New Lighting Technology To Wipe Out Wi-Fi Access?

Richard Evans writes "Focus on Broadband Wireless Internet Access has an article [cached by google ] on the potentially catastrophic interference to Communications Users Of The 2.4 GHz Band e.g. Wi-Fi, DECT and Bluetooth by a new lighting technology called RF Lighting."

Comments

WTF?!?!

[TheDick]

They finally learn, and put a link to the Google Cache, IN THE FUCKING ARTICLE???? I'm so impressed.

I thought regular fluorescent lighting already fucked shit up, since its not really a steady light (like incandescent) but really flickers on and off REALLY fast. Some guy thought a cool way to basicly broadcast info from these lights was by slightyly altering the timing to transmit data....

Who needs RF lighting anyway? I'd rather have a wireless laptop/pda.

Re:WTF?!?!

[gorilla]

Incadescant flickers on and off too. It's not so prounced, because the tungsten takes time to cool down, but it's there. Connect a light sensor up to an oscilloscope, or those old fashioned 'tell if your record player is revolving at the correct speed' gizomes, and you can see it.

Re:WTF?!?!

[MoneyT]

Because of the natuere of incandescent lighting (I believe the basic principle is resistance) when the current turns off in that brief moment while it is switching directions, the bulb remains lit with residual energy. Esentialy, the bulb remains consistanty light.

Florecent lighting however does indeed turn off (or at least loose most of it's energy) when the current switches direction. Hence florecent light is very irritating when exposed to for a long time (ever wonder why all those business execs commit suicide? It isn't cause they aren't getting enough air, it's cause the lights are so friggen annoying)

Re:WTF?!?!

[evilpenguin]

You obviously don't know much either. Incandescent and flourescent lighting both "flicker" because they are powered by alternating current. Incandescent lights work by heating a wire so hot it glows white (that's what "incandescent" means). Flourescent lights work by using high voltage to excite a gas. That gas emits UV light which strikes phosphor compounds on the inside surface of the tube. These compounds emit visible light when struck by UV (they "flouresce," hence "flourescent").

Whether or not flicker is visible depends on the "persistence" of the phosphors and the cooling rate of the incandescent wire. They all flicker. The flicker is a result of the alternating current. Of course, you can use DC to make an incandescent bulb work. You can't do that with flourescent lights because AC is required to keep high voltage coming out of a transformer (transformers only work with changing magnetic fields - put DC into them and you only get output voltage when DC comes on and again when it shuts off).

nonsense

[tps12]

RF lighting is a great idea...just not for humans. While normal "visible" light (like what is coming out of your computer screen right now) consists of tiny waves called "photons." These are the base quantas of light energy. Bizarrely, radio waves consist of the exact same photons, but at vastly different energy levels! Heat also consists of photons, again with different energy or frequency amounts.

So RF lighting is just normal lighting at a different frequency. A frequency that humans can't even see! Trying to listen to the radio or use wireless networking in the presence of RF lighting would be like trying to watch TV with a spotlight in your face.

Re:nonsense

[BigBir3d]

I thought photons were particles!

And I think it would be more like watching a TV with a broken tube.

Re:nonsense

[GigsVT]

I bet it's RF energy excited sustained plasma, ala the microwave plasma ball experiments on that microwave site.

Re:nonsense

[anthony_dipierro]

I've found the description at PhysicsClassroom to be useful for explaining light. Now, it's geared toward high school students, and as such is not strictly accurate (most notably, light is a transverse wave, whereas the picture seems to imply that it is longitudinal), but at the least it answers the often asked question of "why does light only travel at c in a vacuum". It's a good site overall, I'd definately recommend it.

Re:nonsense

[maraist]

Define "particle".

Effectively, a particle in quantum physics is a cohesive bundle of energy. We measure the mass of that energy in "electron-volts" (eV), which you can think of as a electron-level volt-meter. It's similar to measuring the voltage of a battery; we can't directly see how much charge is in a battery, but we can see how hard it pushes / pulls a test charge. Likewise, we can't see how big a proton or electron or up-quark is, but we can see how it affects other particilars of similar size (e.g. an electron as a reference point). Due to the massive deviances in particular masses, it's hard to know for sure if a photon is truely massless (even though it carry's energy). post-modern quantum physics speculates that photons, neutrino's, and even gravitons have mass. (Yes, this does imply that gravity has a weight of it's own. More precisely, the emision of the force of gravity adds weight to the space between two particles.)

The substance of the particle is subject to debate. String theorists believe (if I'm not mistaken), that all particles are made of strings of something (which we'll never know), and that those strings wrap around space (which we also can't know it's consistency)- warping it and being stretched by it.

Another point of view is that of Ether, which we tend to hold on to, since quntum physics is so similar to our percieved world that it would be a shame that such patterns could not be known to persist at different scales. One theory that I like is called
Aethero-kinematics. It's based on the idea that tiny hard balls (perfectly elastic, like steel) bounce about in different patterns (mostly vortexs, like in a drain). All energy is in the form of the kinetic energy present from these bouncing balls. The cohesion allows for quantum particles. The augmentation / contraction of mass (via Einsteins special relativity) is explained away the same as Mach-theory (where an the air-resistance increases exponentially as you exceed the speed of sound). The "speed of light" is merely the average velocity of the balls. The explained reason why we can't perceive relative motion against the ether of space is that earth is not moving with respect to the ether about it; nothing does. Motion is only ever a small fraction of a difference in speed from it's surrounding ether. Lastly, the concept of experimentally determined transverse nature of light is nicely explained away in Aethero-kinematics in common sence ways. (having to do with the probability distribution of collisions of particles in an ideal gass)

Modern quantum physics simply ignores the what's and hows of particles, and simply says they exist with certained measured properties.. That's it, that's all, that's ugly. Because of this, I tend to look at models like the above (so long as they fit the experimental data) as a way of putting my mind at ease. The problem is that until the theory's demonstrate validity, we can't take the analogies they present (ideal gas, or strings) too far in extrapolation / interpolation.

