https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&user=162.158.94.32&feedformat=atomexplain xkcd - User contributions [en]2024-03-28T09:45:31ZUser contributionsMediaWiki 1.30.0https://www.explainxkcd.com/wiki/index.php?title=Talk:2072:_Evaluating_Tech_Things&diff=165959Talk:2072: Evaluating Tech Things2018-11-15T13:03:14Z<p>162.158.94.32: </p>
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Do we need a reason to do things other than the fact it is freaking awesome? [[User:Linker|Linker]] ([[User talk:Linker|talk]]) 17:42, 14 November 2018 (UTC)<br />
:Look on the other end of the scale -- some of the freaking awesome things we do have devastating long term effects for all of humanity. But not this one. {...mentally weighing...} Probably. [[User:N0lqu|-boB]] ([[User talk:N0lqu|talk]]) 18:29, 14 November 2018 (UTC)<br />
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Ok, I'll setup the google alert: https://www.google.com/alerts/feeds/03781144062642195102/9931051611942254792 [[Special:Contributions/108.162.245.58|108.162.245.58]] 18:17, 14 November 2018 (UTC)<br />
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The Black Mirror-Mythbusters scale. Or, to give it it's proper name, the Brooker-Hyneman Scale. [[User:GranadalandDreamer|GranadalandDreamer]] ([[User talk:GranadalandDreamer|talk]]) 23:59, 14 November 2018 (UTC)<br />
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I'm amazed that no one has flown a drone into a tornado yet. Or is it just that they've yet to recover any footage from the mangled remains of the poor smashed drones? --[[User:Quantum7|Quantum7]] ([[User talk:Quantum7|talk]]) 09:07, 15 November 2018 (UTC)<br />
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Explanation seems pretty complete. Anything missing really? The comic is not very deep to need a longer explanation than it currently is. --[[Special:Contributions/172.69.134.207|172.69.134.207]] 11:16, 15 November 2018 (UTC)<br />
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Is Cueball vacillating over which opinion he has, or does he have both and is wondering which to express?[[Special:Contributions/162.158.94.32|162.158.94.32]] 13:03, 15 November 2018 (UTC)</div>162.158.94.32https://www.explainxkcd.com/wiki/index.php?title=Talk:2071:_Indirect_Detection&diff=165840Talk:2071: Indirect Detection2018-11-12T16:51:07Z<p>162.158.94.32: </p>
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Genius reference in the title text to 'throwing shade', linking modern slang with something 2,400 years earlier! --[[User:OliReading|OliReading]] ([[User talk:OliReading|talk]]) 13:33, 12 November 2018 (UTC)<br />
:Should I be concerned that I got the Plato reference from >2K years ago, but had to look up what "throwing shade" is? I feel so old now.[[User:Daemonik|Daemonik]] ([[User talk:Daemonik|talk]]) 15:26, 12 November 2018 (UTC)<br />
::You're not the only one, if that makes you feel better![[Special:Contributions/162.158.94.32|162.158.94.32]] 16:51, 12 November 2018 (UTC)<br />
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Sorry, first time entry editor, turned out I really couldn't add that much but I just really wanted to at least put this. I mean, what an awesome joke! [[User:Lheticus|Lheticus]] ([[User talk:Lheticus|talk]]) 13:50, 12 November 2018 (UTC)</div>162.158.94.32https://www.explainxkcd.com/wiki/index.php?title=899:_Number_Line&diff=165788899: Number Line2018-11-11T17:05:47Z<p>162.158.94.32: /* Explanation */</p>
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<div>{{comic<br />
| number = 899<br />
| date = May 16, 2011<br />
| title = Number Line<br />
| image = number line.png<br />
| titletext = The Wikipedia page List of Numbers opens with "This list is incomplete; you can help by expanding it."<br />
}}<br />
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== Explanation ==<br />
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Once again, [[Randall]] seems to be just messing around, this time with a number line.<br />
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*'''Negative numbers''' have the same magnitude as positive numbers but can only be used to represent the removal of that same magnitude (hence the term "difference" being used for subtraction).<br />
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*'''0.<span style="text-decoration: overline;">99</span>'''.... is {{w|0.999...|equal to 1}} because there is no number between 0.<span style="text-decoration: overline;">99</span>.... and 1. 1 &minus; '''0.0000000372''' is 1 bit less than the {{w|IEEE_floating_point|IEEE 754 32-bit floating-point representation}} of 1.<br />
