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Yep. Although I'm always surprised at how much energy humans consume. A 1200 kcal meal eaten quickly, for example an apple with 180g peanut butter (which I ofte

Yep. Although I'm always surprised at how much energy humans consume. A 1200 kcal meal eaten quickly, for example an apple with 180g peanut butter (which I often consume in a few minutes or so) is the equivalent of "charging" my body at the rate of almost 21 kilowatts! For comparison, that's the power consumption equivalent of running 40 household washing machines, a ceiling fan, a router, printer, bright LED lighting, a fridge+freezer, a large color TV, ten smartphones, a laptop, an electric heating blanket, two table fans, two smaller TVs, an electric shaver, a scanner, twenty more smartphones, three more table fans to keep them cool, two fountains or other water features, a small vacuum cleaner and a partridge [0] in a pear tree. [0] Potts, G. R. 1986. The partridge: pesticides, predation, and conservation. (Daily food consumption of a partridge ranges from 71 kcal/day at 15C to 155 kcal/day at -15°C, which works out to be roughly 3.5-7.5 watts, or roughly the power consumed by a few smartphones.)

stuaxo 10y ago
Is that the total energy the body uses from those things or the energy contained in them ?
- ohyoutravel 10y ago
  Contained in them. It's shocking to see the difference. I saw this video the other day which is relevant. An Olympic cyclist powering a toaster to toast some bread. https://youtu.be/S4O5voOCqAQ https://youtu.be/S4O5voOCqAQ
amelius 10y ago
True. But that's a bit like unplugging a harddrive from one computer and plugging it into your computer, and claiming that you just had a data transfer rate of petabytes per second, and then claiming that that's the equivalent of the bandwidth of all US citizens and corporations combined.
- owenversteeg 10y ago
  Hmm, not really. First of all, unplugging my laptop's 256gb hard drive and plugging it into another laptop, in ten seconds, would be equal to 25.6 gb/sec, or 0.0000256 petabytes per second. Even if you're doing the swap with desktop computers that are right next to each other, the largest hard drive [0] you can buy, and really fast switching, you would get a transfer rate of 0.003 petabytes/second. The US currently consumes an absolutely enormous amount of data, more than 23 exabytes/month [1]. (I looked up these numbers mostly because I was curious, and I gotta say 23 exabytes a month surprised me.) Secondly, the power that the human body can store in just a few minutes is pretty cool. You can think of a person who eats 2300 calories a day as a 2700 watt-hour battery. Such a battery would be pretty powerful: it holds the equivalent of roughly 300 smartphone charges. You can "charge" the human body in just a few minutes of eating calorie-dense food like nuts or peanut butter or fatty food. But to charge a 2700 watt-hour battery, comparable to the human body, you'd need to draw the maximum power you could (from a wall in a house with standard wiring) - for about two hours. Sure, I agree that the human body isn't really consuming the power until it gets fully digested. But the reality is that if I'm in a rush, I can wolf down an apple+190g peanut butter and be done 4 minutes later with 1200 calories in my body. Which is pretty useful in real life, at least for me. If my body instead "charged" from a wall outlet (which can usually deliver a lot of power, 1440W or so continuously) it would take an hour to provide me with 1200 calories. Sure, people often do eat slowly. But there have been many times in my life when there's not enough time for whatever reason, and taking an hour to eat a meal would be unacceptable. And it's times like that when I really appreciate that I can eat something fast, and "charge" my body at the rate of tens of kilowatts. [0] http://www.pcworld.com/article/3096292/storage/seagates-10tb-barracuda-pro-is-the-worlds-largest-consumer-hard-drive.html http://www.pcworld.com/article/3096292/storage/seagates-10tb... [1] http://www.cisco.com/c/m/en_us/solutions/service-provider/vni-forecast-highlights.html# http://www.cisco.com/c/m/en_us/solutions/service-provider/vn...

stuaxo 10y ago

Is that the total energy the body uses from those things or the energy contained in them ?

ohyoutravel 10y ago
Contained in them. It's shocking to see the difference. I saw this video the other day which is relevant. An Olympic cyclist powering a toaster to toast some bread. https://youtu.be/S4O5voOCqAQ https://youtu.be/S4O5voOCqAQ

amelius 10y ago

True. But that's a bit like unplugging a harddrive from one computer and plugging it into your computer, and claiming that you just had a data transfer rate of petabytes per second, and then claiming that that's the equivalent of the bandwidth of all US citizens and corporations combined.

owenversteeg 10y ago
Hmm, not really. First of all, unplugging my laptop's 256gb hard drive and plugging it into another laptop, in ten seconds, would be equal to 25.6 gb/sec, or 0.0000256 petabytes per second. Even if you're doing the swap with desktop computers that are right next to each other, the largest hard drive [0] you can buy, and really fast switching, you would get a transfer rate of 0.003 petabytes/second. The US currently consumes an absolutely enormous amount of data, more than 23 exabytes/month [1]. (I looked up these numbers mostly because I was curious, and I gotta say 23 exabytes a month surprised me.) Secondly, the power that the human body can store in just a few minutes is pretty cool. You can think of a person who eats 2300 calories a day as a 2700 watt-hour battery. Such a battery would be pretty powerful: it holds the equivalent of roughly 300 smartphone charges. You can "charge" the human body in just a few minutes of eating calorie-dense food like nuts or peanut butter or fatty food. But to charge a 2700 watt-hour battery, comparable to the human body, you'd need to draw the maximum power you could (from a wall in a house with standard wiring) - for about two hours. Sure, I agree that the human body isn't really consuming the power until it gets fully digested. But the reality is that if I'm in a rush, I can wolf down an apple+190g peanut butter and be done 4 minutes later with 1200 calories in my body. Which is pretty useful in real life, at least for me. If my body instead "charged" from a wall outlet (which can usually deliver a lot of power, 1440W or so continuously) it would take an hour to provide me with 1200 calories. Sure, people often do eat slowly. But there have been many times in my life when there's not enough time for whatever reason, and taking an hour to eat a meal would be unacceptable. And it's times like that when I really appreciate that I can eat something fast, and "charge" my body at the rate of tens of kilowatts. [0] http://www.pcworld.com/article/3096292/storage/seagates-10tb-barracuda-pro-is-the-worlds-largest-consumer-hard-drive.html http://www.pcworld.com/article/3096292/storage/seagates-10tb... [1] http://www.cisco.com/c/m/en_us/solutions/service-provider/vni-forecast-highlights.html# http://www.cisco.com/c/m/en_us/solutions/service-provider/vn...