Locklin on science

“AI” and the human informational centipede

Posted in fraud, stats jackass of the month by Scott Locklin on September 2, 2017

Useful journalism about technology is virtually nonexistent in the present day. It is a fact little commented on, but easily understood. In some not too distant past, there were actually competent science and technology journalists who were paid to be good at their jobs. There are still science and technology journalists, but for the most part, there are no competent ones actually investigating things. The wretches we have now mostly assist with press releases. Everyone capable of doing such work well is either too busy, too well paid doing something else, or too cowardly to speak up and notice the emperor has no clothes.

Consider: there are now 5 PR people for every reporter in America.  Reporters are an endangered species. Even the most ethical and well intentioned PR people are supposed to put the happy face on the soap powder, but when they don’t understand a technology, outright deception is inevitable. Modern “reporters” mostly regurgitate what the PR person tells them without any quality control.

The lack of useful reporting is a difficulty presently confronting Western Civilization as a whole; the examples are obvious and not worth enumerating. Competent full time reporters who are capable of actually debunking fraudulent tech PR bullshit and a mandate to do so: I estimate that there are approximately zero of these existing in these United States at the moment.

What happens when marketing people at a company talk to some engineers? Even the most honest marketing people hear what they want to hear, and try to spin it in the best possible way to win the PR war, and make their execs happy.  Execs read the “news” which is basically marketing releases from their competitors. They think this is actual information, rather than someone else’s press release.  Hell, I’ve even seen executives ask engineers for capabilities they heard about from reading their own marketing press releases, and being confused as to why these capabilities were actually science fiction. So, when your read some cool article in tech crunch on the latest woo, you aren’t actually reading anything real or accurate. You’re reading the result of a human informational centipede where a CEO orders a marketing guy to publish bullshit which is then consumed by decision makers who pay for investments in technology which doesn’t do what they think it does.

centipede pyramid

How tech news gets made

Machine learning and its relatives are the statistics of the future: the way we learn about the way the world works. Of course, machines aren’t actually “learning” anything. They’re just doing statistics. Very beautiful, complex, and sometimes mysterious statistics, but it’s still statistics. Nobody really knows how people learn things and infer new things from abstract or practical knowledge. When someone starts talking about “AI,” based on some machine learning technique, the Berzerker rage comes upon me. There is no such thing as “AI” as a science or a technology. Anyone who uses that phrase is a dreamer, a liar or a fool.

You can tell when a nebulous buzzword like “AI” has reached peak “human information centipede;” when oligarchs start being afraid of it. You have the famous example of Bill Joy being deathly afraid of “nanotech,” a previously hyped “technology” which persists in not existing in the corporeal world. Charlatan thinktanks like the “center for responsible nanotechnology” popped up to relieve oligarchs of their easy money, and these responsible nanotech assclowns went on to … post nifty articles on things that don’t exist.

These days, we have Elon Musk petrified that a near relative of logistic regression is going to achieve sentience and render him unable to enjoy the usufructs of his toils. Charlatan “thinktanks” dedicated to “friendly AI” (and Harry Potter slashfic) have sprung up. Goofball non-profits designed to make “AI” more “safe” by making it available as open source (think about that for a minute) actually exist. Funded, of course, by the paranoid oligarchs who would be better off reading a book, adjusting their exercise program or having their doctor adjust their meds.

Chemists used nanotech hype to drum up funding for research they were interested in. I don’t know of anything useful or interesting which came out of it, but in our declining civilization, I have no real problem with chemists using such swindles to improve their funding. Since there are few to no actual “AI” researchers existing in the world, I suppose the “OpenAI” institute will use their ill gotten gainz to fund machine learning researchers of some kind; maybe even something potentially useful. But, like the chemists, they’re just using it to fund things which are presently popular. How did the popular things get popular? The human information centipede, which is now touting deep reinforcement networks as the latest hotness.

