Flying Only with the Heat of the Sun

If you picture a flying machine, you probably imagine a craft which is heavier than air, somehow kept aloft with wings or propellers. Heavier-than-air flight dominates discourses about aviation. “Sustainable” crafts are designed to be as light as possible (whilst remaining heavier than air), so that they require less energy from whatever renewable source they use for lift. These machines include human-powered planes such as those using pedals to rotate a propeller. Lighter still are kites and gliders, which remain heavier than air, but rely on air resistance and lighter air around them to fly.

Less discussed are flying machines which are lighter than the air they fly through because the weight of their materials and passengers is counterbalanced by the hot air or light gases they contain. [1] Perhaps this is because most of us experience flight in passenger airliners, not Zeppelins. In theory, making lighter-than-air flight sustainable is simple: heat a container full of air with sunlight so that it rises. In January 2020, Leticia Noemi Marqués flew freely in the Aerocene Pacha solar balloon, the first Fédération Aéronautique Internationale certified fully-solar, untethered, manned flight. Previous flights of this kind went uncertified or relied on propane burners or inflation generators [2]. Aerocene Pacha flies on solar energy not from solar panels or batteries but absorbed directly in the envelope (the fabric of the balloon). [Read more…]

July 24, 2021 by Francis Rogers Filed Under: Airships, Aviation, Balloons, Random

Drying clothes near the ceiling

“It’s winter in northern Europe, and there’s no electricity. How can you dry your laundry? One of the best places of all is a laundry room in the servants’ quarters of a mansion house. A generous ceiling height means you can have frames for wet clothes and household linen in the warmest, dryest part of the room. The estate handyman would make them, and by the later 19th century he would probably add ropes and a pulley to raise and lower the rack. No need to climb on a chair to hang laundry.”

Read more: Drying clothes near the ceiling, HomeThingsPast.

July 9, 2021 by Francis Rogers Filed Under: Clothes, Laundry, Random

What to limit, and how and why

A common argument made by proponents of degrowth, supported by historical evidence, is that economic growth is ecologically unsustainable and entails an increasing inequitable distribution of resources. In Tools for degrowth? Ivan Illich’s critique of technology revisited, Silja Samerski discusses Ivan Illich’s (1926-2002) argument that limits to growth are needed not only for ecological or distributive justice, but for social freedom. Any limits must be politically decided, and applied not primarily to the economy, but to technology. [Read more…]

July 5, 2021 by Francis Rogers Filed Under: Economy, Ivan Illich, Technology