Photonic Structure Increases Light Bulb Efficiency 226
An Anonymous Coward writes "A new experimental microscopic tungsten lattice
can increase the efficiency of an incandescent
electric bulb from 5 percent to greater than
60 percent. This is done by converting waste
heat into visible light. "
Question (Score:2, Troll)
Re:Question (Score:3, Funny)
Second, I love this. They don't even have a THEORY on why this works. It just does.
Third, If they get it working in the visible light spectrum, they'll have a bulb that's SIXTEEN time more powerful than tungsten bulb.
That's one hell of a flashlight. I'll call mine "Little Boy". I promise to only use it in self defense. And to start small fires.
Re:Question (Score:5, Informative)
Well, I'm an undergraduate Electrical Engineer, so I only have superficial understandings of how semi-conductors interact with light, but it doesn't seem too great a stretch of the imagination.
First, semi-conductors work based on the principle of the band-gap (which they even mentioned) (correct me if I'm wrong with any of this, I'm doing it straight from rusty memory).
A little background:
The outer 8 electrons held by an atom are the most important (the valence) - They are responsible for the bonding of other atoms. The configuration of all the electron orbitals in free space is nicely geometric; the first two electrons form a spherical shell (s-shell), the second 6 form dumb-bells in each of three axis's (p-shell). These types of configurations affect the geometries of the connection of the atoms. Configurations get more complex as the number of electrons grow (which is somewhat independent of the atomic number (number of protons), but such ionized atoms are unstable; especially when the number of electrons differs dramatically from the #protons). The important thing to understand here is that each additional electron takes more energy. Instead of worrying about the geometries, you can plot each electron orbital at a different (successively higher) energy level. Different atoms (characterized by atomic-number and even, to a small degree, the number of neutrons present), have differing characteristic energy-levels. The discrete nature of atoms includes the probabilistic nature wherein electrons have an extremely high probability of occupying the exact energy levels (which can be thought of as the distance away from the center of the nucleus). There is a chance that an electron will pass through any point around the shell of an atom, but it's highly unlikely that it will deviate from its characteristic point.
But, since different atoms have different characteristic levels, warping an atom will warp its points. Warping can occur by simply placing two atoms near each other (such as in an ionic or covalent bond). As it happens, when you squeeze atoms closer and closer together, the discrete lines that represent the energy levels start to merge together. Eventually the 8 outer valence bands merge into one continuous band... As you squeeze them even closer together, this band breaks into two continuous pieces. As you get even closer together, these pieces get further and further apart (I would presume that eventually one of these bands starts to merge with preceding energy levels, but that's not relevant here). This gap of continuous energy levels is called the band-gap.
As it turns out, in perfectly bonded atoms (those where every electron in the valence layer are bonded, and each atom has exactly 8 outer electrons; such as carbon, Silicon, etc) we have a total of 4 electrons that fill the inner continuous shell and 4 electrons that are void in the outer continuous shell. BUT, that outer shell is looped across neighboring atoms. When a diamond-lattice is organized (which is as close as you can possible get multiple atoms to sit next to each other), you have the greatest band-gap you can get for that particular element. Different elements (or even molecules) that can form the diamond-lattice will have differing characteristic band-gaps. What we have here are 4 electrons that are tightly tied to a core atom, and 4 potentially absorbed electrons that can freely be shared across every single atom in the entire crystalline lattice. In semi-conductor crystals, the problem is that every electron is accounted for so there are no free electrons to put into the outer band (which could roam free as current through an almost zero-resistance substrate; due mostly to quantum effects). Impurities are therefore inserted into the crystalline lattice which act as ionic donators of electrons or ionic acceptors of electrons (namely atoms not in the 4-column of the periodic table). Thermal excitation (heat) causes an electron to be ripped from donor atoms and those which are then quickly swept up in the outer-most continuous band.