My copy of Sutton and Barto was published in 1998. It’s a tremendous and interesting bunch of techniques, and the TD-gammon solution to Backgammon is a beautiful result for the ages. It is also nothing like “artificial intelligence.” No reinforcement learning gizmo is going to achieve sentience any more than an Unscented Kalman filter is going to achieve sentience. Neural approaches to reinforcement learning are among the least interesting applications of RL, mostly because it’s been done for so long. Why not use RL on other kinds of models? Example, this guy used Nash Equilibrium equations to build a pokerbot using RL. There are also interesting problems where RL with neural nets could be used successfully, and where an open source version would be valuable: natural language, anomaly detection. RL frameworks would also help matters. There are numerous other online approaches which are not reinforcement learning, but potentially even more interesting. No, no, we need to use RL to teach a neural net to play freaking vidya games and call it “AI.” I vaguely recall in the 1980s, when you needed to put a quarter into a machine to play vidya on an 8-bit CPU, the machines had pretty good “AI” which was able to eventually beat even the best players. Great work guys. You’ve worked really hard to do something which was doable in the 1980s.

“The bot learned the game from scratch by self-play, and does not use imitation learning or tree search. This is a step towards building AI systems which accomplish well-defined goals in messy, complicated situations involving real humans.”

No, you’ve basically just reproduced TD-gammon on a stupid video game.  “AI systems which accomplish well-defined goals in messy … situations” need to have human-like judgment and use experience from unrelated tasks to do well at new tasks. This thing does nothing of the sort.  This is a pedestrian exercise in what reinforcement learning is designed to do. The fact that it comes with accompanying marketing video (one which probably cost as much as a half year grad student salary, where it would have been better spent) ought to indicate what manner of “achievement” this is.

Unironic use of the word “AI” is a sure tell of dopey credulity, but the stupid is everywhere, unchecked and rampaging like the ending of Tetsuo the Iron Man.

Imagine someone from smurftown took a data set relating spurious correlations in the periodic table of the elements to stock prices, ran k-means on it, and declared himself a hedge fund manager for beating the S&P by 10%. Would you be impressed? Would you you tout this in a public place? Well, somebody did, and it is the thing which finally caused me to chimp out. This is classic Price of Butter in Bangladesh stupid data mining tricks. Actually, price of butter in Bangladesh makes considerably more sense than this. At least butter prices are meaningful, unlike spurious periodic element correlations to stock returns.

This is so transparently absurd, I had thought it was a clever troll. So I looked around the rest of the website, and found a heart felt declaration that VC investments are not bets. Because VCs really caaaare, man. As if high rollers at the horse races never took an interest in the digestion of their favorite horses and superfluous flesh on their jockeys. Russians know what the phrase “VC” means (туалет). I suppose with this piece of information it still could be a clever Onionesque parody, but I have it on two degrees of Erdős and Kevin Bacon that the author of this piece is a real Venture Capitalist, and he’s not kidding. More recently how “Superintelligent AI will kick ass” and “please buy my stacked LSTMs because I said AI.” Further scrolling on the website reveals one of the organizers of OpenAI is also involved. So, I assume we’re supposed to take it seriously. I don’t; this website is unadulterated bullshit.


Gartner: they’re pretty good at spotting things which are +10 years away (aka probably never happen)

A winter is coming; another AI winter. Mostly because sharpers, incompetents and frauds are touting things which are not even vaguely true. This is tragic, as there has been some progress in machine learning and potentially lucrative and innovative companies based on it will never happen. As in the first AI winter, it’s because research is being driven by marketing departments and irresponsible people.

But hey, I’m just some bozo writing in his underpants, don’t listen to me, listen to some experts:





Edit Add (Sept 5, 2017):

Congress is presently in hearings on “AI”. It’s worth remembering congress had hearings on “nanotech” in 2006.


“By 2014, it is estimated that there could be $2.6 trillion worth of products in the global marketplace which have incorporated nanotechnology. There is significant concern in industry, however, that the projected economic growth of nanotechnology could be undermined by either real environmental and safety risks of nanotechnology or the public’s perception that such risks exist.”

Edit Add (Sept 10, 2017) (Taken from Mark Ames):


Kickstarter: muppets threaten lawsuits!

Posted in fraud by Scott Locklin on March 5, 2013

I received this childish threat via email today from Mr. Tommy Joseph. Obviously, he has never heard of SLAPP laws.  I’ll remove the photo of his dumb idea, because I am a nice guy, though it certainly does not infringe on any copyrights, and provide a link instead. The text of my assessment of their project will remain unaltered, as is my “fair use” quote from his pitch.

