You can see it right in the Slashdot thread where people link to Youtube videos of this being done a long time ago. The idea of "stick a filter on a fan" isn't new because that's PRECISELY what air filters are. They don't make any bones about it.

So, why doesn't everyone do it? Well because it turns out DIY isn't much cheaper if you want it to work well. When I first heard of the idea, on Youtube, I said "let's try that!" Went and got out one of my box fans, bought a filter at Home Depot, and taped it all together. Well I quickly discovered two flaws with this system:

1) Furnace filters aren't near as good as HEPA filters, particularly not the multi-stage system good units have. It did reduce particle count, but not a ton. I could buy better filters, for sure, but then the cost goes up. Buying a filter with a large surface area like good units have gets quite expensive, much like the filters they have themselves.

2) A regular fan is not well suited to the static pressure you get trying to push through a filter. It had very little airflow. Better sealing would have helped some of that, but of course that's more money and effort, but part of it is you just need a good fan. That is again one of the things that the high end units have. They have a fan particularly made to deal with high static pressure, and a case made force lots of air through the filters.

So easier, and not really any more expensive in the long run, to just buy a filter unit. On the cheaper end of things, there's Austin Air units. Basically you pay $250 for a metal box with a powerful fan in it, and another $250 for a huge filter. Every 5 years or so, you pay another $250 for a new filter. Not the world's best filtration stats, but pretty good, better than furnace filters, and cheaper when you look at how long it lasts. At the high end that's IQAir. $1000 for a unit, but the unit and filters last a long time. I particular their HEPA filter can last a decade or more, provided you replace the prefilters when it tells you to.

That's the thing here: This is NOT a new idea, people were talking about it online a minimum of 6 years ago, and it is also not a hard idea since it is literally doing what the filters do. They are simple devices, they have diagrams of how they work on their websites. The cost is in a good fan, and good filters.

Finally, with regards to particle count, you need to be careful that you specify what size and have a counter that can deal with it. One of the reason IQAir units cost so much is they filter extremely tiny particles, like clean room level, viruses and so on. That is much harder to do than larger stuff. Now maybe you don't care, ok fair enough, but don't try and act like it is the same level of performance. You can very well get cheaper air filters that don't filter as well, or as small a particles.

There are reasons to want to own an air purifier even if you live in a place that doesn't have tons of pollution.

The most common would be allergies. If you get a decent one, it can nab pollen out of the air no problem. This can make living in a place where you have allergies to something much more tolerable.

They also help with dust accumulation. I live in the desert so we get lots of particles in the air, humans or no humans. An air filter can help clean that up. Makes it easier to keep the house clean.

Also the real good ones can get bacteria, even viruses, they filter things so small. So it can help limit the spread of disease in your house. Not a silver bullet by any means, but it can help keep the could a kid brought some from spreading.

Not saying China doesn't need to clean up their act, but these things weren't made because of their problems. The big names in it are western anyhow. IQAir (Switzerland) and Austin Air (US) are probably the two best known for high end, small units. In particular if you are talking a $1000 unit, that's IQAir. Their filtration is clean-room levels of good.

Cool. I hadn't noticed that feature.

So there really is no advantage to browsing in physical stores.

Yep, when it gets cheap enough people say "I wants," and that is all the more thought it takes. They may never get around to playing it, doesn't matter, they wanted to have it and now they do and they got a "good deal" on it so they are happy.

I do that ALL the time. I have more games than I can play. Not only that, I'm one of those who's very happy to replay old favourites. I really should buy new games pretty sparingly. However, when they are cheap, I buy them just to have them. As such a have a big list of games kicking around, particularly indy titles that tend to be cheaper.

Nonsense.

Look at Baen's model... the first few chapters of all of their books are available for free, all on-line, all trivially easy for you to browse and sample, at no risk, wherever and whenever it's convenient to you. For that matter, they offer full novels from their top authors for free. So you can read the first book of a 15-novel series at no cost, hooking you for the other 14.

How can book stores, with their limited shelf space and immobility, compete with that?

Of course, that's Baen, not Amazon. Because Baen is a publisher, they have the freedom to do things like offer the first ~50 pages free, while Amazon has to obey the publishers' rules. But in a world where browsing bookshelves is gone, Baen's approach, or something like it, will be necessary to generate sales, so it will be done.

Just because you're accustomed to one way of finding good reading material doesn't mean it's the only one, or even the best one.

Recode.net quipped that for an extra million, Alexander would show them the back door (state-installed spyware mechanisms) that the NSA put in consumer routers.

Only ONE of them?

What does this story have to do with Linux?

I assume you were going for "funny".

But on the off chance you (or some reader) is asking this seriously...

Slashdot is about things that are of interest to nerds. The approval process for new drugs (which might save, enhance, damage, or end their lives) is one of those subjects.

No dude, your books are not so incredible that people will buy them no matter what the price. There may be a few people who are like that, but most aren't. Price matters in entertainment. Turns out, when you make something cheap enough so that people don't need to think about spending the money and even more so they feel like they are getting a "Great deal" they'll spend very freely.

Steam has figured this out with videogames and siphons tons of money out of people's pockets, and has people thank them for doing it. People get drawn in by the "savings" of the sales and spend tons. I should know, I'm one of them. Not only do I have games I haven't played, I have games I haven't installed. I see something that I'm interested in that is a good price and I say "Oh man, I should get that," and I do. If they are more expensive, I think about it more, I wait until I really want a new game, I go and replay something I already enjoy.

Cheaper books will lead to bibliophiles just collecting the things. I know my mom would. You get them cheap enough and she'll drop hundreds a month on stuff she'll never read, just because she wants to have it.