Normally, electrons must have a precise energy-value in order to live in an atomic orbital. When an atom absorbs an electron, it gives off a photon of the remainder of the energy. To change orbital-levels, it has to accept a photon of exactly the correct amount of energy. It can accept a larger energy photon, but it will again give off the remainder of energy. Eventually that excited electron will fall back to its lower energy level, giving off another photon which will have the exact energy as the distance between the two energy levels.
In the continuous region of these silicon atoms, excitation between energy levels isn't apparent, since an electron can have any value within the region. The only difference is that separating the band gap... An electron from the inside can jump into the outer band if it's given at least enough energy to make the jump... This gap is usually enormous for semi-conductors. I believe its 1.2 electron Volts for Silicon, and 10 electron Volts for Carbon. The 1.2V is within the range of thermal excitation. That means that heat (in the form of vibrating atoms in the crystal) is enough to shake an electron free; e.g. jump the gap (like water successfully spitting to the lid of a boiling pot). In carbon, however, room-temperature heat is no where near enough to make the jump. This property (along with others) is why we don't use carbon-based semi-conductors. Germanium and silicon are much more practical in our particular earth climate.
There is another aspect to the band-gap that is relevant to our discussion. Each electron has not only an associated energy, but a quantum-form of momentum. You must not only have conservation of energy, but conservation of momentum. I'm a little fuzzy on this topic, but this momentum is represented by the letter k, and we can plot energy verses k for different things. For semi-conductors, we get parabolas, and inverted parabolas, but with discrete points. This says that while we have a continuous set of energy levels within a region, we have only a certain set of allowable energy+momentum values for the electrons. And like the discrete energy levels of atomic orbitals, you can only have one electron occupying a given state. In a rather unfulfilling way, I'll stop talking about things that I don't fully understand and simply say that this multitude of characteristic parabolas says that in order to have an electron jump, you have to not only have a precise amount of energy absorbed or emitted, but you have to be able to transition your momentum somehow. Energy transition occurs through photons, and momentum transition occurs through phonons - which is energy present in lattice vibrations (e.g. packets of heat).
Gallium arsenide is an example where the lowest point of the upper parabola and the highest point of the lower inverted parabola are aligned with respect to momentum. This means that the smallest amount of energy needed to make an electron jump the gap requires zero change in momentum. Because of this, gallium arsenide crystals easily will easily absorb or emit light with no dependence on the heat of a lattice. For this and other reasons, GaAs is great for laser diodes. Silicon, on the other hand requires a momentum change for its lowest energy transfer. Thus lots of heat is generated and absorbed; (Not to mention that silicon doesn't conduct heat as well as some other semi-conductors).
Given this superficial description, what I get out of this is that heat of a certain resonant point (in the form of vibrating atoms in the crystal) could provide the proper momentum shift needed for efficient electron excitation. You'd still need to provide photonic energy for the transition, but you'd have a perfect combination of heat + light absorption. Eventually (due to statistical decay), the electrons would fall back to their lower-energy-level states. But they'd give off light of specific frequencies.
Putting all this together, my initial impression from the article was that that the tungsten injection into a silicon substrate change the characteristic e-k curves enough to absorb the phonon-heat generated by IR light. The result is a 60% efficient absorption of the heat + light (e.g. nearly perfect efficiency). That energy is retransmitted as diode light (e.g. an exact energy level transition, producing a constant level of energy photons, which requires an equally constant frequency of light).
What I don't know at the moment is if this is actually emitting mono-chromatic light, or if a multitude of frequencies (e.g. white-light) permeates. The only way I could see white-light emitting is if the standard tungsten light-bulb is making it, and the Tungsten semi-conductor is amplifying a particular frequency.
Re:Question (Score:5, Funny)
Britney Spearse Guide to semiconductors [britneyspears.ac]
Re:Question (Score:2)
Yeah, I always wanted a flashlight strong enough to kick when you turn it on...