I’ve been threatened with lawsuits by scarier people than Mr. Tommy, and would dearly love for him to attempt to follow through with this. As far as I know, the laws of physics are still protected by the laws of the United States. This will also be forwarded to kickstarter and kicktraq. Mr. Tommy is encouraged to defend his project online, though I’m happy to take his money should he attempt to follow through with this lawsuit.


Sent by Certified Mail and Email

March 5, 2013

Dear Scott Locklin,

I am writing on behalf of Epiphany Laboratories LLC (Epiphany) to notify you that your unlawful copying of Epiphany’s materials on your website infringes on Epiphany’s exclusive copyrights and trademarks. Accordingly, you are hereby directed to CEASE AND DESIST ALL COPYRIGHT AND TRADEMARK INFRINGEMENT.

All copywrightable and trademarkable aspects of Epiphany’s materials, including its logos, names, word marks, images, and videos are protected under United States intellectual property law and Epiphany Laboratories LLC is the owner of such copyrights. Under United States intellectual property laws, Epiphany’s copyrights and trademarks have been in effect since the date that the materials were created.

It has come to our attention that you have been copying our materials. We have copies of you unlawful copies to preserve as evidence. Your actions constitute copyright infringement in violation of United States copyright laws. Under 17 USC 504, the consequences of copyright infringement include statutory damages of between $750 and $30,000 per work, at the discretion of the court, and damages of up to $150,000 per work for willful infringement. If you continue to engage in copyright infringement after receiving this letter, your actions will be evidence of “willful infringement.”


In addition to infringing Epiphany’s copyrights, you have made allegations on your website that are without substance, untrue, and that we regard as damaging to our reputation and the reputation of our customers. At this time, we demand that you remove such allegations from the web and cease and desist from making any allegations or passing any false and unsubstantiated public comment directly or indirectly on our company, products, services, or companies who may use our technology.

1) Cease and desist your unlawful copying of Epiphany’s materials
2) Contact all persons and entities to whom you have directly or indirectly provided copies of Epiphany’s materials and inform them that such copyright/trademark-protected materials belonging to Epiphany Laboratories LLC were provided improperly in infringement of the rights of Epiphany Laboratories LLC.
3) Provide Epiphany Laboratories LLC with contact information for all such persons and entities
4) Cease and desist from making any unsubstantiated allegations or passing any false or unsubstantiated public comment directly or indirectly relating to Epiphany, its products and services, or customers who may use Epiphany’s technology.
5) Send written retractions to all persons and entities to whom you have directly or indirectly distributed the unsubstantiated allegations relating to Epiphany’s products or services
6) Remove all content and references to Epiphany (including Epiphany and/or onE Puck) from the website https://scottlocklin.wordpress.com, and any mirrors and references and replace your original “Kickstarter: muppet graveyard part 2” article with the following statement:

“Epiphany Laboratories LLC has requested that I remove my original article entitled ‘Kickstarter: muppet graveyard part 2’ as it contained numerous inaccuracies and material subject to their copyright and trademark protection. I would also like to apologize to Epiphany for misrepresenting the capabilities of their products and for distributing copyrighted and trademarked content without permission.”

7) Provide Epiphany with prompt written assurance by 12:00pm EST on March 7, 2013 that you will comply with the foregoing.

If you do not comply with these cease and desist demands within this time period, please be advised that Epiphany Laboratories LLC will pursue all available legal remedies, including seeking monetary damages, injunctive relief, and an order that you pay court costs and attorney’s fees. In addition, Epiphany is entitled to use your failure to comply as evidence of “willful infringement” of copyright and seek monetary damages and equitable relief for your copyright infringement. In the event that you fail to meet this demand, your liability and exposure under such legal action could be considerable.

Before taking these steps, however, Epiphany Laboratories LLC wishes to give your one opportunity to discontinue your illegal conduct by complying with this demand by 12:00 PM on March 7th, 2013.

Accordingly, please send written assurance of compliance with this letter to:

Epiphany Laboratories LLC
825 N. Croton Ave.
New Castle, PA 16101

With an email copy to: accounts@epiphanylabs.com.

If you or your attorney have any questions, please contact me directly.
Tom Joseph
Epiphany Laboratories LLC


Further conversation with Mr. Tommy:

Thank you for your prompt response and for removing our images and video. However, the Epiphany Laboratories wordmark and Epiphany onE Puck wordmark remain our intellectual property and must also be removed.

