https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&user=172.68.141.170&feedformat=atomexplain xkcd - User contributions [en]2024-03-29T14:15:37ZUser contributionsMediaWiki 1.30.0https://www.explainxkcd.com/wiki/index.php?title=Talk:2340:_Cosmologist_Genres&diff=197079Talk:2340: Cosmologist Genres2020-09-12T07:59:17Z<p>172.68.141.170: Dance/Electronic</p>
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An ultra-early comic, after the prior quite-early one. Is Randall (suddenly now) getting enough sleep? [[Special:Contributions/162.158.154.71|162.158.154.71]] 08:31, 31 July 2020 (UTC)<br />
:Perhaps his sleep schedule has become completely hopeless instead. [[Special:Contributions/108.162.238.37|108.162.238.37]] 11:08, 31 July 2020 (UTC)<br />
:what do you mean ultra early?<br />
::(Remember to sign...) As a metric, look at the page-creation times of the last few comic pages (i.e. View History). The times, at least for me as an anon-IP with no settings changed, are that of the server's home, not Randall's, but consistent tor all that.<br />
::Quite often, the comic page is created shortly after midnight and the auto-filled date has to be corrected to the assumption it was published on the Mon/Wed/Fri by Randall, not the Tue/Thu/Sat of the server (which seems to check/listen for a new comic periodically, ready to create and pre-populate the page ASAP after it is commentable-about).<br />
::Wednesday (prior comic) was very much still within Wednesday, and this one was about ''twenty hours'' ahead of normal (4am, server's Friday, rather than midnight+ on server's Saturday). No sign yet of Monday, when I checked just now, so perhaps ⅔rds of last week was just a transient anomaly. [[Special:Contributions/162.158.154.71|162.158.154.71]] 13:27, 3 August 2020 (UTC)<br />
::Can we find a match between publication times and the 28-hour-week? [[Special:Contributions/141.101.69.165|141.101.69.165]] 10:09, 11 August 2020 (UTC)<br />
Is the 'pop' not considered a metal possibly referring to the 'pop test' for Hydrogen gas that I had to do hundreds of times in high school? [[Special:Contributions/162.158.2.230|162.158.2.230]] 10:13, 31 July 2020 (UTC)<br />
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Is "Lite" a play on "Light" - i.e. photons during the big bang?[[Special:Contributions/108.162.245.106|108.162.245.106]] 17:39, 31 July 2020 (UTC)<br />
:Nope. (Probably not, anyway.)[[Special:Contributions/172.69.63.169|172.69.63.169]] 18:31, 31 July 2020 (UTC)<br />
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Why 'pop' is 'lite'?<br />
[[Special:Contributions/162.158.238.6|162.158.238.6]] 19:29, 31 July 2020 (UTC)<br />
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I'd say it's because pop is the most commonly played music genre, just as hydrogen and helium are the most common elements. [[Special:Contributions/162.158.93.109|162.158.93.109]] 20:35, 31 July 2020 (UTC)<br />
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Surely Pop is 'Lite' because it refers to the Big Bang - or 'Big Pop' in this case. And it was all Hydrogen or helium at that moment therefore 'lite' not 'metal'. <br />
:I get why ''pop'' is lite, but why "Lite". Is that a collective term in cosmology for Hydrogen and Helium? [[User:Kapten-N|Kapten-N]] ([[User talk:Kapten-N|talk]]) 07:21, 3 August 2020 (UTC)<br />
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I'd like to point out that astronomers don't always refer to non-H/He stuff as "metal". When you start talking about exoplanets, asteroids and meteoroids, there's a different classification (albeit nearly as reductive):<br />
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*Gas: H<sub>2</sub> and He<br />
*Ice: anything made out of CHON<br />
*Rock: basically the ordinary meaning - mostly metal silicates and sulfides<br />
*Metal: native metals<br />
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Each of these has much less variation in density and volatility than the variation between categories (I listed them in ascending order of density and descending order of volatility), so these tend to stick together both in terms of what stays on a planet and in terms of forming layers on a planet (e.g. Earth has no Gas, a light dusting of Ice in the form of the biosphere and oceans, Rock crust and mantle, and a Metal core; Neptune's outer layers are Gas, most of the planet is Ice, and the core is Rock and Metal). [[User:Magic9mushroom|Magic9mushroom]] ([[User talk:Magic9mushroom|talk]]) 05:57, 1 August 2020 (UTC)<br />
:That calls for a sequel involving both drugs and music. I don't see how to make sex fit. --[[Special:Contributions/172.69.69.110|172.69.69.110]] 08:47, 1 August 2020 (UTC)<br />
I assumed pop->bang->big bang->(let there be) lite<br />
[[User:Ysth|Ysth]] ([[User talk:Ysth|talk]]) 08:03, 3 August 2020 (UTC)<br />
