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		<id>https://www.explainxkcd.com/wiki/index.php?action=history&amp;feed=atom&amp;title=2478%3A_Alien_Visitors_2</id>
		<title>2478: Alien Visitors 2 - Revision history</title>
		<link rel="self" type="application/atom+xml" href="https://www.explainxkcd.com/wiki/index.php?action=history&amp;feed=atom&amp;title=2478%3A_Alien_Visitors_2"/>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;action=history"/>
		<updated>2026-04-16T07:25:30Z</updated>
		<subtitle>Revision history for this page on the wiki</subtitle>
		<generator>MediaWiki 1.30.0</generator>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=382604&amp;oldid=prev</id>
		<title>FaviFake: added Category:Alien Visitors using HotCat</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=382604&amp;oldid=prev"/>
				<updated>2025-07-29T11:08:23Z</updated>
		
		<summary type="html">&lt;p&gt;added &lt;a href=&quot;/wiki/index.php/Category:Alien_Visitors&quot; title=&quot;Category:Alien Visitors&quot;&gt;Category:Alien Visitors&lt;/a&gt; using &lt;a href=&quot;http://commons.wikimedia.org/wiki/Help:Gadget-HotCat&quot; class=&quot;extiw&quot; title=&quot;commons:Help:Gadget-HotCat&quot;&gt;HotCat&lt;/a&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left&quot; data-mw=&quot;interface&quot;&gt;
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				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr style=&quot;vertical-align: top;&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;Revision as of 11:08, 29 July 2025&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l53&quot; &gt;Line 53:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 53:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Aliens]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Aliens]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Airships]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Airships]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot;&gt;&amp;#160;&lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Category:Alien Visitors]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>FaviFake</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=377162&amp;oldid=prev</id>
		<title>FaviFake at 16:26, 10 May 2025</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=377162&amp;oldid=prev"/>
				<updated>2025-05-10T16:26:42Z</updated>
		
		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left&quot; data-mw=&quot;interface&quot;&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;Revision as of 16:26, 10 May 2025&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l46&quot; &gt;Line 46:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 46:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{comic discussion}}&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{comic discussion}}&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;−&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Category:Alien Visitors]]&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot;&gt;&amp;#160;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Comics sharing name|Alien Visitors 2]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Comics sharing name|Alien Visitors 2]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Comics featuring Ponytail]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Comics featuring Ponytail]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>FaviFake</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=377161&amp;oldid=prev</id>
		<title>FaviFake at 16:26, 10 May 2025</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=377161&amp;oldid=prev"/>
				<updated>2025-05-10T16:26:27Z</updated>
		
