That's not gravity powered, that's human power being stored in a potential-energy battery :P. Though it's perhaps more efficient to have a human eat plants and do that than to convert it to bio-oil first, I can't imagine that it is...
That's not gravity powered, that's human power being stored in a potential-energy battery :P. Though it's perhaps more efficient to have a human eat plants and do that than to convert it to bio-oil first...
yes it is, the method to raise the weight is your whole argument, which is pretty petty,
it is a simple, good light, but how many of these great ideas really make it? (to those that need it that is)
yes it is, the method to raise the weight is your whole argument, which is pretty petty
No what I mean is, that energy actually has to come from somewhere, and it comes from food. To put out any decent lighting, you'd have to mathematically match the same amount of energy as any other source, so I'm skeptical of whether it's actually cheaper to transport food to human bodies and then get them to do the work powered by said food chemistry, it seems like it has to be a less efficient way of converting energy into light mathematically, somehow.
Though I'm under the impression that nobody in the world is starving any more except for where food-controlling warlords and dictatorships are involved, so maybe it's easier to just power by inevitable excess food consumption.
(I mean you could achieve the same thing with a crank, and call it 'free energy', though this is probably a better battery).
The effort required to ignite a kerosene lamp, go and collect fuel all the time for the lamp requires food energy as well. I think there would be more effort and food energy consumed in the people walking to a place of fuel every day/week/month than it would take to lift a bag of dirt.
So even in your food energy argument nerfy, they are still mathematically better off.
From what calculations I could find, this would power a remotely decent bright light for about 14 seconds, not including all the energy that goes into manufacturing, transport, wear & tear, etc.
Gravitational Potential Energy:
Ep = MgH
10kg * 2m *9.879m/s^2 = 197.58 Joules
or we can use position formula to get velocity and multiply by max kinetic energy.
4/9.879 = t^2
t = 0.63631696606626456176697849992884s
v = 9.979m/s^2 * t = 6.286175307768627605695980600797m/s
Ek = (1/2) v^2 = 197.58 Joules
This will run a 15 watt bulb for about 13 or 14 seconds...ideally...
It will run a 1 watt bulb for 3 minutes 17 seconds...ideally.
In order to get any appreciable light from this contraption, they'd need to lift a few tons with a pulley or something.
With normal amounts of mass the light won't be enough to even get you back to your chair.
If they are getting light from this, then something is seriously screwed up with the definition of "Energy"..
I'd recommend they spend the $5 on Kerosene or 2 bags of sugar which they could burn. It will provide more light during it's lifetime.
Amount of energy in a bag of sugar: 28,602,000 Joules (as food calories).
If you're going as pathetic as 1 watt, the bag of sugar can give you light for 11 months, and even at U.S. rip-off prices, you can get 2.5 bags of sugar for $5...
But if you are going to be lifting on rocks and stuff to power a gravity lamp all the time, well if you ate those same food calories, your body is only 10% efficient, and the gravity light is probably only 20% efficient, making the whole system 2% efficient. Takes food calories to lift those rocks (conservation).
Burning bags of sugar for lighting is 125 times cheaper, and won't break your back in the process...
^ i.e. the food would go (a theoretical) 125 times further if it was just burned instead of eaten first... This is less efficient than just burning food for light.
Where does the energy that powers your body come from? i.e. what is the fuel that powers you? How efficient is it to gain, consume, and work it, compared to gaining and burning kerosene? How much light will you realistically get for that amount of energy? (according to those equations, negligible amounts).
It would be more efficient to just burn food for light, than put it through the human body and try to convert its energy into potential energy.
Where did you get that equation from? I can't see it on the linked page.
Simple but effective, uses the same ideas as the wind up one, but instead uses a weight. Good stuff, always love seeing old ideas transformed into something useful today.
Ignore Nerf... it's not complicated how it works, and he just wants to seem smarter than he is o_0
The same place as the energy used to create kerosene, which is just shitloads of compressed solar power. At a much more efficient ratio to weight, at that.
Well there is no way I can check it myself but if it's accurate it makes this whole thing a scam doesn't it?
I think by omission that the laws of physics prevent providing a realistically comparable light to kerosene without spending far more on food than you would oil, yes, it is an intentional lie and thus a scam.
If food ever becomes cheap enough for this to be equal value for money to kerosene, then biofuels or just burning the food outright would still be better than using the human body to do a lossy conversion of the energy into lifting and then potential energy.
Perpetual motion machines will solve world hunger. It already exists and the lizard people elite living inside the hollow earth are keeping it a secret.
Pretty much this. Anybody who claims to offer 'free' power is lying or stupid, there is always a cost somewhere - the cost of whatever the energy source is. And it takes a whole crapload of solar grown biomass to match the same amount of light from kerosene (compressed solar grown biomass), putting it through the human body first is even more costly.
It would be more efficient to just burn food for light,
What the fuck fantasy world do you live in? So lifting a bag of rocks a couple of feet in the air gives them half an hour of light, how much energy do you think you have to expend to lift a bag of rocks a couple of feet in the air every half an hour? I'd be guessing not very fucking much. So how do you ever reach the conclusion that its more efficient to burn food than to lift a bag of rocks a small distance every half an hour?
What the fuck fantasy world do you live in? So lifting a bag of rocks a couple of feet in the air gives them half an hour of light, how much energy do you think you have to expend to lift a bag of rocks a couple of feet in the air every half an hour? I'd be guessing not very fucking much. So how do you ever reach the conclusion that its more efficient to burn food than to lift a bag of rocks a small distance every half an hour?
The mathematical explanation was pretty clearly provided in the quotes?
It's not hard to understand. * Burn fuel (i.e. food) directly == the chemical bond energy released as light. * Put fuel through human body to then lift wear-and-tear machine == multiple stages of inefficient energy loss. No comparable amount of light without immense lifting and a lot of fuel (food).
It's just like powering a generator to turn another generator, there's a lot of lost power.
I think the thing is that 30 minutes of light is a complete false, and in reality it is only seconds of light being generated from their system if it's a 15 watt bulb.
As soon as I saw gravity powered I suspected it was a scam. The same way I suspect things when the creators claim it is magnet powered or whatever. Scammers always use things like gravity and magnets (how do they work?) to bamboozle people because they seem to act like magic.
Nobody's claiming free energy. The places where this would be useful is where lighting fuel is expensive compared to manual labor. Also, burning things is always going to be a highly wasteful way of generating light - all that heat produced is energy not doing useful work.
Nobody's claiming free energy. The places where this would be useful is where lighting fuel is expensive compared to manual labor.
They're claiming usefully comparable light, which is impossible without eating the equivalent amount of energy (or more, actually).
nerf are you assuming that when you burn the kerosene/sugar/whatever that 100% of it's energy is converted into light?
Far more than the amount of energy from food that is getting converted into light here. Not that all light isn't hot anyway...
Both sources are using the stored solar energy which bound the organic molecules together, breaking the bonds in a human body or in a fire is going to release the same amount of energy, but the human body has far more stages to pass through where energy is going elsewhere, before lifting a rock to then spin a magnet to then generate new light with the remainder of that, which will generate more heat then anyway.
They're claiming usefully comparable light, which is impossible without eating the equivalent amount of energy (or more, actually).
