07:43, 27 February 2015 (UTC)
: This has nothing to do with color-blindness, but probably with certain arbitrary constants related to white-balance adjustment that differ brain-to-brain. Many people I know insist that even though the picture looks blue, it's a dress illuminated by a blue light, and based on this assumption their brain may essentially redden the whole picture to adjust for this light. The actual picture was taken in white light, not blue light. [[Special:Contributions/173.245.55.28|173.245.55.28]] 07:46, 27 February 2015 (UTC)

::It may also be related to white-balance of the MONITOR. I see original dress like black and blue and the one on left here as gold and light blue. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 10:00, 27 February 2015 (UTC)

Apparently for some people the left-hand-side's general blueishness is adjusted against by the visual system enough to make the dress look white and gold instead of blue and brown. I am not one of those people. [[Special:Contributions/173.245.55.28|173.245.55.28]] 07:43, 27 February 2015 (UTC)

Description says left for both [[Special:Contributions/141.101.98.219|141.101.98.219]] 08:37, 27 February 2015 (UTC)
:Now changed. (Saw it myself before I saw your comment, and just lept straight in there. Hopefully I changed the right left so that it's right and not left the wrong left whilst producing the wrong right. Alright?) [[Special:Contributions/141.101.98.192|141.101.98.192]] 09:30, 27 February 2015 (UTC) (Also, "hello near-IP neighbour!"... The same digits, even. Creepy.)
::Y'all are both from London, and probably live on the same street. Congrats! You made a friend! :) [[Special:Contributions/108.162.216.192|108.162.216.192]] 16:25, 27 February 2015 (UTC)

Are they really the same colour? 'Cause to me on the blue side it looks blue and black- while on the white side it looks white and gold. Is this normal? {{unsigned|FlyingPiggy}}

The figure on the right definitely has a beard. [[Special:Contributions/108.162.249.182|108.162.249.182]] 09:38, 27 February 2015 (UTC)

I checked with ColorZilla and the RGB values are identical. From my perspective, in the one on the left the dress appears pale blue with darker brown/gold stripes, and the one on the right appears a darker blue with lighter brown/gold stripes. [[Special:Contributions/141.101.98.63|141.101.98.63]] 10:10, 27 February 2015 (UTC)

This is just a polychromatic version of that checker shadow illusion, right? http://en.wikipedia.org/wiki/Checker_shadow_illusion [[Special:Contributions/108.162.231.38|108.162.231.38]] 10:12, 27 February 2015 (UTC)
:That's what I thought too. But it looks the same (doesn't it?) and is the same (that, thankfully is non-subjective and verifiable with as little as MSPaint), so I'm at loss as to why this deserves a comic. [[Special:Contributions/141.101.104.136|141.101.104.136]] 10:47, 27 February 2015 (UTC)
: This is a common optical illusion (at least I've seen this many times) - most peoples eyes perform a white balance adjustment automatically which affects the perceived colours. If your eyes don't do this then you will do well in the paint colour matching business. http://www.moillusions.com/hue-optical-illusion/ I apologise for the jarring colours in the link. {{unsigned ip|141.101.98.220}}
:Here's a particularly good demonstration of the underlying "color perception" illusion (i.e. the Checker-Shadow illusion referred to above): https://www.youtube.com/watch?v=z9Sen1HTu5o [[User:Arcanechili|Arcanechili]] ([[User talk:Arcanechili|talk]]) 15:45, 27 February 2015 (UTC)

The comic is a reference to the debate around the coloration of [http://amd.c.yimg.jp/amd/20150227-00000070-zdn_n-000-2-view.jpg this dress]. The band in the middle of the image shows some of the material of the dress. To some people, including me, the dress is obviously, unquestionably black and blue. But to others, including my wife, it's obviously, unquestionably, black and gold. {{unsigned ip|103.22.200.196}}
:And to others it's apparently a number of other combinations - I've seen claims of white/gold and blue/orange. However, surprisingly few people seem to have seen [http://www.romanoriginals.co.uk/invt/70931?colour=Royal-Blue this link] to the manufacturer's page for what appears to be the same dress; available in 4 colour combinations which according to the manufacturers' descriptions are ivory/black, scarlet/black, pink/black and royal-blue/black, with pictures available of all versions. As such I'm happy to accept the pictures doing the rounds are probably the blue/black variant (although most of the over-exposed versions I've seen appear light-blue/goldish-brown to me. {{unsigned ip|141.101.99.77}}

Our eyes are too efficient, which makes this illusion work. In dim light we dilate our eyes, so an enclosed room with one lamp seems bright, though it is a cave compared to the outdoors. If the bulb in our lamp is of a warm tone, our eyes adjust so we believe we see colours as though in daylight. I think that's what's happening in the dress illusion -- we are trying to allow for perceived lighting conditions in the photo -- so the actual illusion is in our guess as to what those light conditions actually are. And finally an artist quote: "I can paint you the skin of Venus with mud, provided you let me surround it as I will." - Eugene Delacroix [[Special:Contributions/108.162.242.84|108.162.242.84]] 13:28, 27 February 2015 (UTC)

Some Notes on camera color correction: it's worse than, and is not just an optical illusion. It's a camera screwup.