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*The '''{{w|golden ratio}}''' or '''ϕ''' (phi) is the number <math>\tfrac{1+\sqrt{5}}{2}</math>, about 1.61803. It has many interesting mathematical properties, mostly relating to geometry, and has occasional appearances in nature, such as spirals formed by the seeds in sunflowers. It is also subject to many less credible claims, such as the belief that phi appears in {{w|Parthenon}} (a well-disputed claim) or that rectangles proportioned after phi are more aesthetically pleasing.<br />
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* The approximate range from 2.1 to 2.3 is marked as '''The Forbidden Region'''. Why Randall marked this range as forbidden is really anyone's guess; it seems to be an entirely arbitrary designation.<br />
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*'''{{w|e (mathematical constant)|e}}''' (Euler's number) is 2.71828... and '''π''' (pi) is 3.14159265...<br />
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*'''2.9299372''' is a {{w|President's Day}} reference. It is the average of e and π just as the American Presidents' Day is always observed on the 3rd Monday of February (between {{w|George Washington}} and {{w|Abraham Lincoln}}'s birthdays). Washington and Lincoln were the 1st and 16th Presidents of the USA, respectively. Each has a celebrated place in American history.<br />
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*'''{{w|Gird}}''', '''ᛟ''' is a purely fictional number. (The glyph that Randall uses seems to resemble an older shape of the digit 4, such as seen on [http://www.bl.uk/learning/images/mappinghist/large2296.html archaic maps].). Canon and orthodox are references to organised religions. Gird could be a reference to any or all of:<br />
**[http://www.strangehorizons.com/2000/20001120/secret_number.shtml Bleem] - a fictional integer between 3 and 4<br />
**iCarly's [http://icarly.wikia.com/wiki/Derf Derf] - a fictional integer between 5 and 6<br />
**George Carlin's [http://www.urbandictionary.com/define.php?term=bleen Bleen] - a fictional integer between 6 and 7<br />
**[http://www.scp-wiki.net/scp-033 SCP-033] - a fictional number that causes freaky things to happen<br />
**Saturday Morning Breakfast Cereal's [http://www.smbc-comics.com/index.php?id=3913 Sorf] - a fictional integer between 2 and 3 <!--This is incorrect as the SMBC comic is predated by this xkcd--><br />
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*'''Site of the Battle of 4.108''' is another map joke, implying that 4.108 is an actual location, where an eponymous battle was previously fought. It may be a reference (or homage) to the {{w|Battle of Wolf 359}}, a famous military conflict in the fictional universe of Star Trek.<br />
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*An '''Unexplored''' region obscures the line approximately ranging all values from from 4.5 to 6.7. In the days when the Earth was still being mapped out, territories that had yet to be properly explored and charted were labelled in a similar manner. The placement of the '''Unexplored''' region on the number line indicates that all numbers in that range, including the integers 5 and 6, are completely unknown. This is, of course, patently ridiculous, and the humor seems to derive solely from how nonsensical and unbelievable it is.<br />
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*It is often the case in the media that "It has been 7 years..." or "In the last 7 years..." etc. It is made to seem like a believable statistic but cannot always be true. Alternatively, it is intended as an absurd joke that the number 7 is just "not to be believed".<br />
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*'''8''' is not the largest even {{w|prime number}}, nor is it a prime at all. The largest (and only) even prime is 2. A joke intended for those who clearly know that the claim is false.<br />
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*The last entry seems to be a reference to certain fields of {{w|pure mathematics}}, which focus less on performing calculations with numbers and more on understanding structures that may be described using logic. It finishes off the tone of the comic that seems to be shaping the number line terms of what is commonly useful to certain areas of applied mathematics, rather than a complete, accurate version of the number line.<br />
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The title text is a literalism joke, implying that Wikipedia would like its "{{w|List of numbers}}" page to include every number from negative infinity to infinity. It could also be a reference to {{w|Gödel's incompleteness theorems}}, which [[Randall]] has used as comic fodder before in [[468: Fetishes]]. Gödel's theorems roughly assert that a number theory could never be fully complete. The equivalent for a list of numbers is {{w|Cantor's diagonal argument}}, which is a proof that any list of real numbers can never be complete even if the list is infinitely long. Either way, any "true" Wikipedia article named "List of numbers" would perforce forever be incomplete, no matter how much it was expanded. Both Gödel's incompleteness theorems and Cantor's diagonal argument feature prominently in {{w|Gödel, Escher, Bach}} by {{w|Douglas Hofstadter}}, to whom Randall devoted later comic [[917: Hofstadter]]. It may also be referencing his previous statements about Wikipedia being the home of compulsive list-makers, who make the most astonishingly complete lists imaginable.<br />