Incorrect, burning kerosene is not an efficient release of energy as it releases a substantial amount of heat energy. Since an LED has a much much higher light:heat ratio it is converting energy in a far more efficient manor, therefore requiring less energy to create the same amount of light as it is not wasting as much to heat.
nerfy, you are wrong and these are the following reasons
1) because
2) using maths, fucking your sister/mother/goat is best as it expends the least amount of time/effort/money
3) kero (to power the lamps) has to be purchased from somewhere, which may take time, and money, it will also take energy, and as some of these places are over a days walk to the shops, pulling a weight is much easier
4) many of these place grow (little) food, the time saved by not getting fuel can be used to grow food stuffs (the extra food needed to cover the difference) this is done at no price, (so already youre not having to outlay money so are better off)
5) kero isn't grown locally or even in many of these countries, so that all all money that is leaving the country, food however is often grown, that would mean that the money stays in country, and famers invest back into the farm, which in turn would make the food cheaper! (again countering the extra food required)
so, hope that gives a little more to think about (also, friends dont let friends fuck thier own family, so no more of that okay)
So for 4 hours, a good LED (which, from what I'm reading, may only work directionally, drops off faster, and may not be good for viewing details like colour) will need 14400 Joules to produce a similar brightness (40 lumens).
According to the above calculations, one lift of 10 kilograms to 2 metres, before any loss with rotating pullies etc, would produce at best 197.58 Joules.
So you'd need to lift the thing 72 times to get the same amount of light as .1 litre of kerosene, or 10 kilograms 9 times per 30 minutes to get the same brightness. Which, is actually better than I thought at least :P, but still nothing like as advertised, and that's presuming best-theoretically-possible power generation for 10 kilos at 2 metres.
kero (to power the lamps) has to be purchased from somewhere, which may take time, and money, it will also take energy, and as some of these places are over a days walk to the shops, pulling a weight is much easier
As does food. There is a reason that we still burn oil in our cars, and not biofuels.
where the math for engery required to get the kero
also, there isn't any accounting for the money side of things, because honestly if the cost of the food required to creat the engery to lift the weights is less than the cost of the kero, then you're ahead already
also nerf, there is a BIG difference between between us using oil in our cars etc, and some poor village that has to hike a day for fuel oil
this seems to be a big thing that you are overlooking in an effort to sound knowladgable
Ok then we'll play it your way just for shits n giggles, how much energy to lift the kerosene off the truck, pour a measured amount into the lamp, move the lamp to height, lift the book of matches, strike the match etc etc, see where I'm going with this?
also given LED's with 200+ lm/w as already pointed out are available, your efficiency for LED is way off.
where the math for engery required to get the kero
As I said, there is a reason that we still burn oil in our cars, and not biofuels. There is a cost to getting food, and there is a cost to getting oil.
When food becomes more economical for energy than oil, we will change, and that's not even considering food as a fuel to be inefficiently put through the human body for manual power.
It would take 9 lifts of 10 kilos to 2 metres in a best-possible-theoretical power generation to achieve similar brightness to burning kerosene as they currently do (and LEDs seem to be far less pragmatically useful from what I've read).
Ok then we'll play it your way just for shits n giggles, how much energy to lift the kerosene off the truck, pour a measured amount into the lamp, move the lamp to height, lift the book of matches, strike the match etc etc, see where I'm going with this?
You guys keep not getting this. If food was a cheaper power source (before even considering using an inefficient machine like a human body for converting it) then it would be cheaper than oil. It's not, because oil is the same thing but extremely compressed. As oil becomes harder to find, then food will become comparable in value.
but nerf, currently the fuel insome of these country's IS more costly than food
and it isn't a matter of a short walk to buy fuel (they dont have cars), as i said, it can be upto a days walk just to get to the shops, many aid org's dont provide fuel, just food
Lol, not for the maths, for a description of what LED versus Kerosene light is like for those who have tried both.
Give it a break really, nobody's impressed.
What does this even mean? "We don't like no maths around here, we've already decided that we want it to be true and are applying special pleading to the cost of acquiring food kilojoules compared to oil power."
If you want to live in a fairy tail land free from the limits of reality, I can't stop you. I'm just hoping that people understand that the claim is very suspicious before donating to this.
You guys keep not getting this. If food was a cheaper power source (before even considering using an inefficient machine like a human body for converting it) then it would be cheaper than oil. It's not, because oil is the same thing but extremely compressed. As oil becomes harder to find, then food will become comparable in value.
no nerf, you dont seem to be getting it, you seem to be disregarding the effort required to get the kero in the first place, fact is there is alot more effort in these countrys than in this one,
nerf maths, energy of burning kero vs energy of lifting wieght
real world effort required to get kero (excluding the cost/money factor) carrying the container to the "shop" effort required to decant into the container, effort to carry kero home then effort decanting heavy container into lamp lighting match/lamp vs lifting weight
but nerf, currently the fuel insome of these country's IS more costly than food
That may or may not be true (I'd like to see where you get that from), but it doesn't change the fact that this does not work as advertised.
For a (seemingly inferior) LED light, you'd need to lift - at a theoretical best - 90 kilograms 2 metres every 30 minutes, which isn't what they advertised. Since they're not going to achieve a theoretical best (I'm going to wildly presume 20% efficiency?) then that's 300 kilograms lifted 2 metres every 30 minutes for (reportedly inferior) light.
real world effort required to get kero (excluding the cost/money factor) carrying the container to the "shop" effort required to decant into the container, effort to carry kero home then effort decanting heavy container into lamp lighting match/lamp vs lifting weight
And how much does the fuel cost to lift 300 kilograms 2 metres every 30 minutes? To transport that? When did food/plant matter suddenly become so much more economically energetically potent than super compressed plant matter?
If manual power was so much more potent than oil, then we'd all be winding up our cars and saving a fortune.
Have not read the whole thread so forgive me if this has been pointed out.
Gravitational Potential Energy:
Ep = MgH
10kg * 2m *9.879m/s^2 = 197.58 Joules
or we can use position formula to get velocity and multiply by max kinetic energy.
4/9.879 = t^2
t = 0.63631696606626456176697849992884s
v = 9.979m/s^2 * t = 6.286175307768627605695980600797m/s
Ek = (1/2) v^2 = 197.58 Joules
You know they use shit like magnets (don't ask me how they work lol!), resistors, coils and springs to generate the energy right? Probably like a wind up light or watch, so simply calculating the energy generated by the weight falling isn't going to give you anything,
Also the whole Kerosine lights are better thing, they cause cancer.
You know they use shit like magnets (don't ask me how they work lol!), resistors, coils and springs to generate the energy right?
Yes I know, that's why I said maximum possible efficiency, so it would be much worse than that. (It looks like the best dams can do 70 to 80%, I doubt that can be translated to small scale & cheap generators, since the big ones use gas and whatnot afaik).
I'm not saying that kerosene is good, it's horrible for health and the environment. I'm saying that these guys are making some very misleading seeming claims.
wholly fuck, where to you get 90kgs from for that little bag????
In that working that I provided?
And that's not what I said. I said to generate the same amount of light in the same amount of time, you'd need to lift the thing a shittonnes of times. At 100% efficiency, you'd need to raise 90 kilograms to 2 metres to have enough potential energy to power a similarly-bright LED for half an hour.
Yes I know, that's why I said maximum possible efficiency, so it would be much worse than that. (It looks like the best dams can do 70 to 80%, I doubt that can be translated to small scale & cheap generators, since the big ones use gas and whatnot afaik).
Where do you get that from? Unless you are an electrical engineer and know something that wasn't in that video, why are you assuming that the kinetic energy generated by the dropping of the bag is the only thing involved?