Re:Question (Score:3, Informative)
I wonder how the matrix holds up as the tungsten evaporates from the filiment?
SD
Re:Question (Score:2, Insightful)
The article leaves a lot of unanswered questions. I suspect the scientists are more interested in the phenomemom than its practicality.
Re:Question (Score:2)
Yeah, I thought of that too. These bulbs would be able to produce the same light running on far less electricity and last practically forever. Guess those florescent bulbs are doomed now.
Re:Question (Score:1)
Re:Question (Score:3, Interesting)
Not that I'm satisfactorily answering your question, but throwing out some food for thought.
-Michael
Blackbodies and greenhouses (Score:2)
I think the greenhouse effect has more to do with absorption than with angle of incidence. Blackbody emission peak wavelength decreases with temperature. The Sun, a 6000 K blackbody, emits visible light, which passes through the windows and is absorbed by the interior. The interior, a 300 K blackbody, emits infrared, which is absorbed by the windows.
In his autobiography, 19th century instrument maker John A. Brashear [clpgh.org] describes a project to make lenses out of salt crystals for an astronomer who wanted to make infrared observations. Salt is supposed to be much more transparent than glass in that band of the spectrum.
Re:Blackbodies and greenhouses (Score:2)
Re:Question (Score:2, Insightful)
I think you'll find operating in the infra-red range was the point - it absorbs what's in the infra-red range, which is good, because that's what you want to get rid of.
The absorbed energy can then be re-emitted at visible wavelengths...
Sorry.. (Score:4, Funny)
Q: How many programmers does it take to change a broken light bulb?
A: None, it's a hardware problem.
Easy Bake (Score:1, Redundant)
Re:Heinlein--YES... (Score:2)
Yes, there's a Heinlein book called The Man who Sold the Moon [wegrokit.com]. It's a collection of Future History stories, with the story "The Man who Sold the Moon" as its "title track".
I've never read it, because I assumed that The Past Through Tomorrow contained all the Future History stories.
Believe it when you see it (Score:1)
The work was performed with a photonic crystal operating in the mid-infrared range, but no theoretical or practical difficulties are known to exist to downsizing the structure into the visible light range.
So, they don't have any theory to explain this, but "theoretically" there won't be any problem turning this into something useful. Yeah, sure.
Or you could just buy a flourescent (Score:2, Insightful)
Re:Or you could just buy a flourescent (Score:3, Informative)
Re: (Score:2)
Re:Or you could just buy a flourescent (Score:2)
I've replaced all my regular bulbs with fluorescent bulbs and there's no perceptible flicker. They have little bits of electronics in the base of the bulb which stops them flickering.
Go read: http://www.fujilite.com/product-features.htm
Re:Or you could just buy a flourescent (Score:3, Informative)
Every flourecent bulb I have seen flickers by almost 100%, and while it is not usually visible unless the bulb is failing, can still cause fatigue.
Much more importantly is that incandecent bulbs have a more natural color spectrum than most flourecents, since they work by black body radiation. I don't know why the "full spectrum" flourecents are not more popular, but they can really make a difference.
Re:Or you could just buy a flourescent (Score:2)
Bull shit, if somebody installs them incorrectly or the mounting is cheap, the damn flouros flicker like a son of a bitch. The ones in my computer room create a strobe light effect that actually fucks up your perception of moving objects. Not to mention is fucking up my eyes more and more every day.
Floros are also HORRID to have around computers, not a good thing, especially if they are in really close proximity.
They also have this shitty ass tinting to them that makes doing any sort of color sensitive work under them suck (not that incan's are much better, but floros have a much worse color distortion problem).
I want a LED light array, oooh yaaah. The higher quality ones are about as close to pure white as you are likely to get, and oh yah, they will likely last you longer then you will live, or at least a significant percentage of that time. Sweet.
Re:Or you could just buy a flourescent (Score:1)
Re:Or you could just buy a flourescent (Score:1)
Re:Or you could just buy a fluorescent (Score:2)
Older fluorescent technologies maybe but the current crop of products in the shops come in different colours and shades of light.
