explain xkcd - User contributions [en]

3112: Geology Murder

2025-07-07T22:02:08Z

Tommears: noted uncomfotMably vs uncomfortably

{{comic
| number = 3112
| date = July 7, 2025
| title = Geology Murder
| image = geology_murder_2x.png
| imagesize = 327x359px
| noexpand = true
| titletext = After determining that his body was full of pipes carrying iron-rich fluid, our current theory is that the dagger-shaped object precipitated within the wound.
}}

==Explanation==
{{incomplete|This page was created by an IRON-RICH BOT. Don't remove this notice too soon.}}
Someone has been stabbed dead and two geologists are looking at the corpse. Take note of the spelling in the dialog, it's "uncomforMably" not "uncomforTably". An "uncomformity" in geology is geologic strata where there is a gap of missing strata between an upper and lower layer. Implying that there is missing information about how the man came to be lying on the desk.

As they apparently have no forensic experience or ability, they apply their geological knowledge. The "iron-rich intrusion in his back" refers to the dagger that killed him; an {{w|intrusion}} is rock formed when magma slowly cools below ground, and the geologists are speculating that the dagger formed after steel flowed into place in and on the body (and somehow became dagger-shaped). The dagger is "iron-rich" because it's made of steel, which is composed largely of iron. "{{w|Clastic rock|Clastic}}", mentioned by one geologist, refers to rock made up of broken pieces of older rocks. In this case she's speculating that a {{w|rift}} - a gap - opened up in the person's back and the dagger fell in. Having long linear gaps appear is something that happens to the Earth's crust, and can lead to clastic rock when other rock is swept into the gap. However, this doesn't normally happen to people's backs.{{cn}}

The "pipes carrying iron-rich fluid" are the person's blood vessels, as blood has a large amount of the iron-rich molecule {{w|hemoglobin}} to help it transport oxygen. The geologists speculate that the iron {{w|Precipitation (chemistry)|precipitated}} - sedimented out - out of the blood to form the dagger, which is of course ridiculous.

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

[There's a lab bench with a dead Cueball lying on it, with a dagger sticking out of his back. Another Cueball is standing to the left of the table, Ponytail is standing to the right. They're each wearing lab coats and looking at the dead body.]

Cueball: We found him lying uncofmortably on the lab bench. I wonder if the iron-rich intrusion in his back is related.

Ponytail: It could be clastic. Maybe a rift opened in his body, and the intrusive material later fell into the hole.

[Caption below the comic:]

The Geology Department investigates their first murder.

{{comic discussion}}<noinclude>

2463: Astrophotography

2021-05-14T23:49:05Z

Tommears: Added tidbit about simultaneous Eclipse & Transit of Venus. https://skyandtelescope.org/astronomy-resources/astronomy-questions-answers/will-mercury-and-venus-ever-transit-the-sun-simultaneously/

{{comic
| number = 2463
| date = May 15, 2021
| title = Astrophotography
| image = astrophotography.png
| titletext = [One hill over, a competing astrophotographer does a backflip over a commercial airliner while throwing a tray of plastic space stations into the air, through which a falcon swoops to 'grab' the real one.]
}}

==Explanation==
{{incomplete|Created by a BACKFLIPPING ASTROPHOTOGRAPHER. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
Astrophotographers like to take photos of things transiting the Sun. Typical things include planes, the International Space Station, and the Moon. In this comic there seems to be an abundance of things:
* There is a partial solar eclipse (the view of the sun is partially obscured by the moon on the upper right). The sun is much larger than the moon, but the moon is able to block a significant fraction of the sun's light from reaching Earth because it is much closer to the Earth. The same optical arrangement is popular in photography, where it is possible to show the silhouette of a person or a cityscape in front of a full moon, making the moon look comparatively larger or smaller by adjusting the distance to the closer subject, and then the lenses used by the photographer to make them both fill just the right amount of the frame.
* A person slightly below the peak of a mountain is juggling, with several of the balls also in front of the sun.
* An archer at the peak is firing arrows from a bow, and one arrow has pierced what at first appears to be one of the juggling balls, but is probably a Transit of Venus. §
* Two airplanes flying above them are pulling signs with the words "nice" and "shot" (which could refer to either the archer or the photograph).
* The ISS can be seen transiting on the upper left.

Taking the picture required combining various photography techniques to arrange all of the subjects in front of the eclipse.

§ A simultaneous Eclipse and Transit of Venus is actually expected in the future, but not until April 5, 15232.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Cueball and Megan stand on a hill with the sun behind them. Cueball is at the top-left of the hill, holding a bow in his left arm, which has been recently shot, with the arrow to right. Megan is at the bottom-right of the hill, juggling some balls. There are two planes going in opposite directions with banners on them. Above the planes is the ISS. All these items are silhouetted against the sun partially eclipsed by the moon in the upper right.]

:[Banners]: Nice Shot

:[Caption beneath the panel]:
:Our astrophotography community's one-upmanship is getting out of hand.

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Space]]

2463: Astrophotography

2021-05-14T23:33:53Z

Tommears: I think, using the perspective trick mentioned earlier, the arrow is meant to appear as if it pierced a Transit of Venus

{{comic
| number = 2463
| date = May 15, 2021
| title = Astrophotography
| image = astrophotography.png
| titletext = [One hill over, a competing astrophotographer does a backflip over a commercial airliner while throwing a tray of plastic space stations into the air, through which a falcon swoops to 'grab' the real one.]
}}

==Explanation==
{{incomplete|Created by a BACKFLIPPING ASTROPHOTOGRAPHER. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
Astrophotographers like to take photos of things transiting the Sun. Typical things include the planes, the International Space Station, and the Moon. In this comic there seems to be an abundance of things:
* There is a partial solar eclipse (the view of the sun is partially obscured by the moon on the upper right). The sun is much larger than the moon, but the moon is able to block a significant fraction of the sun's light from reaching Earth because it is much closer to the Earth. The same optical arrangement is popular in photography, where it is possible to show the silhouette of a person or a cityscape in front of a full moon, making the moon look larger or smaller by adjusting the lenses used and the photographer's distance to the closer subject.
* A person slightly below the peak of a mountain is juggling, with several of the balls also in front of the sun.
* An archer at the peak is firing arrows from a bow, and one arrow has pierced what at first appears to be one of the juggling balls, but is probably a Transit of Venus.
* Two airplanes flying above them are pulling signs with the words "nice" and "shot" (which could refer to either the archer or the photograph).
* The ISS can be seen transiting on the upper left.

Taking the picture required combining various photography techniques to arrange all of the subjects in front of the eclipse.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Cueball and Megan stand on a hill with the sun behind them. Cueball is at the top-left of the hill, holding a bow in his left arm, which has been recently shot, with the arrow to right. Megan is at the bottom-right of the hill, juggling some balls. There are two planes going in opposite directions with banners on them. Above the planes is the ISS. All these items are silhouetted against the sun partially eclipsed by the moon in the upper right.]

:[Banners]: Nice Shot

:[Caption beneath the panel]:
:Our astrophotography community's one-upmanship is getting out of hand.

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Space]]