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This is most likely in reference of https://xkcd.com/2205 where approximation in cosmology is usually in orders of magnitude instead of precise value. In this case only "pop" music is lite and everything else is "metal" with nothing in between. [[Special:Contributions/162.158.62.45|162.158.62.45]] 15:57, 3 August 2020 (UTC)<br />
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Fun fact (feel free to delete if not allowed): you can take any of the genres on the left and combine it with "metal" to get a subgenre of metal that actually exists!<br />
::"Metal Metal"??? (And remember to Sign, just for courtesy...). [[Special:Contributions/162.158.154.131|162.158.154.131]] 19:21, 3 August 2020 (UTC)<br />
:::Not exactly, but quite close: https://nanowarofsteel.bandcamp.com/track/true-metal-of-steel [[User:Elektrizikekswerk|Elektrizikekswerk]] ([[User talk:Elektrizikekswerk|talk]]) 07:52, 5 August 2020 (UTC)<br />
::Wait, are there subgenres called "Latin Metal" and "Folk Metal"?[[Special:Contributions/172.69.63.79|172.69.63.79]] 18:56, 5 August 2020 (UTC)<br />
:::Why, sure. https://en.wikipedia.org/wiki/Latin_metal https://en.wikipedia.org/wiki/Folk_metal [[User:Elektrizikekswerk|Elektrizikekswerk]] ([[User talk:Elektrizikekswerk|talk]]) 07:58, 6 August 2020 (UTC)<br />
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I'm trying to figure out why cosmologists don't consider "Dance/Electronic" to be "Plasma" [[Special:Contributions/172.68.141.170|172.68.141.170]]</div>172.68.141.170https://www.explainxkcd.com/wiki/index.php?title=Talk:2334:_Slide_Trombone&diff=194825Talk:2334: Slide Trombone2020-07-18T16:14:38Z<p>172.68.141.170: Responding to comment acknowledging a point I had forgotten on earlier comment.</p>
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I can't find any source saying that the CPS 2000 was discontinued ''because it was too powerful''. There's plenty of reasons why products get discontinued, and this product had various points of criticism apparently. --[[User:NeatNit|NeatNit]] ([[User talk:NeatNit|talk]]) 21:09, 17 July 2020 (UTC)<br />
: It's not verified but it appears likely. The nozzle of the CPS 2000 was 2.5x larger than advertised on the box and had a prominent safety warning affixed to it. It shot water with higher pressures than ever before. There was a hullabaloo around somebody losing an eye from it; there's no proof this happened but such hullabaloos are still bad for business. The model was discontinued and no water gun with comparable power has ever been mass produced for consumers since. It's notable that you can shoot water with as much pressure as you want to the point of cutting metal from a distance (see water cutter, found in well funded makerspaces as an improvement from the laser cutter, plasma cutter, cnc machine) and the metal of a brass instrument could be made to hold higher pressure than plastic. CPS 2000 information from https://nerfpedialegacy.fandom.com/wiki/CPS_2000 [[Special:Contributions/108.162.219.192|108.162.219.192]] 23:58, 17 July 2020 (UTC)<br />
::Industrial water cutters use an abrasive (often garnet), as it is hard cut a material with something softer than that material. The water isn't doing the cutting, it is just there to provide pressure. In theory a high enough pressure pure water jet would cut metal, but it probably wouldn't be clean. To quote Randall, imagine throwing a ripe tomato into a cake. [[User:Probably not Douglas Hofstadter|Probably not Douglas Hofstadter]] ([[User talk:Probably not Douglas Hofstadter|talk]]) 05:05, 18 July 2020 (UTC)<br />
:::For clarity, these cutting machines usually referred to as {{w|waterjet cutters}} (or "waterjets"), rather than "water cutters." [[User:JohnHawkinson|JohnHawkinson]] ([[User talk:JohnHawkinson|talk]]) 12:59, 18 July 2020 (UTC)<br />
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::There are actually two versions of the CPS 2000, and although it is true the original version is the most powerful retail super soaker, the mk2 version was only slightly less powerful. Several water guns were released 1996-2000 with comparable power. Take the CPS 2500 - it was released 2 years later in 1998 with the same pressure chamber as the mk2 CPS 2000, while adding a nozzle selector. It is my personal belief that Laramie (the company behind Super Soakers) actually shortened the pressure chamber in the mk2 to make it more reliable, not to make it safer. The mk1 longer bladder chamber (and associated higher pressure) can cause the firing valve to get stuck closed by the high pressure behind it, causing trouble as either the trigger broke or users over-pressurized and burst the bladder. Could be wrong, but you can only work with so much pressure using plastic parts. In any case, my source on the question of comparable power http://www.isoaker.com/Armoury/soaker_listing.php has a list of all known water guns sortable by their output, range, power, reservoir size, etc.; sscentral.com has really in depth information on the physics of water guns, including a list of water gun related patents (http://www.sscentral.org/patents/ [https://patents.google.com/patent/US5799827 this] one is I think the one that most closely resembles the technology and design of a CPS 2000, Figure 4-6 diagram the pressure bladder, Figure 7-9 the other mechanisms of the gun). Hopefully these provide enough information as to how these water guns work. [[Special:Contributions/172.69.23.7|172.69.23.7]] 06:15, 18 July 2020 (UTC)<br />