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== Transcript ==<br />
:[Number line ranging from &minus;1 to 10.]<br />
:[Arrow pointing left, towards negative numbers] Negative "imitator" numbers (do not use)<br />
:[Line right before the number one] 0.99... (actually 0.0000000372 less than 1)<br />
:[Line at the golden ratio.] Φ Parthenon; sunflowers; golden ratio; wait, come back, I have facts!<br />
:[Line at a region between two and 2.2] forbidden region<br />
:[Line at Euler's number.] e<br />
:[Line a bit before 3] 2.9299372 (e and pi, observed)<br />
:[Line at π.] π<br />
:[Line at 3.5 with ᛟ as the numeral] Gird – accepted as canon by orthodox mathematicians <br />
:[Line a bit after 4.] site of battle of 4.108<br />
:[Blob between 4.5 and 6.5 labeled unexplored.]<br />
:[Line at seven.] Number indicating a factoid is made up ("every 7 years...", "science says there are 7...", etc)<br />
:[Line at eight.] Largest even prime<br />
:[Line at 8.75.] If you encounter a number higher than this, you're not doing real math<br />
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{{comic discussion}}<br />
[[Category:Math]]<br />
[[Category:Wikipedia]]</div>162.158.94.32https://www.explainxkcd.com/wiki/index.php?title=2063:_Carnot_Cycle&diff=1647232063: Carnot Cycle2018-10-24T23:48:09Z<p>162.158.94.32: It's not the y-axis. It's the P-axis.</p>
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<div>{{comic<br />
| number = 2063<br />
| date = October 24, 2018<br />
| title = Carnot Cycle<br />
| image = carnot_cycle.png<br />
| titletext = The Carnot cycle is more properly known by its full title, the "Carnot-Tolkien-Wagner Ring Cycle."<br />
}}<br />
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==Explanation==<br />
{{incomplete|Please edit the explanation below and only mention here why it isn't complete. Do NOT delete this tag too soon.}}<br />
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This comic shows a {{w|Pressure–volume diagram}} which is used in this case for a {{w|Carnot cycle}}, a theoretical thermodynamic cycle and covers most thermodynamics classes which looks very much like the figure drawn. However in this case, [[Randall]] has replaced the labels of the 4 stages of the real Carnot cycle with new ones.<br />
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Pressure–volume diagrams were first developed to understand the efficiency of steam engines and plot the change of pressure ''P'' with respect to volume ''V'' for a specific process. The process forms a cycle and the amount of energy involved can be estimated by the area under the curve on the chart. The Carnot cycle describes the ideal efficiency that such an engine can achieve during the conversion of heat into work, or vice versa like in a refrigeration system. The real steps are called:<br />
#'''Isothermal expansion'''<br />
#'''Isentropic expansion'''<br />
#'''Isothermal compression'''<br />
#'''Isentropic compression'''<br />
An isothermal process is a change of a system, in which the temperature remains constant but in this diagrams the volume increases (expansion) or decreases (compression). The term isentropic describes a lossless process where no matter or energy is transferred, here the increased volume only causes a further decrease in pressure; it is also called adiabatic process.<br />
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Each step in this comic is explained below:<br />
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'''1. Isometric expansion.''' When heated, the gas becomes larger due to increasing volume<br />
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The comic text uses a circular argument. Additionally, "isometric" (equal dimensions) could mean that the gas does ''not'' change in volume, in contrast to the change in volume here.<br />
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'''2. Isotonic expansion.''' The gas expands further due to dark energy while percent milkfat remains constant.<br />
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{{w|Isotonic}} is a descriptor commonly associated with sports drinks (and not thermodynamics), which contain similar concentrations of salt and sugar as in the human body. {{w|Dark energy}} is hypothesized to be a cause for the expansion of the universe, which obviously isn't relevant to thermodynamics. The density of milk[https://hypertextbook.com/facts/2002/AliciaNoelleJones.shtml] depends on milkfat and solids-non-fat, which includes lactose. Fortified milk has increased solids-non-fat but the same percentage of milkfat, resulting in increased calories and an increased density. So the fortification of milk results in increased calories, possibly referred to as dark energy, and a contraction, as less space is needed for 1 kg of milk. However, this explanation does not match the expansion suggested in the comic.<br />
