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[Dvice] 230% efficient LEDs seem to violate first law of thermodynamics

11K views 78 replies 59 participants last post by  Zero4549 
#1 ·
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Physicists hellbent on destroying the universe have come up with a tiny LED that produces 69 picowatts of light while using just 30 picowatts of power. That's an efficiency of above 100%, which should be impossible, but isn't. And in other breaking news, up is down, black is white, and zebras look the same.

So, how does this not totally and completely invalidate the conservation of energy? We have to look at how energy flows through the entire system, not just at the electricity in and light out. When the LED gets more than 100% electrically efficient, it starts to cool itself down, which is another way of saying that it's stealing energy (in the form of heat) from its environment and converting that heat into those over-unity photons.

This cooling effect has some interesting implications for low-power electronics, but most importantly, we can all rest just a little bit easier knowing that the basic physical rules that frame our perception of the universe have survived for one more day.
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#4 ·
I'm curious how bright these actually are though at such low power levels.
 
#5 ·
That is freakin' awesome. I'm at school so I can't view the link, do they have a price for one of these monstrosities? Also, these things are the spirit bomb! They absorb surrounding energy! Let's make a whole field of them and kill some deer and grass
 
#7 ·
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You guys all know that 69 picowatts of light is 6.9 x 10 to the -11 watts of light, right? It's the same power output as a single cell in your body. It's almost nonexistant. Bright LEDs can use about 3 watts, that's 3,000,000,000,000 picowatts!
Food for thought from the comment section at the source.

I doubt this tech will scale to usable levels anytime soon.
 
#8 ·
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Originally Posted by Sparhawk View Post

Quote:
You guys all know that 69 picowatts of light is 6.9 x 10 to the -11 watts of light, right? It's the same power output as a single cell in your body. It's almost nonexistant. Bright LEDs can use about 3 watts, that's 3,000,000,000,000 picowatts!
Food for thought from the comment section at the source.

I doubt this tech will scale to usable levels anytime soon.
If you put enough of them together and added more heat that they can absorb, wonder how bright they can actually make them.
 
#10 ·
Awesome!

I know that level of power is somewhere at the level of a single cell of a human body, so it is very small, but think of micro LED's and a sheet of 1million of them.

Machines that power themselves?
 
#11 ·
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Originally Posted by Aparition View Post

Machines that power themselves?
Not possible. Heat will always be lost as a by product of expended energy. You will never see a 100% recovery of that energy.

What this means is that if this tech scales, we may be looking at a far more efficient form of energy usage. That's about it.

Still, this is huge. I was wondering when engineers would find a way to harness all that lost heat.
 
#13 ·
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Originally Posted by Mad Pistol View Post

Not possible. Heat will always be lost as a by product of expended energy. You will never see a 100% recovery of that energy.
What this means is that if this tech scales, we may be looking at a far more efficient form of energy usage. That's about it.
Still, this is huge. I was wondering when engineers would find a way to harness all that lost heat.
But isn't that the whole thing? It's not just using its own heat but also absorbing heat from its surroundings.
 
#14 ·
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Originally Posted by PappaSmurfsHarem View Post

But isn't that the whole thing? It's not just using its own heat but also absorbing heat from its surroundings.
Yes, but his point was that the heat it produces won't be enough heat to let it produce that much light/heat over again. So these couldn't just power themselves, but they are more efficient than an LED that didn't absorb any heat to produce light.
 
#15 ·
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Originally Posted by Eduardv View Post

That's freaking awesome,i hope this technology comes to consumers in commercialized products.

Energy bill will be alot lower with this
smile.gif
Not true, as energy efficient products lower energy grid demands the cost of electricity itself will be raised to compensate. Greed...

Sent using tapatalk
 
#16 ·
Misleading article title is misleading.

It's not actually %230 efficient. If it were it would put out more energy than it took in and would therefore be self-sustaining (if an apparatus to capture the energy with no loss and redirect it back through the system could be built). It's %230 efficient relative to the amount of electricity it is supplied, not taking into account any other factors.

The fact that it's using the environments heat doesn't mean you can discount that energy on the front of the equation though. It has to be accounted for and when you factor in the amount of energy put in by electricity and then the amount put in by heat, the total output is less than those combined.

My question is, what happens in a cold environment?
 
#19 ·
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Originally Posted by Mad Pistol View Post

Not possible. Heat will always be lost as a by product of expended energy. You will never see a 100% recovery of that energy.
What this means is that if this tech scales, we may be looking at a far more efficient form of energy usage. That's about it.
Still, this is huge. I was wondering when engineers would find a way to harness all that lost heat.
You already can with thermocouples. The Prius uses thermocouples to recover waste heat from the engine to feed back into the battery.

By the way, that's one of the ideas I came up with when I was like 15, only to find out some engineer had done it like two years earlier.
tongue.gif
 
#22 ·
This is some very interesting news. I'd like to see how it is applied in the future.
Quote:
Originally Posted by EVGA Phaedrus View Post

You already can with thermocouples. The Prius uses thermocouples to recover waste heat from the engine to feed back into the battery.
By the way, that's one of the ideas I came up with when I was like 15, only to find out some engineer had done it like two years earlier.
tongue.gif
OT.

Phaedrus? OUR OCN Phaedrus?? Is that you? You work for EVGA now? Holy carp! They got the ultimate PSU guy on their team! EVGA's freakin' unstoppable now!
 
#23 ·
[quote name="Aparition" url="/t/1226431/dvice-230-efficient-leds-seem-to-violate-first-law-of-thermodynamics#post_16662382"]Awesome! I know that level of power is somewhere at the level of a single cell of a human body, so it is very small, but think of micro LED's and a sheet of 1million of them. Machines that power themselves?[/quote] 1 million of them would output 6.9 × 10-5 watts of power. You would need 500 billion of them to output the same amount of light as a typical 3w LED. And even then, disregarding the massive cost to produce such a thing, the light would not be nearly as focused due to the large size of the unit. This tech, as it stands, is wholly impractical.
 
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