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		<updated>2026-05-01T09:21:43Z</updated>
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	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=1463:_Altitude&amp;diff=81281</id>
		<title>1463: Altitude</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=1463:_Altitude&amp;diff=81281"/>
				<updated>2014-12-23T05:23:06Z</updated>
		
		<summary type="html">&lt;p&gt;Alpineracer: Corrected symptoms of hypoxia&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 1463&lt;br /&gt;
| date      = December 22, 2014&lt;br /&gt;
| title     = Altitude&lt;br /&gt;
| image     = altitude.png&lt;br /&gt;
| titletext = &amp;quot;TURN OFF THE LASER GUIDE STAR&amp;quot; &amp;quot;WHY&amp;quot; &amp;quot;STAR CATS&amp;quot;&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|}}&lt;br /&gt;
In this comic, Randall is making fun of how {{w|Altitude sickness|oxygen deprivation}} can lead to reduced mental acuity. In this case, mental state of the researchers devolves as they approach the high altitude telescope, and reaches such a poor state when they arrive as to lead to juvenile (almost intoxicated) behavior. Dizziness, lightheadedness, impaired judgment, and euphoria are symptoms of oxygen deprivation, or hypoxia.&lt;br /&gt;
&lt;br /&gt;
It must be also noted that the phrase &amp;quot;low oxygen&amp;quot; is misleading, as oxygen at high elevations is approximately 2/9ths of the atmosphere, the same proportion as at sea level.  The partial pressure of oxygen is reduced, in proportion to the total air pressure.  In other words, the concentration of oxygen per unit volume is lower, but the concentration per mole of air is unchanged.  The altitude sickness is caused by lowered atmospheric pressure which leads to smaller amount of oxygen actually delivered (&amp;quot;pushed&amp;quot;) into bloodstream.&lt;br /&gt;
&lt;br /&gt;
The title text refers to a device used to make artificial reference points in the sky for astronomical observation. The reference points are created by shooting a powerful laser into the sky. The concern of the astronomer in the comic is that an imagined &amp;quot;star cat&amp;quot; may be attracted to the laser in the same way cats on Earth playfully chase laser beams projected on surfaces.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:Commentary: Because of low oxygen, astronomers working at high altitude telescopes may need to write down their plans ahead of time while at sea level.&lt;br /&gt;
&lt;br /&gt;
:[Some astronomers are inside a sea-level research facility]&lt;br /&gt;
:Astronomer #1: Ok, let's head up to the observatory.&lt;br /&gt;
&lt;br /&gt;
:[The astronomers drive uphill]&lt;br /&gt;
:Astronomer #1: When we reach the summit, we'll check the iodine cell and do a general calibration.&lt;br /&gt;
:Astronomer #2: Sounds good.&lt;br /&gt;
&lt;br /&gt;
:[The astronomers have reached the high-altitude observatory]&lt;br /&gt;
:Astronomer #1: My head feels funny.&lt;br /&gt;
:Astronomer #2: Look at those telescope domes. I hope they don't roll away.&lt;br /&gt;
:Astronomer #3: Maybe we should tape them down.&lt;br /&gt;
&lt;br /&gt;
:[The astronomers are inside one of the domes]&lt;br /&gt;
:Astronomer #1: Haha, look at this mirror! My face is huge!&lt;br /&gt;
:Astronomer #2: I see your face in the telescope! I discovered you!&lt;br /&gt;
:Astronomer #3: Let's make out!&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;/div&gt;</summary>
		<author><name>Alpineracer</name></author>	</entry>

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