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:: From Wikipedia (citing [http://www.isoaker.com/Armoury/Analysis/1996/super_soaker_cps2000.php this page]): "The CPS 2000 has been criticized for its low field life (how long it can last between refills) depleting its pressure chamber in only 1 second and only being able to fire 4 or 5 such shots before needing to be refilled, and the large number of pumps that it takes to fully pressurize (20-24 depending on version)."<br />
:: I'm no expert when it comes to water guns, but shooting for just 1 second, with 20 pumps (!) required in between, does not sound fun. Maybe it was discontinued because they came up with more fun models?<br />
:: --[[User:NeatNit|NeatNit]] ([[User talk:NeatNit|talk]]) 15:24, 18 July 2020 (UTC)<br />
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::Good point, I'm trying to imagine kids really getting a kick out of pumping for 10 seconds, firing once, and having to pump again. Not fun. Combine that, reliability issues, and all around better models (from your link, iSoaker.com, lists lots of guns with better overall ratings), and I don't see the CPS 2000 lasting long in the marketplace. Plus it probably cost more, being bigger, which probably didn't help sales. [[Special:Contributions/172.68.141.170|172.68.141.170]] 16:14, 18 July 2020 (UTC)<br />
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This should come standard with all spit valves. [[Special:Contributions/108.162.219.192|108.162.219.192]] 21:36, 17 July 2020 (UTC)<br />
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Maybe I'm too knowledgeable about musical instruments, but this doesn't seem funny even as a satire. And there are lots of musician jokes about trombonists. [[User:Cellocgw|Cellocgw]] ([[User talk:Cellocgw|talk]]) 23:34, 17 July 2020 (UTC)<br />
: Randal probably doesn't play these instruments. I don't either and don't yet understand why the joke is painful to you. It would be good for us to learn to respect musicians like you better. Is it because it's disrespectful of an expensive loved instrument that requires great dedication to own? [[Special:Contributions/108.162.219.192|108.162.219.192]] 23:58, 17 July 2020 (UTC)<br />
:: No, we are good at disrespecting each other. It's just that the proposed "pump action" is nothing like how a 'bone works, or could work. Maybe I'm just being too picky[[User:Cellocgw|Cellocgw]] ([[User talk:Cellocgw|talk]]) 11:57, 18 July 2020 (UTC)<br />
::: Seems to me that in this comic a super soaker was embedded within the trombone. Not at all related to the normal operation of a trombone, and not intended to be. --[[User:NeatNit|NeatNit]] ([[User talk:NeatNit|talk]]) 15:10, 18 July 2020 (UTC)</div>172.68.141.170https://www.explainxkcd.com/wiki/index.php?title=2327:_Oily_House_Index&diff=1942152327: Oily House Index2020-07-03T03:23:07Z<p>172.68.141.170: /* Explanation */</p>
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<div>{{comic<br />
| number = 2327<br />
| date = July 1, 2020<br />
| title = Oily House Index<br />
| image = oily_house_index.png<br />
| titletext = We're underwater on our mortgage thanks to the low price of water.<br />
}}<br />
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==Explanation==<br />
In economics, an {{w|index (economics)|index}} is a statistical measure of change in a representative group of individual data points. Common indices include NASDAQ (a measure of a range of stock prices) and a consumer price index (a measure of retail prices)<br />
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This chart demonstrates an invented index, the "Oily House Index", which measures a ratio of oil price to average house prices, over time.<br />
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The numerator is the average price of a new home (presumably in the US), in USD per square foot ($/sqft). It does not specify what kind of home, or where. One available metric is the [https://www.statista.com/statistics/682549/average-price-per-square-foot-in-new-single-family-houses-usa/ average price per square foot of floor space in new single-family houses in the United States] which was $118.91 in 2019. The caption refers to converting the ''mortgage'' of the new house (that is, how much the purchaser borrowed, which could be zero), while the definition simply refers to the ''new home price'' (the total value). It is not clear which of these two is used in the chart. <br />
