Here, information. I went and took 5 pictures, true daylight, LED neutral, LED cool, LED warm, and mixed LED neutral/cool/warm, of my hand and a bundle of colored wires (rescued from the side of the road, a snow plow tore this out from somewhere and made a mess of it). All at ISO 100, all at "Cloudy" White Balance, let the camera pick aperture and shutter. A bit half-assed, but I think it supports both our claims. Cool white, not soo good for white/yellow. Warm white, not so good for orange/red/brown. Mix them up, it's pretty good, in a pinch, "neutral" is not bad.
But nothing beats daylight.
I suppose, for completeness, I should repeat the experiment other other light bulbs of various sorts. We've got some halogens kicking around.
It's not just phosphor excitation -- apparently (says a physicist I once carpooled to a ski-trip with) it is wavelength multipliers, and the shape of the originally emitted spectrum makes a difference. Ionized-gas lights generate light at a handful of specific frequencies, period. You look at a CFL through a diffraction grating, you multiple different-colored images of the light -- like 5, or 8, and that's it.. An LED, for whatever reason, produces light in a continuous little (bell-?) curve of frequencies centered on "the color" of the LED. Multiply out those wavelengths, you get a bigger smear.
Which is to say, the spectrum is flatter than you think it is already, and if you mix the color temps (like I do) it gets flatter yet (CFL spectrum is a small set of spikes, so it's hard to image that it could ever be "flat"). High-color-temp LEDs have the worst CRI and the least-flat spectrum of the bunch, and are missing a lot down in the yellow-red range (as you discovered). As long as you are using flashlights as your example LED, you will always be disappointed, because the best ones use cool-white (high lumen) LEDs, and the worst ones use really crappy cool-white LEDs. Or to put it differently, the existence of crappy LEDs does not prove the non-existence of good ones. I've got no financial interest in this, I started out doing it for bicycle illumination, and eventually got brave enough to use them indoors. And again -- cool white, is for flashlights, or to blue-up the mix.
And apropos of nothing, except for spectrum trivia -- amber LEDs (the low beams on my bicycle) don't illuminate dog eyeballs, at least not well enough to be seen by humans.
Looks like a maybe-so -- I'd like to know the source of the LEDs. The efficiency suggests it is generation N-2 LEDs, meaning they are flying cheap, so I would very much like to see the color curves on them. And again (as I said in some other comment) avoid the high color temperatures for indoor use.
Okay, so your problem is, all those flashlights, are using very high color temperature LEDs, because those maximize "lumens" (a human-weighted measure) and maximize your nighttime binary (see it/don't) vision. DON'T USE THOSE INDOORS! (or use them sparingly). I tried some experimentally in one place, it looked like a dadgum welding torch. If you copy my project properly, you won't use more than 33% cool white LEDs, and you'll (probably) be happy enough with the light that you'll think about doing it somewhere else.
I'll admit that LEDs are not as smooth as blackbody, but they are in an entirely different category from CFLs. Get out a diffraction grating, look at a CFL through it. You won't see a brighter-dimmer smear rainbow smear of the light; you will see about 6, differently colored, copies of the light source. White LEDs tend to have a blue spike, embedded in a fat smear. Mix your color temperatures, and you get overlapping smears. My wife (who has plenty-good color sense) complains about CFLs; she does not complain about mixed arrays of white LEDs.
Problem is I deal primarily in home-made. I'm going to go see if I can spot the frequency on the ones I have downstairs (I have a cheap solid-state scope; it can see 120Hz, that's for sure). I looked, whatever it is, the ripple is too low, and the frequency too high, so you damn sure cannot see it with your puny human eyes.
So, the problem #1 is, I would not trust anything made with a truck load of those itty-bitty discrete LEDs. There's a world of snake oil salesmen out there. Problem #2 is, good stuff is not cheap. Problem #3, retrofitting into a bulb socket is a PITA, because bulbs are often in confined spaces, and though LEDs don't emit a lot of heat, they emit some, and they hate it very much (bad for efficiency, bad for lifetime, bad for light output). I think LEDs will come into their own when people just build them in; given that they last 30,000 hours if run hard (1 Amp, e.g., for the typical power LED) or 70-100,000 hours if they are run easy (350 mA), in many cases you ought to just assume they are semi-permanent.