Where do you get that from? Unless you are an electrical engineer and know something that wasn't in that video, why are you assuming that the kinetic energy generated by the dropping of the bag is the only thing involved?
I just said the opposite. There is loss in all the stages, I presumed a 20% efficiency before, though it may go higher (dams seem to achieve about 70 to 80).
And I have done a few undergraduate semesters studying electrical engineering, not that you need it here to understand why a generator (food & oxygen powered human) charging up another generator (gravity potential) is not efficient.
So 90 kilograms to 2 metres at 70% efficiency, is 128 kilograms to 2 metres for 30 minutes of LED light. They advertised it as 9 kilograms to about 1.5 metres for 30 minutes, so unless they have a magical LED or better-than-theoretical-maximum-possible generator with no loss, they're selling this rather suspiciously.
edit edit: Actually, those are for pumping-during-offpeak dams, the best dams may reach 90%, though I doubt this can be replicated in cheap tiny generators http://new.wvic.com/index.php?option=com_content&task=view&id=7&Itemid=44 - and going through the human body first would lose so much efficiency on the food.
And I have done a few undergraduate semesters studying electrical engineering, not that you need it here to understand why a generator (food & oxygen powered human) charging up another generator (gravity potential) is not efficient.
But as pointed out burning kerosene is not without it's energy losses (heat) or human mechanical effort either, you just seem to want to ignore that.
As for the math, it does check out if you are willing to accept a very high efficiency in the generator, and since we don't have manufacturer specs available but do know high efficiency LED's exist within the required ranges, you cannot say that the device is not plausible.
But as pointed out burning kerosene is not without it's energy losses (heat) or human mechanical effort either, you just seem to want to ignore that.
What? I answered that.
As for the math, it does check out if you are willing to accept a very high efficiency in the generator,
What? No it doesn't, I just did the math like 2 posts ago. Even at an impossible 100% efficiency it would take lifting 90 kilos to 2 metres to power a single weak LED for 30 minutes.
but do know high efficiency LED's exist within the required ranges, you cannot say that the device is not plausible.
I'm hoping that one of you can actually tell me what is wrong with this when saying that I'm wrong:
U = mgh (If m is expressed in kilograms, g in m/s2 and h in metres, then U will be calculated in joules)
Leading LEDs do 40 lumens per watt in non-burst-test scenarios.
Watts = Joules / Second
So 1 Watt for 30 minutes means (1*60*30) = 1800 Joules required for an LED (presumably provides emergency level directional lighting only, ok for finding one's way around in better than pitch dark, but not good for a whole lot else..)
Potential Energy = Mass * Gravity * Height
So 1800J = Mass * 9.8 * 2 (presuming raising the mass to 2 metres in height)
Mass = 1800/(9.8 * 2)
Therefore 91.83 kilograms needed to be raised to 2 metres for 30 minutes of light at @ 100% maximum possible efficiency.
Presuming dam level best-efficiency @ 90% = 102 kilograms to 2 metres for 30 mins of LED light Presuming dam level regular efficiency @ 70% = 131 kilograms to 2 metres for 30 mins of LED light Presuming that these small generators make only @ 20% efficiency = 459 kilograms to 2 metres for 30 minutes of LED light
I think its fucking retarded to compare lifting a bag up to start the motion of the device to be compared to the consumption of food to give enough energy to do so vs the cost of kerosene....
Why the fuck would you even consider it to start with, physical motion of lifting a bag of rocks is nothing in comparison to the travel requirements to get the kerosene etc.
I would assume (I will let you do the math) that just the walk to the place and back, to pick up the kerosene would expend more energy, therefore more food power, than lifting the bag of rocks?
Since they're talking about light fixtures, I'd say this is about LED droop (basically, LEDs are more effective in a low current setup like this gravity lamp than they are in a light socket). Of course, people are working on ways to fix that anyway: http://news.sciencemag.org/sciencenow/2012/05/how-leds-got-their-shine-back.html
I think its fucking retarded to compare lifting a bag up to start the motion of the device to be compared to the consumption of food to give enough energy to do so vs the cost of kerosene....
The fact that food is so much less potent than kerosene is what reveals this to be a very suspicious claim, as the human needs to be powered in some way.
Why the fuck would you even consider it to start with, physical motion of lifting a bag of rocks is nothing in comparison to the travel requirements to get the kerosene etc.
That it is essentially nothing is why the maths doesn't work in their favour. It seemingly won't do what they say it will simply due to the laws of physics.
I would assume (I will let you do the math) that just the walk to the place and back, to pick up the kerosene would expend more energy, therefore more food power, than lifting the bag of rocks?
They'd have to carry back more weight in food than oil to power this by the same amount.
Either way it doesn't matter, there simply doesn't seem to be a way for a human being to produce the same amount of lighting without lifting constantly (hundreds of kilograms to two metres per hour). If they use this as a bare minimum emergency lighting system, it's probably a plus, at the least this maybe could be used in conjunction with kerosene off-hours, but it almost certainly doesn't do what they imply.
Dunno seemed to me to contain a number of spots for gearing which could make the transformer/magneto whatever run at a significant potential faster then the weight moves toward the ground.
I think the word "gravity" is being used too loosely, the bag isn't falling at the speed of gravity towards the ground, gravity and the weight of the bag as well as tightly wound gearing is causing whatever to spin at a rate exponential to the bags actual decent speed.
I think the main thing is that a lot of the energy we intake as humans probably leaves us as waste. Obviously the amount varies wildly from person to person, but it's reasonable to say that for most people doing a bit of additional lifting is probably just going to be using some of the energy that would've otherwise passed on out. We probably don't have to consider that the exact amount of energy we expended lifting the weight, was needed to be supplied by additional food that we otherwise wouldn't have eaten.
Do enough extra work though and you most likely will need extra food to maintain it - the energy isn't free which is all nerf started out saying
Dunno seemed to me to contain a number of spots for gearing which could make the transformer/magneto whatever run at a significant potential faster then the weight moves toward the ground.
I think the word "gravity" is being used too loosely, the bag isn't falling at the speed of gravity towards the ground, gravity and the weight of the bag as well as tightly wound gearing is causing whatever to spin at a rate exponential to the bags actual decent speed.
The potential energy doesn't change, there's no way to get more energy out of it than was used to lift it up to that height.
but it's reasonable to say that for most people doing a bit of additional lifting is probably just going to be using some of the energy that would've otherwise passed on out.
Yeah I mentioned at one point that if they're overeating, which perhaps more and more people are now, then it's at least not necessarily a food budgeting problem. They'll still never generate a comparable light to kerosene using it as it was advertised however, the raw maths simply demands lifting 10 kilos to 2 metres over 9 times per half hour with a maximum theoretically possible power generation method, or having an extremely dim light (which might be useful for being able to tone down kerosene when not eating etc, but they didn't advertise it as such).
ok so you have an extra spoonful of porridge, still easier than getting kerosene, you're cutting a whole thing off the list, that'll save you
You're still ignoring that you can't even power a low level LED without lifting this thing dozens of times per hour even with improbably good $5 generator efficiency...
Oh noes, he's bringing maths and the laws of physics to a very suspicious sales pitch.
Anybody who thinks that I ruined anything here (aside for my own sanity after trying to talk to a few extremely simple folk) needs to get their priorities sorted.
Using a human to charge a generator still has the same mathematical limits as any other power source. Though apparently being a cocky douchenozzle is more valuable than plain and simple scientific truths on this board, I don't know why I bother with you lot. Should have quit with Billy.
