What Will The Future Bring?

[guiri]

The definitions of lumen and watt are fixed, as are the conversions. It is not open for debate and it is not a matter of what we know and don't know, it just is.

Again, says who?

Bet that might change 100 years from now but again, I'm just speculating and NOT making claims

 

[SemiMan]

They are definitions.... we as HUMANS define them as what they are. This is not a case where we say the world is flat because we don't know any better or that the earth is the center of the universe. This is more like UP is UP and DOWN is DOWN. They are simply definitions and as such as not disputable. There is a conversion factor between watts and lumens at a given frequency of light. Again, this is a definition.... not really up for debate, but potentially refinement as the CIE curve which defines the conversion has changed. To that end you will never get more than 683 lumens/watt ... ever... as that is what the definition allows.

There are some "arguments" that people use against this, but they are wrong:

1) I put in 0.2watts and through some magic process (call it cold fusion), the equivalent of 10 watts of light comes out.... the reality is that while you may be putting in 0.2watts through some external source, some other mechanism, (call it cold fusion) is generating another 9.8 (or 10) watts of energy. You are not magically getting more than the theoretically maximum lumens/watt, you are generating extra power through another mechanism.

2) Increase in perceived brightness. There has been a lot of research that shows that pulsing LEDS at a specific duration and repetition can make LEDs be perceived as brighter than the amount of "total light emitted". This is absolutely true....running continous with power X may generate Y lumens but pulsed with power X may be PERCEIVED to be 2Y lumens. Again, it is PERCEIVED. The definition did not change. Is it "brighter"... as far as anyone that is looking at it, of course it is. But the definition of watt and lumen did not change.

Does that make it any clearer?

 

[maxa beam]

Batteries are advancing so fast it's not even funny, we have good enough batteries to run cars now. (Google Tesla roadster.)

So I don't see them as an issue. Here's how I think advances will go as far as LEDs.

1: 200-300ish lumen per watt cap. Improved energy loss form heat.
2: Improved color tempurature, along with improved thermal efficiency.
3: Manufacturers start working on variable wavelength.
4: Smaller LEDs get brighter?

Imagine a small, single-die LED with 250 lumens per watt and no real need for a heatsink, along with multiple wavelengths and enormous run-time.

 

[guiri]

Does that make it any clearer?

Well, kinda. I just still think that 100 years from now if we are still alive, things are going to be very different and a lot of stuff scientists took for granted or as absolute or definite will change but again, that's my opinion and as such is not absolute either

 

[guiri]

Imagine a small, single-die LED with 250 lumens per watt and no real need for a heatsink, along with multiple wavelengths and enormous run-time.

At this point, I would trade output, or rather, more future output for longer runtime. Lights are basically bright enough to do just about anything practical but we need more runtime.

I would love to have a light that will give me 1000's of hours on low. You know, if you get stuck in the wilderness or a deserted island or something.

 

[maxa beam]

At this point, I would trade output, or rather, more future output for longer runtime. Lights are basically bright enough to do just about anything practical but we need more runtime.

I would love to have a light that will give me 1000's of hours on low. You know, if you get stuck in the wilderness or a deserted island or something.

No, LED lights aren't. When a LED light can out-throw and out-perform the Maxablaster is the day I say LEDs are done with brightness. You can't signal a boat miles away with a low-low.

 

[guiri]

Well, no, but you can have one that you can switch to low for all your normal uses and when you really need it, you can switch it into high gear for signaling or blinding someone.

Bottom line is, in really dark woods, I don't need much output but if I'm there for a week, it would be comforting to be able to use it when you need it and face it, if you're stuck on an island like tom hanks, you need 3 years worth of output

 

[jtr1962]

Bottom line is, in really dark woods, I don't need much output but if I'm there for a week, it would be comforting to be able to use it when you need it and face it, if you're stuck on an island like tom hanks, you need 3 years worth of output

In the desert island situation, you just need a solar powered rechargeable light with enough runtime to get you through a few cloudy days.

Well, kinda. I just still think that 100 years from now if we are still alive, things are going to be very different and a lot of stuff scientists took for granted or as absolute or definite will change but again, that's my opinion and as such is not absolute either.

The converse of that is how many things which were absolute 300 years ago still are today. The Earth is round, it orbits the sun, etc. Trust me, the limit on lumens per watt is absolute. The only way we'll get around that is if we change the definition of lumen because the human eye sensitivity changes. Fat chance of that happening on anything less than a geological time scale. And regardless of how lumens are defined, the ultimate conversion efficiency of an LED can't ever exceed 100%. If it did, then by definition it would be generating energy by some internal mechanism. This energy would have to come at the expense of lost mass so it couldn't continue forever. A good analogy here is using a tiny electric spark to detonate tons of expelosive. You could in a manner of speaking say the spark liberated more energy than it consumed, but the fact is it was just a catalyst for the larger explosion. Same thing with a hypothetical >100% efficient LED. It wouldn't be >100% efficient. The power input would merely be a catalyst for some other form of energy release. In short, you can't get something for nothing. People have tried for years to push such perpetual motion machines. They're always frauds as they violate basic tenets of physics.

 

[guiri]

Well, I didn't know/understand that the previous numbers meant 100%, if I had, then I would have felt differently but regardless of the LED's or anything else, I still think that in the future, some of the laws of physics as we know them might change although I don't expect to be around for that

Thanks for the explanation

 

[Burgess]

Re: What Will The Future Bring?



And maybe . . . .


Just MAYBE . . . .



Mag Instrument will finally get their act together,

and give the world a nice line of LED flashlights.



We can always Dream, can't we ? ? ?

:sleepy:
_

 

[guiri]

and boy are they behind..