Kid asks an innocent question about bridge load limits, and Dad unleashes the full artillery of structural engineering matrices. Those equations? Just the casual finite element analysis that engineers use to model stress distribution across bridge structures. The colorful simulation in the third panel shows exactly how much math goes into making sure you don't plunge into the river below.
The kid's "Oh, I should've guessed" response is the universal reaction of anyone who's ever asked an engineer to explain something "simply." Next time you see a "10 TONS" sign, remember there's an engineer somewhere with 47 pages of calculations who'd be thrilled to explain it to you in excruciating detail.