So whats your point nerf that the use of gravity in the name as though it suggests free power is bogus or misleading?
That you can only power a kerosene equivalent light for a few seconds or minutes with 10 kilos raised to 2 metres, even if presuming incredible unrealistic kinetic-to-electrical conversion and amazing unrealistic LEDs.
You could basically power one of those little keychain lights for like 1 minutes or something with this, for half an hour it would have to be so dim that it would be like a floater in your vision in the dark.
Nerf has it right this time. Like fpot, I thought scam as soon as I saw the title. Watching the video just reinforces that suspicion. The computation really is as simple as Nerf gave. You will get jack shit amounts of energy from lifting a bag of rocks up.
this method of powering things is old, and works (grandfather clocks)
the human body is using energy all the time, and lets be honest here nerf, you are glossing over a few facts to make a point
while you might have to carry a higher wieght in food to make the same amount of light, you are not accounting for the fact that a) many of these people grow small crops at home, (far less walking) b) kero isn't sold in a nice package, you have to carry a container to the point of sale (extra energy)
also, there are many places that get food drops, and have small outlets that sell/trade food, these are like 7/11's, everywhere however the places that sell kero are not as common, the market is much less, and the cost much higher
this would mean that you would have to travel greater distances to get the kero, (this could be time better spent tending to other things)
what if i eat the food, then burn my shit and bask in the light and odours given off?
You'd need to store your shit somewhere and dry it in the sun. Depend on the shit it could be runny in which it would be useless, but if it was a nice full shit with a good shape you would need for it to dry for a few days and hope that the person has sufficient cellulose in their diet to burn. The flame wouldn't produce much light, it would most likely smoulder and cause an insanely awful smell.
What i dont understand nerf is why you would argue this with us "simple folk" when you could post elsewhere and discuss it with people who know their shit. I mean if you think its fake, just call fake, but if you wanna prove it then i dont think here is the place to do it.
Nerf's entire argument is about getting the equivalent amount of energy from this device as a kerosene lamp, but isn't it possible that a kerosene lamp produces more light than they actually need, and because it's a flame, that the light is a lot less directable, so much of it is wasted?
An LED is a much more efficient, compact, concentrated and directable light source than a kerosene flame. OK yes, you can't create the equivalent amount of energy, but if it's still a useful, servicable amount of light, who cares?
If I had the choice between buying fuel, storing it, and burning it in lamps (creating as much heat as light in an already hot environment) or never having to get fuel again, and simply needing to lift 10kg 1.5m every 30 mins for a couple of lamps that produce much less (but still enough) light, I know which one I'd choose.
Beats me if it's a scam or not, but it seems like a bit too simplistic of an argument to say you can't create the equivalent amount of energy that a kerosene lamp releases therefore the entire concept is completely bogus.
Nerf's entire argument is about getting the equivalent amount of energy from this device as a kerosene lamp, but did you ever consider that a kerosene lamp produces more light than they actually need
Nah, aside from kerosene lamps being shit anyway, my point is that you can't even power a very weak LED with this, even with impossibly good efficiency.
Ultimately its almost all from the sun. Non-solar sources of energy are pretty miniscule in the biosphere.
Assuming it works, it seems like a good idea, depending on how expensive and difficult it is to create the devices, and how quickly the dynamo wears out.
If we use the claimed weight of 9 kg we instead get almost exactly one tenth of a Watt (of course, this is assuming 100% efficiency). ... While gravity lights might sound like a good idea, by doing some basic calculations we can find that they simply don't store enough energy to be useful in real-world scenarios.
You just don't store enough energy in lifting a few kilos to do enough work to create useful light. Canna beat the laws of physics, cap'n.
just watched the video I'd like to see a test of these lighting up a room in a useful way. as far as I can tell from some googling, they don't seem to be making any claims in LED tech and given that the energy converted by hanging some weight from a string is quite measurable and predictable, it sounds like these things wouldn't give off much light, and wouldn't give it off for very long. even the wording in their video says 'adjusted up for a task light, or adjusted down for a gentle glow which lasts over half an hour'
I'm curious why they don't even seem to publish the output of it anywhere
if anything, the biggest point of interest in this is how effective the LED is at replacing a kerosene flame. the power source is very weak as has already been demonstrated by maths in this thread
and emotional outbursts about grandfather clocks are pretty useless really, unless you've seen a grandfather clock able to power a light to the point where you could use it to replace a kerosene lamp
Nah, aside from kerosene lamps being shit anyway, my point is that you can't even power a very weak LED with this, even with impossibly good efficiency.
To be fair, they do specifically say in the video that "the brightness of the light can be adjusted up for a task light, or down for a gentle glow which lasts over half an hour", not that it will produce bright light for half an hour.
So while the video does seem somewhat misleading in that they say it can produce half an hour of light at the start of the video while showing it at full brightness, I don't think it's a total scam, just not as good as the impression given in some parts of the video.
fact is that getting power from a weight is a prove and old tech (this is a new aplication)
Yeh, but 200 joules just isn't a lot of energy, there's a reason it sounds amazing and easy! Even with super efficient dynamos and new tech LEDs you're just not going to get much light lifting a few kilos of weight every 30 minutes. I think that the cognitive issue here is that holding 9 or 10 kilos for 30 minutes is a lot of work, but that's not the same as turning a dynamo.
Now if you had a system that lifted a few hundred kilos via a pulley system or something you might get a useful storage of energy, but again you'd need to do a fair bit of work to store it. Might be a cool idea for a home gym, store your energy and power some low-level lighting around the house or recharge your phones?
I guess it also depends on what use you need the light for (like in my first post, great for camping, at that point where you need the barest amount of light to help find the bottle opener or your next beer)
if youre studying then you'll need a bright light source, however, set to minimum my guess is that you'll have enough light to have dinner by, move around the place, and wipe up and put cookware away,
however, set to minimum my guess is that you'll have enough light to have dinner by, move around the place, and wipe up and put cookware away,
I reckon you're over estimating 10 lux. You'd need one every metre or so to attempt that sort of lighting, and meanwhile its super easy to just flick on a single, compact 9(12?)V lithium battery light for the task?
Because questioning amazing claims about seemingly free energy is a bad thing?
Dear lord. The cost of feeding the humans who have to fill, light and maintain the kero lights, versus the cost of feeding the humans who have to move a sack of weight?
Your physics argument is null, because this is an economics question.
Now if you had a system that lifted a few hundred kilos via a pulley system or something you might get a useful storage of energy, but again you'd need to do a fair bit of work to store it. Might be a cool idea for a home gym, store your energy and power some low-level lighting around the house or recharge your phones?
The whole video aims at third world application. Not for around the house / home use. Its for areas that electricity is not likely to reach in the foreseeable future. In areas where there are no city lights, even a very weak LED can light up a small room / tent enough so you can walk around / not run into shit. The areas that they aim to provide for, don't exactly read novels and search for the TV remote. I understand the maths proves that the light will be very dim for a short period of time, but if they don't have to buy fuel, they will lift that bag 10 times an hour to get the light they need so they can buy food and clothes instead.
Certainly are a lot of people in this thread who would have been scammed out of their money donating to this thing.
Not immediately dismissing a project as a scam is a long stretch from being willing to donate to it. What are people expecting in return from donating to this thing anyway?
(Also fucking lol at the "would have" as though you've valiantly saved all these poor fools from pouring their money into this heinous scam! What a hero!)