Regarding you analysis of the laws of physics, you are mostly correct, but your assumptions about our methodology are not. Out of respect for your abilities as a scientist and seeker of truth, we will be happy to send you a onE Puck when they go into production so you can see for yourself that it does, indeed, work as promised.
Tom Joseph”

*****************my reply******************************

Your video was never even linked on my website. I actually took the picture from someone else’s website; it is very obviously public domain. Like I said: I’m a nice guy. If it hurts your feelings to use your picture to debunk your project; a link is just as good. If you continue to piss me off, I’ll simply put it back up. It has no digital watermark or copyright on it, and even if it did, parody is protected in this country.

As for those other things: you do not have the right to regulate what I say about your company because of “intellectual property” laws. Not in the US. Not even in Singapore. If that were true, there would be no reviews of products, anywhere, ever. If you have a registered trademark on them, show me the paperwork and, I’ll put <tm> after them. Just as soon as every other link to your project on the internet does the same thing.

I’m not mostly correct: I’m correct. While I am not active in academic research, I, too, have a Stirling project. I also have significant background in experimental physics; they even gave me a Ph.D. for some reason. As I said in my original post, if you have come up with something which works anything like you say, I’ll apologize profusely. Hell, I’ll probably invest in your company. Until then, my assessment stands.

I respect your entrepreneurial spirit, but I have no respect for your cowardly and ultimately laughable attempts to cow me into not saying bad things about your idea. Maybe you should spend more time building the freaking thing, and less time making enemies: you’ll get more done.

You have already done yourself significant damage; your threat will probably be linked on kicktraq, it has had about 1000 views in the few minutes since I posted it to my blog, and I’m about to send it to kickstarter, along with this conversation. Why don’t you quit while you are ahead?

Kickstarter: muppet graveyard part 2

Posted in fraud, investments by Scott Locklin on March 1, 2013

Perhaps people think I engage in hyperbole about Kickstarter projects. No, I merely speak the obvious truth. It is a place of fraud and deception, a place which takes advantage of well meaning nerds who don’t think critically. Remember my five criteria for a perfect Kickstarter marketing pitch? Let’s review.

  1. Make it hardware related. Most internet dorks know nothing about hardware and are acutely aware of  and embarrassed by their lack of interaction with the real world. This is how stupid  ideas like solid printing get traction. Keyboard warriors want to work in meatspace, but they don’t know how. For a small donation, they can be hardware hackers!
  2. Make it “open source.” Keyboard muppets luuuurve open source, as it gives them “free” toys to play with. It doesn’t matter if it costs money, it doesn’t matter if it actually functions; what matters is that it is freeeeeeee.
  3. Make it related to their nerd-dildo (aka their “smart phone”). Modern techno-muppets have a relationship with their nerd-dildo not unlike that between Gollum and his precious. Polishing the nerd dildo and giving it even more power … tapping into the love affair between a nerd and his dildo strikes powerful emotional chords.
  4. Make noises about a super great prototype which will be distributed via junky open source rep-rap solid printing.
  5. Make it related to some fashionable moral crusade. If this were a mere gadget, only the most devoted Gollum would care, but keyboard warriors are going to save the goddamned planet with their open-source nerd dildo!

My next example embodies at least three of the five points. It is a piece of hardware. It is supposed to power an iphone. And it is supposed to save the environment. What is it? A Stirling engine which powers an iphone using the energy from a coffee cup. Behold, the Epiphany onE Puck!


Quote from kickstarter site:

The idea behind the Epiphany onE Puck is to use a stirling engine powered solely by heat disparities, such as a hot or cold drink, a candle, ice, etc. These heat sources will provide enough power to the stirling engine to fully charge your cell phone battery. There’s nothing new about Stirling engines – they were invented in the early 1800s – but thanks to modern materials and modern electronics, we are able to put them to use in ways that weren’t previously possible.

So, now the new question is, How can a small device that powers my cell phone change the world?

Well, the fact of the matter is, it won’t change the world. It also explicitly violates the laws of thermodynamics, so it won’t do anything but line the pockets of the people pitching it. How do I know this? Well, several ways.

