It's a fairly straightforward physics question, and Gemini Pro thinks the thrust to weight ratio is too low, by more than an order of magnitude, even before adding the weight of the frame and propulsion system.

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tim333 a day ago | parent [-]

Straightforward physics suggests the lift is a function of how fast you spin them. I'm sure with a fast enough spin you could get enough lift. Maybe rocket engines on the tips?

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chopin a day ago | parent [-]

The tips need to stay subsonic. A bigger rotor must turn slower. AFAIK the tips of current wind turbines are already close to this limit.

	▲	tim333 a day ago \| parent [-]
		Still subsonic speeds can produce a lot of lift. I mean jet aircraft weighing 200 tons lift off at about 160 mph. But googling wing tip thrust, jet engines are probably more practical than rockets.