Your physics argument is null, because this is an economics question.
Sigh, ignoring physics doesn't make physics go away. The insignificant amount of energy gained from such a system cannot simply be increased by ignoring the real world limitation of (at best equal) energy out for energy put in.
Dear lord. The cost of feeding the humans who have to fill, light and maintain the kero lights, versus the cost of feeding the humans who have to move a sack of weight?
There simply doesn't exist a mechanism to get power out of your body that you didn't have to put in first. If you want to get the same amount of energy from food as you're currently getting from oil, you simply just have to be spending significantly more on food than oil, as food is a worse power source (and even more if you plan on using a human body a the power converter, it would almost certainly be more efficient to just burn the food).
What you're not understanding (still) is, that if you power this by a regular human's abilities, you're not going to get any light. Want more light? You'll need the fuel from somewhere, you cannot magically gain energy. Want more fuel? Well, buying extra food is more costly than buying oil, for the equivalent energy.
the stuff to burn is reserved for party members only.
getting poor people used to low lighting conditions is just step one on the road to prepping them for the spice mines.
Sigh, ignoring physics doesn't make physics go away. The insignificant amount of energy gained from such a system cannot simply be increased by ignoring the real world limitation of (at best equal) energy out for energy put in. .
wow, nerf, you I hope you can see that there is more to the problem than the physics, yes it might be a better use of power if you ignore the whole economics factors
your argument is correct if you ignore outside factors such as energy required to obtain the kero, or the energry require to get the funds to pay for the kero
this is where the saving is
if the world was all about doing what physics said was the best method, then the world would be a different place, for better or worse, but that isn't how it works,
we are like geese, not turkeys, (if youre unsure what i mean by that, look at the farming of these animals, it will explain itself)
hoggy>>>> I see your point, however on the day you have to get kero, that is a whole day (in some cases) lost just to get kero, plus the extra work in that sun to earn the money to pay for that kero,
I thought I was on a winner with the gravity storage workout thing. After all, a good solid workout involves a couple of million joules (2,000 kilojoules), right? If 200 joules is REMOTELY useful to a third world bumpkin, we should be able to do some super shit with TWO MILLION while getting a workout!
Some back of envelope shit says that you might pull 250 watt hours out of a workout if you could reclaim the energy with very good efficiency. That's about 6 cents per workout, save you 10 bucks a year if you smash those weights three times a week and use all the energy ...
copuis: Have you looked into the cost of the kero in the third world and its accessibility? Its one thing to declare that the economic argument is valid, but if you don't have numbers then how can you assert it? Does it cost a day to get a litre of kerosene? How long does it last? Is it used for things other than lighting, like cooking, so there are other benefits - if you need the kero anyway, why not use it to light the place?
How much effort is needed to obtain it?
I suspect that a couple of litres of kerosene will go a long way, be more convenient and do the job better than this endless lifting of weights. The energy density of kero is very high and the cost still quite low in developing nations.
A kilo of cooked rice has 5,500 kilojoules. You also need input energy to cook it, and the body isn't tremendously efficient at converting that to mechanical work to lift the weight.
So going by those numbers you are much, much better off chasing more efficient kerosene lighting (and better distribution) than human-powering lighting. The device in the video is a toy that solves no real problems...
nerf, get a grip sun, (get it, sun, being a solar energy thing)
I'm not saying that engery in kero is less than in lifting wieghts, remove that thought
what you are saying is that kero is a better light source as it using less energy than lifting a wieght, I get that
what you dont seem to get is that the energy expended for that person to get the kero is far great than the energy used to lift the wieghts, or the energy used to get the extra food to lift the wieght
hoggy>>>> yes, but again, a kilo of dry rice makes more than a kilo of cooked rice
also many of these villages grow (or try to grow) crops, so the distance to take the food is vastly less, than the distance to obtain the kero,
also, as pointed out by other, as a light souce is it the greatest at turning that energy into light,
factor in lost time away from tending crops, or learning better growing methods or doing other jobs just to make enough to buy the kero, then time lost to get said kero (something they might do only once or twice a month if they are lucky)
if kerosene is even remotely available in this imaginary location, chances are they're getting it anyway- probably on their 90mile round trip over hot coals for clean water
Why are people talking about the energy in kerosine? You know that,
a) has little to do with the amount light created from a kerosine lamp as much of it is lost in heat and gases.
b) isn't relevant anyway since it's not about producing something of equal value but something of useable value and removing an expensive and carcinogenic light source.
The only energy of worth in this conversation is the input/output of the device. Assuming the input is purely from the weight of the bag and no thermal, chemical or other energy source is incorporated we can completely ignore the cost of human energy used in lifting the bag as at this point you've already shown the unlikelihood of the device working as stated.
If you wanted to compare the energy of kerosine to that created by this device then you should be talking about a kerosine generator which would probably be more efficient that simply burning kerosine for light.
If you wanted to compare the energy of kerosine to that created by this device then you should be talking about a kerosine generator which would probably be more efficient that simply burning kerosine for light.
That's this bit:
So going by those numbers you are much, much better off chasing more efficient kerosene lighting (and better distribution) than human-powering lighting.
I do not envy the jobs of highschool physics teachers now knowing that there's people like copuis out there. >_
what, people that take in more than one factor when looking at a problem?
in the real world there are many OTHER things to look at when trying to tackle an issue or problem like this
transport storage access
all things that give a greater understanding of the problem (and thus any savings) all factor you seem to want to ignore to make your point (my point is mearly that there are other factors, so it isn't a problem that can be solved purely by maths, something you are failing at)
ahh, but nerf is comparing the use of both devices,
and ignoring the need to collect the kero from a point, and ignoring the extra effort required to earn money for said kero
says that the kero lamp is better because it uses less energy to run
now, i am not arguing which is a better use of energy at the point of use, i'm arguing that the system required to maintain a kero lamp (earning extra money to buy kero, time/energy used to collect kero) negates the seeming negitive of lifting a bag of earth every now and then
What I said is that a human being cannot realistically power this to within even a magnitude of the same brightness as a kero powered lamp, we simply don't eat that amount of energy. If you want that much energy, you're going to have to get it from somewhere, and eating the shitloads of food that would be required to generate the equivalent from yourself is an incredibly bad way of going about it.
Stop being rubbish, no, that's wrong.What I said is that a human being cannot realistically power this to even within a magnitude of the same brightness as a kero powered lamp, we simply don't eat that amount of energy. If you want that much energy, you're going to have to get it from somewhere.
which I pointed out to you ignores the extra energy required to obtain kero, and you ignored this, and pushed your point
you said that their claims are false, because it will use more energy, and if you look at only one point of whole picture, you are correct, but ignoring the rest of the picture makes you wrong
The general guideline is that extraordinary claims/promises require extraordinary evidence.
The GravityLight makes extraordinary promises, but I am yet to see any mathematical/scientific material from them demonstrating that their fundamental assumptions and goals are realistically sound.
You can't just start building something and hope to overcome basic physics/chemistry.