There's a comment by me (out of several) somewhere in this article with 2 links to my blog, one of them shows most of the construction steps for a 9 LED (11 watts at the wall) set of undercabinet lights -- about 860 well-directed lumens. Materials cost is $100, which is pretty high for equivalent of a 60-Watt bulb. If electricity is $.20/kWH, the savings are about $.01/hour (50WH = 1/20 kWH). Breakeven is 10,000 hours. What makes it more acceptable, is that lights that go under cabinets are usually expensive or crappy, or both.
Since LEDs are DC, there's no particular reason for them to have ANY flicker. Perhaps ultra-cheap ones use some circuit that flickers, but not the ones I've seen. They're typically driven by switch power supplies, with ripple below 10%, at frequencies well in excess of 100kHz.
It's possible that the point source of light (for LEDs) could be doing you in (I have a friend who has migraines triggered that way) which means you need to shield them and use indirect lighting, or use some sort of diffuser.
Problem is, the consumer is an idiot, if the consumer thinks that the heat from a light bulb, is a good source of heat. Using electricity for resistive heating isn't a crime, but it ought to be. My 60-year-old oil-fired furnace is 2-3x as efficient (according to the service tag) at converting fuel into heat, as a lightbulb, because you lose the majority (maybe 2/3) of the energy in fuel used for electric generation either at the plant or in distribution. That's ok if you're going to do something electrical, mechanical, or otherwise interesting with the electricity, but to convert it back to heat, without using a heat pump? That's an atrocity.
Is this monochromatic? (hint: I used a diffraction grating to help you get the correct answer)
http://gallery.me.com/dr2chase#100277/LEDSpectrum
These are three different Luxeon Rebel LEDs, driven at 350mA, I believe the color temperatures are 3000K, 4000K, and 5000K.
Still not as cheap as I would like, but coming down (cheaper than before) and the light is creeping up. Another good choice is Cree; I have 9 last-gen Cree neutral-whites (4000K, I think) in my kitchen under the cabinets, and they look good there, too. As long as I am blogwhoring (since I just went and took these pictures to give a proper reply for you, I think I am entitled), here:
http://dr2chase.wordpress.com/2011/02/20/undercabinet-lights-basement-kitchen/ (used for the picture above, mixed spectrum)
http://dr2chase.wordpress.com/2008/10/19/more-undercabinet-lights/ (all neutral white, an earlier effort)
Note that these are "do not look at LED with remaining eye" grade lights.
I have never heard of this, and I grew up in an orange grove, and my great grandfather was a citrus grower. The tools used to warm fruit in Florida are: burning tires (no longer legal, made for a beautiful purple sunrise), burning fuel oil, spraying water (70 degrees, out of the ground; it's hard to imagine resistive heating being competitive against that), and mixing air with fans (most freeze are still air on a clear night, and as little as a sheet thrown over a plant will protect it from the cold).
Do you really know of citrus growers who do this? The fact that you call them "farmers" makes me think your info is 2nd or 3rd hand.
There's also a dimmable controller for LEDs -- http://www.national.com/pf/LM/LM3445.html . Someone must be using them in something we can buy. In my copious free time, I hope to use one to build a couple of custom LED controllers for two lights in our house that are dimmable, and need to be dimmable.
There's prudence, and there's fault. Most times, when a car hits a pedestrian, it is the driver's fault. Drivers have the option to slow down whenever they see a pedestrian near the road, and if they don't, it's their choice that made them "unable to stop in time". And if conditions make them unable to see, then they can slow down for that, too.
This blame-the-victim shit drives me nuts. A car is a great huge comfy armored motorized chair, with climate control and music. What's wrong with slowing to a prudent speed whenever it looks like something bad could happen? It's not like you are suffering while you wait.