		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
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				&lt;tr style=&quot;vertical-align: top;&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;Revision as of 16:26, 10 May 2025&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l8&quot; &gt;Line 8:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 8:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Explanation==&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Explanation==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot;&gt;&amp;#160;&lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;This comic follows the previous comic in the mini-series, [[2477: Alien Visitors]]. The aliens now return to show us even more &amp;quot;advanced&amp;quot; inventions. As with the previous strip, the only innovations they offer are not only things that humans know how to build, but things we figured out some time ago, and are now obsolete. As with the pyramids and Stonehenge, these inventions might have been impressive in their time but now offer nothing to humanity.&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;−&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del class=&quot;diffchange diffchange-inline&quot;&gt;This is the second comic in a [[:Category:Alien Visitors|series]], following the previous comic [[2477: Alien Visitors]].&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{w|Biplane}}s are planes with two sets of wings, which provide more of the necessary lift at slow speed than a contemporaneous {{w|monoplane}}, but develop increased drag and aerodynamic and air-frame issues as higher &lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;airspeeds &lt;/ins&gt;became possible/necessary. Biplanes have been obsolete for most purposes since the 1930s, though they remain in use for agriculture and aerial sports.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;−&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;#160;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot;&gt;&amp;#160;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;−&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del class=&quot;diffchange diffchange-inline&quot;&gt;The aliens now return to show us even more &amp;quot;advanced&amp;quot; inventions. As with the previous strip, the only innovations they offer are not only things that humans know how to build, but things we figured out some time ago, and are now obsolete.&amp;#160; As with the pyramids and Stonehenge, these inventions might have been impressive in their time, but now offer nothing to humanity.&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot;&gt;&amp;#160;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;−&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;#160;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot;&gt;&amp;#160;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;−&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{w|Biplane}}s are planes with two sets of wings, which provide more of the necessary lift at slow speed than a contemporaneous {{w|monoplane}}, but develop increased drag and aerodynamic and air-frame issues as higher &lt;del class=&quot;diffchange diffchange-inline&quot;&gt;air-speeds &lt;/del&gt;became possible/necessary. Biplanes have been obsolete for most purposes since the 1930s, though they remain in use for agriculture and aerial sports.&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot;&gt;&amp;#160;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;A {{w|blimp}} is a lighter than air aircraft with no internal structure. These aircraft were traditionally filled with hydrogen gas to provide the needed buoyancy, due to the lower density of hydrogen and a US monopoly on helium limiting availability for the German blimp manufacturer. Hydrogen is highly flammable and thus presents a safety issue: however, its use has gradually increased, considering that it is far cheaper than helium. The famous {{w|Hindenburg_disaster|''Hindenburg'' disaster}} is widely seen as a reason hydrogen airships are unlikely to be widely accepted. However, it is still disputed whether the hydrogen or the coating of the airframe caused the fire. Blimps are still used today, but only rarely, in niche applications, such as for advertising or for aerial photography/videography. Modern airships generally use helium as a lifting gas, which is more expensive, but non-flammable. &amp;#160;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;A {{w|blimp}} is a lighter than air aircraft with no internal structure. These aircraft were traditionally filled with hydrogen gas to provide the needed buoyancy, due to the lower density of hydrogen and a US monopoly on helium limiting availability for the German blimp manufacturer. Hydrogen is highly flammable and thus presents a safety issue: however, its use has gradually increased, considering that it is far cheaper than helium. The famous {{w|Hindenburg_disaster|''Hindenburg'' disaster}} is widely seen as a reason hydrogen airships are unlikely to be widely accepted. However, it is still disputed whether the hydrogen or the coating of the airframe caused the fire. Blimps are still used today, but only rarely, in niche applications, such as for advertising or for aerial photography/videography. Modern airships generally use helium as a lifting gas, which is more expensive, but non-flammable. &amp;#160;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l21&quot; &gt;Line 21:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 18:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The final invention appears to be a reference to {{w|Juicero}}, a defunct and short-lived brand of juicer, which has become iconic of the absurdity of modern technology investment. The company produced a high-tech, internet-connected juicer which sold for $700, and only worked on the company's proprietary branded single-serving bags of pulped fruit, which were available by subscription for $5-$7 per serving. The company raised over $100 million in startup capital, but quickly went out of business because most consumers considered the expensive product to be nearly useless, coupled with a rather damning [https://www.youtube.com/watch?v=5lutHF5HhVA video by Bloomberg] demonstrating said packets could easily be squeezed by hand. The title text singles this invention out, calling it one of the &amp;quot;mistakes of the past&amp;quot;. &amp;#160;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The final invention appears to be a reference to {{w|Juicero}}, a defunct and short-lived brand of juicer, which has become iconic of the absurdity of modern technology investment. The company produced a high-tech, internet-connected juicer which sold for $700, and only worked on the company's proprietary branded single-serving bags of pulped fruit, which were available by subscription for $5-$7 per serving. The company raised over $100 million in startup capital, but quickly went out of business because most consumers considered the expensive product to be nearly useless, coupled with a rather damning [https://www.youtube.com/watch?v=5lutHF5HhVA video by Bloomberg] demonstrating said packets could easily be squeezed by hand. The title text singles this invention out, calling it one of the &amp;quot;mistakes of the past&amp;quot;. &amp;#160;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;−&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;After the latest showing of unimpressive &amp;quot;inventions&amp;quot;, the humans start questioning how &amp;quot;advanced&amp;quot; the aliens really are. It's traditionally assumed that a species capable of interstellar travel would have a host of other advanced technologies, which is inconsistent with the unimpressive and not only obsolete, but also fatally&lt;del class=&quot;diffchange diffchange-inline&quot;&gt;-&lt;/del&gt;flawed inventions they're offering to humanity.&amp;#160; The humans on the ground ask whether they actually built their own flying saucer. They also consider the wisdom of standing directly under the saucer, implying that, if the aliens did build it, it's likely to be unreliable, and may be at risk of crashing (though perhaps a bit ironically, most of the obsolete inventions were nonetheless reliable: biplanes and Tetraethyllead both work as advertised despite their downsides, and the Juicero was commonly slammed for being needlessly over-engineered).&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;After the latest showing of unimpressive &amp;quot;inventions&amp;quot;, the humans start questioning how &amp;quot;advanced&amp;quot; the aliens really are. It's traditionally assumed that a species capable of interstellar travel would have a host of other advanced technologies, which is inconsistent with the unimpressive and not only obsolete, but also fatally flawed inventions they're offering to humanity.&amp;#160; The humans on the ground ask whether they actually built their own flying saucer. They also consider the wisdom of standing directly under the saucer, implying that, if the aliens did build it, it's likely to be unreliable, and may be at risk of crashing (though perhaps a bit ironically, most of the obsolete inventions were nonetheless reliable: biplanes and Tetraethyllead both work as advertised despite their downsides, and the Juicero was commonly slammed for being needlessly over-engineered).&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Transcript==&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Transcript==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>FaviFake</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=347311&amp;oldid=prev</id>
		<title>172.69.134.93: /* Explanation */</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=347311&amp;oldid=prev"/>
				<updated>2024-07-26T16:05:15Z</updated>
		
