Earlier quoted context omitted.
Probably yes. Annoying pendants are predictably annoying.
I think you mean "pedants". ;-)
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A $5 Lamp Powered Solely by Gravity
51–60 of 91 posts
Re: A $5 Lamp Powered Solely by Gravity
#52Some 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 s…
"To define it rudely but not inaptly, engineering is the art of doing that well with one dollar which any bungler can do with two after a fashion." -- Arthur M. Wellington
My favorite way of expressing the same thing: "Anyone can design a bridge that will stand up. It takes an engineer to design a bridge that will barely stand up."
Not sure where this came from -- Douglas Adams, maybe?
Re: A $5 Lamp Powered Solely by Gravity
#53Earlier quoted context omitted.
Why are you limiting your scenario to only one of these lights?
Because if you used a sufficient number to light a room you would have to hire people to lift the weights continuously, and if you have to to that, it would be far more efficient if you hired them to generate electricity using a pedal powered generator, because that is still the most efficient way to transform human labor into electricity. Come to think of it, pedalling for the time it takes to lift the weight and ch…
A pedal generator would probably cost more than $5, though.
Re: A $5 Lamp Powered Solely by Gravity
#54Earlier quoted context omitted.
It's not very useless. The title suggests a perpetual motion machine, so I was wondering what that was doing on HN. Knowing you have to lift it first (from the article or from the comments) is important to know and lets one think this isn't necessarily made up.
You infer a perpetual motion machine, they say it is 'powered by gravity'.
Which is something I infered as well, and probably many others. The title is confusing and that is all the OP was pointing at, so you know, be nice - he wasn't trying to undermine the achievements, if any.
Re: A $5 Lamp Powered Solely by Gravity
#55Earlier quoted context omitted.
indeed! having lived in india, i get particularly excited by projects that could provide grid-free lighting and clean water to rural areas. also, a quick plug for my blog [ http://aleverlongenough.wordpress.com/ ] rounding up projects like this - it was unfortunately short-lived because life got busy, but i hope to restart it in 2013.
> i get particularly excited by projects that could provide grid-free lighting and clean water to rural areas. The best way to provide lighting and clean water is via the grid: power lines and water pipes.
yes, in the long term i agree, but extending the grid's reach and capacity happens slowly, and in the mean time the poor lead miserable lives. these low-tech stopgap measures are things they can do now to improve their lot, for little up-front cost (in business terms, the grid has lower opex, but way higher capex)
Re: A $5 Lamp Powered Solely by Gravity
#56Earlier quoted context omitted.
Because if you used a sufficient number to light a room you would have to hire people to lift the weights continuously, and if you have to to that, it would be far more efficient if you hired them to generate electricity using a pedal powered generator, because that is still the most efficient way to transform human labor into electricity. Come to think of it, pedalling for the time it takes to lift the weight and ch…
A pedal generator would probably cost more than $5, though.
Not to mention the supercapacitor.
Re: A $5 Lamp Powered Solely by Gravity
#57Earlier quoted context omitted.
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.
Using the numbers above and the typical LED efficiency you get 5 lumen of light per half hour ASSUMING perfect mechanical efficiency. http://www.wolframalpha.com/input/?i=20+kilogram%E2%80%90for... A simple wax candle produces 11 lumen. And there is no way you will get anywhere near perfect efficiency. So at best, this will product maybe 1/3 of the light from a candle. If you directed that light into a small spot, it…
But you can adjust the ballast weight and the height; instead of 20 kg over 1 meter, how about 30 kg over 2 meters? That's a factor of 3 difference.
Re: A $5 Lamp Powered Solely by Gravity
#58Pretty cool idea.
Re: A $5 Lamp Powered Solely by Gravity
#59Earlier quoted context omitted.
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…
> People couldn't lift the weight without consuming energy from food. Doesn't mean that it's powered by food. Actually, it does, and that's the perfect way to analyze this. Food is good for keeping humans alive, but it's a pretty foolish fuel to burn in a human engine to accomplish things. It's perishable, it's eaten by rodents, it's hard to transport, and more. I chuckle darkly when someone tells me that something i…
Food gets its energy from the Sun, so we may as well just call this device solar powered?
Re: A $5 Lamp Powered Solely by Gravity
#60Earlier quoted context omitted.
> People couldn't lift the weight without consuming energy from food. Doesn't mean that it's powered by food. Actually, it does, and that's the perfect way to analyze this. Food is good for keeping humans alive, but it's a pretty foolish fuel to burn in a human engine to accomplish things. It's perishable, it's eaten by rodents, it's hard to transport, and more. I chuckle darkly when someone tells me that something i…
Food gets its energy from the Sun, so we may as well just call this device solar powered?
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