Previously submitted and seriously doubted:<p><a href="http://news.ycombinator.com/item?id=4889266" rel="nofollow">http://news.ycombinator.com/item?id=4889266</a><p>In that thread[0] revelation[1] said:<p><pre><code> 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.
</code></pre>
[0] <a href="http://news.ycombinator.com/item?id=4889426" rel="nofollow">http://news.ycombinator.com/item?id=4889426</a><p>[1] <a href="http://news.ycombinator.com/user?id=revelation" rel="nofollow">http://news.ycombinator.com/user?id=revelation</a><p>[2] <a href="http://www.wolframalpha.com/input/?i=20+kilogram%E2%80%90force+meters+in+milliwatt+hours" rel="nofollow">http://www.wolframalpha.com/input/?i=20+kilogram%E2%80%90for...</a>
Not 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.<p>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.
Some people get excited by F1 racing, the Bugatti Veyron, or stuff like the latest iPhone, telling you they are technology enthusiasts or engineering fans.<p>But if you ask me, it's always at the low end of things - like this project - where the really inventive, exciting engineering happening.<p>Sure, something like an F1 car is impressive after a fashion, but considering the price, yeah, well, it <i>better</i> knock my damn socks off or it just looks stupid. Unlimited budgets do not make for impressive engineering, really.<p>Making something that is truly, spectacularly useful like this for $5 ot $10? That is genuinely impressive.
Maybe I'm stupid for asking but what is the advantage of this over a spring powered wound clock? My wristwatch can tick for two days on a wind, and while it isn't as cheap as this gravity powered wound clock I'm sure it could be made cheaper. There is nothing special about this invention; purely mechanical "gravity powered" clocks have existed for centuries in the form of old grandfather clocks etc.
I use kerosene lights by choice in the winter in weeks like this one when there is no sunshine. So, here's my firstish world problems take on it. May not apply to people for whom a gallon of kerosine is a significant fraction of their monthly income.<p>I have a hard time seeing myself using something like this, except as task lighting. I'd be fine to have to lift a weight if I was only going to be using the kitchen for 30 minutes (it could even serve as a useful timer), or similar. But getting up every 30 minutes rules out using it anywhere I need longer duration light for eg, reading.<p>Also, anywhere I could use this, I could use any of the many inexpensive crank LED lamps available everywhere, which run for similar amounts of time.<p>The pity is that, with the right design, this could support a longer cord for a further lift distance, so it'd run an hour. Or multiple weights used in sequence or parallel so it can be primed for even longer (iirc that's how my grandparent's cuckoo clock worked). From what I can see, it's not designed to be very hackable, and something like this needs hackability.<p>The LED light is the other problem with it; I'd much rather have a well ventilated kerosine light than blue tinged LED for almost any task. (I'm curious to see studies about kerosine health risks however.) Since this light cannot be moved, it has to illuminate the whole area, and its light doesn't seem up to it, so I'd be doubtful about eg, reading by it either.
Similar in concept to the Waka Waka light, except that's powered by a solar panel (and some quite nifty electronics):<p><a href="http://www.wakawakalight.com/" rel="nofollow">http://www.wakawakalight.com/</a>
As always, the devil is in the details here. Does this lamp produce enough light for a family to be motivated to actually lift it every N minutes (e.g. does it produce enough light to read comfortably, or to cook a meal)? Is it durable enough to survive in essentially outdoors conditions in terms of heat and humidity? If the answers to these questions are positive, it's certainly a great invention. If not, back to the drawing board.
As we all argue over whether this is powered by gravity, or food, or nuclear fusion, somewhere in a dark hut someone is lifting a weight to attend to the baby that just woke up in the middle of the night.