RC Macaulay wrote:
Frank, consider the amount of energy expended daily in the quest to reduce fat. People actually pay money to go to the spa and workout. Couple the electric power output from the treadmill to batteries and the energy problem solves itself.
The comedian Jon Stewart has often made this suggestion. Its pretty funny, but I am sure everyone here (including Richard!) realizes how impractical it would be. A person doing an intensive workout generates about 200 Watts of mechanical energy I think. At least, I do, while riding a bicycle. (I can calibrate this by turning on and off the 200 W motor on my bicycle.) We consume about 2 kW average over a 24 hour period. So, during a 1-hour workout you need to generate . . . as much energy as 240 slaves rowing a galley. Or 64 horses.
It shows how amazingly different our life is, compared to the lives of our ancestors.
On a more serious note, this also demonstrates why schemes to use biomass on a large scale are hopeless. We would need at least 20 times more biomass energy than we ourselves consume as food. Since 60% of U.S. the land is already taken up by agriculture, that means we would need 1200% of the land to power our machinery.
Better still ride a bicycle as we will all be riding one soon enough. the most efficent form of transportation the world has seen to date.
By a wide margin! Not only is it the most efficient form of human transport, it is the most efficient form of any animal transport on earth, even better than bird flight, which is the most efficient means of animal movement. Bird flight is both the most energy intensive and the most efficient method of movement. It consumes the most energy per minute but the least energy per kilometer.
Soaring birds don't count, and neither do fish or people in canoes carried along by river or ocean currents.
- Jed
