Title text:
Reductio ad absurdum fails when reality is absurd.
Transcript:
At the left, a teacher is holding a pointer, pointing at a picture on the screen.]
[The picture shows a hydraulic lift, with a small fluid vessel on the left connected to a tube at the bottom, which connects to a large vessel on the right. On top of the large vessel is a weight labeled 1000 and a Cueball. The fluid in the large vessel is labeled with an upward arrow. Megan's hand is over the small vessel, with a downward arrow indicating that she's pressing on it.]
[Cueball, Hairbun, and Blondie are sitting at school desks going right to left.]
Cueball: No, that can't be right.
Cueball: If hydrostatic pressure worked that way, then you could use it to make machines that exert near-infinite force.
Cueball: And ancient people could have demolished entire mountains just by drilling small tunnels and filling them with water.
[Caption below comic:]
When I first learned about Pascal's law, I tried to disprove it by showing that it would lead to absurd consequences, but it turns out hydraulic presses and ruina montium are both real things.
Source: https://xkcd.com/3087/
You joke, but it's partially true.
I heard about a tall building that had its basement flooded with sewage. It turned out that the plumbers had simplified the drains. Rather than install the random turns every couple of floors, they just used a straight pipe. In effect, turds were falling 20+ floors, to smash into an inspection/access hatch. Eventually the screws sheered off, and everything emptied into the basement instead of the sewer.