Phillips for instance do a fluorescent bulb which they describe as warm white is the same shape and is only fractionally bigger than a normal bulb. Fits in a standard socket and lasts for, well, 5 years in my case.
The bulbs are still more expensive than normal ones but you save in buying replacements and in electricity costs.
Re:Or you could just buy a fluorescent (Score:2)
http://www.eur.lighting.philips.com/servlets/Ph
Re:Or you could just buy a flourescent (Score:2)
The light from flourescent lamps sucks.
What's ended up happening is that I use the lamps with "normal" bulbs more than the flourescent ones, because the light just annoys me less. I understand that the fluorescent ones are more efficient. That's why I bought the lamps in the first place. The light that they emit, though, is harsh, cold, brittle and annoying. So I find myself avoiding them.
Given that the electricity difference in my monthly bill in negligable, I choose comfort. Until that equation changes, I don't think fluorescent bulbs are going anywhere.
Re:Or you could just buy a flourescent (Score:2)
If this works, then the new incandescents will be 1200% more efficient than normal incandescents. But the article says 60%, you say? It also says that current tungsten filament bulbs work at about 5% efficiency. Thus, .6/.05=12, or 1200%. (Implying, of course, that the efficient flourescent bulbs you refer to are 30% efficient.) I'd like to note, though, that white LED bulbs are also very efficient, and the 144 LED Medium Base Floodlight Bulb listed here [theledlight.com], for example, is (assuming 5% efficiency for its incandescent cousing) 62.5% efficient, or twice as good as its flourescent cousin. It takes only 12 Watts to generate the same as a 150 watt tungsten incandescent.
Re:Or you could just buy a flourescent (Score:2)
And for the low, low price of... $698.00. I'd rather spend $18 on a 24 watt fluorescent which will be just as bright. It would take a long, long time for it to use enough electricity to have made the LED bulb a better deal.
one but... (Score:1)
-- james
Re:one but... (Score:2)
Imagine the efficiency of flourescent lightbulbs without the initial high cost--a lot of people would love to buy such a lightbulb.
Re:one but... (Score:3, Interesting)
Re:one but... (Score:2)
Remember a couple years back when we invented fire? Yeah, that funny little orangish/yellowish glow from the air around the wood, that's kind of the same principle.
Re:one but... (Score:2)
Minus light from the monitor and the whirring sounds, a computer would practically be a perpetual motion machine if you could reclaim all of the heat it generates. Unfortunately, the laws of thermodynamics don't permit full recovery like that.
Re:one but... (Score:2)
You've got entropy working against you.
What they're doing is reducing the effects of entropy by something like blocking undesirable radiation from occurring.
Yeah .. Tungsten.. (Score:2, Interesting)
If you don't belive me read the book "Uncle Tungsten" [barnesandnoble.com].
Great book, a must for anyone remotly intrested
in chemistry or the history of chemistry.
Ok, so it's a shameless plug.. but I just had to push that damn fine book.
Take That! (Score:1)
Re:Take That! (Score:1)
How does this break the law of conservation of energy? The imput equals the output in terms of energy, just it's done in a manner that produces the desired output energy more efficently,andthus reducing the unwatned energy output.
