4 ms·

we have a 11-story building that rotates each one independently here in Brazil [0]... according to the creator, spinning it uses the same energy as 3 light-bulb

• bombcar 3y ago
  The amount of energy to rotate (or move something on a flat plane) is surprisingly low. This is how you can have a human pull a 747 or a pickup truck pull a plane. There's some technicality of "with enough gearing anything can move anything" but at some point the losses involved overcome the power provided.
  • phh 3y ago
    that being said, the ecological cost of manufacturing probably outweigh largely that power consumption at usage.
  • Dylan16807 3y ago
    > There's some technicality of "with enough gearing anything can move anything" but at some point the losses involved overcome the power provided. I don't see why they would. You can keep your gearing losses low as long as the first stage requires medium force. If we oversimplify, if each stage loses ten percent of the incoming power while applying an 8:1 gear ratio, then you gain 7x more force every stage. The situation where power disappears is when you add so many extra stages that the first stage requires almost no force and has to spin super fast to input work. So don't do that. Design the system so that the input is in the correct speed range for your power source.
  • wanderingstan 3y ago
    Ran across this recently upon finding that time trial bicycles don’t really aim to be lightweight, only aerodynamic. When you’re cycling on flat ground, wind resistance is the greatest drag. (Pun intended.)