		<summary type="html">&lt;p&gt;‎&lt;span dir=&quot;auto&quot;&gt;&lt;span class=&quot;autocomment&quot;&gt;Explanation&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr style=&quot;vertical-align: top;&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;Revision as of 16:05, 26 July 2024&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l21&quot; &gt;Line 21:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 21:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The final invention appears to be a reference to {{w|Juicero}}, a defunct and short-lived brand of juicer, which has become iconic of the absurdity of modern technology investment. The company produced a high-tech, internet-connected juicer which sold for $700, and only worked on the company's proprietary branded single-serving bags of pulped fruit, which were available by subscription for $5-$7 per serving. The company raised over $100 million in startup capital, but quickly went out of business because most consumers considered the expensive product to be nearly useless, coupled with a rather damning [https://www.youtube.com/watch?v=5lutHF5HhVA video by Bloomberg] demonstrating said packets could easily be squeezed by hand. The title text singles this invention out, calling it one of the &amp;quot;mistakes of the past&amp;quot;. &amp;#160;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The final invention appears to be a reference to {{w|Juicero}}, a defunct and short-lived brand of juicer, which has become iconic of the absurdity of modern technology investment. The company produced a high-tech, internet-connected juicer which sold for $700, and only worked on the company's proprietary branded single-serving bags of pulped fruit, which were available by subscription for $5-$7 per serving. The company raised over $100 million in startup capital, but quickly went out of business because most consumers considered the expensive product to be nearly useless, coupled with a rather damning [https://www.youtube.com/watch?v=5lutHF5HhVA video by Bloomberg] demonstrating said packets could easily be squeezed by hand. The title text singles this invention out, calling it one of the &amp;quot;mistakes of the past&amp;quot;. &amp;#160;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;−&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;After the latest showing of unimpressive &amp;quot;inventions&amp;quot;, the humans start questioning how &amp;quot;advanced&amp;quot; the aliens really are. It's traditionally assumed that a species capable of interstellar travel would have a host of other advanced technologies, which is inconsistent with the unimpressive and not only obsolete, but also fatally-flawed inventions they're offering to humanity.&amp;#160; The humans on the ground ask whether they actually built their own flying saucer. They also consider the wisdom of standing directly under the saucer, implying that, if the aliens did build it, it's likely to be unreliable, and may be at risk of crashing (though perhaps a bit ironically, the &lt;del class=&quot;diffchange diffchange-inline&quot;&gt;humans say this in response to the juicer&lt;/del&gt;, and &lt;del class=&quot;diffchange diffchange-inline&quot;&gt;while the actual device it is spoofing was a failure in many ways, one thing it was ''not'' was shoddily built (aside from the fact that you could squeeze more juice by hand than by using the machine...) - one critique of &lt;/del&gt;the Juicero was &lt;del class=&quot;diffchange diffchange-inline&quot;&gt;that it was &lt;/del&gt;needlessly over-engineered).&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;After the latest showing of unimpressive &amp;quot;inventions&amp;quot;, the humans start questioning how &amp;quot;advanced&amp;quot; the aliens really are. It's traditionally assumed that a species capable of interstellar travel would have a host of other advanced technologies, which is inconsistent with the unimpressive and not only obsolete, but also fatally-flawed inventions they're offering to humanity.&amp;#160; The humans on the ground ask whether they actually built their own flying saucer. They also consider the wisdom of standing directly under the saucer, implying that, if the aliens did build it, it's likely to be unreliable, and may be at risk of crashing (though perhaps a bit ironically, &lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;most of &lt;/ins&gt;the &lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;obsolete inventions were nonetheless reliable: biplanes and Tetraethyllead both work as advertised despite their downsides&lt;/ins&gt;, and the Juicero was &lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;commonly slammed for being &lt;/ins&gt;needlessly over-engineered).&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Transcript==&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Transcript==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>172.69.134.93</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=344209&amp;oldid=prev</id>
		<title>162.158.95.14: Added missing category</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=344209&amp;oldid=prev"/>
				<updated>2024-06-11T19:04:09Z</updated>
		