Ode to a Light Bulb (Score:2)
mine heart turns dark for the unmourned waste
when in history we once feared night
and strove to banish it, with undue haste
that good man Edison born forth the device
which only made use of one in twenty
driven by power that which was low in price
and of that juice there would be plenty
now science improves upon that thought
with a tungsten lattice that uses three in five
hidden with answers we long have sought
was the mythic efficiency for which we strive
And nothing remains of that electricity hog
Save twenty-two billion metric tonnes of smog
The real stuff: Nature article (Score:3, Interesting)
Three-dimensional (3D) metallic crystals are promising photonic bandgap structures: they can possess a large bandgap, new electromagnetic phenomena can be explored , and high-temperature (above 1,000 C) applications may be possible. However, investigation of their photonic bandgap properties is challenging, especially in the infrared and visible spectrum, as metals are dispersive and absorbing in these regions. Studies of metallic photonic crystals have therefore mainly concentrated on microwave and millimetre wavelengths. Difficulties in fabricating 3D metallic crystals present another challenge, although emerging techniques such as self-assembly may help to resolve these problems. Here we report measurements and simulations of a 3D tungsten crystal that has a large photonic bandgap at infrared wavelengths (from about 8 to 20 m). A very strong attenuation exists in the bandgap, 30 dB per unit cell at 12 m. These structures also possess other interesting optical properties; a sharp absorption peak is present at the photonic band edge, and a surprisingly large transmission is observed in the allowed band, below 6 m. We propose that these 3D metallic photonic crystals can be used to integrate various photonic transport phenomena, allowing applications in thermophotovoltaics and blackbody emission.
Doesn't this look like some explanation: the material (unlike metals) has a bandgap, i.e., is insulating and cannot absorb or emit radiation at low frequencies. So the energy has to be dissipated at higher (visible) frequencies. Apparently the output is higher than naive calculations would predict. So the puzzle is not why the frequency of the emitted light is so high, but why the output is so strong for a given temperature.
Re:The real stuff: Nature article / Link (Score:1)
Did anybody see the Naked Gun? (Score:2)
To avoid having this fall into the hands of Westinghouse or GE, do not create a company and go public.
...or get an identifiable tatoo on your ass.
It's the only way to save the world.
My obligatory haiku... (Score:3, Interesting)
tungsten evaporating:
produce more photons!
Re:My obligatory haiku... (Score:2)
Try a compact fluorescent
'til you can buy these.
Re:My obligatory haiku... (Score:2)
who with verse did try to attack
my position as king
of this poetry thing
you gotta wonder if he smokes crack
Re:My obligatory haiku... (Score:2)
your panties all wadded up
over my haiku.
100% efficiency (Score:1)
Re:100% efficiency (Score:2)
Think of the children... (Score:5, Funny)
And what about when my daughter finds a birds nest that has fallen out of a tree and we need to fabricate a incubator out of a box and a 25 watt light bulb to keep it warm?
This is horrible news. Think of the children. Call your congressman and ban this insanity.
Re:Think of the children... (Score:2)
It's going to ruin your lava lamp, too, it'd have to be blindingly bright to get the lava going properly.
--
Benjamin Coates
Re:Think of the children... (Score:2)
If only we could clock motherboards up into the frequency of visible light. Then we could use Rack Lighting for illumination from the stray "RF". (Does it worry anyone else that we're starting to clock motherboards up into microwave frequencies?)
Re:Think of the children... (Score:1)
Re:Think of the children... (Score:2)
The thing is, no one will be buying 60 watt bulbs anymore, since 10 watt new bulbs will put out the same light. Actually, I seriously doubt that old-style bulbs would disappear any time soon - there'll always be a lava lamp and easy-bake oven market for them.
Comment removed (Score:4, Interesting)
Re:60 percent? Oh, My, GOD! (Score:2)
Re:60 percent? Oh, My, GOD! (Score:2)
Cool stuff. Literally.
Projector Bulbs (Score:2, Insightful)
What is amazing is that this is about 3x more efficient than flourescent or High Intensity Discharge lamps! That doesn't quite sound possible... but that is what they are saying!
Re:60 percent? Oh, My, GOD! (Score:2)
Re:Math challenged? (Score:2)
Of course, watts are a measure of consumption, not output. The entire premise of measuring light output via the bulbs power consumption is wrong.
Yes, very true. But try exaplaining that to Joe Sixpack who doesn't even understand the difference and relationship between Joule, Watt and Watt hour.