As for waves (also questioned in this thread): a wave is a regular periodic fluxuation. Longitudal waves are like a wripple in a violin string or cresting waves on the ocean. If you just look at a single water molecule, however, you'll see that it doesn't move forward, but instead up and down (just like a boat). You could also look at a police-car flashing light. The color of the light slowly fluxuates from red to blue and back again in a definite period. If you took a cardboard box and punched a hole through it, you'd see on a wall the color fluxuation. If you look more closely, the fluxuation is merely caused by a rotation of two light bulbs. Photonic transverse waves are the fluxuation of the state of the photon from electric to magnetic (hense the phrase, electro-magnetic). An electron sitting still has only an electric field (which applies force to other adjacent electric objects (pretty much anything but a neutron; and even it, if you break it down into quarks). When an electron moves in a circle, it applies a strange perpendicular force which only affects other spining electrons. You can understand that it's different than charge because two electrons are attracted to each other when they counter-rotate (or rotate, I forget which). It turns out that rotation has nothing to do with it; it's the motion of the electrons (but the math gets harder). So here are two completely independent characteristics of a charged particle. As it turns out the transmission of photons accounts for both activities, so the photon is both a messenger particle for magnetic fields and charged-fields (electric-fields). Since a photon must always travel at the speed of light (relative to it's medium), it should be apparent that it works within a magnetic context (e.g. charge in motion). It seems that the photon fluxuates between the two in a sinusoidal pattern with respect to time (independent of it's physical motion). The "frequency" of the photon is the speed at which it oscilates a full transition between electric and magnetic. Such a periodic transverse wave-pattern has many astonishing properties. Most notibly that the same beam of photons when reflecting back apon itself can have interference patterns; namely that the waves can cancel each other out (or amplify one another). The best example of this is to take a beam of monochromatic polarized light and send it through a cardboard box with two slits on it. On the other side of the box, you should see a periodic pattern of light and dark spots.

I'm not a physisist, but I am an electrical engineer, so I have more than a lay understanding of the principles.

-Michael

Re:nonsense

[Aceticon]

I thought photons were particles!

Actually they're both wave and particle.
Same thing for electrons.
Actually all mater is both wave and particle.

Trust me on this one!

I hope this clears up all doubts you had.

Re:nonsense

[BigBir3d]

Michael,

I just wanted to thank you. Your reply was very thought provoking, and showed coherent thought. I truly wish my third semester college Physics teacher had been up to the standard you just set.

Again, thank you.
Chris

Re:nonsense

[Afrosheen]

Here's your requested correction.

Schroedinger's cat test is a little more sadistic than that.

You have a box you can't see into. Inside the box you place a vial of deadly poison that will produce instant death if it's broken. Close to the vial you position a hammer that's cocked. It can go off and break the vial at any time.

After you stick the cat in the box, you close it up. What follows is an incredibly simplified base for Quantum physics.

At any time, the hammer is both cocked and uncocked, the vial both broken and unbroken, the cat both alive and dead. None of the objects are in a definite state until you take a measurement, in which case you determine all three.

The nature of light is similar. It is both a particle and a wave, depending on how you measure it. In most experiments, researchers focus upon either light's particle aspects (by counting photons, for instance) or wave aspects (by measuring an interference between electromagnetic fields, to cite a simple example). Hence the dual nature of light and the relation to Schroedinger's cat experiment.

A good page with further explanation is cached at google here http://216.239.35.100/search?q=cache:fbyF8_1R6_4C: users.ox.ac.uk/~jsw/Schroedinger.html+schroedinger %27s+cat&hl=en

Re:nonsense

[ShavenYak]

Of course, an object the size of a cat does not normally appear to be affected by quantum phenomena. The whole point of the thought experiment is that the hammer is triggered by the radioactive decay of an atom. Since this decay is governed by quantum phenomena, it is assumed to be in an indeterminate state until observed.

One question raised is, does the cat count as an observer? Or, for that matter, does the hammer? Our everyday experience indicates that cats, hammers, and glass vials are either alive/dead, up/down, broken/whole, and cannot exist in superpositioned states. So, when the box is sealed, do we have a cat that is neither dead nor alive until we open it, or does the fact that the cat is affected by the decay collapse the wave function?

Re:nonsense

[ShavenYak]

they are somehow using a material that absorbs this higher-frequency radiation and converts it to visible light.

Um, microwaves are lower frequencies than either visible or UV light.

Re:nonsense

[matrix29]

I bet it's RF energy excited sustained plasma, ala the microwave plasma ball experiments on that microwave site.

Tried it. Then I figured out there was a metal ring in the base of the candle (for molding purposes to keep the wick upright) which was causing the plasma discharges. All other experiments with burning toothpicks failed. The candle test failed completely once the bottom area holding the metal ring was cut off.

Re:nonsense

[GigsVT]

That's interesting, but you still had plasma, which was the goal.

After posting this comment, my suspicions were confirmed, several credible posts said that these lights are indeed microwave megnetrons beaming sulphur doped tubes and creating sustained plasma. They also said that they were prone to failure, had moving parts, and consumed a lot of energy. Oh well. Nice idea in theory at least.

Re:nonsense

[Afrosheen]

No, the cat isn't counted as an observer because it can't report to the scientists. The box is sealed and you can assume it's soundproofed for the sake of completeness. This way the cat is both alive and dead, meowing and quiet, the hammer is cocked/uncocked etc. etc.

Repeater stations

[Keighvin]

Why not make these play nice and use the lights as repeater stations? Install a recepter on each one, wire'em up to the LAN and have even more ubiquitous access.

Re:Repeater stations

[SEWilco]

Exactly what I was thinking. If you don't have enough LAN traffic to keep the lights on, stream Usenet.
:-)

You agreed to this when you bought your equipment

[Anonymous Coward]

If consumers would bother to read the FCC-mandated disclosures that come with all of their new high-tech toys, they would see the following quote:

Operation of equipment marketed under this waiver is subject to Section 15.5 of the Commission's Rules. Any operation shall not interfere with authorized radio services; operations shall accept any interference that may be received, including interference that may adversely affect the operation of the units authorized under the waiver. No user of the equipment sold under the waiver shall be deemed to have any vested right to any part of the RF spectrum employed by the equipment.

It's there, plain as day. If you're mad that somebody nearby is trying to reduce dependence on foreign energy and save the environment by using highly efficient magnetron-powered lights, you have nobody to blame but yourself. There is no substitute for proper consumer education.

Yawn...next scare tactic please!

[grinwell]

This article is from July/August 2001.

The website it cites: Link is *still* blank at least a year after it was cited.

The article also goes into very little detail as to *why* this new lighting technology will be either popular nor necessary. It's vaguely referred to as "very high efficiency."

Summary: Call us when you have real news.

Re:Yawn...next scare tactic please!

[kisrael]

The front page of Fusion Lighting is blank, but Google can point you to a promotionalish page on Sulfur Lighting as well as a Technology Page.

