how many lumens does the sun put out???

[scaredofthedark]

so how many lumens does the sun put out?
any way to calculate that?

[Amonra]

that should be relatively easy.......just pop it into an integrating sphere

[eluminator]

Lumens isn't everything. Reliability has to be considered also. The sun only shines in the daytime, when you don't need it.

By the way shouldn't we be using candle power, not lumens, in this forum?

[jtr1962]

Working backwards a little, the sun's total output without the earth's atmosphere in the way is about 1350 W/m². About half that is visible light, and the luminous efficacy of the solar spectrum is about 199 lm/W, so we get roughly 135,000 lumens/m². At the distance of the earth's orbit this energy falls on an imaginary sphere with a radius of 150 million kilometers, or 1.5 x 10^11 meters. The surface area of this sphere is 4*pi*r², or 2.827 x 10^23. Multiplying this by 135,000 lumens per m² gives us 3.816 x10^28 lumens, or put another way 38,160 trillion trillion lumens. Of course, this is an approximation, but it gives you some idea of the order of magnitude we're talking about here.

I heard the next release from Luxeon is going to have a similar output.

[LuxLuthor]

Originally Posted by jtr1962

or put another way 38,160 trillion trillion lumens. Of course, this is an approximation, but it gives you some idea of the order of magnitude we're talking about here.

I would have expected much higher.

[dbedit]

So jtr1962 what your really saying is just a bit less than my NLS huh

[PoliceScannerMan]

Originally Posted by LuxLuthor

I would have expected much higher.

Really?? 38,160,000,000,000,000,000,000,000,000 Lumens

That is a lot of lumens!


jtr1962, great post man!! You really know your Science, thats impressive.

[greg_in_canada]

Originally Posted by jtr1962

Working backwards a little, the sun's total output without the earth's atmosphere in the way is about 1350 W/m². About half that is visible light, and the luminous efficacy of the solar spectrum is about 199 lm/W, so we get roughly 135,000 lumens/m². At the distance of the earth's orbit this energy falls on an imaginary sphere with a radius of 150 million kilometers, or 1.5 x 10^11 meters. The surface area of this sphere is 4*pi*r², or 2.827 x 10^23. Multiplying this by 135,000 lumens per m² gives us 3.816 x10^28 lumens, or put another way 38,160 trillion trillion lumens. Of course, this is an approximation, but it gives you some idea of the order of magnitude we're talking about here.

I heard the next release from Luxeon is going to have a similar output.

So if you used 100 lumen Luxeon III's you would need 3.8 x 10^26 of them. I don't know their weight but let's guess 1 gram. So that would be 3.8 x 10^23 kg of luxeons.

According to google the earth's mass is about 6x10^24 kg (= 60 x 10^23). So you only need 6.3% of the mass of the earth in Luxeon's to match the sun's output. The heatsinking and power supply might be a deal-breaker though

Greg

[CLHC]

If a pinhead sized piece of the sun's core could be placed here on earth—well we can't get within ninety (90) miles of it. That HOT! and That BRIGHT!

[scaredofthedark]

thanks jtr1962 i suspect you have some kind of engineering degree to know all that physics

[Trashman]

38,160 trillion trillion lumens? If it is indeed written like PSM had it, that'd be 38 octillion, 160 septillion lumens!

[3rd_shift]

Well, that's our own little cordless star doing all that.
What about other stars in just the milky way alone?
There must be some better "binned" ones out there without that *V1* tint we gotta put up with literally every day.

[LEDcandle]

Originally Posted by jtr1962

Working backwards a little, the sun's total output without the earth's atmosphere in the way is about 1350 W/m². About half that is visible light, and the luminous efficacy of the solar spectrum is about 199 lm/W, so we get roughly 135,000 lumens/m². At the distance of the earth's orbit this energy falls on an imaginary sphere with a radius of 150 million kilometers, or 1.5 x 10^11 meters. The surface area of this sphere is 4*pi*r², or 2.827 x 10^23. Multiplying this by 135,000 lumens per m² gives us 3.816 x10^28 lumens, or put another way 38,160 trillion trillion lumens. Of course, this is an approximation, but it gives you some idea of the order of magnitude we're talking about here.

I heard the next release from Luxeon is going to have a similar output.

Does the heatsink have to be the size of the Earth's core?