Joules, Watts. (Score:3, Interesting)
If your target audience uses a calculator to get fifty percent of a hundred, you don't want to inflict our silly Sumerian time scale on them. (Was it the Sumerians who did the base-sixty nonsense? Or was that the Babylonians?)
--grendel drago
Re: (Score:2)
Other uses? (Score:2)
AFAIK, solar cells only use some wavelengths efficiently, other are wasted.
Posible savings? (Score:1)
What part of our total electricity production is going into creating light?
What part of creating light is done with conventional light bulbs?
Are the energy savings of this new type of lamp higher than with current 'green' light-bulbs?
What would the cost offset be compared to conventional lighting? The only thing mentioned is it will be cheap due to the fact that silicon technology production is cheap. How cheap is that compared to conventional light-bulb production? Can't be cheaper.
Does it cost more in waste-processing?
Only if we answer all of these we'll know if this will be cheaper for the total product-life-cycle.
---
Light emitting technology (Score:5, Interesting)
If we extrapolate from the given 5%->60% levels given in the article, that would raise incandescent lights to nearly the levels of flourescent, without the warm-up time flourescent has.
Now, the problem with LED vs. flourescent is cost - LEDs are much more expensive in terms of lumens per doller than flourescent. Would microstructured tungsten be any cheaper?
Re:Light emitting technology (Score:3, Interesting)
Re:Light emitting technology (Score:2)
Re:Light emitting technology (Score:2)
Night vision (Score:3, Insightful)
making flourescent light less harsh... (Score:2)
Economics works against flourescent bulbs... generally you have a choice in sizes, but there aren't any choices in "mood" (soft, tinted, etc).
The answer of course is reflected light, or otherwise hiding the bulb. Lampshades and light bounced off the ceiling works great. Not to mention, these things *greatly* reduce the air conditioner strain during the summer (I used to live without AC, but New England summers are rather hot now.).
It's sad that standard incandescent lightbulbs are not efficency-regulated out of existence. You pay LESS for efficent lighting, if you factor in all the increased energy taxes which come about due to pollution.
Re:making flourescent light less harsh... (Score:2)
- The phosphors on the bulbs have been changed so as to put out a soft "warm" white light just like a regular incandescent bulb. (rather than the traditional "cold" bluish light from the long tube fluorescents.)
- The bulbs been shrunk even futher to fit nearly every type of lamp fixture.
- The bulbs are started with electronic balasts (instead of the old magnetic kinds). This eliminates "flicker" and allows the bulbs to start instantly rather than taking a few seconds to start.
- The life of these bulbs is usually around 10,000 hours (exceedingly longer than the measly 750 to 1,500 hours of most incandescents.)
- Energy Efficiency of most of these bulbs exceeds 75%! (still much better than this "improved" incandescent that this thread is about.)
A small handful of states subsidize purchase of these bulbs. Check out The Energy Guide [energyguide.com] for great deals on Fluorescent bulbs. I've changed all the incandescents in my house to compact fluorescents, and I've knocked at least $10 / month off my electricity bill!
Re:making flourescent light less harsh... (Score:2)
Re:making flourescent light less harsh... (Score:2)
What about LED's? (Score:4, Interesting)
LED's are almost there--and efficiencies are climbing. Main problem right now is that they're expensive. But already, I see they're being used for the red, and, increasingly, the green lights in traffic lights around here.
By the time this stuff makes it out of the lab, LEDs will be cheap and even more efficient than they are now.
And, of course, all the gee-whiz wizards-of-the-labs articles never say how much the new technology is likely to COST. And the stated efficiencies tend to decline as the devices start to approach reality...
If they can really make these things twelve times as efficient as LED's AND give a pleasant, flattering light spectrum AND get the cost down, it will be interesting.
Re:What about LED's? (Score:2)
1) Conventional traffic lights have to be replaced once a year to make sure they are working, whether they have died or not. LED based traffic lights last up to 10 years.