Satellite Radio

[kwishot]

This article says that Sirius and XM Radio will be effected. That's really bad. Part of the reason it's worth paying for is because of the sound quality...having this happen in it's relative infancy could be realllly bad. I wonder if there's a way to shield these lights...like some sort of compound mixed into/spread on the glass that reduces the RFI. Either that or, as a geek community, we should just hope that this idea doesn't take off!

Duuuude, puff puff give!

[Neck_of_the_Woods]

Man with those lights I can grow weed, light my pit of an appartment, completely screw the wireless network the guy next door who has to play mp3's at the highest possible bass level at 3 in the AM!

Pro's:

Heat, grows good herb, and kills the wireless network.

Con's:

ahhh, shit I forgot...pass that would ya!

you have to install the lighting first

[cats-paw]

I don't know what this lighting is, although I suspect it may be "sulfur" lighting.

However if it's going to trash your wireless network then the chances are good that you won't even install it in the first place. That takes care of homes and _probably_ office buildings.

The problem is going to be "public areas" where the lighting is installed to save on electricity costs, and then interferes with ISP's as the article stated. This of course assumes that the lighting is so much more efficient than sodium or mercury vapor that it's worth the expense of installing it in the first place.

And it's going to take years.

Far from an ELE.

Re:you have to install the lighting first

[nologin]

From the specifications, it is indeed a sulfur-based lamp. The major difference is that it uses RF energy, rather than an electrical charge to excite the sulfur atoms to produce light.

The big advantage is that by using RF energy, they are essentially boosting the efficiency of the bulb. For instance, incandescent bulbs are approximately 2-4% efficient, mercury and sulfur based fluorescent bulbs are about 25-35% efficient. With this new bulb, they are indicating about 70-80% efficiency. These bulbs should also last much longer, as the magnetron device (producing the RF energy) doesn't wear down like electrodes do.

While to ordinary Joe Consumer, this isn't that much of a big thing, imagine for instance the amount of electricity used by a large city just to keep the lamp posts lit. They would achieve the same amount of light on half the electricity bill.

Unfortunately, that would mean that every lamp post (so equipped) would become an instant RF source. It would certainly be far too minuscule to cook you, but definitely enough to cause some interference on wireless RF equipment in that spectrum.

bye-bye to wi-fi?

[jdbo]

does this mean that I have to re-wire all of my "wi-fi" devices?

worse, does this mean that I'll have to start referring to them as "wi-wi"?

Re:bye-bye to wi-fi?

[b1t r0t]

That would be "fi-wi". As in Fixed-Wired.

Easy Solution:

[frantzdb]

To prevent interference, RF lights should simply practice exponential backoff for colision avoidance like everyone else in the 2.4GHz range. What's more, the lights would then become an effective network load monitor.

--Ben

Re:Easy Solution:

[istartedi]

This is your pilot speaking. Nevermind the turbulence, just keep your eyes on the blinkenlights.

If they actually caused THAT much interference...

[nherc]

Couldn't the RF Light manufacturer just shield the light fixtures e.g. a Microwave Oven?

In fact, I would think the FCC would make them, if they had an output over a certain threshold.

2.4Ghz - the new CB

[ch-chuck]

Whoever has the most powerful transmitter wins. I'm sure Powell Jr. at the FCC loves it that way.

But 802.11a (5 GHz) won't be affected!

[Anonymous Coward]

That's why 2.4 GHz will rapidy become unreliable for wireless LANs.

Luckily, 5 GHz wireless LAN products (802.11a) are now becoming available (called WiFi-5, I believe). Since they
do not use the 2.4 GHz frequency range, they will not be affected by this issue.

FCC

[Kallahar]

I'm not a big supporter of the FCC (who frequently overstep their bounds), but this is exactly why parts of the radio spectrum need to be regulated. The entire reason that the FCC keeps such tight control is so that companies that invest in radio equipment have some assurance that the guy next door won't simply drown out his signal with more powerful equipment.

But then again, every time my boss walks by with his cell phone, my monitors fuzz out and my speakers make strange noises from whatever signals the cell phone is emitting...

Travis

Re:FCC

[anthony_dipierro]

I'm not a big supporter of the FCC (who frequently overstep their bounds), but this is exactly why parts of the radio spectrum need to be regulated.

I agree that the radio spectrum needs to be regulated (like any other common good), but unless my photons are crossing state boundries, why should it be regulated by the federal government?

Re:FCC

[uslinux.net]

I've got money saying your boss uses a Nextel phone, eh? Nextel uses IDEN instead of GSM/PCS/etc. Noisy. You'll notice your speakers in your car pop every time a call comes in.

Re:FCC

[MoneyT]

Regardless, all items which fall under FCC regulations are of course liable to be charged, and must opperate in their levels resonably. For example, while the bosses cell phone is permited to distrbute some interference, if it was enough interference to shut out every other cell phone withing 10 ft, that would be grounds for the FCC to step in a regulate. The FCC is here to regulate for the common good. If it harms the majority, it won't get aproved.

Re:FCC

[blair1q]

chit-chit-chit-chit-chit

Telephone!

BLEBLEBLEBLEBLEBLEEEEEP!

Hello?

How to be your own Radar O'Reilly.

--Blair

P.S. It's not just Nextel. This happens with Moto and Samsung and Nokia and Ericsson phones, in my personal experience. It's the phone bursting back after receiving a connection request. If you're in a crummy cell, it's worse, because the phone has to stay at full xmit power all the time.

Re:FCC

[anthony_dipierro]

Are you implying that radio signals observe state boundaries and just stop when they hit one?

No, I'm implying that it's possible to send a radio signal from one point to another without crossing state boundaries.

Re:FCC

[MoneyT]

I wasn't the original poster of the tread.

Re:FCC

[shogun]

No, I'm implying that it's possible to send a radio signal from one point to another without crossing state boundaries.

Are these two points within the same state though? If not I assume your way off topic talking about some advanced tech based around Einstein Rosen Podolski pairs..

Re:FCC

[anthony_dipierro]

Are these two points within the same state though?

Of course. The point is I can send a radio signal from my house to my neighbor's house, without affecting anyone outside of my state, and the federal government shouldn't be able to regulate that at all.

If my radio signals cannot be detected outside my state, then the government does not have beyond a reasonable doubt evidence that I have committed a federal crime.

