explain xkcd - User contributions [en]

3189: Conic Sections

2026-01-03T03:54:43Z

Aufa: Added wiki links for conic section and Kepler orbit, and reword the explanations.

{{comic
| number = 3189
| date = January 2, 2026
| title = Conic Sections
| image = conic_sections_2x.png
| imagesize = 288x322px
| noexpand = true
| titletext = They're not generally used for crewed spacecraft because astronauts HATE going around the corners.
}}

==Explanation==
{{incomplete|This page was created recently. Don't remove this notice too soon.}}
A {{w|conic section}} is a a curve formed by the intersection of a plane and a cone. This results in four possible curves: a circle, ellipse, parabola, or hyperbola, depending on the angle of the plane relative to the cone's axis. In real life, the cone does not have a base, instead extending into infinity.

A {{w|Kepler Orbit}} describes the simplified motion of two celestial objects around each other based only on their gravitational forces, ignoring any other factors such as gravity of other objects, atmospheric drag, non-spherical body, etc. Such an orbit will form a conic section.

In the comic, however, a "Keplerian" orbit's conic section's cone has a base, resulting in the orbit having sharp corners. Astronauts would hate going around the corners due to the rapid and sudden change in direction. The change in momentum would exert a large G-force, which will be very uncomfortable for them.{{citation needed}}

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}
:[A view of the Earth, focused on Asia and the Indian Ocean with East Africa at left and the Western Pacific and Australia at right. A satellite is shown in an unusual orbit around the planet.]
:[Caption below the panel:]
:All Keplerian orbits are conic sections. For example, this one uses the base of the cone.
{{comic discussion}}<noinclude>

[[Category:Space]]
[[Category:Geometry]]

Talk:2471: Hippo Attacks

2021-06-03T04:15:53Z

Aufa:

'Hippo violation' refers to Health Insurance Portability and Accountability Act of 1996 (HIPAA or the Kennedy–Kassebaum Act) - probably ;) [[Special:Contributions/172.69.35.95|172.69.35.95]] 22:08, 2 June 2021 (UTC)
:I've worked with demographic data and experienced the removal of datapoints with only a couple people in them, because the statistics would reveal the details of the people. [[Special:Contributions/172.70.114.48|172.70.114.48]] 22:26, 2 June 2021 (UTC)
:Strictly speaking, wouldn't this be a HIPOO violation? [[Special:Contributions/172.68.142.171|172.68.142.171]] 22:47, 2 June 2021 (UTC)
:Alternatively, it may refer to violation of [https://en.wikipedia.org/wiki/Hippocratic_Oath Hippocratic Oath] which include provision to respect patients' privacy [[User:Aufa|Aufa]] ([[User talk:Aufa|talk]])

Talk:2471: Hippo Attacks

2021-06-03T04:03:24Z

Aufa: