https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&user=174.239.196.155&feedformat=atomexplain xkcd - User contributions [en]2024-03-28T13:22:49ZUser contributionsMediaWiki 1.30.0https://www.explainxkcd.com/wiki/index.php?title=Talk:1116:_Traffic_Lights&diff=48804Talk:1116: Traffic Lights2013-09-11T06:09:29Z<p>174.239.196.155: </p>
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<div>I doubt that this comic carries any deeper meaning. [[Special:Contributions/108.233.253.211|108.233.253.211]] 16:29, 4 October 2012 (UTC)<br />
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Traffic signals really are one of the most inscrutable inventions to ever be made. I mean, red means stop, yellow means caution, green means go. Unless you're in a turn lane, which means you have to watch for the green arrow, if there is one, or wait for an opening. Unless you're turning right, which is permitted to turn at any time providing there aren't any cars. Unless there's a sign that says "No Right Turn On Red". There's also the crazy cities that have special right turn lights. Then there's the intersections that have a sign for each lane telling what can and cannot be done. Or, if you're really lucky one of those intersections that has the LED screen that dynamically changes what the lane can and cannot do. And to top it all off, the Colorado Department of Transportation (as well as a few other states I'm sure) are testing out a 4-stage left turn light to increase the safety of drivers. [https://www.auroragov.org/cs/groups/public/documents/document/003604.pdf] Yes, you read that pamphlet correctly. There is a special 4th light, just to blink yellow, because you couldn't just make the yellow light blink, like it does anyway after 9pm. No. There has to be a whole special light that indicates when a left-turn-er must use special caution to turn.<br />
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: Note that New York City doesn't allow right turns on red, unless a sign is posted that says otherwise. I suppose this helps reduce the incidence of pedestrians being run into/over. You might also think it helps keep vehicles out of crosswalks, but it doesn't. [[User:CityZen|CityZen]] ([[User talk:CityZen|talk]]) 01:13, 6 October 2012 (UTC)<br />
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: What about turning left on red from a one way street onto another one way street? I don't know how prevalent that is but it's fairly common in downtown Columbus Ohio (my locale) and to a lesser extent some smaller towns around here. [[Special:Contributions/74.218.18.210|74.218.18.210]] 12:30, 9 August 2013 (UTC)<br />
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Nope. I'm done driving. Bring on the self-driving cars, people are officially idiots. [[User:Lcarsos|lcarsos]] ([[User talk:Lcarsos|talk]]) 16:52, 4 October 2012 (UTC)<br />
: There is a problem with a blinking yellow arrow. Blinking yellow is already used. It means you have the right of way, but the other direction may proceed as well. What is wanted here is blinking red, which means that you stop, but may proceed, as someone else has the right of way. As for adding a fourth light, this just confuses things even more, particularly with respect to color blind individuals. Having said that, Virginia's variant is to have lights with both left arrows and solid greens. If it is green arrow, you have the right of way, while solid green means the other direction also has a green. There is almost always a sign reading "left turn yield on &lt;solid-green-circle&gt;" [[User:Divad27182|Divad27182]] ([[User talk:Divad27182|talk]]) 18:19, 4 October 2012 (UTC)<br />
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::so the blinking yellow left arrow generally means the same as a round green light - you can go when it's clear, but the opposite traffic has a green light too. I love this idea because a lot of the time where there is a separate left-turn signal, there are advanced lefts for both ways, and then left turners get a red left arrow and have to stop while people going straight get a green - so even where there's no oncoming traffic, you can't turn. this way, you just lose your "advance" status and go back to the regular rule of "turn if you can, otherwise you end up turning as the lights go yellow"<br />
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::I think what Lcarsos is pointing out if you check the PDF link, is that the new left-turn lane has 4 lights, all of which are left-arrow shaped. Thus, his point is why couldn't they make the 2nd light (yellow left arrow) blink, instead of installing a third light which is also a yellow left arrow whose job is to blink?<br />
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::I can think of a few possible reasons - first, perhaps an all-blinking light has different bulbs which are more efficient for blinking and won't burn out as much; second, because they want to distinguish between the two lights more strongly (i.e. if you glance over between blinks, you don't have to wait a moment to see if it will blink - if you see the 3rd light up, you know it's going to blink without waiting for it to actually blink); similarly, I suppose there could be colour blindness issues where they want to make it clear which light is which.<br />
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::PS: Right on Red is more common in north america than other places, but even here there are a few exceptions that do not allow right turns on red lights. New York City is one. Montreal is another. Most of Mexio is a third. [[User:TheHYPO|TheHYPO]] ([[User talk:TheHYPO|talk]]) 21:19, 4 October 2012 (UTC)<br />