Industry's fault, I suppose

[rnelsonee]

So basically, Wi-Fi was developed to take part in a area of the spectrum that's licensed to other products. The people who started it knew that this was a potential problem. Granted, this area was a relatively large chunk of the spectrum, but why didn't they realize the possible impact of this interference? It's is much more dangerous to digital communications that other products. Was there really no other place in the spectrum to go? Perhaps find one that the FCC can give exclusive rights to?

From the article...

(1) [Each Part 15] device may not cause harmful interference, and (2) [Each Part 15] device must accept any interference received, including interference that may cause undesirable operation.

How RF/Fusion Lighting Works

[jsimon12]

http://www.fusionlighting.com/technology.htm

Re:How RF/Fusion Lighting Works

[infinite9]

Can someone tell me what this has to do with fusion? What are we fusing? I think fusion lighting is the bright light given off by nuclear explosions. Mixing fusion and lighting is like mixing turbos and lasers.

We're trying to destroy them sir, but they're evading our turbo lasers.

I should get a job pointing out the ridiculous. It's my calling.

Is this a real light technology?

[hackman]

The article makes a big point out of the collision between the frequency spectrums, however I personally am interested to find out more about the lighting technology that is "high efficiency and RF based". It seems the article kind of missed that explanation, and I can't find much information on it. The lighting's website is down that is referred to, and as far as I know this could be a "made up" problem (by this dude who wrote the article) primarily because it's only a problem if the lighting technology catches on.

Are the light technology elements mounted in the ceilings like conventional flourescent lights or does it use some kind of a central light-source idea. If it's high-brightness and high-efficiency anyway, the light source could be placed at a central (shielded) location and fiber optics used to distribute the light.

I'm all for new light technologies, although often flourescent lights are pretty good, there is still a lot of room for improvement. (Time delay to full brightness, hazardous materials, cheap ballasts that buzz, bad fluorescent tubes that put off funny-colored lights) But interfering with wireless spectrums (even unlicensed ones) seems like a bad idea in general... the amount of noise in any spectrum is becoming a serious concern for the design of "robust" wireless technologies.

and also...

[Schlemphfer]

Let's see an electric use cost comparison between this RF lighting and fluorescents. It's pretty slipshod that the article didn't bother to address the question of whether this lighting offers significant savings.

Until it's clear that there are compelling cost advantages associated with microwave lighting, the issue of whether this technology could endanger communications doesn't merit discussion.

Re:and also...

[stormcrow969]

Yeah, those were the promises. I really wish it would have worked out better. a few details of the problems:

#1 - the BULBS might last 11.4 years, but the magnetron that shoots the microwaves into the bulb, and the motor that turns both the fan (that cools) and the bulb (to prevent the plasma from burning through the glass of the bulb) burn out VERY fast. 1st generation units had 50% of the magnetrons burn out within 6 months. We were told this was due to the power supplies. 2nd gen units seemed much more solid in the power department.

#2 - the fan motor / bulb turner would break/no longer rotate. It didn't appear to us that they had a high enough quality motor on these... a large percentage of them would break within 3-6 months. If the motor stops turning that bulb it goes POOF when the plasma burns through.

#3 - the light is NOT white. it is kinda green.. pretty noticibly green actually. People do not seem to like greenish light. Most of us are used to either a yellowish or blueish tint. We had several people complain of feeling sick.. Dunno why green light would do it, but it didn't make our customer happy.

#4 - the high temps that these units achieve lead to a break down in both the reflectors and in plastics used to feed the light into useful places. We replaced many lights with one of these units (like a 5 to 1 ratio maybe) and then used a plastic tube as a 'light pipe' to deliver the light where it was needed. The material in the reflector would either a) degrade, or b) get deposited on the plastic tube due to the high temps. Also the plastic joins on the tubes would degrade seriously in a short (months) time frame. Maintenance costs were incredibly high.

In short: great idea, bad implementation. I have no doubt that if the engineering of these untis was higher (with the subsequently higher cost) that these would work. But then these already pricey (very) units would not be able to compete with existing technologies (like metal halide).

Crow

Re:Would This Be Legal?

[JordoCrouse]

Read the article:

Eventually the FCC decided to offer a Faustian bargain: Industry could use the existing ISM spectrum if they adhered to certain technical limitations with no expectation of protection.

In other words, as long as you stay within the 2.4 GHz spectrum, you can do what ever you want, as long as you didn't expect to be protected from interference from other devices.

Bluetooth and 802.11B have already violently clashed in this space already. I have seen it myself - with a 802.11B card in one PCMCIA slot, as soon as I turn on a bluetooth card in the other slot, my average ping time on the 802.11B goes up considerably.

Jump from RF to Solid State

[4of12]

Why get all in a lather about RF lighting?

If solid state lighting takes off we'll get great efficiency and no 2.4 GHz spectrum pollution.

Another product press release becomes a /. story.

[Artifice_Eternity]

Earlier today it was the dual-screen laptop. They seem to publish these stories totally uncritically.

Dudes, if you're that desperate, just regurgitate something from Space.com, Wired News, or the Register.

This is not a troll.

this is why I rarely read slashdot anymore !

[noahbagels]

This article is utter garbage!!!

The first link (off-site) from the article referred to, in fact the makor of said "RF-Lightning-Craptacular VC-Money Whoring" company has a "our website is under construction" on it.


C'mon people - stop posting obvious flamebait articles at the highest level. This was a freakin waste of everyone's time.

Pacemakers?

[jsimon12]

Seeing as this technology uses tiny microwave emitters to excite sulfur ions what effect would it have on pacemakers? If they have to sheild it for pacemakers and stuff then shouldn't the effect be minimal or seeing as the 2.4 ghz area is open can they just dump as much radiation as they want into that spectrum? I mean I don't see problems when I use my 2.4ghz cordless of WiFi laptop when my microwave oven is running, so shouldn't the lights be sheilded to the same standard?

Who would want them?

[gunnk]

If the RF lights get shielding on them then we don't have to worry about them interfering with network devices too much.

Then again, if they DON'T get shielding they'll never sell. Try telling your employees that you are going to replace all the lights in their workspace with lights that spew radiation at the same frequency that their microwave uses, but without the shielding! Sure, the output would be WAY below a microwave, but who wants to sit under a bank of them eight or ten hours a day from now until retirement?

Re:You agreed to this when you bought your equipme

[hackman]

Yes, I would assume you're right.. "legally" we don't have a right for RF technologies to always work. FCC regulated or not, it comes down to your local area when you're using or considering using wireless phones, WiFi, or other wireless devices. When I was in grad school I was in a building where 2.4GHz was kind of noisy, I expect it was due to science research experiments and a steel-frame building. We just bought antennas and didn't worry about "legal" reasons. Seems everybody is too quick to complain about legality these days.