* [http://40.media.tumblr.com/a391a1b4b46dd6b498d379e50f96ecbc/tumblr_nkcjuq8Tdr1tnacy1o1_500.jpg Here is the original photo] as [http://swiked.tumblr.com/post/112159166305/katze-geht-meow-ijustloveyoutubers seen here]

* [http://media.tumblr.com/ec387ec0bb03230268a9e905d74097d9/tumblr_inline_nkeezsjAuH1svicb3.jpg Here is a second photo of the same dress in normal light] As [http://swiked.tumblr.com/post/112164479015/can-we-have-more-pictures-of-the-dress-please-we seen here]

* [http://www.romanoriginals.co.uk/invt/70931?colour=Royal-Blue Here is the online store where you can buy the dress]

* [http://www.romanoriginals.co.uk/content/ebiz/romanoriginals/invt/70931/70931rbl_zoom1.jpg Here is a high quality photo of the dress from the store]

* [http://imgur.com/RY2dTnW.jpg Here is an example of the color "correction" that happens when you calibrate things so that Dark Blue = White.] NOTE: This is a major readjustment of colors and there is no real color matching between the two images. White is not actually blue in this image, and up is not down, and you are not going crazy

Cheap cameras will try to adjust colors based on formulas that guess what the correct color scheme is.

If you take a photo while in the shade on a sunny day, you likely get most of your light from the bright *BLUE* sky. This can make you look awful. The camera is set up to guess the correct exposure. In this case the camera follows the rules, and guesses, wrongly, that the the overall majority color in the center of the photo is white, and transforms the rest of the colors to match

It's a camera screwup. It also depends on how bad your viewing device is behaving, because, based on how dark the screen is, you then get the optical illusion effect that Randall posted.

This is a secondary effect, and not the real reason why behind what is going on in the first place. The correct rendering of the camera screwup is going to be, on most devices with normal color rendition, white with gold. Because some monitors are lighter or darker depending on viewing angle, this also impacts color perception.

We can then get the actual optical illusion after all that. But as we have seen with good photos of the actual dress in normal light, the camera got it wrong.

TL;DR: It's a cell phone camera screwup. [[Special:Contributions/173.245.52.170|173.245.52.170]] 14:22, 27 February 2015 (UTC)ruary 2015 (UTC)

Is it possible that there's a connection between this comic and [[690: Semicontrolled Demolition]]? Some discussions I've seen about this topic involve the choice between white/gold and blue/black, so Randall coloured his dress gold/blue. --[[Special:Contributions/108.162.216.122|108.162.216.122]] 16:20, 27 February 2015 (UTC)
: It's more likely due to the fact that the colors of the actual picture - that is, if you use a color picker - are roughly the same as those in the comic. [[Special:Contributions/108.162.216.111|108.162.216.111]] 17:06, 27 February 2015 (UTC)

I'm reminded of [[356: Nerd Sniping]], only the perpetrator has managed to snipe the entire interwebs {{unsigned ip|141.101.106.107}}

No one has yet mentioned that ignoring color, the two images are also mirror images of each other. On the left, the figure is looking slightly toward her own right shoulder; while on the right she is looking slightly to her own left. Most likely not at all relevant to this discussion, but usually folks on this forum are very quick to point out even insignificant details (like I'm doing right now) :)
[[Special:Contributions/108.162.216.42|108.162.216.42]] 19:01, 27 February 2015 (UTC)

;Similar Illusions and explanation

I feel like this line seems out o place, or at least badly worded (using half the URL as the text...):

''"Similar types of illusions can be seen at Optical illusion#Color_and_brightness_constancies and at echalk. (requires Flash®player)."''

Also, this seems similar to the [http://web.mit.edu/persci/people/adelson/checkershadow_illusion.html checker shadow illusion] (link to page on website with explanation of said illusion).

On another note, this page seems rather disorganized and uniformative about the phenomenon behind this illusion.

[[User:Zweisteine|Zweisteine]] ([[User talk:Zweisteine|talk]]) 19:04, 27 February 2015 (UTC)

This explanation is lacking in a particular detail: in Randall's drawing, what colors do the dresses look. I'm color blind, so they don't look different to me, but I couldn't name them. [[Special:Contributions/173.245.52.173|173.245.52.173]] 00:13, 28 February 2015 (UTC)
:I guess it depends. For ME it is blue and gold. --[[User:DaB.|DaB.]] ([[User talk:DaB.|talk]]) 01:57, 28 February 2015 (UTC)