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::You can also white a white 'cigar' light that is inteded for busses only.<br />
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:From the first traffic light in London 1868 until standardization in the 1920s people tried out many crazy lights (see http://dx.doi.org/10.1109/T-VT.1970.23426) including---literally---bells and whistles to announce changes. It seems this phase is still not really over.[[Special:Contributions/134.169.34.172|134.169.34.172]] 10:33, 5 October 2012 (UTC)<br />
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Hmm... not one to do the actual analysis, I still wonder whether there could be some message encoded in the pattern of lights -- in binary ASCII, baudot, Morse, or something. Hmm... [[Special:Contributions/208.54.40.227|208.54.40.227]] 19:12, 4 October 2012 (UTC)<br />
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This explanation mentions a lot of hands where no hands exist. "The right-hand lane," for example. This is a pet peeve of mine. People just adding the word, "hand" randomly into a sentence. It's superfluous and it's annoying. It should be removed before someone slaps whoever did it with their right-hand hand.[[Special:Contributions/173.25.252.230|173.25.252.230]] 14:35, 14 June 2013 (UTC)<br />
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:I believe "right-hand" is used to differentiate "the opposite from the left" from "the opposite of wrong". If I say "get in the right lane", there is a chance for confusion and/or a cliche joke. If I say "get in the right-hand lane", my meaning is clearer.{{unsigned|Tryc}}<br />
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;Red and yellow<br />
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In Poland you can sometimes stumble upon '''red and yellow''' -- while yellow alone means that there shortly would be a red, and you can proceed if you are at or almost at crossing, but stop otherwise, red and yellow is to mean that there shortly would be green (go), and to prepare oneself. But it is quite rare. [[User:JakubNarebski|JakubNarebski]] ([[User talk:JakubNarebski|talk]]) 06:45, 5 October 2012 (UTC)<br />
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:In Germany all traffic lights behave this way. [[User:Joha.ma|Joha.ma]] ([[User talk:Joha.ma|talk]]) 07:45, 5 October 2012 (UTC)<br />
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::At least some lights in Czech behave this way too. -- [[Special:Contributions/89.177.52.2|89.177.52.2]] 08:04, 5 October 2012 (UTC)<br />
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This is the way ALL UK lights behave.<br />
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Some lights in the US use '''red and yellow''' to mean that a pedestrian is crossing, although I've only seen this when the light is blinking red/yellow to start with (yes, I've seen full 3-bulb traffic lights that are only used to flash red/yellow). [[User:Zer0keefie|Zer0keefie]] ([[User talk:Zer0keefie|talk]]) 11:42, 27 March 2013 (UTC)<br />
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In Brazil some cities have greens and red in a row, and they decrease to indicate how long the green or red will last. something like http://www.guiasjp.com/fotos_noticias/foto_1165344648.8822.jpg [[Special:Contributions/189.125.162.182|189.125.162.182]] 20:22, 5 October 2012 (UTC)<br />
In BRazil too, in GoiĆ¢nia there's a nice one here for pedestrians, with leds, that show an animated pedestrian walking and when the time is running out HE RUNS FASTER! Like, it's about to go green for the cars, but feel free to cross... IF YOU'RE FAST!<br />
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In Tianjin China they have a traffic signal that is a single bar of light. If it is green it starts subtracting bar length segments. When there is about a quarter left it turns yellow and then red. It then start subtracting bar length segments from the other end until it gets to about a quarter length and then turns green again. http://www.flickr.com/photos/bob406/3428844012<br />
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;Obvious<br />
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It's how traffic engineers troll you when you are going the wrong way on a one-way. Learn to read signs!<br />
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;Reference to previous comic<br />
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This comic has some tongue in cheek self reference to [[277: Long Light]]. #Meta And definite trolling, by [[Randall]]<br />
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:What about [[781: Ahead Stop]]?<br />
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:Turing Machine?<br />
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Any chance it is one?<br />
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;Etc<br />
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I was almost expected to see the Konami code in the left light, though I'm not sure how "B A Start" would have been shown. [[User:CityZen|CityZen]] ([[User talk:CityZen|talk]]) 01:13, 6 October 2012 (UTC)<br />
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;Music<br />
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I am no musician, but I can't help but wonder if there could be a hidden music chart in there somehow.<br />
Also, if you want confusing, try understanding parking signs in Montreal.<br />