The first way is common sense. It’s obvious this won’t work if you have ever looked at a small gamma Stirling engine like this one. There used to be a home made coffee machine powered gamma Stirling in the lab. It was made by a skilled machinist who built scientific apparatus every damn day, and it made just enough mechanical energy to overcome friction and turn over; and this from a very hot coffee machine. There are others that actually do work on just a coffee cup; they don’t produce much more useful work than is required to overcome friction either. Small home made Stirlings are fragile things that end up using graphite pistons to overcome friction; it is a big achievement to make a little one that turns over at all. Check the model engine builder groups if you don’t believe me.

The second way is knowing about practical Stirling engines that do useful work. The ones that are actually efficient use complex mechanical tricks to extract as much energy as possible. One of the main necessities is for a better working fluid than air; so you end up with lots of pressurized seals and such, to keep in compressed helium or whatever they use. The very best ones are completely sealed and connect to the dynamo via magnet. They also require extremely efficient regenerators; this one pretty obviously has no regenerator. The efficient ones are always much larger than a coffee cup, to fit all the necessary mechanical junk in it. The model shown in the pitch is a toy gamma Stirling with none of these advanced features. One that never actually functions on video, mind you: an LED lighting up doesn’t impress me. Therefore, they fail at this project on inspection. I once had an idea to cool a beer can with a hand made, hand powered reverse Stirling cycle cooler. It can theoretically be done, but the design so far is intensely complex. Having gone through this exercise, I know they didn’t by looking at their proposal. Example from history: Philips spent decades making a 200 watt Stirling engine which, well, go look at it. It is hugely complex, and ultimately failed because it was too costly to manufacture.

The third way is to do math. How much energy is needed to charge a cell phone? Batteries in them hold 1200mAH at 3.7 volts, for 4800mWH. They use around 60mW when they’re suspended, which is why you need to keep your dumb phone hooked up to a charger all the time. But anyway, is there 4-watt-hours in a cup of coffee? That’s 4 times 860 calories, or 3440 calories. A calorie is conveniently the amount of energy required to raise 1 gram of water by 1 degree C. So, their 6 ounce coffee mug or 177 grams, at a generously hot 70 degrees C with generously cool 20 degrees in your room yields 12390 calories. So, all we have to do is get out a quarter of the energy in a hot cup of coffee to do this! I’m all excited. OK, how? Stirling engines? Let’s forget about all the practicalities of designing one, and just use the most theoretically efficient heat engine: the Carnot cycle. The efficiency of a carnot cycle is

efficiency = 1 - \frac{T_c}{T_h}

T_h and T_c must be in absolute temperature, Kelvin. So, what is the maximum possible efficiency of a heat engine at these temperature differentials?

efficiency = 1 - \frac{273+20}{273+70} = 0.15

It seems tantalizingly close, right? But it’s not. T_h is an exponentially decaying function of time, even without assuming the Stirling engine sucks energy into it. Integrating over time (an exercise for the reader; that’s enough LaTeX for you), you get an average efficiency number closer to 0.08. Only 1000 calories of mechanical energy can be retrieved even in principle from a coffee cup heat source. That’s assuming Carnot perfection. Real Stirling engines, using the maximum of tuning and technical innovations achieve 0.5 times Carnot on the heat pumped into them. Now we’re down to 0.04, or 500 calories. This is leaving out the fact that the design they are using is at best 5% Carnot; probably significantly less than 1%. What’s left in our calculation? Oh, actually, a Stirling engine can’t magically suck all the heat out of a coffee cup: most if it is radiated to the world. Call that a generous 10%. 50 calories left! What is that in mWH? 0.05. Less than the phone uses at idle. Adding back in friction, dynamo inefficiencies and real world gamma Stirling efficiency, the real result is pretty much zero.

There is a small chance I’m wrong about this one. Maybe they have some very innovative technique which actually can extract significant energy from a coffee cup. Should they make one that does something more than light up an LED, I will apologize profusely for saying nasty things. But it sure fails the sniff test from where I am standing.

Why do I bother? I hate it when people are paid for stupid technological shit. It robs the credulous and makes people who do real things look bad. Stirling engines are cool; I hope serious people continue to work on them. I just wish muppets would leave them alone. If you want a real Stirling engine, send money to the guys at Sunpower. They’re actual experts who can get shit done.