2) Conventional traffic lights use colored glass to filter the broad spectrum light into the desired color, wasting large amounts of the generated light. LED based lights do not require a filter so the power savings are huge.
fyi
Re:What about LED's? (Score:2)
If you look closely, you'll notice that the red lights usually have two bulbs. That way, if one fails, there's still the other one, no need to "pre-emptively" replace bulbs.
Green and yellow have only one bulb, but the potential of damage when these fail is much less (... and the cynical could argue that failure of yellow is actually good for the city finances [slashdot.org])
Re:What about LED's? (Score:2)
getting power from these structures (Score:2)
A breakthrough in solar energy ?
I wonder what the energy density from the sun is in the IR spectrum ?
revolutionary (Score:2, Interesting)
But this is superlatively revolutionary. Take the two possible big-hit applications: massive energy efficiencies coupled with a 20-30% increase in photovotalic efficiency (read: reduced cost) and this is a big step toward alternative energy.
Imagine a mass-produced fuel cells and increased efficiency photovotalics with lighting generated by these things. Who needs a power company?
nice, but no solution to energy problem (Score:3, Insightful)
Re:nice, but no solution to energy problem (Score:2)
So this technology is a possible solution to the energy problem, but only if it gets sold at roughly the same price point as current lightbulbs. But you can expect that they'll be sold at a premium even if the manufacturing costs are the same, simply because they're better, and so the problem of high energy consumption will remain.
Color? (Score:2, Insightful)
I think the color of the light produced would be very important for its potential uses.
Re:Efficiancy? (Score:2, Funny)
Where I work the beatings usually continue until the morale and efficiency improve.
Re:Efficiancy? (Score:1)
Re:Efficiancy? (Score:2)
I wonder how this compares to modern flourescent light fixtures.
/Janne
Re:Efficiancy? (Score:3, Informative)
60% is positively huge, although I wonder how cheaply they'll be able to put microscopic tungsten lattices in flashlight bulbs and relatia.
Re:Efficiancy? (Score:2)
Fluorescents certainly do not top out at 12 - 15%. Most flourescents exceed 75% efficiency! Sometimes they even hit close to 80%.
The new models use electronic balasts, so they don't flicker at the frequency of the powersupply. And they start instantly, too. (altho for some reason a bunch of them require a 1 to 2-minute warmup period to reach full strength.)
And you can buy fluorescent bulbs that emit soft, warm light (instead of the traditional harsh, cold light of long tube fluorescents.)
Now if this new technology that's being pimped in the article in this thread ultimately exceeds 80% efficiency, then I'm switching to this new technology (assuming it is cost effective). Until then, fluorescents all the way baby!!
Re:Efficiency? (Score:2)
If that were true, a 40-watt flourescent tube would output ~20000 lumens, not ~3000.
100% efficiency would be about 680 lumens per watt. Flourescents do about 80, incandescents do about 18.
Oh, and misspelling words like "flourescent" and "ballast" hurts your credibility.
Re:Efficiency? (Score:2)
So that white powder inside the tubes is flour? Cool; I've always wondered what that stuff was...
C'mon, it's obvious he knows how to spell it, and just made a typo--he spelled it correctly 4 of the 5 times. Whereas you misspelled it 3 of out 3 times. 3 strikes and you're out!
Entropy. (Score:2)
References, anyone?
--grendel drago
Re:Efficiancy? (Score:2)
C//
Why USians by SUVs (Score:2)
but it's true that by buying something else than SUVs and 7.9l engine cars
USian drivers buy SUVs because they don't want to get hurt in a potential wreck with an SUV.
stupid speed limitations! (Which are here precisely because cars' engines eat too much!)
Actually, U.S. roadways have speed limits because of the reaction time of the average USian driver, especially taking into account effects such as highway hypnosis.