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'''3. Isopropyl compression.''' While inflation is held constant, the gas contracts due to tightening interest rates.<br />
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{{w|Isopropyl alcohol}} is commonly used for cleaning. Inflation and contraction could refer to changes in gas volume, but the reference to {{w|interest rate}}s puts them in the context of {{w|macroeconomics}}. Raising ("tightening") interest rates tends to reduce {{w|inflation}} and/or "contract" the economy. In economics (and other sciences) to better understand model parameter relations, some parameter may be held constant in theory. This could refer to the {{w|Fisher equation}}. Holding one parameter constant is also done in the Carnot cycle (for a physical parameter): not only in theory but also in practice! (In free market economies the inflation cannot be directly held constant).<br />
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'''4. Decline and fall.''' The gas diminishes and goes into the West while remaining Galadriel, completing the cycle.<br />
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{{w|Galadriel}} is a character in ''{{w|The Lord of the Rings}}''. She is one of the leading {{w|Elf (Middle-earth)|elves}}, a race that in the time of the book is said to be dwindling (in number and importance) in {{w|Middle Earth}} and migrating westward to {{w|Valinor}}. Galadriel is one of the last elves to leave, after successfully resisting temptation to take the One Ring and become an all-powerful queen who dominates Middle-earth, instead saying "I will diminish, and go into the West, and remain Galadriel." The title is a reference to {{w|Edward Gibbon}}'s 18th century masterpiece ''{{w|The History of the Decline and Fall of the Roman Empire}}''.<br />
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The title text refers to {{w|Richard Wagner}} and {{w|J.R.R Tolkien}}. Wagner's ''{{w|Der Ring des Nibelungen|Ring Cycle}}'' consists of four operas. Tolkien wrote ''{{w|The Lord of the Rings}}'', which some have [[wikipedia:J. R. R. Tolkien's influences#Wagnerian_influences|suggested]] was inspired by Wagner's Ring. Their works are known as {{w|literary cycle}}s.<br />
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==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
:[A cartesian plot in the first quadrant with axes labeled "P" on the vertical axis and "V" on the horizontal axis, with a rhombus-shaped set of four points with arrows between them.]<br />
:[Caption above the graph:]<br />
:The four stages of the '''Carnot Cycle'''<br />
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:[The first line starts at the top-left point and goes right and slightly downwards to the next point. The label is:]<br />
:'''1. Isometric Expansion'''<br />
:When heated, the gas becomes larger due to increasing volume<br />
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:[The next line starts at the last point and goes downwards and a little to the right.]<br />
:'''2. Isotonic Expansion'''<br />
:The gas expands further due to dark energy while percent milkfat remains constant<br />
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:[The next line starts at this last point and goes to the left and slightly upwards.]<br />
:'''3. Isopropyl Compression'''<br />
:While inflation is held constant, the gas contracts due to tightening interest rates<br />
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:[The last line goes upwards and slightly to the left, returning to the first point.]<br />
:'''4. Decline and Fall'''<br />
:The gas diminishes and goes into the west while remaining Galadriel, completing the cycle<br />
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{{comic discussion}}<br />
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[[Category:Line graphs]]<br />
[[Category:Physics]]<br />
[[Category:LOTR]]</div>162.158.94.32https://www.explainxkcd.com/wiki/index.php?title=2050:_6/6_Time&diff=1636572050: 6/6 Time2018-10-04T08:48:37Z<p>162.158.94.32: /* Explanation */</p>
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<div>{{comic<br />
| number = 2050<br />
| date = September 24, 2018<br />
| title = 6/6 Time<br />
| image = 6_6_time.png<br />
| titletext = You know how Einstein figured out that the speed of light was constant, and everything else had to change for consistency? My theory is like his, except not smart or good.<br />
}}<br />
