Editing 2088: Schwarzschild's Cat

{{comic
| number    = 2088
| date      = December 21, 2018
| title     = Schwarzschild's Cat
| image     = schwarzschilds_cat.png
| titletext = Cats can be smaller than the critical limit, but they're unobservable. If one shrinks enough that it crosses the limit, it just appears to get cuter and cuter as it slowly fades from view.
}}

==Explanation==
{{incomplete|Created by a SMALL CAT WITH NO CONCEPT OF FIELD EQUATIONS. Could use more information on the relevant theoretical physics. Do NOT delete this tag too soon.}}

This comic is primarily a wordplay joke about the {{w|Schwarzschild radius}}, or the distance from a black hole corresponding to the {{w|event horizon}}.The Schwarzschild radius for a given body is the limit to which a given mass can be shrunk down before it becomes a black hole - the Schwarzschild radius also represents the event horizon of this newly-created black hole. The event horizon, in turn, is the limit from which nothing can leave a black hole; not even light. The joke is that, apparently, smaller cats are cuter, and there is a limit below which a sufficiently small cat (but larger than zero) will approach infinite cuteness, in a similar pattern to the way time's rate for an observer will approach infinity, the closer they get to the event horizon of a black hole.

It's also an oblique reference to the {{w|Schrödinger's cat}} thought-experiment, since the names (Erwin) "Schrödinger" and (Karl) "Schwarzschild" are somewhat similar and both men were early 20th-century physicists who exchanged ideas with Albert Einstein. However, the actual comic doesn't bring up {{w|quantum superposition}}. 

The title text makes two allusions. First, it alludes to what happens when an object falls into a black hole. From an outside observer's point of view, such objects appear to slow down and take an infinite amount of time to cross the event horizon due to the time dilation of {{w|General relativity}}. The object's photons become increasingly red-shifted, fading as they lose energy to the black hole's gravity well. The scientific consensus suggests that from the falling object's point of view, it should continue to experience time and cross the Schwarzschild radius, but that event is unobservable from the outside (hence the term "event horizon"). 

Second, the title text is a play on the {{w|Cheshire Cat}} from Alice in Wonderland, which slowly fades from view until only its grin remains.

Randall previously discussed the superiority of tiny mammals in [[1682: Bun]], and drew graphs relating to the perceived cuteness of cats in [[231: Cat Proximity]].

==Transcript==
:[A graph is shown. The x-axis is labeled "Cat size" and the y-axis, "Cat cuteness". Parallel to and a short distance from the y axis is a dashed line the same length as the y-axis line, representing a vertical asymptote; the space between the y axis and the dashed line is labelled "Critical Limit". Graphed is a function coming down from infinity, starting close to the dashed line; it then levels off and does not reach zero on-screen. At the top end of the graph is the text "Schwarzschild's Cat" and an arrow pointing upwards outside of the graph.]

{{comic discussion}}
[[Category:Physics]]
[[Category:Cats]]