		<summary type="html">&lt;p&gt;Added missing category&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr style=&quot;vertical-align: top;&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;Revision as of 19:04, 11 June 2024&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l56&quot; &gt;Line 56:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 56:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Comics featuring Megan]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Comics featuring Megan]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Aliens]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Aliens]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot;&gt;&amp;#160;&lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Category:Airships]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>162.158.95.14</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=303949&amp;oldid=prev</id>
		<title>SilverTheTerribleMathematician at 04:22, 3 January 2023</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=303949&amp;oldid=prev"/>
				<updated>2023-01-03T04:22:43Z</updated>
		
		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr style=&quot;vertical-align: top;&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;Revision as of 04:22, 3 January 2023&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l15&quot; &gt;Line 15:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 15:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{w|Biplane}}s are planes with two sets of wings, which provide more of the necessary lift at slow speed than a contemporaneous {{w|monoplane}}, but develop increased drag and aerodynamic and air-frame issues as higher air-speeds became possible/necessary. Biplanes have been obsolete for most purposes since the 1930s, though they remain in use for agriculture and aerial sports.&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{w|Biplane}}s are planes with two sets of wings, which provide more of the necessary lift at slow speed than a contemporaneous {{w|monoplane}}, but develop increased drag and aerodynamic and air-frame issues as higher air-speeds became possible/necessary. Biplanes have been obsolete for most purposes since the 1930s, though they remain in use for agriculture and aerial sports.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;−&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;A {{w|blimp}} is a lighter than air aircraft with no internal structure. These aircraft were traditionally filled with hydrogen gas to provide the needed buoyancy, due to the lower density of hydrogen and a US monopoly on helium limiting availability for the German blimp manufacturer. Hydrogen is highly flammable and thus presents a safety issue: however, its use has gradually increased, considering that it is far cheaper than helium&lt;del class=&quot;diffchange diffchange-inline&quot;&gt;.&lt;/del&gt;. The famous {{w|Hindenburg_disaster|''Hindenburg'' disaster}} is widely seen as a reason hydrogen airships are unlikely to be widely accepted. However, it is still disputed whether the hydrogen or the coating of the airframe caused the fire. Blimps are still used today, but only rarely, in niche applications, such as for advertising or for aerial photography/videography. Modern airships generally use helium as a lifting gas, which is more expensive, but non-flammable. &amp;#160;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;A {{w|blimp}} is a lighter than air aircraft with no internal structure. These aircraft were traditionally filled with hydrogen gas to provide the needed buoyancy, due to the lower density of hydrogen and a US monopoly on helium limiting availability for the German blimp manufacturer. Hydrogen is highly flammable and thus presents a safety issue: however, its use has gradually increased, considering that it is far cheaper than helium. The famous {{w|Hindenburg_disaster|''Hindenburg'' disaster}} is widely seen as a reason hydrogen airships are unlikely to be widely accepted. However, it is still disputed whether the hydrogen or the coating of the airframe caused the fire. Blimps are still used today, but only rarely, in niche applications, such as for advertising or for aerial photography/videography. Modern airships generally use helium as a lifting gas, which is more expensive, but non-flammable. &amp;#160;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{w|Tetraethyllead}} ((CH&amp;lt;sub&amp;gt;3&amp;lt;/sub&amp;gt; CH&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;)&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;Pb) is a chemical added to gasoline (mostly from the 1920s to the 1990s &amp;amp;mdash; although some countries [https://web.archive.org/web/20171115235249/http://wedocs.unep.org/bitstream/handle/20.500.11822/17542/MapWorldLead_March2017.pdf?sequence=1&amp;amp;isAllowed=y still use it to this day]) to prevent {{w|engine knocking}}. Lead is toxic and bio-accumulative, and there's substantial evidence that its use in gasoline caused widespread lead exposure, impacting public health on a huge scale. The aliens seem surprised to learn of these toxic effects, and their concern implies that they may be using leaded gasoline themselves, but it's unclear whether they might think that their biology may by vulnerable to lead as well or whether they never considered that biologies alien to theirs would be.&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{w|Tetraethyllead}} ((CH&amp;lt;sub&amp;gt;3&amp;lt;/sub&amp;gt; CH&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;)&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;Pb) is a chemical added to gasoline (mostly from the 1920s to the 1990s &amp;amp;mdash; although some countries [https://web.archive.org/web/20171115235249/http://wedocs.unep.org/bitstream/handle/20.500.11822/17542/MapWorldLead_March2017.pdf?sequence=1&amp;amp;isAllowed=y still use it to this day]) to prevent {{w|engine knocking}}. Lead is toxic and bio-accumulative, and there's substantial evidence that its use in gasoline caused widespread lead exposure, impacting public health on a huge scale. The aliens seem surprised to learn of these toxic effects, and their concern implies that they may be using leaded gasoline themselves, but it's unclear whether they might think that their biology may by vulnerable to lead as well or whether they never considered that biologies alien to theirs would be.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>SilverTheTerribleMathematician</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=303948&amp;oldid=prev</id>
		<title>SilverTheTerribleMathematician: /* Explanation */</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=303948&amp;oldid=prev"/>
				<updated>2023-01-03T04:21:57Z</updated>
		
		<summary type="html">&lt;p&gt;‎&lt;span dir=&quot;auto&quot;&gt;&lt;span class=&quot;autocomment&quot;&gt;Explanation&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr style=&quot;vertical-align: top;&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;Revision as of 04:21, 3 January 2023&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l15&quot; &gt;Line 15:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 15:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{w|Biplane}}s are planes with two sets of wings, which provide more of the necessary lift at slow speed than a contemporaneous {{w|monoplane}}, but develop increased drag and aerodynamic and air-frame issues as higher air-speeds became possible/necessary. Biplanes have been obsolete for most purposes since the 1930s, though they remain in use for agriculture and aerial sports.&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{w|Biplane}}s are planes with two sets of wings, which provide more of the necessary lift at slow speed than a contemporaneous {{w|monoplane}}, but develop increased drag and aerodynamic and air-frame issues as higher air-speeds became possible/necessary. Biplanes have been obsolete for most purposes since the 1930s, though they remain in use for agriculture and aerial sports.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;−&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;A {{w|blimp}} is a lighter than air aircraft with no internal structure. These aircraft were traditionally filled with hydrogen gas to provide the needed buoyancy, due to the lower density of hydrogen and a US monopoly on helium limiting availability for the German blimp manufacturer. Hydrogen is highly flammable and thus presents a safety issue. The famous {{w|Hindenburg_disaster|''Hindenburg'' disaster}} is widely seen as a reason hydrogen airships are unlikely to be widely accepted. However, it is still disputed whether the hydrogen or the coating of the airframe caused the fire. Blimps are still used today, but only rarely, in niche applications, such as for advertising or for aerial photography/videography. Modern airships generally use helium as a lifting gas, which is more expensive, but non-flammable. &amp;#160;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;A {{w|blimp}} is a lighter than air aircraft with no internal structure. These aircraft were traditionally filled with hydrogen gas to provide the needed buoyancy, due to the lower density of hydrogen and a US monopoly on helium limiting availability for the German blimp manufacturer. Hydrogen is highly flammable and thus presents a safety issue&lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;: however, its use has gradually increased, considering that it is far cheaper than helium.&lt;/ins&gt;. The famous {{w|Hindenburg_disaster|''Hindenburg'' disaster}} is widely seen as a reason hydrogen airships are unlikely to be widely accepted. However, it is still disputed whether the hydrogen or the coating of the airframe caused the fire. Blimps are still used today, but only rarely, in niche applications, such as for advertising or for aerial photography/videography. Modern airships generally use helium as a lifting gas, which is more expensive, but non-flammable. &amp;#160;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{w|Tetraethyllead}} ((CH&amp;lt;sub&amp;gt;3&amp;lt;/sub&amp;gt; CH&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;)&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;Pb) is a chemical added to gasoline (mostly from the 1920s to the 1990s &amp;amp;mdash; although some countries [https://web.archive.org/web/20171115235249/http://wedocs.unep.org/bitstream/handle/20.500.11822/17542/MapWorldLead_March2017.pdf?sequence=1&amp;amp;isAllowed=y still use it to this day]) to prevent {{w|engine knocking}}. Lead is toxic and bio-accumulative, and there's substantial evidence that its use in gasoline caused widespread lead exposure, impacting public health on a huge scale. The aliens seem surprised to learn of these toxic effects, and their concern implies that they may be using leaded gasoline themselves, but it's unclear whether they might think that their biology may by vulnerable to lead as well or whether they never considered that biologies alien to theirs would be.&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{w|Tetraethyllead}} ((CH&amp;lt;sub&amp;gt;3&amp;lt;/sub&amp;gt; CH&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;)&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;Pb) is a chemical added to gasoline (mostly from the 1920s to the 1990s &amp;amp;mdash; although some countries [https://web.archive.org/web/20171115235249/http://wedocs.unep.org/bitstream/handle/20.500.11822/17542/MapWorldLead_March2017.pdf?sequence=1&amp;amp;isAllowed=y still use it to this day]) to prevent {{w|engine knocking}}. Lead is toxic and bio-accumulative, and there's substantial evidence that its use in gasoline caused widespread lead exposure, impacting public health on a huge scale. The aliens seem surprised to learn of these toxic effects, and their concern implies that they may be using leaded gasoline themselves, but it's unclear whether they might think that their biology may by vulnerable to lead as well or whether they never considered that biologies alien to theirs would be.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>SilverTheTerribleMathematician</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=283463&amp;oldid=prev</id>
		<title>Theusaf: Reverted edits by Donald Trump (talk) to last revision by CRLF</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=283463&amp;oldid=prev"/>
				<updated>2022-05-26T19:59:20Z</updated>
		