I think the real issue is more practical, who buys the technology not knowing that it will heavily interfere with certain wireless equipment. (I'm thinking office environments are the biggest issue) Doesn't the consumer have a right to know things like interference before purchasing a product? After reading the article I personally got the idea that I need to check out the lighting technology and be cautious of where it is installed. That's all, it's an old technique where you just don't buy something if you don't like the side effects.

Seen this lighting.. It bites.

[stormcrow969]

The company I used to work for did the very first large scale (non-test) installation of their lighting products in the US. It sounded like an awesome product. It would provide MORE light for LESS power with LESS maintenance.

We installed a HUGE area with this stuff (took many months to do the install). A year later we ended up yanking every bit of it out. Why? Well, there were SEVERAL technical problems with these things that they hadn't worked out. The short version of how they work is that they irradiate a glove with some sulfur in it with microwaves and turn it into a glowing plasma. Well, that stuff is a bit hot, so you have to continuously rotate the 'bulb' This rotational part breaks, so the light breaks.. the reflectors can't stand the heat, etc.

so don't worry.. they are in bankruptcy... :)

Re:Seen this lighting.. It bites.

[david duncan scott]

they irradiate a glove

Sounds like an expensive system. Is that why Michael Jackson only had the one?

Re:Seen this lighting.. It bites.

[david duncan scott]

It might be hard to heat a glove to plasma, but in the case of M. Jackson, I think we should try. :)

Yeah, I figured it was a typo, but "glove" was more fun.

I ride the DC metro a couple of days a week, including today as it happens, and change trains at Gallery Place. I'll look around this time, instead of wandering about in my normal fog.

You know what just occurred to me...when you were testing them, was there a smell to them? I recall that there's a faint scent of, well, I was thinking gunpowder, but perhaps it's related. I don't recall it in either of the other two stations I frequent.

Re:Seen this lighting.. It bites.

[Wraithlyn]

OK so we don't need to worry about THIS one, but what about the next one?

I think the larger issue here is that the huge installed base of communications equipment which operates in the 2.4GHz band is not legally protected from interference, and it could be only a matter of time before some widespread technology comes along which renders all 2.4 comm devices useless because of this loophole.

Re:Seen this lighting.. It bites.

[Wraithlyn]

OK yes, it was probably not the best word choice.. but I still think it fits. From dictionary.com:


loophole
n. 1. A way of escaping a difficulty, especially an omission or ambiguity in the wording of a contract or law that provides a means of evading compliance.


From the FCC regs:

[Each Part 15] device must accept any interference received, including interference that may cause undesirable operation.

This allows Part 18 manufacturers to escape the difficulty of designing devices which don't interfere with Part 15 devices.

Re:Seen this lighting.. It bites.

[Fesh]

"If the glove is a plasma.... Er... The prosecution has asthma! Yeah! That's the ticket!"

Re:Seen this lighting.. It bites.

[david duncan scott]

The aroma of cordite? Hell, I commute here from Baltimore, the City That Reloads.

Go check out the prototype installations in D.C.

[Animats]

Prototypes of this "sulfur lamp" technology are in place at two public places in the Washington, D.C. area, the front of Department of Energy headquarters and the Gallery Place Metro station. So get down there with your Wi-Fi equippped laptop and see what the situation is.

This looks like a niche product. It's not even clear that Fusion Lighting is still in business. Their web site is essentially defunct. Their web site used to have some nice pictures of glass bulbs and more info, but now, it's just a starter page.

Actually, bit problem.

[RobinH]

It sounds like that rule doesn't apply to the 2.4 GHz band. That band was reserved specifically for use by Microwave ovens, etc., which transmit but don't receive.

Manufacturers started using it for communications equipment because you don't need an FCC license to use this band - you just have to prove that it doesn't create too much interference in other bands. As long as you stay in the 2.4 GHz band, then the FCC, more or less, doesn't care. All you have to do is make your device work well enough for people to buy it.

This also means that if some manufacturer wanted to deliberately create a device to block all 2.4 GHz communications in a local area, they could apply under Section 18 (or whatever it was) to have such a device approved. There's nothing that the cordless phone manufacturers could do about it.

Frankly, they should have known better. However, we tend to support a throw-away society, so you'll just have to go and buy something that works in the 5 GHz band now. At least now there's bandwidth specifically allocated to communications in that frequency range.

Re:Actually, bit problem.

[Rick the Red]

It sounds like that rule doesn't apply to the 2.4 GHz band. That band was reserved specifically for use by Microwave ovens, etc., which transmit but don't receive.

OK, I'll admit my inital comment about the FCC was probably wrong. I'm not up on Section 18 and perhaps should have held my tongue (or keyboard). However, this does not negate part 2 of my arguement: "frankly, I won't want to sit near one if it's not shielded."

Microwave ovens do not transmit; they are shielded, have double interlocks on the doors, etc., to prevent you from cooking yourself while you heat your pizza/tea/etc. If Fusion Lighting's products are not shielded, consumers won't want them and if not the FCC then the FTC/FDA/somebody won't allow them. Or damn well ought not allow them (with W in office, who knows?)

no interfererence

[macpeep]

All this talk about interference between WLAN and Bluetooth is more or less rubbish in my experience. Both at work and at home, I work every day with both Bluetooth and WLAN at the same time and I've never had any problems or slowdowns of either one. On my laptop, I have both and both are enabled at all times - no problems, ever. At work, just two rooms over from mine, people code Bluetooth code every day with several Bluetooth devices, some of which are experimental. The same office space has a WLAN network and nobody ever complains about interference.. *shrug*

power issues

[OpenMind(tm)]

It seems unlikely to me that these things will be all that catastrophic in their effects. To be power-efficeint light sources, each bulb will have limited power with which to generate interference. To be power-efficient enough to make a difference in this market, this technology should probably consume <10 watts for the equivalent of a 60-watt light bulb. Considering that most of that energy will be going into visible light, it can't be a very strong signal source. Even in large installations like gas stations, where many such small sources would exist, the effect should fall off quickly. Don't use them in your home, and your wireless LAN should be safe.

The reason the satelite radio providers are running scared is that these things are mainly slated for use in street lights. Since cars tend to drive under street lights, and car users are the big market for satelite radio, someone's business model will have to give. Even small intereference feilds can be a big problem if they interupt your line of sight, particularly with high frequencies.