Kickstarter: muppet graveyard

Posted in fraud, investments by Scott Locklin on January 22, 2013

If another person sends me a kickstarter proposal, Lord Humongous help me, I’ll go light the nitwits who founded it on fire. I’m sure someone reading will say, “you mean ‘bad kickstarter proposal'” but that’s uselessly tautological: I have never seen a kickstarter proposal which wasn’t on the short bus. Mind you, I’m all for capitalism, the arts and  charity, but kickstarter is a place where all socially and technologically inept proposals go to … needlessly gather internet attention that would otherwise be more productively spent on cat memes. Just because it is on the internet and you need … technology … to see it, doesn’t mean it isn’t completely imbecilic.

The most successful kickstarter proposals I’ve seen seem to embody everything that is wrong with modern life. People who wallow in self righteous moral certitude will fund monumentally stupid ideas. Are you a professional vaginal kvetcher, worried about the tremendous social injustice of video games not having enough female characters which appeal to your personal neurono-libidinal peccadilloes? Do mean, nasty, pimply faced video game players make you cry when they laugh at your impostures? No need to do anything productive and hilarious, such as attempting to write a feminist video game: idiots will give you money to further whine about it in public.  The givers get to marinate in their superior state of enlightenment over pimply faced video game players who think feminist princesses are silly. The taker gets to continue her project of publicly proving the futility of a modern liberal arts education.

Subsidies for dyspeptic feminist dunderheads are probably the best use for kickstarter. More hilarious and offensive are ding dongs who think they can build environment-saving spectrometers out of cardboard and bits of DVD, and want you to pay for their “researches.” The pitch is a model of kickstarter imbecilities, and should be preserved in amber for it sheer perfection in catering to the tastes of the  modern day techno-muppet. Let me break it down:

  1. Make it hardware related. Most internet dorks know nothing about hardware and are acutely aware of  and embarrassed by their lack of interaction with the real world. This is how stupid  ideas like solid printing get traction. Keyboard warriors want to work in meatspace, but they don’t know how. For a small donation, they can be hardware hackers!
  2. Make it “open source.” Keyboard muppets luuuurve open source, as it gives them “free” toys to play with. It doesn’t matter if it costs money, it doesn’t matter if it actually functions; what matters is that it is freeeeeeee.
  3. Make it related to their nerd-dildo (aka their “smart phone”). Modern techno-muppets have a relationship with their nerd-dildo not unlike that between Gollum and his precious. Polishing the nerd dildo and giving it even more power … tapping into the love affair between a nerd and his dildo strikes powerful emotional chords.
  4. Make noises about a super great prototype which will be distributed via junky open source rep-rap solid printing.
  5. Make it related to some fashionable moral crusade. If this were a mere gadget, only the most devoted Gollum would care, but keyboard warriors are going to save the goddamned planet with their open-source nerd dildo!

I might  support such a thing if I thought it were possible or doable. Why not arm environmentalists with a bunch of spectrometers, and have them go hunt for pollution of various kinds? At least they’d be basing their ideas on something resembling science, and lowering the preposterous levels of chemical pollution is something all sane people can get behind. The matter is: the “engineering” on this gizmo is pathetic. It is some kind of refugee from a Make magazine project; it is abundantly obvious that nobody with a passing acquaintance with optics, let alone spectroscopy was involved in this project. In fact, the principal is a media guy with no apparent remedial physics making him qualified to build spectrometers. Not that this is a horrible thing; many self-taught amateurs have made important contributions to engineering and science. The thing is, amateurs need to know shit first. This guy seems to know nothing.

In a past life, I dabbled with spectrometer design. I knew enough about it that Zeiss (greatest, oldest and most careful optics company in the world) nearly hired me straight out of college to work on semi-spectroscopic optics that heals people’s eyeballs. If I weren’t unnaturally honest, I’d probably be in Jena, laboring in lucrative obscurity, pullling 6 week vacations and waiting for my Krauty pension to kick in. As such, I have a few (very rusty) bona fides in spectrometer design and can explain in laymans terms why this idea is completely retarded.