		<summary type="html">&lt;p&gt;Reverted edits by &lt;a href=&quot;/wiki/index.php/Special:Contributions/Donald_Trump&quot; title=&quot;Special:Contributions/Donald Trump&quot;&gt;Donald Trump&lt;/a&gt; (&lt;a href=&quot;/wiki/index.php?title=User_talk:Donald_Trump&amp;amp;action=edit&amp;amp;redlink=1&quot; class=&quot;new&quot; title=&quot;User talk:Donald Trump (page does not exist)&quot;&gt;talk&lt;/a&gt;) to last revision by &lt;a href=&quot;/wiki/index.php/User:CRLF&quot; title=&quot;User:CRLF&quot;&gt;CRLF&lt;/a&gt;&lt;/p&gt;
&lt;a href=&quot;//www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;amp;diff=283463&amp;amp;oldid=281873&quot;&gt;Show changes&lt;/a&gt;</summary>
		<author><name>Theusaf</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=281873&amp;oldid=prev</id>
		<title>Donald Trump: Reverted edit by anti-crap user</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=281873&amp;oldid=prev"/>
				<updated>2022-05-26T19:03:58Z</updated>
		
		<summary type="html">&lt;p&gt;Reverted edit by anti-crap user&lt;/p&gt;
&lt;a href=&quot;//www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;amp;diff=281873&amp;amp;oldid=280376&quot;&gt;Show changes&lt;/a&gt;</summary>
		<author><name>Donald Trump</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=280376&amp;oldid=prev</id>
		<title>CRLF: Reverted vandalism with User:CRLF/OneClickUndo.js</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;diff=280376&amp;oldid=prev"/>
				<updated>2022-05-26T18:02:04Z</updated>
		
		<summary type="html">&lt;p&gt;Reverted vandalism with &lt;a href=&quot;/wiki/index.php/User:CRLF/OneClickUndo.js&quot; title=&quot;User:CRLF/OneClickUndo.js&quot;&gt;User:CRLF/OneClickUndo.js&lt;/a&gt;&lt;/p&gt;
&lt;a href=&quot;//www.explainxkcd.com/wiki/index.php?title=2478:_Alien_Visitors_2&amp;amp;diff=280376&amp;amp;oldid=278007&quot;&gt;Show changes&lt;/a&gt;</summary>
		<author><name>CRLF</name></author>	</entry>

	</feed>