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The denominator is the price of oil in USD per {{w|barrel (unit)|barrel}} ($/BBL). This is also not well defined, although the chart's caption suggests that it is based on crude oil. There are many different indices for different blends of oil in different locations, such as [https://www.investopedia.com/terms/w/wti.asp West Texas Intermediate], which is a crude oil commonly used as a global oil benchmark. (Others include Brent and Dubai Crude). The WTI price fluctuated around $55-60 throughout 2019. A barrel is a standard unit of oil volume, defined as 42 U.S. gallons (roughly 5.615 cubic feet or 0.16 cubic metres).<br />
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The comic then applies {{w|dimensional analysis}} to this index: dividing $/sqft by $/bbl yields a result whose dimension is a linear measurement, which can be called length. 1 barrel is 42 gallons, a gallon is 231 cubic inches, and a cubic foot is 12<sup>3</sup>=728 cubic inches, so a barrel is approximately 5.6146 cubic feet and a cubic foot is approximately 0.1781 barrel. The average price per square foot of a new single-family dwelling in the USA in 2019 was about $119/square foot, while the price of oil in mid 2019 was about $60/BBL or $10.7/cubic foot. Dividing $119/square foot by $10.7/cubic foot gives approximately 11.1 foot. This is slightly lower than the value shown on the chart of around 15.<br />
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The chart's caption then interprets that length as the depth that a new home could be filled with the crude oil that could be purchased with its price. For scale Cueball and Megan has been drawn, and the ceiling height of a typical house has been indicated, showing that only in time with deep crisis will the oil not fill the house.<br />
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The index is high when house prices are high and oil prices are low (such as during the 1999 oil glut), and low when house prices are low and oil prices are high (such as during the 1979 energy crisis). See details about the [[#Chart|chart]] below.<br />
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The title text, "We're underwater on our mortgage thanks to the low price of water", is a pun. A mortgage on a property is considered to be [https://www.investopedia.com/terms/u/underwater-mortgage.asp "underwater"] when the value of the mortgage exceeds the value of the property. This is bad for both the owner (who owes more money than the property is worth) and the bank (who now have a loan which is not fully secured against a default: if the property owner defaults, the bank will lose money in selling the property). <br />
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The title text is hinting at an alternative index based on the ratio of house price to the price of water instead of oil. At the 2019 rate of $118.91/ft² and a rough [https://www.pvwc.com/story_of_water/html/costs.htm average water price of $0.0015/gallon], a house would have to be filled with water to a depth of 1060 ft for the house cost to match the water cost. If the price of water fell or the house cost per square foot rose, then the index would rise, causing the house to be even deeper in water (following the metaphor of the index as filling the house with physical water). This situation could arise even if the property value remained high, although Randall may be humorously suggesting that the increase in the index would literally flood the property with water, which would then damage it, obviously decreasing its value. (If the index continues to be computed on average house prices, then this single event would not materially impact the index as a whole.)<br />
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In {{what if|11|What If #11 "Droppings"}}, Randall commented that "unit cancellation is weird" after making a similar calculation about fuel efficiency -- the European convention of presenting fuel mileage as "liters per 100 kilometers" represents an area (volume/distance), which can be physically interpreted as the cross-sectional area of a tube of gasoline with the total volume of fuel burned stretched out over the length of the journey.<br />
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===Chart===<br />
;{{w|1979 oil crisis|1979 energy crisis}}<br />
:In the wake of the {{w|Iranian Revolution}}, global oil supply reduced by only 4%, but caused widespread panic and a huge increase in oil price.<br />
;{{w|Gulf War}}<br />
:The {{w|Gulf War}} (August 1990 - Feb 1991) was the invasion of Iraq by the US, which decreased oil supplies and caused a spike in prices.<br />
;1999 oil glut<br />
:In early 1999, Iraq increased its oil production, while the Asian Financial Crisis reduced demand. Prices briefly fell to as low as $16.[https://oilprice.com/Energy/Oil-Prices/A-Recent-History-Of-Oil-Prices-History-About-To-Repeat-Itself.html]<br />
;Ceiling height<br />
