A $5 Lamp Powered Solely by Gravity
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A $5 Lamp Powered Solely by Gravity
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Re: A $5 Lamp Powered Solely by Gravity
#2Previously submitted and seriously doubted:
http://news.ycombinator.com/item?id=4889266
In that thread[0] revelation[1] said:
At perfect efficiency, this seems to give you about
55mW for a hour, if I asked Wolfram correctly (for
20kg lifted one meter) - [2] - So probably a hoax.
[1] http://news.ycombinator.com/user?id=revelation
[2] http://www.wolframalpha.com/input/?i=20+kilogram%E2%80%90for...
Re: A $5 Lamp Powered Solely by Gravity
#3Technically powered by the effort of lifting it.
Re: A $5 Lamp Powered Solely by Gravity
#4Not to nitpick, bit it's not powered by gravity, it is powered by people going over every 30 minutes and lifting a weight back up to its top position.
EDIT: Apparently people don't understand that using gravity to generate energy is a thing, and the title "Powered Solely" suggested someone found a way to do that.
Re: A $5 Lamp Powered Solely by Gravity
#5Previously submitted and seriously doubted: http://news.ycombinator.com/item?id=4889266 In that thread[0] revelation[1] said: At perfect efficiency, this seems to give you about 55mW for a hour, if I asked Wolfram correctly (for 20kg lifted one meter) - [2] - So probably a hoax. [0] http://news.ycombinator.com/item?id=4889426 [1] http://news.ycombinator.com/user?id=revelation [2] http://www.wolframalpha.com/input/?i=…
If you read some of the followups and tweak the math a little bit, it works out reasonably well. Instead of 20kg and 1m, 20lb and 2m, which comes out about the same (49.42mWh). If you have to lift it every half hour, that's 100mW for a half hour. That's more than enough power to get a useful amount of light out of an LED.
For example, this LED uses 68mW https://www.sparkfun.com/products/531 and is marketed as "so bright that it hurts to look directly at them"
Re: A $5 Lamp Powered Solely by Gravity
#6Previously submitted and seriously doubted: http://news.ycombinator.com/item?id=4889266 In that thread[0] revelation[1] said: At perfect efficiency, this seems to give you about 55mW for a hour, if I asked Wolfram correctly (for 20kg lifted one meter) - [2] - So probably a hoax. [0] http://news.ycombinator.com/item?id=4889426 [1] http://news.ycombinator.com/user?id=revelation [2] http://www.wolframalpha.com/input/?i=…
Um, please read the entire previous thread before dismissing this as a hoax. As you can see from a number of posts that I and others made there, the light is comparable to a kerosene lamp, which is what it's intended to replace. It is not, of course, comparable to the kind of light we in developed countries are used to, but that's not what it's intended for.
Re: A $5 Lamp Powered Solely by Gravity
#7Not to nitpick, bit it's not powered by gravity, it is powered by people going over every 30 minutes and lifting a weight back up to its top position. EDIT: Apparently people don't understand that using gravity to generate energy is a thing, and the title "Powered Solely" suggested someone found a way to do that.
People couldn't lift the weight without consuming energy from food. Doesn't mean that it's powered by food.
The machine converts gravitational potential energy to electromagnetic radiation. People generate the gravitational potential energy by lifting the weight using kinetic energy, which was likewise created by converting chemical energy.
It's easier just to say "Gravity" because, without gravity, it wouldn't work with its inanimate weight.
Re: A $5 Lamp Powered Solely by Gravity
#8Not to nitpick, bit it's not powered by gravity, it is powered by people going over every 30 minutes and lifting a weight back up to its top position. EDIT: Apparently people don't understand that using gravity to generate energy is a thing, and the title "Powered Solely" suggested someone found a way to do that.
Gravity is the storage mechanism. When someone says something is battery-powered, do you start an argument about how that technically isn't correct?
Re: A $5 Lamp Powered Solely by Gravity
#9Technically powered by the effort of lifting it.
Technically powered by the food eaten to lift it.
Technically powered by the sun.
Technically shut up with useless pedanticism.
Re: A $5 Lamp Powered Solely by Gravity
#10Some people get excited by F1 racing, the Bugatti Veyron, or stuff like the latest iPhone, telling you they are technology enthusiasts or engineering fans.
But if you ask me, it's always at the low end of things - like this project - where the really inventive, exciting engineering happening.
Sure, something like an F1 car is impressive after a fashion, but considering the price, yeah, well, it better knock my damn socks off or it just looks stupid. Unlimited budgets do not make for impressive engineering, really.
Making something that is truly, spectacularly useful like this for $5 ot $10? That is genuinely impressive.