beyond
Explanation
This comic features two panels, each set on a beach with cavemen looking out at the ocean. In the first panel, labeled "CAVEMAN," a caveman simply says, "Us not know what on other side of ocean" -- a straightforward admission of ignorance about what lies beyond the visible horizon.
In the second panel, labeled "CAVEMAN PHYSICIST," a more intellectual-looking caveman declares: "Past ocean, science break down. Is OCEANIC SINGULARITY." The other caveman responds with an impressed "Wowwww."
The joke is a parody of how physicists talk about singularities and the limits of scientific knowledge. In modern physics, a "singularity" (such as the center of a black hole or the moment of the Big Bang) is a point where our current mathematical models break down and cannot make predictions. Physicists sometimes describe these boundaries in ways that can sound mystical or profound, when in reality they may simply represent the limits of our current understanding rather than genuinely exotic features of reality.
Weinersmith draws a parallel between a caveman not knowing what's across the ocean and a physicist not knowing what's inside a black hole. The "caveman physicist" doesn't actually know any more than the regular caveman -- he just repackages ignorance in fancier, more impressive-sounding language ("oceanic singularity"). The humor comes from the recognition that dressing up "we don't know" in technical jargon can make it sound like a profound scientific insight rather than a simple admission of ignorance.
This is a gentle satire of scientific communication and the tendency to make the boundaries of knowledge sound more exotic than they may actually be.