There are a couple of ways to do spectroscopy, all of which involve light interference. The one being used here utilizes a diffraction grating. A diffraction grating is, more or less, an optical gizmo with lines etched into it, which are similar in dimensions to the wavelengths of light which are of interest. When the wave front of light hits the grating, it bounces off in different path lengths, dictated by the grating dimensions. The resulting interference pattern reflects different wavelengths of light from the grating at different angles. So, red light will reflect off the grating at a different angle from blue light, because red has a longer wavelength than blue. It’s not important that you understand this, though college physics will suffice. The important thing to remember: different wavelengths of light, different angles. Here’s a useful infographic I stole from a real optics company:

FAQ Optics - Grating Equation

The way a spectrometer with a reflective diffraction grating works, you take a small spot of light of many wavelengths, illuminate the grating, and the grating reflects the different wavelengths of light to different angles. To turn this into a spectrum, you need to detect the light at the different angles; use the grating equation to get the answer, and voila, you are a spectroscopist. Otherwise, you’re just looking at rainbows. What good is it? Well, different kinds of atoms and chemicals absorb light at different wavelengths; you see lines in the resulting spectrograph on your detector. Like this:


The light into the contraption needs to be small in physical dimension, otherwise, you won’t be able to distinguish one wavelength from the other. Remember, you have to distinguish things, otherwise these lines will overlap. You can generate the light all kinds of ways; by burning interesting shit, sticking it into an electrical discharge or by passing some other kind of  white light through something semi-transparent which absorbs distinguishing lines; whatever. The spectrometer needs to be rigid; if anything moves inside it, you’re going to be integrating a jittery blur, rather than building up a nice sharp line on the detector. The grating spectrometers I’ve used are often bolted to giant pieces of granite to avoid this sort of noise. Also, oh yeah, your grating has to be perfect, or it won’t have any ability to resolve the sharp little lines. You can see why in the grating equation; it depends on the grating ruling, d; if it varies, you get smeared out lines. If it scatters light, or has an imperfect optical figure, it will distort the image on the detector, making for blurry lines, assuming you can see any lines at all. Oh yeah, it helps if your detector is perfect as well, or at least very big, so you can resolve tiny little lines. If you have some shitty 980 pixel wide camera like in an iphone, well, you had better be able to move the detector versus the diffracted image through lots of different angles if you want it to be able to resolve thin lines.

How do they solve all these problems? Well, they use a piece of DVD for a grating, and a piece of cardboard for the rest of the “spectrometer.” I’m not exaggerating: go look at it. They have a slightly better one which doesn’t work with phones, but it’s also made of cardboard.

As you might guess, an old DVD  makes a  shitty diffraction grating. The lines on the DVD grating are not even; they’re not even really lines; more like dots and dashes. If they were perfect or even vaguely useful, physicists would use them for diffraction gratings, because they’re a lot cheaper than ones you get from Richardson or Zeiss.

There are other Ph.D. thesis worthy matters wrong with this thing, such as calibration, integration time, polarization, scattering; it’s not even worth going over these things. These objects will never do what they’re supposed to do, which is perform as spectrometers. All these things will ever do is make rainbow patterns on a camera. That is not spectroscopy. That is looking at rainbow patterns on cameras. Go look at their results! I defy anyone to point to any results of theirs and characterize it as anything but looking at rainbow patterns; something you could do more effectively with the common prism; $7.99 at Edmund Scientific. Less for a whole spectrometer with much better resolution!

It gets worse. Imagine you could build a good spectrometer out of all this junk; one which does their claimed resolving power of 200. Congratulations; you have just spent a lot of time and energy building something you could purchase for a few hundred dollars. Without shopping around, I found a really awesome one, designed by people who are not walking, grinning tomatoes,  with much better sensitivity, resolving power, software and bandwidth, calibrated by real optical engineers, brand spanking new and with intelligent technical support for a grand total of $2k. How much money is your time worth? If I wanted a mini spectrometer, I’d get a job at MacDonalds and purchase one that is guaranteed to work. I mean, I could actually build a really badass visible light mini spectrometer in my workshop, but … why?

Oh yeah, we’re saving the environment with our cardboard cutout spectrometers. Right. Are visible light grating spectrometers useful for environmental remediation? No, they are not. If you want something like that, you need a much more powerful spectrometer.  Best bet is to use a mass spectrometer, which is another sort of spectrometer. Second best, and distant relative, maybe an FTIR. Finally, for a couple hundred bucks, the amateur environmentalist can buy a useful spectrophotometer and do Real Things, rather than jerking off with costly open source nonsense that will never work.

“Kickstarter the startup” is probably a great idea. The way the world presently works, people will fork out money for good intentions and bullshit that sounds cool. Kickstarter ideas… A functioning market would allow me to short things.