:Reinforcing the connection with the metaphorical house filled with oil, "ceiling height" here is shown at somewhere just below 10 feet. The standard ceiling height in US homes is 9 feet for ground floor, and 8 feet on higher floors. [https://rethority.com/standard-ceiling-height/]<br />
:Only twice has the height been below ceiling height, during the 1979 energy crisis, and in the beginning of the financial crisis of 2007-2008.<br />
;Oil and housing crashes partly cancel out<br />
:As a result of the {{w|financial crisis of 2007-2008}}, oil prices crashed from $147/BBL in July 2008 to $30 in December 2008. Meanwhile, {{w|United States housing bubble|falling house prices}}, which had partially triggered the financial crisis, continued to slump across the US, with the Case-Shiller home price index reporting its largest ever price drop in December 2008. Since both oil price and house prices were falling, the effect of dividing one by the other means that the index didn't change significantly, remaining around 8-15 feet.<br />
;{{w|2010s oil glut}}<br />
:In 2014-16 there was a serious surplus of {{w|crude oil}}, partially caused by increasing shale oil from the US and Canada, a slowdown in demand from China, and increasing fuel efficiency and use of renewable energy. Prices dropped from $125/BBL from 2012 to below $30 in January 2016. By October 2018, prices had recovered to $85/BBL. ]<br />
;OHI briefly became infinite as oil prices reached zero in 2020<br />
:In April 2020, the {{w|coronavirus pandemic}} dramatically reduced vehicle and air transport, crashing oil demand. [https://www.cnbc.com/2020/04/25/scary-visceral-unprecedented-traders-describe-oils-wild-week-and-fall-to-negative-prices.html Oil futures actually went to zero], and even below, several times: oil producers paying consumers to take their oil, to avoid the costs of storing it. Dividing anything by zero officially has no defined result, but in many thought experiments yields infinity, hence the "infinite oily house index". The graph should actually wrap around to the negative axis at this point.<br />
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==Transcript==<br />
:[A line graph is shown. Above it is a rectangular frame with formulas inside. Most of the top part of the frame is removed and instead a heading is written over the missing section of the frame. The formula is written in three parts, with the first two parts having a division line with text written above and below.]<br />
:Dimensional economic analysis <br />
:New home price ($/sqft) / Oil price ($/BBL) = $/area / $/volume = Length<br />
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:[The graph has a labeled Y-axis with four ticks, which have values, and also the origin has a value. The X.axis is a time-line without label. There are five labeled ticks.]<br />
:X-axis: 1980 1990 2000 2010 2020<br />
:Y-axis label: OHI (feet)<br />
:Y-axis: 40 30 20 10 0<br />
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:[Above the line graph there is a caption:]<br />
:'''Oily House Index:''' How deep you could fill the average new home if you converted its mortgage to crude oil<br />
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:[The graph begins around 15 before 1980, then dips below 10, rises slowly until about 1988 when it rises sharply. It stays high but has several peaks, and one deep valley until 1999 when there is a very high peak, which then drops fast. A few more peaks, and then a decline to the lowest point in 2008, which is followed by a small peak, and then another drop. From there it stays low until 2015 when it rises quite fast and has one very high peak. It then drops of, until 2020 when there is a really sharp peak. Above the top of the peak is a dotted line extending to the top of the graph (i.e. the top of the Y-axis, not the top of the panel). Then it drops down but not very low as it reaches the present.]<br />
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:[There are six labels with arrows pointing from them to notable peaks and valleys along the graph. They are written both above and below the line. From left to right they are:]<br />
:1979 energy crisis<br />
:Gulf War<br />
:1999 oil glut<br />
:Oil and housing crashes partly cancel out<br />
:2010s oil glut<br />
:OHI briefly became infinite as oil prices reached zero in 2020<br />
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:[From 2005-2010 there is a dotted horizontal line that hits the valley at 2008. This is labeled with an arrow pointing to it:]<br />
:Ceiling height<br />
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:[Below the line is a drawing of Cueball and Megan standing on the X-axis near 1990. Next to them is a label with an arrow pointing to them:]<br />
:People (for scale)<br />
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{{comic discussion}}<br />
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[[Category:Line graphs]]<br />
[[Category:Timelines]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Megan]]</div>172.68.141.170