No such thing as a "USian". Let's settle this. (Score:3, Offtopic)
You see, some countries in the world are called "The United States of X". Generally because, accurately or otherwise, they're supposedly a federal union of autonomous "states".
People who live in one of these "United States" countries are called after the place where the states are located.
Citizens of the United States of Mexico are called.... Mexicans.
Citizens of the United States of Brazil are called.... Brazilians.
Citizens of the United States of America are called.... Americans.
But the entire Western Hemisphere should be called "America"! It's unfair that just the USA uses that name!
Unfair in what way? Brazil doesn't lack a name. Canada's not hurting for a moniker unrelated to the name of its continent.
Besides, geographical names are blurry anyway. By "Africa'' a lot of people mean simply "sub-Saharan Africa". Peru used to mean all of non-Brazilian South America, not just one Andean country. Some names (e.g. Iraq, Pakistan) are simply made up out of nowhere.
So why invent the ugly term "USian", which could equally well apply to several different countries, when everybody the world over knows what an "American" is?
Re:Still no such thing as a "USian". (Score:2)
So if we have a United States of Africa, do we call them African? How about United States of Asia? Asians?
You get the point?
What point? Hypothetical countries need hypothetical names?
But, sure, we can play that game. Let's say we had a hypothetical federation of European nations, which we'll call the "European Union". What are people from within this Union supposedly called? Europeans. What about places which are in Europe but not in the European Union, like Norway? Norwegians.
Re:Energy, efficiency... (Score:2)
I would be really surprised if SUVs are actually safer than a regular car on the whole. I don't think i'd ever seen a rollover on city streeets until SUVs became popular--vehicles on their side or top used to be a sight only seen in severe highway accidents, but apparently it's practical to tip or flip a SUV at 35-45 mph judging from a recent accident or two.
And when they hit get hit hard, they get twisted up just like a family car.
--
Benjamin Coates
Re:Energy, efficiency... (Score:2)
No, I'm pretty sure they're not. They have longer braking distances and poorer maneuverability than cars, in addition to their rollover problems. Also, they tend to be more rigid in construction, which seems as if they wouldn't absorb collision energy as effectively as a car with all its "crumple zones". Their only advantage is sheer size, which is negated because of the numbers of them on the road (you're driving a big vehicle, but you're more likely to collide with another big vehicle). In fact, some SUV drivers obviously get some sort of "invulnerability complex" when they get behind the wheel, causing them to be a greater danger to themselves and others on the road.
Anyone who thinks size = safety has obviously never seen an Indy car driver walk away from the mangled wreckage of his car after a 200+mph crash.
Note: I don't think SUVs should be banned, or that everyone that drives one is an idiot. They do have their uses, and for some folks they may nearly be a necessity. There are a lot of folks, though, that buy them for no good reason, and it is these people that I dearly wish would get a clue.
What are you thinking??! (Score:2)
They've got an OC-48 2.5 Gbps link to San Francisco. That was in 2000, they may have upgraded since then...
yeah, I know, they may have outsourced the web server to a 56k modem line, but somehow I doubt it...
Re:What are you thinking??! (Score:2)
Obviously over optimistic about the power of The Mighty Slash Dot.
Maybe if it wasn't a nice spring weekend with 90% of the geeks out there seeing Spider Man for the tenth time....
Re:Life Span of Bulb... (Score:2)
You conspiracy freaks are so delusional sometimes. There are multi year bulbs you can buy right in the store, you know?
C//
Re:Interesting (Score:2)
An 8 pin DIP and a 15A+ Triac. (If there isn't an existing chip for it, volume sales would make it worthwhile to make one.) Lightbulbs always blow when you switch them on, never during usage.
There have been recifier gimicks for lamp sockets, but I doubt those do very much.
I put this idea in the public domain (not that I can copyright ideas), and all that I (hopefully) ask for is a bunch of these (for site testing) so that I don't have to keep replacing those damned bulbs!
How many hardware engineers does it take to not change a lightbulb?