ideal
Explanation
The Joke
The comic is set in a physics classroom. A professor announces, "Okay class, today we're going to talk about Earth as an ideal point mass," and draws a diagram on the chalkboard showing Earth reduced to a dot in an orbital diagram. A student raises their hand and asks, "What's an ideal point mass?" The professor snaps back: "A point mass where you don't get asked questions that were on the fucking handout."
The joke operates on a double meaning. In physics, an "ideal" point mass is a theoretical simplification where an object's entire mass is treated as if concentrated at a single point, ignoring its actual size and shape. This is a standard technique used in introductory mechanics and orbital dynamics. But when the student asks for a definition, the professor redefines "ideal" in the colloquial sense -- an "ideal" situation being one where students actually read the assigned materials before class.
The Humor
The humor captures the universal frustration of educators who spend time preparing handouts, syllabi, and reading materials only to have students ask questions that are already answered in those documents. The professor's profanity-laden response is a cathartic expression of that exasperation. The comic also gently mocks the physics convention of "ideal" simplifications -- spherical cows, frictionless planes, point masses -- by suggesting that the most idealized scenario a professor can imagine is simply one where students come to class prepared.
References
The concept of treating objects as "ideal point masses" is fundamental to Newtonian mechanics and is typically introduced in first-year university physics courses. It is part of a broader tradition in physics of making simplifying assumptions (famously parodied as "assume a spherical cow") to make problems tractable.