Re:power issues

[Alsee]

To be power-efficeint light sources, each bulb will have limited power with which to generate interference.

You are completely missing the energy scale. A gas station using these for exterior lighting would probably run a few hundred watts. 1% of a few hundred watts is a few watts. Communication devices are measured in milli-watts. It's kind of like looking for stars during the day.

-

Re:power issues

[Alsee]

The alarmists in the original article were expecting a gas station with this lighting to blackout all wirless for a mile.

Yeah, the "mile" sentence bugged me too. It will certainly stomp all over the neighbors though. A lot of people are going to be screwed if these lights are even marginally successful for any catagory of use.

-

Something is missing

[Spazmania]

The article is rather light on details about how exactly the lights are going to interfere.

2.4ghz is special in that its the resonance frequency of the water molecule. That's why microwave ovens operate at that frequency: vibration = heat.

So how exactly are these folks going to sell a product which emits high wattages at that frequency? Sitting under one would be like sticking your head in a microwave.

Answer: They're not stupid enough to sell a product that is like sticking your head in a microwave. Some critical facts are missing here.

The wireless stuff isn't particularly dangerous since its emitting at such a low power: well under 1 watt where the typical microwave emits at up to 1000 watts. And the spread spectrum technology does a good enough job of ignoring noise that the technology works despite the leakage from those ovens. If the wireless stuff does OK in the presence of leakage from 1000 watt Microwave Ovens, it'll do fine in the presence of other safe 2.4ghz devices.

RF light needs to coexist in order to sell

[Roached]

One thing that strikes me about all of this is that places that install high efficiency lighting are probably companies of various kinds. These same places will generally also purchase things like wireless networks (802.11b is all over the place now from gas stations to big companies). If a company finds that their new lighting system will disrupt day to day business, I doubt they'll invest and this will be bad news for Fusion Lighting since 802.11b was there first.

Question on FCC Rules/Interference

[Saige]

Perhaps someone could answer a question for me that I've always wondered about.

Exactly WHY are devices, such as the 2.4 GHz Part 15 devices mentioned in the article, required to accept all interference? What is gained by not allowing products to be [shielded] from unwanted interference/RF signals?

Re:Question on FCC Rules/Interference

[user32.ExitWindowsEx]

rant Rant_For_This_Article = new rant();
Rant_For_This_Article.type = "paranoid";
Rant_For_This_Article.contents="The government wants to be able to control all our electronic devices remotely, I tell you....It's all part of the conspiracy!!!"

PhysicsGenius?

[wiredog]

Is that you?

Frequencies that cook food?

[Krieger]

I've been wondering about this for a while. Why is that people seem to be so unconcerned about frequencies that operate in their microwave to cook food, but are perfectly willing to put handsets that operate at similar frequencies right next to their head, or laptops that use Wi-Fi in their laps? I know it is based off of different power outputs, but still some of these we use for hours at a time. It hardly seems safe.

Now lights with a potential solution being offered of going up to the 5 GHz spectrum for communication devices.

Amateur radio operators I plead with you (since I am one, but am not active enough to remember some of this stuff) to provide info on use of various handsets at high frequencies next to your head.

Re:Frequencies that cook food?

[anthony_dipierro]

Why is that people seem to be so unconcerned about frequencies that operate in their microwave to cook food, but are perfectly willing to put handsets that operate at similar frequencies right next to their head, or laptops that use Wi-Fi in their laps?

I think there's a typo there somewhere, but I can't figure out exactly where.

Microwaves cook food. My head is not food. So why should I think that microwaves will cook my head?

Re:Frequencies that cook food?

[Krieger]

I'm sure there's a typo. ;)

You head may not be food, but as far as a microwave is concerned... if you put your head in one, it would cook just like food. It's that whole contains water thing.

Re:Frequencies that cook food?

[BeBoxer]

I'm not an RF expert, but I'll tell you why I personally don't worry. The 2.4GHz band was set aside as an ISM band precisely because it is very well absorbed by water. Which is how a microwave oven works. The several hundred watts of microwaves emitted inside of the oven will bounce off the metal walls until they get absorbed by something. Usually this is your food. Or more accurately, the water in the food. Which is why it heats it up so well.

You don't want to be around the output of a microwave oven for precisely the same reason you don't want to stick your hand on the stove when it's on. You'll get burnt, plain and simple. With microwaves, you could actually get burnt on the inside. Most internal organs don't like extra heat. Witness how little of a fever you have to have before it becomes life threatening.

Now, back to wireless devices. The power output of your typical 802.11b device is between 30mW and 100mW. A typical microwave oven will produce up to 1000W of power. 10,000 times the power of your wireless card. Can the output of your wireless card or phone heat up your head? Of course. Will it heat it up enough to matter? Not likely.

Re:No problem.

[phliar]

The FCC's rules are simple. If your product causes interference then you can't sell it. Period. Fusion Lighting is SOL unless they can shield their product

Please go and read the article.

Pay attention to what Part 15 and Part 18 of the FCC regulations are.

Re:If they actually caused THAT much interference.

[sigwinch]

Couldn't the RF Light manufacturer just shield the light fixtures e.g. a Microwave Oven?

Microwave ovens aren't shielded any better. (In fact, the RF lamps are nothing more than microwave ovens that heat a quartz bulb with a tiny bit of sulfur in it. The sulfur gets hot, vaporizes, and glows.) The problem is that the magnetrons used in ovens and lamps don't have very good frequency control. Their spectral peak could land anywhere inside the ISM band at 2.4 GHz. Wi-Fi (802.11b) was designed to work around ovens by hopping between a bunch of narrow little bands, the theory being that if you have several microwave ovens in the building there will still be zones that are free of interference.

That works fine for most buildings. There are only perhaps a dozen ovens at most, and they only run for a few minutes at a time. But there could be hundreds of RF lamps, and they could operate 24X7 in a warehouse environment. The lamps could potentially make the RF environment orders of magnitude more hostile to data service, so that's why people are in a lather over it.

Re:You agreed to this when you bought your equipme

[Alsee]

The really stupid part about that is eventually 5 GHz will have the exact same problem.

Read the article more carefully. It states a section in the 5 GHz range reserved for communication devices only.

-

Re:If they actually caused THAT much interference.

[Sabalon]

Oh...like the door on our microwave that causes the 2.4Ghz baby monitor to freak whenever it's run?

