Practical Engineering uses fake poo to demonstrate how sewers work

Originally published at: Practical Engineering uses fake poo to demonstrate how sewers work | Boing Boing


Bookmarked for a full viewing, but will drop that I heard elsewhere that they use peanut butter in the movies…


I think you meant “sham poo.”


In this Seymour and Powell TV show from the late '90s, Japanese toilet manufacturer Toto uses a soya paste mixed with polystyrene beads to adjust buoyancy.

The relevant bit is at 23:20…

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Not always.


I regret that I have but one heart to give…


Teaching biochem for oh-so-many years we maintained an informal list of recurring questions. What was question #1? (perhaps ironically that it wasn’t #2?): “Why is ‘poo’ brown?”. (well, it can be other colors but there should be a reason for that, including potential health issues)

In very terse terms: the heme(oglobin) of spent red-blood cells is about the most colored thing likely dominant in the final lengths of one’s colon. And hemoglobin breaks down as bilirubin* and that molecule has a whole lot of conjugated double bonds so it absorbs in blue end of the spectrum and that leaves yellow/brown. Fun, eh? impress your friends! (and this will not be on the test)

* aka: 3,3′-([12(2) Z ,6(72) Z ]-13,74-Diethenyl-14,33,54,73-tetramethyl-15,75-dioxo-11,15,71,75-tetrahydro-31 H ,51 H -1,7(2),3,5(2,5)-tetrapyrrolaheptaphane-12(2),6(72)-diene-34,53-diyl)dipropanoic acid


If there’s not a guest appearance by Mr. Hankey, I’m not interested.

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Great video.

However, and I’m assuming it’s my own lack of imagination but the thing I wanted to know was how do you keep the pipe on a slope over expanding areas, like a city. If I build a house and have to connect to the main sewer, is that it’s always much deeper than the lines running into it?

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