No. Fucking no. Oncoming traffic should be paying attention. If your first priority when driving is not "DON'T HIT PEOPLE", then you are doing it wrong. If there's a car stopped, there might be a person you can't see. And if the car is stopped in a funny place or funny way, be even more prepared.
And given all the other crazy interlocking defenses our bodies have evolved over the years, if it were "simple", random chance should have stumbled across it over time, and THAT would spread through the population because it confers a survival advantage for your family/tribe. If there is a silver bullet, it will be something so wacky or foreign that it is truly improbable, even given the long history of evolution and genetic roulette.
Not so sure. The thorium fanatics have got me interested in trying that experiment. PITA to get fission bombs out of it, though I suppose dirty bombs are an option (the waste is contaminated with a short-lived hard gamma emitter).
I am pretty sure there are other provisions that make it difficult for them to jack up rates. Other countries (Germany, Switzerland) deliver universal care in the same way. It's the most expensive way to deliver universal care, but that's what our "fiscally responsible" conservative legislators decided was best, jerks. As for what universal care is for, pretty much everything. That is what works in all the other countries, that spend less than we do, most of them with longer lifespans, more healthy years, and lower infant mortality. I see no reason to innovate or theorize about what people "should" do, given how horrible our current system is, we should simply copy some other country's system. We are NOT the experts, and we should quit pretending that we know what we are talking about with all our moralizing and free-market prattle, and we should learn from what works in other countries.
Believe it or not, I think the answer to "how can I travel without a car" is supposed to be (a) you can buy a bus ticket and/or (b) bicycles. There are interstates out west, I am told, where bicycles ARE allowed (unlike most places) because of precisely the access problem you describe (*). And as you note, this is clearly a conditional right -- so what's wrong with one more condition, if it serves a public good?
Recall that cars have been in wide use for only about a century, and my grandmother never got a license. Lots of people are too disabled to drive (blind, e.g.) or ought to be (dementia), or are too young, or never learned, or cannot afford the expense.
(*) Whether this has any bearing on attempts to require license, registration, insurance, tags, etc for bicycles, I leave for real lawyers to argue.
Try calling your boss and telling him/her that you will be unable to make it in because you are a little sleepy and can't drive.
It depends. New parent, people tend to cut you a lot of slack. Make a habit of it, maybe not. And depending on the job, he might not want you there anyway. Are there really no other choices for getting there? I can ride my bike (*), I can walk or bike to transit and take the bus (slower than biking, but it's an option), I can perhaps carpool, I can take a cab.
I think, also, that we need to be careful to define our terms. According to the Wikipedia BAC charts, and my experience with how I feel after drinking, I am in no mood to drive at 0.04% BAC (not exactly happy at 0.02, either). I've been that tired, but it takes serious lack of sleep, not just up a little late reading a good book.
(*) Not necessarily the safest for me, but I won't hurt anyone else, which makes it a more responsible choice, right?
My understanding of what it takes to get me to 0.08% (100 kilos, drink a couple of beers a day, for medicinal purposes, of course) tells me that I don't want people driving at that blood alcohol level. It takes four beers to get me to 0.08 (says Wikipedia); if I have two, I'm not driving, not till I have sat for a while to digest it. This is not "just like being sick" or "just like being tired" -- this is really impaired.
I am pretty well stunned to see, again and again and again, excuses for careless driving. I see enough bad driving from allegedly sober people (tailgating, in the dark, in the rain, with two lanes to the left someone could use to pass, and best of all, grabbing the steering wheel at the top, so that if that airbag goes off, there will definitely be broken bones), we don't need to liquor them up on top of that.
Slashdot Mirror
Here, information. I went and took 5 pictures, true daylight, LED neutral, LED cool, LED warm, and mixed LED neutral/cool/warm, of my hand and a bundle of colored wires (rescued from the side of the road, a snow plow tore this out from somewhere and made a mess of it). All at ISO 100, all at "Cloudy" White Balance, let the camera pick aperture and shutter. A bit half-assed, but I think it supports both our claims. Cool white, not soo good for white/yellow. Warm white, not so good for orange/red/brown. Mix them up, it's pretty good, in a pinch, "neutral" is not bad.
