Altitude
Altitude
Because of low oxygen, astronomers working at high altitude telescopes may need to write down their plans ahead of time while at sea level.
[Some astronomers are inside a sea-level research facility.] Astronomer #1: Ok, let's head up to the observatory.
[The astronomers drive uphill.] Astronomer #1: When we reach the summit, we'll check the iodine cell and do a general calibration. Astronomer #2: Sounds good.
[The astronomers have reached the high-altitude observatory.] Astronomer #1: My head feels funny. Astronomer #2: Look at those telescope domes. I hope they don't roll away. Astronomer #1: Maybe we should tape them down.
[The astronomers are inside one of the domes.] Astronomer #1: Haha, look at this mirror! My face is huge! Astronomer #2: I see your face in the telescope! I discovered you! Astronomer #1: Let's make out!

In this comic, Randall is making fun of how oxygen deprivation can lead to reduced mental acuity. Dizziness, lightheadedness, impaired judgment, and euphoria are symptoms of oxygen deprivation, or hypoxia. Those researchers would benefit from having a written list or plan developed while they were still functioning at peak mental acuity.
Note that high altitude does not lead to severe effects as described in the comic.
Here, two astronomers are heading up a mountain, towards the observatory they work at. Initially, they discuss what they are planning on doing once they reach the summit, mentioning Iodine cells , used for wavelength calibrations of high-resolution RV spectra between 501 and 610 nm. As they continue, the mental clarity of the researchers devolves as they approach the high altitude telescope, leading to increasingly juvenile and almost intoxicated behavior. One researcher mentioned her head feels funny, while the other makes a remark about taping down the observatories to prevent them from rolling away, an absurd remark considering observatories are firmly rooted and even if they weren't, tape would not be sufficient to stop them ( [ citation needed ] ;  enough tape can hold anything).
Once inside the observatory, they have completely forgotten about their original plans. Instead of doing a general calibration, they are playing with the telescopes, looking at each other's faces through them and deciding to make out with each other. This is why Randall mentions that astronomers working at high altitude observatories must write down their plans ahead of time at sea level, as the low oxygen leads to reduced mental acuity.
It should be noted that the phrase "low oxygen" refers to the lower partial pressure of oxygen at altitude. The proportion of oxygen at high elevations is still approximately a fifth of the atmosphere, the same as at sea level. The altitude sickness is caused by lowered atmospheric pressure which leads to smaller amount of oxygen actually delivered ("pushed") into bloodstream.
The title text refers to a laser guide star a device for focusing telescopes by making artificial reference points in the sky. 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 "star cat" may be attracted to the laser in the same way that cats playfully chase laser beams projected on surfaces. Cats' reactions to laser pointers were previously explored in 729: Laser Pointer .
Because of low oxygen, astronomers working at high altitude telescopes may need to write down their plans ahead of time while at sea level.
[Some astronomers are inside a sea-level research facility.] Astronomer #1: Ok, let's head up to the observatory.
[The astronomers drive uphill.] Astronomer #1: When we reach the summit, we'll check the iodine cell and do a general calibration. Astronomer #2: Sounds good.
[The astronomers have reached the high-altitude observatory.] Astronomer #1: My head feels funny. Astronomer #2: Look at those telescope domes. I hope they don't roll away. Astronomer #1: Maybe we should tape them down.
[The astronomers are inside one of the domes.] Astronomer #1: Haha, look at this mirror! My face is huge! Astronomer #2: I see your face in the telescope! I discovered you! Astronomer #1: Let's make out!
