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Let's assume that a typical floating camera has a field of view of 100 m^2. That means to cover 1 km^2 of land, we would need 100 floating cameras. Now the tota

by yosyp 10y ago

Let's assume that a typical floating camera has a field of view of 100 m^2. That means to cover 1 km^2 of land, we would need 100 floating cameras. Now the total surface area of land (not water) on Earth is about 150,000,000 km^2, so we would need 150,000,000,000 (150 billion) such cameras. Next, let's assume that the micro controller powering the camera, transmission, wifi, and drone circuitry requires 200mA and 1.2V [1], or 240mW. Let's also assume this whole assembly is reduced to just a single motor, and draws better-than-ideal current [2], which would require another ~1.1W/377 minutes of flight time, or 175mW/hour, in addition to the 240mW/hour to power the camera and related circuitry. This is absurdly ideal, as current quadcopters require about 250 Watt to fly for 20 minutes with a weight of 600 grams, or 750 Watt/hour, a two orders of magnitude difference. Since we would have 150,000,000,000 such drones, we would need .175 Watt/hour*150,000,000,000 = 26.25 Gigawatt/hour to power this system (but in reality more like 112.5 Terawatt/hour). To put that in perspective, the Three Gorges Dam hydroelectric plant (the largest in the world) produces 22.6 Gigawatt/hour at peak capacity and 98.8 TWh/year. Maybe solar can help? Recently flexible solar cells were fabricated with 12% efficiency and a power-per-weight ratio of 23 Watt/gram. To power our quadcopter, we would need about 32g of these new solar panels, and continuously sunny conditions (since adding power storage to a solar powered quadcopter would add weight). Of course the bigger challenge is logistics. How do you produce 150 billion of anything? If it takes 1 second to produce 1 drone, that's over 4,700 years to get them all. Do you work in parallel? Do you make 3D printers to print other 3D printers to then print these drones? Even at a failure rate of 0.001%, that's 1.5 million drones failing at any given time. What about costs? $1/drone? That's the annual GDP of Belize. tldr; Invest in solar cell research and 3D printing. [1] http://arduino.stackexchange.com/questions/8659/measure-total-microcontroller-current http://arduino.stackexchange.com/questions/8659/measure-tota... [2] http://multicopter.forestblue.nl/lipo_need_calculator.html http://multicopter.forestblue.nl/lipo_need_calculator.html [3] http://www.nature.com/nmat/journal/v14/n10/full/nmat4388.html http://www.nature.com/nmat/journal/v14/n10/full/nmat4388.htm...

Reason077 10y ago
Of course the bigger challenge is logistics. How do you produce 150 billion of anything? Nanotechnology. Molecular assemblers. Self replication. These things won't be handcrafted! They'll build themselves. If it takes 1 second to produce 1 drone, that's over 4,700 years to get them all. Not if millions are being produced simultaneously. You seem to be thinking about this in very conventional terms. Do you make 3D printers to print other 3D printers to then print these drones? Even at a failure rate of 0.001%, that's 1.5 million drones failing at any given time. Yes, failure rates would certainly be high as they'll be constantly attacked by the environment. But as long as the replication rate (birth) balances with failure (death), then they'll be ok. What about costs? $1/drone? Not even close. After amortization of R&D costs, they'll essentially be free if they can take materials from the environment and self-replicate.

by yosyp 10y ago

Reason077 10y ago

Of course the bigger challenge is logistics. How do you produce 150 billion of anything? Nanotechnology. Molecular assemblers. Self replication. These things won't be handcrafted! They'll build themselves. If it takes 1 second to produce 1 drone, that's over 4,700 years to get them all. Not if millions are being produced simultaneously. You seem to be thinking about this in very conventional terms. Do you make 3D printers to print other 3D printers to then print these drones? Even at a failure rate of 0.001%, that's 1.5 million drones failing at any given time. Yes, failure rates would certainly be high as they'll be constantly attacked by the environment. But as long as the replication rate (birth) balances with failure (death), then they'll be ok. What about costs? $1/drone? Not even close. After amortization of R&D costs, they'll essentially be free if they can take materials from the environment and self-replicate.