Authors/publishers/developers/etc need to get over this idea of their digital goods being "worth" a certain amount. No, you need to figure out what you need to do to maximize your profits since there is zero per unit cost. Usually, that is going to mean selling cheap, but selling lots.

I'm getting a little bit tired of the never ending fascination with QM 'weirdness', because it seems to me that it tries to see everything as 'weird' simply because it is 'quantum', with the danger that that it makes people blind to what might be explainable by more intuitive means.

In this case I think we see an illustration of the fact that the notion of a particle as a mathematical point in space - something with zero dimensions - is an abstraction; an approximation that works well enough because we can't in that much detail any way, and it makes the equations so much easier. We have always known, somewhere, that this is not true - things like the mysterious wavefunction that mysteriously collapses as soon as we measure it is a big hint, I would say. As explanations go, that one has always sounded a bit strained - hopefully we will be able to handle the maths of a better model in the not too remote future.

A more likely scenario, in my view, is that what we call particles is something more distributed in space, and that somewhere in that 'distributed particle' we can explain how a particle can travel through several paths at once. I mean, it isn't even an altogether new observation - the famous electron diffraction experiment shows something similar.

Obviously the only thing to do is to actually write a book about Amelia Bedelia's antics. Then all would be well with the world.

/ off to write a wiki article about how humanoid sexbots will free humanity from its chains

Now, why do I put such a subject header on my comment, when I know it will have me branded as 'anti-Semit' before I even start? Well, because it doesn't actually make much difference - as soon as anybody voices any concern over what Israel does to the Palestinians, they are stamped that way, no matter how carefully and well-intended their put their words. But maybe, just maybe, if I start out being provocative, I can get at least somebody in the automatically responding, pro-Israel faction to at least think and try to see the issue in a more nuanced way.

I am not against Israel's right to exist as a nation; I am pragmatic about it. The state that calls itself Israel is no doubt founded on a historically dubious justification, but it is a current reality and that is what we have to consider. But on the other hand, I don't think what Israel is doing is right, not by many miles. It is not right to annex palestinian territory - if it wasn't right of the European nations to establish colonies all over the world in the 18th and 19th centuries, then it isn't right for Israel to do this now.

And how can it be right for Israel to smash up Gaza's infrastructure, hospitals and schools, killing 10 - 100 Palestinians for every Israeli? The answer is of course, that it isn't. And the outcome in the long run is inevitably that Israel will erode the support it has in the rest of the world. The West has been far too permissive with Israel, because of a long, bad conscience for the Holocaust; but the power of Europe and America is on the wane, and the new powers don't have that historical background. At some point you guys will lose all your allies - what will you do then?

Most of us criticise Israel because we care, and because we expect that you can do so much better - if only you would try. But arguing with you is like arguing with Scientology or Jehovah's Witnesses; there is no honest dialogue taking place. All you do is look for ways to mishear or misinterpret any criticism, and find ways to twist it around as a weapon. Sometimes I don't think you guys want friends in the world; sometimes I think you are addicted to this never ending conflict, because if it ends, you have to look at yourselves and see what miserable creatures you have become; caricatures of the evil bullies that broke you during the Holocaust.

As wikipedia likes to say [citation needed]. You are right they report usage. You are wrong that zero is bad. Look up how FICO works.

Depending on the card it may not matter. I haven't used my amex card in years and they don't seem to mind keeping it open. I have had other cards close due to inactivity.

Also with regards to the 3% charge rate, that is something that likely wouldn't go away, even if everyone went cash. Thing is, cash takes a lot of work to manage. You have to count it (*and account for it) secure it, get it to the bank, etc. If you look at a cash heavy place like a Las Vegas casino you can see the large amount of infrastructure they have in dealing with that. It isn't free. Turns out 3% isn't such a bad charge for not having to deal with that.

My parents ran a small business and they really didn't care for cash transactions. They took it, of course, and it was maybe 10% of their business. However despite not having 3% (or I think like 2.7% with their processor) shaved off the top, they prefered less cash because of the extra work. If they had a cash heavy day it meant having to cycle money out of the register in to the safe, potentially having to go to the bank to get more smaller bills/coins, and having to make bank runs more often per week. All the time spent doing that was time not spent doing something else for the business.

Cash costs money too, which is why most places don't really mind the credit surcharge. Cash might not have a direct surcharge, but there's a cost to dealing with it and the more you deal with it, the more it costs, just like the credit surcharge.

Also, in the rare occasion you do find a business that'll give you a discount for cash (contractors are often like this) you always have the option of using it. It isn't like Visa pays for goons to follow you around and force you to use your card.

You have no idea how it works, do you?

Debt collectors are nearly always separate companies. So what happens is you get way behind on a payment, the company you owe tries and tries to get money, but they fail. Finally, they just write it off. They then sell your debt to a debt collector. These debt collectors buy it cheap, usually 10% or less of the original amount. The company takes the loss and goes on with it. The collector then tries to get money so that they make a profit on the debt, and not a loss.

Companies do not want to sell a debt because there's no way they can sell it for what it is worth. They'd much rather have the money.

Student loans are a little different, since Sallie Mae does both loans AND collections, and student loans they offer are usually government insured (so they get their money no matter what) and you can't discharge student loan debt. Also they are a complete cluster fuck of stupidity since they are basically the worst combination of private enterprise and government agency (they were originally government, now private, but have something of a special status). They are currently under investigation regarding their practices.

Normal consumer debt though, they don't want you to default on. What they would like is that you run up a lot of debt and they pay it off slowly, paying a lot of interest, but pay it on time and completely. They would not like you to default.