2011-09-22
Explanation
This comic plays on the common defense of evolution that compares it to gravity. In the first panel, a woman at a debate podium states: "Evolution isn't a 'theory' in the common sense. Evolution is as well understood as the 'theory' of gravity." This is a frequently used argument by science communicators to counter the misconception that "theory" in scientific usage means "guess" -- pointing out that gravity is also called a theory, yet no one doubts its existence.
The second panel is captioned "Somewhere, in a theoretical physics lab..." and shows a physicist watching the debate on television, reacting with alarm: "What the... is she saying we don't understand evolution?!" The humor comes from an unintended interpretation of her comparison. While her point is that evolution is as solid and well-established as gravity, the theoretical physicist -- who works at the cutting edge of gravitational physics where many deep mysteries remain (quantum gravity, dark energy, the nature of spacetime) -- reads it the opposite way. To him, saying evolution is as well understood as gravity implies that evolution is deeply mysterious and poorly understood, because from his perspective, gravity actually is one of the least understood fundamental forces in physics.
The votey panel reinforces the joke with a graph showing "How much the universe makes sense" on the y-axis and "Physics knowledge" on the x-axis. The curve rises steeply at first, then drops off sharply at high levels of physics knowledge. This illustrates the well-known paradox in physics: the more you learn, the more you realize how much remains unexplained. It is a humorous validation of the physicist's reaction -- at a surface level gravity seems simple, but at deeper levels it is profoundly confusing.