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The original image has a link to a previous comic [https://xkcd.com/1061/ 1061: EST] which is explained [[1061: EST|here]].<br />
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==Explanation==<br />
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[[Cueball]] suggests a regional time system similar to that used in many societies prior to the invention of [https://www.scientificamerican.com/article/experts-time-division-days-hours-minutes/ mechanical time keeping], such as [https://wiki.samurai-archives.com/index.php?title=Telling_Time Japan during the Edo period] or the {{w|Roman timekeeping|Roman Empire}}, where the day is separated into two parts based on night and day and then subdivided by hour, minute, and second to give season-variable lengths for each. This method is also named [https://en.wiktionary.org/wiki/temporal_hour temporal hour], and still in use in the Jewish religion time table.<br />
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Exact points in time such as noon, sunrise, or sunset vary on the {{w|Longitude|longitude}} from east and west, while the length of day and night depends on the {{w|Latitude|latitude}}. The first problem is solved today by using {{w|Time zone|time zones}} in which at noon the sun is in most cases at or close to the {{w|Zenith|zenith}} and sunrise/sunset happens at different times. The second issue is attributed to the tilt of Earth's axis and the curvature of its surface; in summer days are longer than nights and vice versa in winter. In the polar regions there are very long days (and nights) and by Cueball's suggestion the entire months-long polar day would last only 12 of the newly defined "hours".<br />
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The caption lays out the punchline in which [[Randall]] has very strong feelings and opinions on how standards of time ''should'' be measured, but as bad as he believes the official standards are he also recognizes that his own rules would not be popular with other people. After coming to recognize this he has made a hobby or game out of making the worst possible system of measuring time and sharing it with other people.<br />
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The caption, though vague, can also be assumed to relate to the gradual deviation of certain regions from the {{w|Coordinated Universal Time}} (UTC) zones with "{{w|Daylight Saving Time}}" that is observed inconsistently and smaller regions opting for awkward fractional increments of deviation from Coordinated Universal Time.<br />
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The title text refers to Einstein's {{w|Special relativity|special theory of relativity}} which postulates that the speed of light is the same for all observers, regardless of the motion of the light source (or the observers). An observer at high speed measures the same speed of light as an observer with no motion, measured from the same light source. In classical physics the speed of the moving observer would be added up but in special relativity this isn't true, instead the time runs slower for the moving observer. And additional to this {{w|Time dilation|time dilation}} there is also a {{w|Length contraction|length contraction}}, without which the geometry wouldn't work.<br />
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"Today is one of the two days each year when my clocks run at the same speed as everyone else's" refers to the autumnal equinox, when day and night are the same length, therefore causing his clocks to match the world.<br />
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==Transcript==<br />
:[Cueball and White Hat are walking.]<br />
:Cueball: Under my time system, the sun rises at 6 am and it sets at 6 pm, as it '''''should'''''.<br />
:Cueball: The length of the second is different each day and night, and the current time shifts with your latitude and longitude.<br />
:Cueball: Today is one of the two days each year when my clocks run at the same speed as everyone else's.<br />
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:[Caption below the frame:]<br />
:Time standards are so unfixably messy and complicated that at this point my impulse is just to try to make them worse.<br />
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==Trivia==<br />
*In the title text the name Einstein was originally misspelled as "einstein".<br />
*This comic was released two days after the {{w|September equinox}} 2018 in the [http://aa.usno.navy.mil/seasons?year=2018&tz=-5&dst=1 US]<br />
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{{comic discussion}}<br />
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[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring White Hat]]<br />
[[Category:Physics]]<br />
[[Category:Astronomy]]<br />
[[Category:Time]]</div>162.158.94.32