Hmmm...is the baby awake? No..the neighboor just turned on their new lights :)

Re:You agreed to this when you bought your equipme

[grahammm]

So maybe there should be some lobbying of delegates to the next international frequency allocation conference, which I think is next year, to get a recognised allocation for "portable data communications equipment".

Re:You agreed to this when you bought your equipme

[Alsee]

While 100% correct, that is not nessecarily the end of the story. The FCC regulates spectrum for the common good. The use of section 15.5 expanded far beyond the FFC's expectations. The FFC has the *option* to alter its rules to take the current reality into consideration.

-

In the future...

[leighklotz]

When I was a kid, I had a set of encyclopedias of the sort that were parodied in Science Made Stupid a wonderful book if you don't have it.

Anyway, one illustration that stuck with me was a drawing of a man at home at a desk, reading a book. In the background are baseboard radiators with little squiggly lines coming out of them. The caption reads "In the future we will save energy in home heating by using microwave radiation to heat, people but not the furniture." This article on microwave lighting reminds me a little of that picture.

This lighting system pre-dates 'wi-fi'

[kesuki]

This company has been working with 3M and a few others since at least the mid-nineties to make a microwave powered commercial lighting solution.
They're finally about ready to deploy a finished product and in the meantime the spectrum they've got every legal right to use has been crowded with the Wireless craze. Fortunately though the 5 GHz spectrum still has some free spectrum for wireless devices.
Also, the article takes a sort of doomsday approach. Basically all the lights will do is generate a lot of static on the 2.4 GHz range, so your 2.4GHz phone will drop calls a lot, and have terrible fits of static, not stop working completely. Wi-fi will run into the same problem, you'll get fewer packets through, and less bandwith (and range) as a result.
Also, the 1 mile radius was exagerated. the only places that the static will be strong enough to cause a blackout is probally 100 meters. However, a busy street with lots of gas stations could cause 2.4Ghz free zones within a city, where not even a blutooth device would work without lead shielding.
I'm sure this will lead to zoning laws about where this light can be placed, at least in tech friendly cities.

Re:This lighting system pre-dates 'wi-fi'

[Afrosheen]

I wonder what the FCC will have to say about this. Infringing on another allocated frequency range is a big no-no, especially if these things get popular.

Re:You agreed to this when you bought your equipme

[putzin]

Well, that is true, but the issue at hand isn't really the rule, but rather corporate america's willingness to use loopholes to do business. In effect, an unauthorized RF source is interefering with an unauthorized RF network (or whatever). Since both are unauthorized, they fall in between the cracks of the Section 15 rule, and therefore, could still be subject to legal action. This could also result in a rewrite of the rules by the FCC to account for such issues (which could be good, or very bad, depending).

But most importantly, the courts should (don't read will) be very reticent to kill one company's nifty product in production for anothers. And, I believe that satellite radio is an authorized radio service, so if RF lighting does in fact prove to be a source of interference, then RF lighting is going to have a very tough time. Two established providers v. a new an upcoming technology should be an easy one for any court. If satellite is interferred with, then it is almost a sure bet any WiFi equipment will suffer, and the judge, whose kids may surf the web using the WiFi tech, is most likely going to rule in favor of established products.

Note I'm using the courts in my argument. Due to the FCC's continuing inability to make a decision stand, it is almost inevitible that courts will be involved. Someone will sue someone else in an attempt to force the issue.

News for Doomsayers, FUD that matters?

[Picass0]

Ah Yes! Another loving spoonful of alarmist hype! One company has a technology that conflicts with Wi-Fi and I'm to believe that companies with a vested interest in wireless are going to let this happen!

Wolf! Wolf!

Re:If they actually caused THAT much interference.

[bill_mcgonigle]

Couldn't the RF Light manufacturer just shield the light fixtures e.g. a Microwave Oven?

No. I saw this thing on Hometime a few years ago.

Imagine a regular light bulb where the glass part is removable from the base and filament inside. Where the filament normally is there's a wire wrap (maybe more to it than that). The glass part is coated on the inside, with a coating that glows when hit by RF. Put the glass part on the base, it glows. Take it off, it doesn't.

To shield this, you'd have to put the shielding outside of the light bulb, which would block the light.

Regulation?

[mindstrm]

Things that transmit in the 2.4Ghz ISM band have to follow the rules. It may be unlicensed, but it's not without rules.

Power levels would have to be within tolerance, as would stray EMI from the units, as would a lot of other things.

Re:There are no stupid questions...

[spike hay]

if RF lighting exists at "[a] frequency that humans can't even see" then how the fuck can it illuminate anything?!?

The way I understand it, the RF excites the gas (sulfur and argon), making it flouresce. This makes for a high effieciency white light.

Re:There are no stupid questions...

[maraist]

if RF lighting exists at "[a] frequency that humans can't even see" then how [snip] can it illuminate anything?

Color is directly related to the frequency of the wave of a photon of light. (we'll ignore for now how a photon can be both a partical and a wave). Visible light is a tiny frequency range; IR, microwave, and radio are below it, and ultra-violet, gamma and X-ray are above it.

Additionally, the energy of a photon is directly proportional to its frequency.
E = hf (h is a constant of proportionality; planks constant divided by 2*pi).

When photons hit atoms, they're usually obsorbed. The electrons only obsorb a quantum amount of energy, and give off any remainder. Eventually the electrons re-emit this stored energy. The neat part is that all the emitted photons will have the exact same energy. Different molecules will have different discrete values of energy, and thus give off different colors.

It's possible that multilple low-energy photons can hit the same atom, and cause it to raise it's energy to different levels (each jump will require a different amount of energy, and thus give off different colored photons). It's highly likely that the energy would quickly be given off, but it's possible that the energy will continue to build until when it does give off it's energy, you've achieved a significantly higher frequency photon.

While I haven't looked at Fusion's method, it's completely plausible to accumulate lower energy photons as I've described above.

-Michael

Hum.

[autopr0n]

With a florecent light you go from zero back to the full brightness and back down 60 times a second, whereas a incadecent light will from like 100% to 99%... There is a change, but i wouldn't really call it a 'flicker'.

why don't your read, ass?

[Erris]

AC, you must have been modded up as a denial of inteligent conversation.

First, the article mentions the Section 15.5 rules and considers the issues carefully.

Second, you are a moron. If you would go visit the company's site you would see them bragging of 80% efficency of transmision. While that's all well and good, 20% of your juice is a lot to throw away and I would not put these bright little bulbs in the environmentaly friendly catagory. Want clean domestic electricty? Start building nuclear power plants.