[jtr1962]

Originally Posted by LEDcandle

Does the heatsink have to be the size of the Earth's core?

More likely the size of a red giant to effectively dissipate the heat for a mass of Luxeons equal to 6.3% of the Earth's mass. BTW, the sun's output from my calculations is roughly 3.8 x 10^26 watts. 3.8 x 10^26 luxeons at about 3 watts power each would need 1.14 x 10^27 watts to power them, or about 3 times the entire solar output. That idea might be feasible if you put a Dyson sphere around a star putting at least 10 times as much power as the sun and cover it entirely with the best solar cells. You would certainly get the power you need. As already surmised, heatsinking becomes problematic. On your side is the fact that space is cold, huge, and with little gravity (except near planets or stars), so you could rig up a heat sink with huge surface area and not too much supporting mass.

Why anyone would want to actually use Luxeons to replace a star is beyond me given that you would need a star (or its equivalent) to power the array anyway. Logistically it would probably be easier to just tow a star to wherever you needed heat or light, but that's another thread entirely.

[jtr1962]

Originally Posted by scaredofthedark

thanks jtr1962 i suspect you have some kind of engineering degree to know all that physics

BSE, major electronics engineering, from the same school Albert Einstein taught at (let's see how many people know that bit of trivia). No, I'm not old enough to have actually met him.

[nemul]

38 octillion lumens

[Lit Up]

Originally Posted by jtr1962

BSE, major electronics engineering, from the same school Albert Einstein taught at (let's see how many people know that bit of trivia).

*smacks buzzer*

What is Princeton, Alex?

[The_LED_Museum]

Originally Posted by 3rd_shift

...What about other stars in just the milky way alone?...

The Sun is a type G main sequence yellow dwarf star; if you measured lumens from a type O blue supergiant star, I'm pretty certain those values would increase substantially.

[carrot]

o/~ The sun is a mass of incandescent gas; A gigantic nuclear furnace; Where hydrogen is built into helium; At a temperature of millions of degrees. The sun is hot, the sun is not; A place where we could live; But here on Earth there'd be no life; Without the light it gives. o/~

[CLHC]

I'm no astro-physicist or the like, but I found this interesting link. Maybe ya'll know about it.

http://www.sec.noaa.gov/Curric_7-12/Activity_4.pdf

[dfred]

Originally Posted by The_LED_Museum

The Sun is a type G main sequence yellow dwarf star; if you measured lumens from a type O blue supergiant star, I'm pretty certain those values would increase substantially.

Yes, but you don't get particularly good runtime with this kind of output. Not much good if you're trying to give a solar system enough time to evolve life -- plus the extreme UV output isn't too helpful either. For shorter tasks, or simply showing off to friends, a blue supergiant might make sense.

[nemul]

Originally Posted by dfred

Yes, but you don't get particularly good runtime with this kind of output. Not much good if you're trying to give a solar system enough time to evolve life -- plus the extreme UV output isn't too helpful either. For shorter tasks, or simply showing off to friends, a blue supergiant might make sense.

lmao good one

[lightlust]

Yes, the sun puts out a lot of lumens.

But what about its lousy 14 billion year runtime?

Where the heck am I gonna get all the hydrogen nuclei I need to get this thing running again? All I have left in the battery drawer are AA's.

[zespectre]

I want to thank everyone for this thread. I had a terrible day and was sorely in need of a good bellylaugh!

Thank you all VERY MUCH!

[CLHC]

And you Sir are Very Much Welcome! ! !

[greg_in_canada]

Originally Posted by lightlust

Yes, the sun puts out a lot of lumens.

But what about its lousy 14 billion year runtime?

Where the heck am I gonna get all the hydrogen nuclei I need to get this thing running again? All I have left in the battery drawer are AA's.

Store your extra hydrogen in the fridge (or freezer) to extend its shelf-life

Greg

[Lit Up]

Originally Posted by lightlust

Yes, the sun puts out a lot of lumens.

But what about its lousy 14 billion year runtime?

Hahaha

What's worse is we can't say with certainty just how much of that 14 billion has already been spent.

[WAVE_PARTICLE]

Now all we need is a giant reflector and an HA-3 hard anodized body.

[Luna]

Originally Posted by Amonra

that should be relatively easy.......just pop it into an integrating sphere

I think we can just use the lightbox apparatus and multiply by 1.4

[Lmtfi]

Twice as much as half of it.