But nothing beats daylight.
I suppose, for completeness, I should repeat the experiment other other light bulbs of various sorts. We've got some halogens kicking around.
http://gallery.me.com/dr2chase#100285
It's not just phosphor excitation -- apparently (says a physicist I once carpooled to a ski-trip with) it is wavelength multipliers, and the shape of the originally emitted spectrum makes a difference. Ionized-gas lights generate light at a handful of specific frequencies, period. You look at a CFL through a diffraction grating, you multiple different-colored images of the light -- like 5, or 8, and that's it.. An LED, for whatever reason, produces light in a continuous little (bell-?) curve of frequencies centered on "the color" of the LED. Multiply out those wavelengths, you get a bigger smear.
Which is to say, the spectrum is flatter than you think it is already, and if you mix the color temps (like I do) it gets flatter yet (CFL spectrum is a small set of spikes, so it's hard to image that it could ever be "flat"). High-color-temp LEDs have the worst CRI and the least-flat spectrum of the bunch, and are missing a lot down in the yellow-red range (as you discovered). As long as you are using flashlights as your example LED, you will always be disappointed, because the best ones use cool-white (high lumen) LEDs, and the worst ones use really crappy cool-white LEDs. Or to put it differently, the existence of crappy LEDs does not prove the non-existence of good ones. I've got no financial interest in this, I started out doing it for bicycle illumination, and eventually got brave enough to use them indoors. And again -- cool white, is for flashlights, or to blue-up the mix.
And apropos of nothing, except for spectrum trivia -- amber LEDs (the low beams on my bicycle) don't illuminate dog eyeballs, at least not well enough to be seen by humans.
Looks like a maybe-so -- I'd like to know the source of the LEDs. The efficiency suggests it is generation N-2 LEDs, meaning they are flying cheap, so I would very much like to see the color curves on them. And again (as I said in some other comment) avoid the high color temperatures for indoor use.
Okay, so your problem is, all those flashlights, are using very high color temperature LEDs, because those maximize "lumens" (a human-weighted measure) and maximize your nighttime binary (see it/don't) vision. DON'T USE THOSE INDOORS! (or use them sparingly). I tried some experimentally in one place, it looked like a dadgum welding torch. If you copy my project properly, you won't use more than 33% cool white LEDs, and you'll (probably) be happy enough with the light that you'll think about doing it somewhere else.
I'll admit that LEDs are not as smooth as blackbody, but they are in an entirely different category from CFLs. Get out a diffraction grating, look at a CFL through it. You won't see a brighter-dimmer smear rainbow smear of the light; you will see about 6, differently colored, copies of the light source. White LEDs tend to have a blue spike, embedded in a fat smear. Mix your color temperatures, and you get overlapping smears. My wife (who has plenty-good color sense) complains about CFLs; she does not complain about mixed arrays of white LEDs.
Problem is I deal primarily in home-made. I'm going to go see if I can spot the frequency on the ones I have downstairs (I have a cheap solid-state scope; it can see 120Hz, that's for sure). I looked, whatever it is, the ripple is too low, and the frequency too high, so you damn sure cannot see it with your puny human eyes.
So, the problem #1 is, I would not trust anything made with a truck load of those itty-bitty discrete LEDs. There's a world of snake oil salesmen out there. Problem #2 is, good stuff is not cheap. Problem #3, retrofitting into a bulb socket is a PITA, because bulbs are often in confined spaces, and though LEDs don't emit a lot of heat, they emit some, and they hate it very much (bad for efficiency, bad for lifetime, bad for light output). I think LEDs will come into their own when people just build them in; given that they last 30,000 hours if run hard (1 Amp, e.g., for the typical power LED) or 70-100,000 hours if they are run easy (350 mA), in many cases you ought to just assume they are semi-permanent.