If transporting fuel was inefficient then we wouldn't do it now would we.
well, we done transport it the same way, and this is a poor troll atempt or your being a little ignorant
if we need some kero, we jump in the car, at go to the shop, it comes in a nice safe container and out we go
if they need kero, they have to walk, sometimes for quite a distance (much further than we drive), carrying the container they are going to use to hold the kero, they buy it, they walk back.
which I pointed out to you ignores the extra energy required to obtain kero, and you ignored this, and pushed your pointyou said that their claims are false, because it will use more energy, and if you look at only one point of whole picture, you are correct, but ignoring the rest of the picture makes you wrong
Why is distributing kerosene a problem that can't be solved, but distributing a few billion $5 gravity lights isn't an issue? Why is human mechanical power a good fit for a portion of the world that has endemic food supply issues, who will still need to obtain and use fuel to cook their meagre meals anwyay?
reload>>> i've not argued physics, i've argued that there is more to consider when looking at problems like these
Hoggy>>>, I see your point, I guess should these devices (provided they work as claimed, which seems a little scetchy) only need to travel once, where as kero is a trip that needs to be repeated
They live in small villages, they likely have a truck that drives around to all the villages delivering shit. There is no need to make any assumptions anyway since you are comparing something that exists to something that doesn't.
It's like saying you could ride a magical unicorn to town that never needs food or just a regular horse that eats, drinks and doesn't poop rainbows. Of course the magical unicorn sounds more efficient but you'd still be sitting on the side of the road waiting for it to materialize while the guy on the horse has long arrived at his destination.
^ Not to mention that, if you were ever going to put out comparable energy with a food-powered generator, you'd need to collect far far far more food anyway.
That's before the fact that copious is just repeatedly ignoring that this thing cannot put out similar light to kerosene lamps for more than a brief flicker of time.
I see your point, I guess should these devices (provided they work as claimed, which seems a little scetchy) only need to travel once, where as kero is a trip that needs to be repeated
But they still need the fuel, so the (apparent) fuel runs still need to happen.
nerf, i'll put it like this so you might understand where i'm comming from
farmer grows apples, every day he works, he gets 6 apples, (now for the purpose of this, apples are magic, and no other food is need to live)
currently the farmer needs 2 apples a day to live, and 1 for is wife, the extra applea are sold the run a kero lamp, which requires a refill every 2 weeks it is a days travel to obtain kero, no apples are grown that day (as the farmer is not there)
this means the farmer makes 78 apples a fortnight 42 apples are eaten by the family each fortnight
now refill of kero costs the farmer 12 apples yet to power the grav lamp the famer would need to eat an extra apple a day,
the grav lamp will be the better option, as this would mean that the farmer would have more time to farm, growing somewhat more, and thus having more to sell for other things,
But they still need the fuel, so the (apparent) fuel runs still need to happen.
if they no longer have the kero lamps, what do they need the fuel for? (unless they are using it for cooking, and then surely then decrease in demand would lower the price a fraction)
the grav lamp will be the better option, as this would mean that the farmer would have more time to farm, growing somewhat more, and thus having more to sell for other things,
Stop it. The farmer still needs to get fuel.
if they no longer have the kero lamps, what do they need the fuel for? (unless they are using it for cooking, and then surely then decrease in demand would lower the price a fraction)
LOL, they use the kero because they don't have electricity... and without electricity all sorts of stuff requires fuel. Lower the price? Now you're just making shit up.
you mean the clay stoves that use wood and dung, not much kero used there, because many place it is all fire, not little pump stoves
I was pretty careful to use 'fuel' a lot as I'm trying to look at the big picture (you know all those factors in play here). Apparently it takes a whole day time to get a few litres of kero but the time to gather wood and dung isn't important. In any case burning dung rather than re-purposing it as fertilizer is appalling.
Getting the world onto the grid (be it centralised or local) is the best solution. Rather than spend billions on toy lights, why not get some actual fucking electricity?
presumably the fuel sources of wood and poo are close by
You're wrong.
Harvesting of firewood is physically demanding and time-consuming work especially for women and girls, who are also responsible for other household duties. Wood is harvested from the surrounding woodland and then stored at home until is ready for use. As the pressure on wood availability develops, the distance travelled and time taken to collect wood also increases. Woman and girls in the studied villages walked more than one kilometre and spent about 2-5 hours per day to harvest firewood. Another study also found that women in Mametja, Limpopo Province spent an average of 4 hours per day harvesting firewood
Getting the world onto the grid (be it centralised or local) is the best solution. Rather than spend billions on toy lights, why not get some actual fucking electricity?
But then you have to pay a carbon tax, did you consider that in your calculations?
hoggy>>> guess it is the same reason that it took so long here, distance, but I agree with you
personally if there was a good safe way to store the energy solar would be good, but i think the the upfront cost of batteries etc is the main thing stopping it
So are you really this dumb or are you one of those trolls whose game is to act as dumb as possible in an attempt to get people flustered at how dumb you are?
Because if it's the latter I have got to admit, you are pretty good at it.
other than weight, 1kg of cook rice has no messurable likeness to 1kg of dry rice fpot
it is like saying that a ton of lead and a ton of feathers are the same amount. amount of what?
we have been talking energy, and the ise of that energy, as well as with methods are going to be of more beneifit, so it would be fair to say that comparing a weight to another weight and seeing which is heavier is not the aim
yes i do enjoy stiring from time to time, this is not that time
and there is (according to you) the same amount of rice in a kg of cook vs dry
There is the exact same amount of rice though, if you had 1 million grains of rice in a 1kg bag and then cooked it you would still have 1 million grains of rice.
There is the exact same amount of rice though, if you had 1 million grains of rice in a 1kg bag and then cooked it you would still have 1 million grains of rice.
but what is was talking about was a kg of cooked rice, vs a kg of uncooked, they wieght the same, but they have vastly different volumes, energy content, only the wieght is the same
Looks like I missed an epic thread while camping :o
Light would be pretty useful for camping providing 2 things; 1. It actually works as advertised (I.e. actual useful lighting, not some piss weak LED Glow) 2. I was able o use any weight. (Such as my 20lt Water Container) Fuck carting around an extra 9kg just for lighting. Weight of some torches is measured in grams...
Sif care about some 3rd world country, hook those bitches up with Solar and be done with it.
Interesting thread, reminds me of something i read where a person hypothesized it was cheaper to drive to the shops than walk/cycle in terms of fuel costs re car vs human.
Can we stop talking about retarded shit like how cooked rice is magical and get back to the interesting science please?
Assuming 100% efficiency we've established that the best you can get is 0.1W over half an hour (you could always make it a shorter time to account for inefficiency), so what kind of LED efficiency would you need to produce useful light from that?
LEDs are already hitting 250 lm/W (obviously the cutting edge of technology isn't feasible for a low cost 3rd world device, but just speaking theoretically/looking to the future), seems like a directed beam of 25lm would be a useful amount of light inside at night, would it not?
From the LED facts/myths page that I linked earlier, apparently numbers like that are only for 'burst' tests, not sustained. Apparently the very best LEDs only sustain about 40 lm/W, and from what I read elsewhere they're already near their theoretical maximum.
Ah, fair enough, sorry couldn't be bothered reading every post in this clusterfuck of a thread. Did it say how the theoretical limit of LEDs is determined?
Man, for a technologically advanced race we're pretty shit at efficiency. Wake me up when we're harnessing nearly 100% of the energy from fission/fusion reactions and are able to convert nearly 100% of that into light.
i'm not sure what copius is going on about but if you boil 1 cup of uncooked rice, it becomes 2 cups or so of cooked rice. but that's because the rice get's all puffy from soaking up all the water, not because more rice magically appears.
You see when you put rocks in a bag and they warm up they become cooked rocks which makes the rocks multiply magically. Only then can the increased rock energy be used to power the gravity lights. For more cooked rock power, remember to use magnets.
