The flush handle is pressed, lifting the flapper, setting in motion about 10 seconds of flushing genius. The lifted flapper releases tank water into the bowl via rim jets and the larger siphon jet.

When you gotta go, you gotta go–even at 30,000 feet. CREDIT: Stuart Dee via Getty Images. Get the Popular Science daily newsletter💡 Breakthroughs, discoveries ...

Breakthroughs, discoveries, and DIY tips sent every weekday. Terms of Service and Privacy Policy. Composting toilets are gaining popularity for a good reason—they ...