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:Might be, but depending on what pitches or sounds you assign to the lights, you could get pretty much every degree of harmony or cacophony you want. - Another possible music reference: Anybody reminded of Hendrix' "The Wind Cries Mary"? "The traffic lights, they turn, uh, blue tomorrow." [[Special:Contributions/89.0.230.165|89.0.230.165]] 08:14, 10 September 2013 (UTC)<br />
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;And You thought 4 stage was bad enough<br />
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Here In BC, in older installations, and I'm not sure whether any still exist, there used to be lights with 5 stages. It wasn't really any different than the standard red-yellow-green-turn combo you generally see where the turning light may come on, it just had the yellow arrow shown when the turning arrow is about to expire in it's own lamp. It behaves pretty expectantly, but it looks very imposing.<br />
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;Race cars<br />
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The second light has quite a resemblance to the "christmas tree" that governs the start of a drag race, where the lights change colors according to a pattern <nowiki>http://www</nowiki> dot nhra dot com/nhra101/basics.aspx [[Special:Contributions/69.121.10.82|69.121.10.82]] 04:32, 27 December 2012 (UTC)<br />
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I sat and watched this increasingly surreal show for about three minutes, then I broke down laughing when one of the lights turned purple. [[Special:Contributions/174.239.196.155|174.239.196.155]] 06:09, 11 September 2013 (UTC)</div>174.239.196.155https://www.explainxkcd.com/wiki/index.php?title=1133:_Up_Goer_Five&diff=488001133: Up Goer Five2013-09-11T05:53:18Z<p>174.239.196.155: /* Explanation */</p>
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<div>{{comic<br />
| number = 1133<br />
| date = November 12, 2012<br />
| title = Up Goer Five<br />
| image = up goer five.png<br />
| titletext = Another thing that is a bad problem is if you're flying up to space and the parts start to fall off your space car in the wrong order. If that happens, it means you won't go to space today, or maybe ever.<br />
}}<br />
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==Explanation==<br />
Most of the jargon used in rocket science is not among the most commonly used words in everyday life. This comic is a commentary on the absurdity of boiling down technical explanations for lay people, with Randall challenging himself to "translate" the blueprints using only the one thousand most commonly-used words in the English language.<br />
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This comic is a diagram of the {{w|Saturn V}} rocket, "Saturn" isn't a very common word apparently, and neither is rocket, so [[Randall]] decided to use "Up Goer" which is a fair approximation of a craft designed to lift a payload from the earth to space. The Saturn V vehicle, which was in use by {{w|NASA}} from 1967 to 1972, is the vehicle as a whole. The engines of the Saturn V (the part that makes it go up) were divided into three stages. The first stage ({{w|S-IC}}) had five {{w|F-1 (rocket engine)|F-1}} engines which burned {{w|RP-1|refined kerosene}} mixed with oxygen as its fuel. That stage burned for 2 minutes 48 seconds and pushed the whole thing up about 61 kilometers (~38 miles) into the sky. After it fell away the {{w|S-II}} stage was activated. It used 5 {{w|J-2 (rocket engine)|J-2}} engines in the same configuration as the F-1s, and burned {{w|liquid hydrogen}} mixed with {{w|liquid oxygen}} for 6 minutes 35 seconds pushing the astronauts up to 184 kilometers (114.5 miles). The third stage ({{w|S-IVB}}) was a single J-2 engine burning liquid hydrogen and liquid oxygen. This stage was used in two parts, the first was to put the spacecraft into a stable orbit around Earth to perform a systems check and make sure the craft will be safe for going to the moon. This would usually take three orbits around Earth. As they came around the Earth they would burn the second part of the fuel, which is called a {{w|trans-lunar injection}} which put them on course for the moon. The first burn took 2 minutes 45 seconds, which put them in orbit 185 kilometers (115 miles) high.<br />
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It was first used as the launch vehicle for the {{w|Apollo 4}} mission, and it was used as the launch vehicle for most of the subsequent {{w|Apollo mission}}s (the exceptions being Apollo 7, Skylab 2-4, and the Apollo-Soyuz Test Project missions, which were launched using the smaller {{w|Saturn IB}} launch vehicle). One of the last missions of this design was the unmanned launch of {{w|Skylab}}, the U.S.'s first space station; for this payloader configuration, the Saturn V launch vehicle was officially designated the {{w|Saturn INT-21}}.<br />
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The Service Module (SM) Oxygen tanks, have a note that "This part had a ''VERY'' big problem once". This is a reference to the {{w|Apollo 13}} mission. 55 hours after launch, mission control requested the oxygen tanks contents be stirred to get an accurate reading of its contents. There was {{w|Apollo 13#Oxygen tank incident|a large bang}}, and power fluctuated throughout the craft. NASA had to scramble to ensure the safe return of the astronauts. Needless to say, the moon landing for that mission was canceled.<br />