No, you need special weights which can only be used with the Gravity Light
Well... if Apple gets involved in the design...
Seriously though, some people would think a fully internal, hard to get to, specially designed 'weight pack' would be a good idea in things like this. Like Batteries that you cant replace without breaking the device to get to them.
I got the 1.8 kilojoules number, presuming a 1 watt LED for 30 minutes.
I was going on the claim here that "Some highly efficient white-light LED lighting fixtures can achieve efficacy of over 40 lumens per watt (lm / W)" and a quote from the wiki kero lamp page from a standford article about kero lamps in India (one of the two third-world extensive kero lamp users) that indicated that the most commonly used type of kero lamp would produce 37 lumens.
I got the 1.8 kilojoules number, presuming a 1 watt LED for 30 minutes.I was going on the claim here that "Some highly efficient white-light LED lighting fixtures can achieve efficacy of over 40 lumens per watt (lm / W)" and a quote from the wiki kero lamp page from a standford article about kero lamps in India (one of the two third-world extensive kero lamp users) that indicated that the most commonly used type of kero lamp would produce 37 lumens.
So we are talking about a tenth of a gram of oats to fuel the work. or half a gram of cooked rice. Did I do the maths wrong?
The first comment that you linked agreed with my numbers (at an essentially impossible 100% efficiency, you're not even within a magnitude of where you'd need to be), and the one after said you'd maybe manage one magnitude less of light than a weak kero lamp at best with a cutting edge LED.
So we are talking about a tenth of a gram of oats to fuel the work. or half a gram of cooked rice. Did I do the maths wrong?
I'm not following, you can't calculate those things since there's no way to measure the efficiency of the human body, other than "almost certainly not a good idea for power conversion". Taking into account that we know that oil is cheaper than synthetic oil at this time, getting useful light from food demands more cost on food, meaning that this is not going to doable by a human taking in a cheap amount of food, pre-emptively revealing that there is something very curious about their claims that they can get human generated light of the same brightness as oil generated light (as confirmed by the actual maths on the amount of energy that you could actually get out of such activity).
I'm not following, you can't calculate those things since there's no way to measure the efficiency of the human body, other than "almost certainly not a good idea for power conversion". Taking into account that we know that oil is cheaper than synthetic oil at this time, getting useful light from food demands more cost on food, meaning that this is not going to doable by a human taking in a cheap amount of food, pre-emptively revealing that there is something very curious about their claims that they can get human generated light of the same brightness as oil generated light (as confirmed by the actual maths on the amount of energy that you could actually get out of such activity).
you are correct, apart from comparing the cost of oil compared to food to achieve the same output because you dont, you only comapre it against the energy factor,
if the food was free, and the oil cost money, would you still say that oil is the best way (in terms of cost)
you are correct, apart from comparing the cost of oil compared to food to achieve the same outputbecause you dont, you only comapre it against the energy factor, if the food was free, and the oil cost money, would you still say that oil is the best way (in terms of cost)
I've told you a dozen times that it doesn't matter how much food costs, my only point is that since we know that food is such a worse energy source, and that the human body is such a poor method for power conversion, we should be pre-emptively suspicious about any claims that they've got a usable human-powered light, because it would suggest that somebody is taking in incredible amounts of energy.
The suspicions were then revealed to be valid by actual maths showing that you won't really get any light out of this, the food question doesn't matter any more.
next you'll be telling me human poweredf flight is impossible because the maths doesn't work out
(I still think it is a novel idea, much like the clockwork radio that came out years ago for use in these areas, while a little time consuming to wind up, it still proved them contact and entertainment, and dynmo lights have been around for donkeys years, (using far worse lighting methods at that) sure it might not be great, but you can't ignore that IF it say gave the same light as 1 candle over a 20min timeframe it wouldn't have some use)
Maybe Nathan was referring to the next comment down in that reddit link?
Richard Berry · University of Virginia I decided to check your numbers. First, I used the actual mass of the bag: So, E = mgh --> 9kg x 9.8m/s2 x 2m = 176 J available potential energy. Second, I tested some small LED lights for reading. The most suitable of those I had on hand was the Photon Micro-Light (use Google to investigate their web site). According to the manufacturers, this tiny light puts out 4.5 lumens. I found this to be adequate for reading 7-point Helvetica type in a book placed 1 m from the light; at that distance the useful circle of light is about 30 cm diameter. I opened the Photon Micro-Light and measured the voltage across the LED (3.56 V) and the current (39.4 mA), so it consumes 140 mW. The GravityLight claims that it powers the LED at maximum brightness setting for 18 minutes. (The 30-minute figure applies to a lower output setting.) The Photon Micro-Light can illuminate a small room (3m x 4m x 2m) sufficiently well that you can move around without bumping into things. So we expend our 176 J in 1080 seconds, which gives 162 mW. Energetically, the device is possible. The design obviously calls for an efficient mechanical and electrical design. According to the standard required illuminance levels table, as a boy Abe Lincoln should not have been reading books by the light of the fireplace, but neither should kids in Africa be reading by kerosene lantern light. On vacations as a kid, I tried reading by kerosene lamp and it gave me a headache. As a 65-year-old, I was able to read a book page set in 9-point Times Roman for 20 minutes by Photon Micro-Light without discomfort. I agree fully that the 2008 Gravia was energetically not possible. However, the GravityLight does appear to be feasible technically, when considered in a realistic context.
next you'll be telling me human poweredf flight is impossible because the maths doesn't work out
Sigh, I didn't say that human powered light was impossible, I said that what they represented in their video doesn't seem to be possible by the constraints of physics.
Maybe Nathan was referring to the next comment down in that reddit link? Thoughts?
I responded to that. It said that with a LED which puts out a magnitude less of light than a bad kero lamp, you could maybe power it if you somehow made an impossible 100% efficient mechanical generator.
This could be useful for a very dim or very concise torch light, for brief moments (a few minutes), then their claim that they can replace or exceed kero with this just doesn't seem scientifically possible.
next you'll be telling me human poweredf flight is impossible because the maths doesn't work out
There were earlier aviators but the history books credit the Wright brothers with the innovation of cooking the grains before using them in the rice powered treadmill.
Richard Berry, whom ever he his seems to think it is doable, based on more than the maths on one of the factors, (he goes to to state luxs that are usable to read by, and move around a room, both the uses this would see)
seem you didn't answer it at all nerf
this I think sums it up really well, "However, the GravityLight does appear to be feasible technically, when considered in a realistic context."
Richard Berry, whom ever he his seems to think it is doable, based on more than the maths on one of the factors
Bullshit, you should learn to read. He said that with 100% efficient power generation, you could power a small directional LED which is a magnitude less bright than a weak kerosene lamp.
Bullshit, you should learn to read. He said that with 100% efficient power generation, you could power a small directional LED which is a magnitude less bright than a weak kerosene lamp.
ahem, practice as one preaches what he wrote was "Energetically, the device is possible. The design obviously calls for an efficient mechanical and electrical design."
and this part here is worth READING "On vacations as a kid, I tried reading by kerosene lamp and it gave me a headache. As a 65-year-old, I was able to read a book page set in 9-point Times Roman for 20 minutes by Photon Micro-Light without discomfort."
what he said was the LED used 140mW and using this math E = mgh --> 9kg x 9.8m/s2 x 2m = 176 J available potential energy. we could if it was 100% efficient power generation have 162mw over 1080 sec, so, by my math, IF you could get the losses down to 22mw over that time frame, you'd still be fine
His tested LED output = 4 lumens (and only doable with this power source by assuming near 100% efficiency) Kerosene output = 37~100 lumens
Their claim was that this won't just compete with kerosene lamps, it will replace them. Their claim was scientifically rubbish. Even going by his figures.
