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==Explanation==
 
==Explanation==
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This comic claims that the {{w|Voyager program|Voyager probes}} communicate with NASA though ridiculously long copper wires. These wires would have to be continuously lengthened as the probes travel away from {{w|Earth}}. Supposedly, because of "high copper prices and budget constraints," they may not be able to afford to lengthen the wires much longer. If this occurred, they would have to either cut the wires or let them break, which would prevent any further communication with the probes. In reality [https://voyager.jpl.nasa.gov/mission/status/ they use radio waves], not long copper wires, so this doesn't actually happen.
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{{incomplete|Created by a WIRE CUT BECAUSE OF BUDG- are you there houston?  it's me v----ger, you'll never guess what I found!  Please change this comment when editing this page. Do NOT delete this tag too soon.}}
  
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If copper wires were dragged by the Voyager probes, assuming a 1 mm² thick cable, 550 tons of copper would be needed per hour and it would add 1 million {{w|ohm}} per hour to the cable resistance. At [https://www.moneymetals.com/copper-prices $8,720/ton], this would cost just over $42 billion dollars/year, which would be nearly twice [https://www.planetary.org/space-policy/nasas-fy-2022-budget NASA's entire annual budget].
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This comic claims that the Voyager probes communicate with NASA though ridiculously long copper wires, when in reality they use radio waves.{{citation needed}} These wires would have to be continuously lengthened as the probes travel away from Earth. Supposedly, because of "high copper prices and budget constraints," they may not be able to afford to lengthen the wires much longer. If this occurred, they would have to either cut the wires or let them break, which would prevent any further communication with the probes. As mentioned earlier, however, they actually use radio waves, not long copper wires, so this will not actually happen.
  
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The resulting wire would slow down the probes by drag unless the wire itself was actively suspended (i.e. accelerated) continuously as it was fed. The wire could not be used for any other mechanical purpose such as a {{w|Space elevator|space elevator}} for this reason.  
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If copper wires were dragged by the Voyager probes, 550 tons of copper would be needed per hour if the cable was 1mm² thick and it would add 1 million Ohm per hour to the cable resistance.  
  
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Since the Earth spins, the wires would also spool around the Earth, slowing the probes down even further. [https://what-if.xkcd.com/157/ Clearly, this is not a good idea.] This problem might be avoided if the wires reached Earth at one of the poles. Or perhaps they could go to an airplane that flies around Earth at exactly 15 degrees of longitude per hour, with periodic {{w|air-to-air refueling}}, so that it is always on the side of the Earth facing the probe.
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The resulting wire would slow down the probes by drag, but be perfect space elevators for lightweight spacecraft.
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Of course, since the Earth spins, the wires would also spool around the Earth, slowing the probes down even further. Clearly, this is not a good idea.{{citation needed}}
  
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Because the Voyager probes aren't in the plane of the Earth's orbit around the Sun, the Earth would not, in its rotation around the Sun, drag these copper wires through the {{w|Sun}}. If it did, the wires would melt, as copper melts at around 1360 {{w|kelvin|K}}, while the Sun's surface is approximately 5700 K.
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This doesn't even factor in how the Earth, in its rotation around the sun, will drag these copper wires in a circular orbit leading the wires through the sun at least once per year. The difference between the melting point of copper and the average core temperature of the sun has not yet been established by reproducible experiment, but is believed to be incompatible with the high quality required for signal transmission.
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The consequence of a cable between a craft in space and a planetary location being suddenly retracted was recently demonstrated in the first episode of the Apple TV series {{w|Foundation}}.  It didn't end well for anyone.
  
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The title text references the phenomenon seen with self-retracting cables, such as are commonly found on vacuum cleaners, where the free end of the cable, where the plug is, oscillates more and more wildly as the cable approaches full retraction, leading to the danger of a painful rap on the hand if it is not withdrawn in time. A planet-sized impact of this kind could cause severe damage.{{Citation needed}}
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When this comic was releaseed, few days ago NASA had [https://voyager.jpl.nasa.gov/news/details.php?article_id=124 reported] to have received corrupted position data from Voyager probe.  
  
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A few days before this comic was released, [https://voyager.jpl.nasa.gov/news/details.php?article_id=124 NASA had reported] receiving corrupted data from the Voyager 1 probe.  The fact that they are receiving any data at all means that the attitude control system must be working (or else the antenna would not point at Earth), but they continue to investigate how that data could be corrupted after that point.
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====Alternate Explanation====
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When Randall Munroe states that Voyager 1 and 2 are cabled to the Earth by copper wires, his assertion deserves serious consideration.{{citation needed}}
  
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'''Spoiler alert'''
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The primary explanation, above, takes the position that this comic is ridiculously wrong.{{citation needed}}  But the insertion of several "citation needed" links suggests that the explanation's position is weak.{{citation needed}}
  
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The consequence of a cable between a craft in space and a planetary location being suddenly retracted was recently imagined in the first episode of the Apple TV+ series ''{{w|Foundation (TV series)|Foundation}}'', wherein a {{w|space elevator}} tether was severed. [https://www.youtube.com/watch?v=huRmvG3zRpg It didn't end well for anyone other than the terrorists] who won the freedom of thousands of inhabited worlds which had formerly suffered under the jackbooted oppression of {{w|Trantor}}'s fascist galactic Empire regime.
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The comic's author, Randall Munroe,{{citation needed}} is well attested as a competent scientist,{{citation needed}} for example see the citations in the [https://en.wikipedia.org/wiki/Randall_Munroe Wikipedia Randall Munroe page].  His books, cited in that same Wikipedia article,{{citation needed}} offer well-researched easy to understand discussions of science and of everyday phenomena.{{citation needed}} Trust him.{{citation needed}}
  
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Another illustration in fiction of a severed space elevator is in Red Mars, part of the {{w|Mars Trilogy}} by Kim Stanley Robinson.
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(For completeness, see another Wikipedia article, [https://en.wikipedia.org/wiki/Disinformation Disinformation].  In its subsection ''Strategies for spreading disinformation'', strategy number 4 is "Directly Sharing Disinformation".{{citation needed}} That is mentioned here only because the top header at the xkcd web site states it is a webcomic of romance, '''sarcasm,''' math, and language.){{citation needed}}
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[[Black Hat]] has previously severed a space elevator tether using a pair of scissors in an [[697: Tensile vs. Shear Strength|earlier comic]].
 
  
 
==Transcript==
 
==Transcript==
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:[In the bottom right corner is a space probe, with large satellite dish and long antenna. Behind it runs a long wire, that makes three loops before it is connected to North America  on the Earth in the top left corner. To the left of the Earth there is a second wire, which goes off-panel to the left.]
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{{incomplete transcript|Do NOT delete this tag too soon.}}
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[There is an image of a space probe, presumably one of NASA's Voyager probes, with a long wire connecting it to a ball, presumably earth. To the left, there is a second wire, which goes offscreen. Below, there is a caption.]
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:[Caption below the panel:]
 
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:Sad news: Due to high copper prices and budget constraints, NASA may finally have to cut the wires that they've been spooling out to communicate with Voyager 1 and 2.
 
  
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Caption: "Sad news: Due to high copper prices and budget constraints, NASA may finally have to cut the wires that they've been spooling out to communicate with Voyager 1 and 2."
 
{{comic discussion}}
 
{{comic discussion}}
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[[Category:Space probes]]
 

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