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The {{w|Hindenburg disaster}} is referenced in the text "The kind of air that once burned a big sky bag and people died and someone said "oh, the [humans]!". The term "big sky bag" is used as the closest approximation of {{w|zeppelin}} which is a big bag filled with a lighter-than-air gas which makes the whole contraption float. The {{w|LZ 129 Hindenburg|Hindenburg}} on the day of the disaster was filled with {{w|hydrogen}}, despite being initially designed for use with {{w|helium}}. Helium is much less prone to catching fire, but was unavailable due to a US export ban on the element. The risks seemed acceptable at the time because the Germans had a history of flying hydrogen-based passenger airships. The original quote is "Oh, the humanity!" [http://www.youtube.com/watch?v=F54rqDh2mWA] (skip to 0:47 for the quote).<br />
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The bottom tank, which [[Randall]] describes as "...full of that stuff they burned in lights before houses had power" is highly refined kerosene, called {{w|RP-1}}, it is similar to jet fuel, burns well and is not likely to explode; unlike {{w|liquid hydrogen}}, which is much more likely to explode.<br />
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An earlier flirt with simple words is in [[547: Simple]].<br />
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The phrase "You will not go to space today" has become something of a catchphrase for xkcd; variants of it recur in the mouseover text in two What If? columns: the one about flying on other planets (the pilot does not want to go to space today) and launching into Earth orbit (if your rocket cannot hit the right "horizontal" speed, you will go to space today, and then you will quickly come back).<br />
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==Transcript==<br />
:US Space Team's Up Goer Five<br />
:The only flying space car that's taken anyone to another world (explained using only the ten hundred words people use the most often)<br />
:[A list of Saturn-V parts, top to bottom, with their "Up Goer" description follows]<br />
:[Launch Escape System (LES)]: Thing to help people escape really fast if there's a problem and everything is on fire so they decide not to go to space<br />
::[LES side nozzle]: Thing to control which direction the escaping people go<br />
::[LES fuel]: Stuff to burn to make the box with the people in it escape ''really fast''<br />
::[LES bottom nozzles]: Place where fire comes out to help them escape<br />
:[Apollo spacecraft]<br />
::[Command Module (CM)]: Part that flies around the other world and comes back home with the people in it and fall in the water.<br />
:::[CM capsule parts]: People box, door, chairs<br />
::[Service Module (SM)]: Part that goes along to give people air, water, computers and stuff. It comes back home with them but burns up without landing.<br />
:::[SM oxygen tanks]: Cold air for burning (and breathing). This part had a ''VERY'' big problem once.<br />
::[Lunar Module (LM)]: Part that flies down to the other world with two people inside<br />
:::[LM descent stage]: Part that stays on the other world (it's still there)<br />
:::[LM feet]: Feet that go on the ground of the other world<br />
:[Instrument Unit]: Ring holding most of the computers<br />
:[S-IVB third stage]: Part that falls off third (this part flew away from our world into space and hit the world we were going toward)<br />
::[Fuel tanks]: Wet and ''<u>very</u>'' cold<br />
:::[Liquid hydrogen (LH2) tank]: The kind of air that once burned a big sky bag and people died and someone said "Oh, the [humans]!" (used for burning)<br />
:::[Liquid oxygen (LOX) tank]: The part of air you need to breathe, but not the other stuff (used for burning)<br />
:::[Helium pressurizing tanks]: Things holding that kind of air that makes your voice funny (it's for filling up the space left when they take the cold air out to burn it.)<br />
::[J-2 engine nozzle]: Fire comes out here<br />
:[S-II second stage]: Part that falls off second<br />
::[LH2 tank]: More sky bag air (for burning) (<u>cold</u> + wet)<br />
::[LOX tank]: More breathing-type air (for burning) (<u>cold</u> + wet)<br />
::[Tank-to-engine fuel lines]: Thing that brings in cold wet air to burn<br />
::[J-2 engine nozzles (qty. 5)]: Fire comes out here<br />
:[S-IC first stage]: Part that falls off first<br />
::[LOX tank]: More breathing-type air (for burning) (<u>cold</u> + wet)<br />
::[Helium pressurizing tank]: More funny voice air (for filling up space)<br />
::[LOX fill line]: Opening for putting in cold wet air<br />
::[RP-1 fuel tank]: This is full of that stuff they burned in lights before houses had power.It goes together with the cold air when it's time to start going up.<br />
::[F-1 engine nozzles (qty. 5)]: Lots of fire comes out here.<br />
:[Bottom of spacecraft]: This end should point toward the ground if you want to go to space. If it starts pointing toward space you are having a bad problem and you will not go to space today.<br />
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==External links==<br />
*[http://history.msfc.nasa.gov/saturn_apollo/documents/First_Stage.pdf First Stage Fact Sheet]<br />
*[http://history.msfc.nasa.gov/saturn_apollo/documents/Second_Stage.pdf Second Stage Fact Sheet]<br />
*[http://history.msfc.nasa.gov/saturn_apollo/documents/Third_Stage.pdf Third Stage Fact Sheet]<br />
*[http://splasho.com/upgoer5/ The Up-Goer Five Text Editor]<br />
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{{comic discussion}}<br />
[[Category:Comics with color]]<br />
[[Category:Charts]]<br />
[[Category:Language]]<br />
[[Category:Physics]]</div>174.239.196.155