Yes, it's possible to power a light with this system, we've all said this. It's not possible to power a light comparable to a kerosene lamp.
i'll post this part again, maybe take a breath, and read slowly and in an understanding fashion his coments again
"the GravityLight does appear to be feasible technically, when considered in a realistic context."
he also went on to state that the light was usable to move around a room with bumping into things, he also stated that reading by this light caused no discomfort when compared to reading by a kero lamp (might have more to do with the wavelengh of the light, not just the pure lux)
also, he never once assumed a 100% effcient power source, he (and i reposted) the figures, there is a margin for loss, it doen't need to be 100%, (but it does need a high effciency)
nerf, I might not be the most learned in this argument, but about now your not coming off as the smartest (which is not good when it is me)
Nope, I give up, this guy is continuously arguing an unrelated point to my criticism of the original pitch.The original claims in the video are very suspicious, seemingly impossible, would not recommend donating.
what, you copied and pasted one view, and refused to look at other aspects
even when it was shown that it is possible you refuse to look at other aspects
you found a negitive view that spouted that it wouldn't be feasible and ran with it,
the way I see it is this
the copy job you did looked at the energy side, and said nar, it can be done
Mr richard berry looked at it and said, wait up, the maths says it can be done, I tested it myself, did a little trial and it could work if the machine is ~87% efficient
I dont see where you are tripping up here, you take the view from a guy you dont know, run with it because it sounds about right, then when faced with another view that counters that you dont wish to consider it?
you keep going like that in life, hear the first view that sounds right, and never waver from that
The fuck is wrong with you man? I've told you how many times that you're addressing a completely irrelevant point?
Here, I'll just repeat my previous answer:
let me spell it out for you:
His tested LED output = 4 lumens (and only doable with this power source by assuming near 100% efficiency) Kerosene output = 37~100 lumens
Their claim was that this won't just compete with kerosene lamps, it will replace them. Their claim was scientifically rubbish. Even going by his figures.
For comparison, a candle provides about 13 lumens. You'd need to lift 4x10 kilos to 2 metres - at near maximum conversion efficiency - to get the same brightness as a candle...
A flickering candle light is a much different light than a constant LED output. It's even a different colour spectrum. I have 2 Dive torches, the difference between a Halogen and an LED light (Same Lumens, Same Beam Angle) in the water is staggering. You can't compare to very different light sources based solely on Lumens.
"What if you had multiple gravity lights, all hooked up to the same weight, so you lift it once and power like 4 or 5 lights."
On the off chance that this is serious, the work would be divided between the lights so each would be proportionally dimmer. There may be some benefit to spreading the light around the room.
I reckon a better idea would be a 500kg weight that was lifted 2-3 metres in the air at sunset with a hoist, or with the aid of a mule or something if a beast of burden was typically handy? At least it would get it done for the night in one go, and you'd have the ability to control the fall speed as a kind of crude dimmer.
It's not possible to power a light comparable to a kerosene lamp.
Sure, but you seem to have an unstated assumption that a) the lumens that a kerosene lamp puts out are the minimum requirement of the intended users and b) that its other qualities of the lighting are equivalent and/or required.
The comment I linked provides (anecdotal) evidence that a lesser amount of lumens as produced by an LED, is suitable for the intended tasks. You can read with it and avoid bumping into stuff.
As I think has already been mentioned, an LED is far more directional. If I have a shack or a tent or whatever and I hang a lamp in the top corner of a room; a kerosene lamp may produce 40 lumens but much of its output presumedly goes in the wrong direction?
Certainly its a fair observation that this thing is not going to be technically equivalent; but for its intended purpose and based on the data available it sounds like it could potentially still be a suitable replacement.
I reckon a better idea would be a 500kg weight that was lifted 2-3 metres in the air at sunset with a hoist, or with the aid of a mule or something if a beast of burden was typically handy? At least it would get it done for the night in one go, and you'd have the ability to control the fall speed as a kind of crude dimmer.
At that point surely you should just look at thermo/solar/wind/magical options?
Amusing thread totally disconected with reality. Nice work guys. Everyone ran their strawman argument which works fine in a textbook situation where the exam is going to give you an A+ if you manage to correctly answer a multi choice simplified question but not a single person has effectively added all the parts together to a community long term cost benefit analysis.
ive been particularly enjoying nerfy getting angrier and angrier. i hope this isnt a hoax just so he can be completely destroyed. (because it could never ever work, due to science)
If we look at how much lux we need in the room lets say about the same as my office or 500Lux.
Now select an led that will do the job say a typical Cree 5mm round led with a 55deg viewing angle so in a room with a ceiling of 2.4m it will give a spread of roughly 5 square meters or a typical humpy.
The C513A-MSS-CV0Y0131 Cree 5mm Warm white (closest color to kero lamp) will give out a min of 2130 Lum (min used because it degrades over time and Tolerance of measurement of luminous intensity is ±15%.) Which will give us 520.9 LuX on the floor in a 2.4m diameter circle.
The power used is p = VI , 0.065 = 3.2 X 0.02
So we need to amuse we want the thing to run for 6hr a night so that 0.065 X 6 = 0.39 WH
Assume the can get 50% energy efficiency max or we need 0.78 WH
1 watt hour = 3600 joules
so that's 2808 joules
So take Nerf's formula
Ep = MgH
10kg * 2m *9.879m/s^2 = 197.58 Joules
Mash it up a bit to find out the mass needed assume height is 2m
M = EP/gH
M = 2808 / 9.879 X 2
M = 142.1 kg
If it was 100% efficient M = 71 kg
The average weight of a person in Ethiopia is 44kg
If we only want to run it off a 10kg bag the sums start again
197.58 Joules halved for efficiency is 98.79 joules
98.79 joules = 0.027441667 WH
Power is still= 0.065w
W = Wh/h
W X Wh = h
= 0.0844 Hrs
Or 5min
If 100% Efficiency was achieved you could run it for 10 min
Summing it up currently their is $318,778 worth of suckers on indiegogo.
So how many people could we feed for a day on that?
Rice is currently $378 a tonne
Rice needed to sustain life for a day
In 2007 people in Thailand ate an average of 103kg of rice
ive been particularly enjoying nerfy getting angrier and angrier. i hope this isnt a hoax just so he can be completely destroyed. (because it could never ever work, due to science)
I'm not angry, I just have ridiculous optimism about being able to help the uneducated.
Think that whoever was going to get it would have got it by page 1 though.
I'm not angry, I just have ridiculous optimism about being able to help the uneducated.Think that whoever was going to get it would have got it by page 1 though.
sorry for knowing alittle about alot, and not alot about a little,
nerf man, no matter how many other people put forward that there are other factors that might be worth looking at, you stuck with you feeling, and math working from someone else. good on you, gold star for tunnel vision
i'll rice, sorry rise to the trolling from you two
where was I wrong about the rice. I might not have articulated it in the best was, but there are big difference potental energy difference between dry rice, and cooked rice of the same weight
and where did sorcery come into to it?
I was trying to get nerf to look at different points (which he wont because he cant get away from the posted math from a different person)
hell others have even expressed that there is more to consider that the pure lux side