There's a comment by me (out of several) somewhere in this article with 2 links to my blog, one of them shows most of the construction steps for a 9 LED (11 watts at the wall) set of undercabinet lights -- about 860 well-directed lumens. Materials cost is $100, which is pretty high for equivalent of a 60-Watt bulb. If electricity is $.20/kWH, the savings are about $.01/hour (50WH = 1/20 kWH). Breakeven is 10,000 hours. What makes it more acceptable, is that lights that go under cabinets are usually expensive or crappy, or both.
Since LEDs are DC, there's no particular reason for them to have ANY flicker. Perhaps ultra-cheap ones use some circuit that flickers, but not the ones I've seen. They're typically driven by switch power supplies, with ripple below 10%, at frequencies well in excess of 100kHz.
It's possible that the point source of light (for LEDs) could be doing you in (I have a friend who has migraines triggered that way) which means you need to shield them and use indirect lighting, or use some sort of diffuser.
Problem is, the consumer is an idiot, if the consumer thinks that the heat from a light bulb, is a good source of heat. Using electricity for resistive heating isn't a crime, but it ought to be. My 60-year-old oil-fired furnace is 2-3x as efficient (according to the service tag) at converting fuel into heat, as a lightbulb, because you lose the majority (maybe 2/3) of the energy in fuel used for electric generation either at the plant or in distribution. That's ok if you're going to do something electrical, mechanical, or otherwise interesting with the electricity, but to convert it back to heat, without using a heat pump? That's an atrocity.
Thus far, you need to build your own. See below for details, pictures, links.
If you want something dimmable, that's a bit more work (more DIY than I have done yet, but it is on my list, they make the controllers).
Is this monochromatic? (hint: I used a diffraction grating to help you get the correct answer)
http://gallery.me.com/dr2chase#100277/LEDSpectrum
These are three different Luxeon Rebel LEDs, driven at 350mA, I believe the color temperatures are 3000K, 4000K, and 5000K. Still not as cheap as I would like, but coming down (cheaper than before) and the light is creeping up. Another good choice is Cree; I have 9 last-gen Cree neutral-whites (4000K, I think) in my kitchen under the cabinets, and they look good there, too. As long as I am blogwhoring (since I just went and took these pictures to give a proper reply for you, I think I am entitled), here:
http://dr2chase.wordpress.com/2011/02/20/undercabinet-lights-basement-kitchen/ (used for the picture above, mixed spectrum)
http://dr2chase.wordpress.com/2008/10/19/more-undercabinet-lights/ (all neutral white, an earlier effort)
Note that these are "do not look at LED with remaining eye" grade lights.
I have never heard of this, and I grew up in an orange grove, and my great grandfather was a citrus grower. The tools used to warm fruit in Florida are: burning tires (no longer legal, made for a beautiful purple sunrise), burning fuel oil, spraying water (70 degrees, out of the ground; it's hard to imagine resistive heating being competitive against that), and mixing air with fans (most freeze are still air on a clear night, and as little as a sheet thrown over a plant will protect it from the cold).
Do you really know of citrus growers who do this? The fact that you call them "farmers" makes me think your info is 2nd or 3rd hand.
There's also a dimmable controller for LEDs -- http://www.national.com/pf/LM/LM3445.html . Someone must be using them in something we can buy. In my copious free time, I hope to use one to build a couple of custom LED controllers for two lights in our house that are dimmable, and need to be dimmable.
Or use LEDs. Brighter, when colder.
Works for me, too. To quote a favorite blog, Gaddafi is Arabic for Ceausescu. Strafe your citizens, do not pass go, do not get a jury trial.
And if you regularly exercise that 120dB dynamic range, you won't have it for very long.
There's prudence, and there's fault. Most times, when a car hits a pedestrian, it is the driver's fault. Drivers have the option to slow down whenever they see a pedestrian near the road, and if they don't, it's their choice that made them "unable to stop in time". And if conditions make them unable to see, then they can slow down for that, too.