The crux of the problem is the limited and wasteful alocation of specturm by the federal government. Fusion lighting's boast of 80% efficiency came from a 430 MHz transmitter, not a magnetatron operating at the only frequency left open for people to use as they please. There are 69 channels on my TV reciever but only five broadcasters in my town, how about yours? If the FCC alows the abuse of 2.4 GHz it will be to protect conventional telcos, ISPs and large publishers from the freedom of expresion technology can give us. It will be a vastly stupid thing to do, but that's why comercial radio and TV is devoid of anything entertianing or educational.

There it is, plane as geometry. If you are in favor of wiping out all 2.4GHz comunication instead of allocating more spectrum to the people to use as they please, you have a pin head.

Who cares?

[autopr0n]

I don't really think this is going to take off. We already have tons of diffrent ways to emit light. I doubt the cost diffrential of these lights would really be less then the loss from not being able to use 2.4ghz devices.

I mean it's not like everyone is going to go out and get rid of their old lights.

Evidence?

[dmiller]

I don't see any evidence of why this would be so catastrophic. I can't imagine why a lighting system would be using anything but a narrowband transmission, whereas all the communication technologies use spread-spectrum techniques to avoid exactly this type of narrowband interference.

Secondly, the RF lighting seems to be targetted at industrial applications (e.g. lighting warehouses and factory floors) without the need to run cables - *exactly* the same market for RF comms technologies and for exactly the same reasons. The RF lighting people are the new entrant, so if *they* don't interoperate then they'll be the one seeking chapter 11 :)

I worked on this product

[dr_hodad]

A few years ago I did academic research funded by FusionLighting to improve their product. Without violating any confidentiality agreements, here's a quick explanation of the technology

The source of light is a gas plasma induced by pulsed microwave radiation. Fluorescent and neon bulbs also use a gas plasma, but they have two electrodes running at 60 Hz. Sodium-vapor and Mercury-vapor arc lamps use plasmas, but also with exposed electrodes.

These bulbs have no electrodes (so they last _much_ longer) and run at microwave frequencies (2.4 Ghz). Why did they choose this freqency? Just to ruin your wireless connection? No. They needed high power magnetrons (things that generate microwaves) but didn't want to pay military prices. Well there's already a large competitive market for high power magnetrons, it's called the microwave oven.

The FusionLighting light bulb I worked on was a bit larger than a golf ball and filled with a secret sauce of gases and other stuff. When lit, it was VERY BRIGHT (you absolutely couldn't look right at it) and provided a spectrum of light much closer to sunlight than fluorencent and even incandescent bulbs.

The light bulb is mounted inside a metal screen box which is the microwave cavity. Light can get out of the metal screen but almost all of the RF stays inside. Actually, once the bulb is on, almost all the energy goes into the bulb (that's why it's so efficient). Apparently, enough leaks out to disturb Wi-Fi etc.

The downsides of this technology (other than ruining your internet connection) were: [note: it may have evolved since I worked on it a few years ago]

(1) The bulb plus magnetron was pretty big, very bright, and somewhat noisy. Typical applications were warehouses and gymnasiums, not your home. Example: the Smithsonian Air and Space Museum replaced 88 soldium-vapor arc lamps with a handful of the fusion lighting bulbs. And they were THROWING HALF OF THE LIGHT AWAY by using diffuser tubes that spread it out and kept your kids from going blind when they looked up.

(2) The bulbs took a few moments to warm up when turned on. During that time, the light was a dim blue-violet color.

(3) Like sodium-vapor lamps, you couldn't turn them back on as soon as you turned then off. They had to cool down.

(2) + (3) = No fun if you forget the keys and then run back in to find them in the dark.

I was working on (2) and (3), as well as improving the efficiency, which would lead to a smaller size. We made some progress on all counts.

Lots of posts about how 802.11 is harmless...

[Tokerat]

...but what about the effects of the RF lights?

What happens when a nearby gas station installs RF lighting... and all 802.11b devices and 2.4 GHz cordless phones for a mile in diameter stop working?

Is this total FUD or is it grounded in facts about these lights? Personally I don't like the idea of RF lights that would interfere for miles. I woudl think they'd need suficiently more power to make light than a cel phone or 802.11 card ( > 4W?). A previous post mentioned that 2.4GHz is the resonant frequency of water. There is some water in gasoline. Sooooo.....gas stations are going to begin randomly exploding?

If my microwave doesn't kill my cel phone connection, it must be shielded prety damn good (it's a big ass 1500W). How come they can't just shield the lights and eliminate the problem?

Long Island Ice Teas

[sharkey]

They've done it again: "New Lightning Technology to Wipe Out Wi-Fi Access". Well, no shit. Lightning will wipe out pretty much every computer component it touches.

Focus, focus.....oooohhhhh, lighting.

I'll believe it when I see it.

[n6mod]

I've heard this before. This was going to put us all out of business when I was at Metricom in '96.

Re:There are no stupid questions...

[MillionthMonkey]

if RF lighting exists at "[a] frequency that humans can't even see" then how the fuck can it illuminate anything?!?

Here's a fun little stunt: Put a small fluorescent tube in a microwave and "cook" it for a few seconds. (The tube won't survive this treatment because the filaments on each end burn out.) I remember a microwave salesman showing this to my parents, back in the seventies when microwave ovens were the next Big Thing and there was such a thing as a microwave salesman.

The oven won't be harmed. Or at least my college roommate's microwave still worked after I tried it on his.

Re:Ether nonsense

[matrix29]

But the Michelson-Morley experiment showed that there is no ether.

That's good. Ether puts me to sleep.

(Waits for comedic drumroll...)

Two words: Electronic Ballast

[ShavenYak]

Modern electronic ballasts run the fluorescent tubes at around 20kHz. I doubt you can see flicker at that frequency.

Re:Incandescents

[MoneyT]

Hz, which is a measure of frequency is the number of times a cycle is completed in a second. A complete cycle consists of one max and one minimum. Therefore, if the are 60 maxes and 60 mins, the frequency is 60 Hz

the waste IS in your backyard.

[Erris]

If you have not noticed, little or no comercial spent fuel has been moved from any power plant. It's all sitting around their spent fuel pools. That puts three waste repositories within 100 miles of me. I go to work right next to it and a live core every day. I'm not loosing any sleep either. As Uranus Hertz points out, reprocessing is better. How about you, AC?

This is supposed to be a thread on light bulbs that blot out the growing free wireless internet. Oh well, there's always a legal solution to technology that treatens established interests.