quantum-gravity
Explanation
The Joke
The caption reads: "The main appeal of funding a quantum gravity research center was getting to name it." The sign in front of a research building reads: "The Advanced Center for Determining Why Australians Don't Fall Off."
The Humor
The joke works by deliberately misunderstanding what quantum gravity research is about. Quantum gravity is one of the most profound unsolved problems in physics — the effort to reconcile quantum mechanics with general relativity. But the wealthy donor who funded the center apparently understands "gravity research" at the most basic, childlike level: gravity is the thing that keeps people stuck to the Earth, and the most puzzling aspect of gravity is why people in Australia (on the "bottom" of the globe) do not fall off into space. The humor lies in the contrast between the incredibly sophisticated actual research and the hilariously naive name, and in the implication that rich benefactors of scientific research sometimes have a very limited understanding of what they are funding. It also pokes fun at the real-world tradition of naming research centers after donors, who sometimes get to choose elaborate, self-aggrandizing names.
References
Quantum gravity is an active area of theoretical physics research seeking to describe gravity according to the principles of quantum mechanics. Major approaches include string theory and loop quantum gravity. The joke about Australians "falling off" the Earth references the common childhood confusion about how people on the other side of a spherical planet do not fall into space — a misunderstanding of how gravity works radially rather than in a single "down" direction.