This blame-the-victim shit drives me nuts. A car is a great huge comfy armored motorized chair, with climate control and music. What's wrong with slowing to a prudent speed whenever it looks like something bad could happen? It's not like you are suffering while you wait.
No. Fucking no. Oncoming traffic should be paying attention. If your first priority when driving is not "DON'T HIT PEOPLE", then you are doing it wrong. If there's a car stopped, there might be a person you can't see. And if the car is stopped in a funny place or funny way, be even more prepared.
That's why I said family/tribe. We live "too long" as is; I'm assuming that there's some advantage to having your grandparents kicking around.
And given all the other crazy interlocking defenses our bodies have evolved over the years, if it were "simple", random chance should have stumbled across it over time, and THAT would spread through the population because it confers a survival advantage for your family/tribe. If there is a silver bullet, it will be something so wacky or foreign that it is truly improbable, even given the long history of evolution and genetic roulette.
Not so sure. The thorium fanatics have got me interested in trying that experiment. PITA to get fission bombs out of it, though I suppose dirty bombs are an option (the waste is contaminated with a short-lived hard gamma emitter).
I am pretty sure there are other provisions that make it difficult for them to jack up rates. Other countries (Germany, Switzerland) deliver universal care in the same way. It's the most expensive way to deliver universal care, but that's what our "fiscally responsible" conservative legislators decided was best, jerks. As for what universal care is for, pretty much everything. That is what works in all the other countries, that spend less than we do, most of them with longer lifespans, more healthy years, and lower infant mortality. I see no reason to innovate or theorize about what people "should" do, given how horrible our current system is, we should simply copy some other country's system. We are NOT the experts, and we should quit pretending that we know what we are talking about with all our moralizing and free-market prattle, and we should learn from what works in other countries.
Thankfully, under Obamacare, that's not legal.
If they can't kick you to the curb, they've got to try Plan B, which is improving your health before you cost them money.
Believe it or not, I think the answer to "how can I travel without a car" is supposed to be (a) you can buy a bus ticket and/or (b) bicycles. There are interstates out west, I am told, where bicycles ARE allowed (unlike most places) because of precisely the access problem you describe (*). And as you note, this is clearly a conditional right -- so what's wrong with one more condition, if it serves a public good?
Recall that cars have been in wide use for only about a century, and my grandmother never got a license. Lots of people are too disabled to drive (blind, e.g.) or ought to be (dementia), or are too young, or never learned, or cannot afford the expense.
(*) Whether this has any bearing on attempts to require license, registration, insurance, tags, etc for bicycles, I leave for real lawyers to argue.
Try calling your boss and telling him/her that you will be unable to make it in because you are a little sleepy and can't drive.
It depends. New parent, people tend to cut you a lot of slack. Make a habit of it, maybe not. And depending on the job, he might not want you there anyway. Are there really no other choices for getting there? I can ride my bike (*), I can walk or bike to transit and take the bus (slower than biking, but it's an option), I can perhaps carpool, I can take a cab.
I think, also, that we need to be careful to define our terms. According to the Wikipedia BAC charts, and my experience with how I feel after drinking, I am in no mood to drive at 0.04% BAC (not exactly happy at 0.02, either). I've been that tired, but it takes serious lack of sleep, not just up a little late reading a good book.
(*) Not necessarily the safest for me, but I won't hurt anyone else, which makes it a more responsible choice, right?
My understanding of what it takes to get me to 0.08% (100 kilos, drink a couple of beers a day, for medicinal purposes, of course) tells me that I don't want people driving at that blood alcohol level. It takes four beers to get me to 0.08 (says Wikipedia); if I have two, I'm not driving, not till I have sat for a while to digest it. This is not "just like being sick" or "just like being tired" -- this is really impaired.
I am pretty well stunned to see, again and again and again, excuses for careless driving. I see enough bad driving from allegedly sober people (tailgating, in the dark, in the rain, with two lanes to the left someone could use to pass, and best of all, grabbing the steering wheel at the top, so that if that airbag goes off, there will definitely be broken bones), we don't need to liquor them up on top of that.