Of 3D printing and electricity from walking

It amazes me how easily people can fall for ideas that don't stand the test of just a little mathematics: there are people who believe that a 3D printer in every garage is as good an idea as generating electrical energy from tiles that people walk on.

As a proposed replacement for mass-produced products, the 3D printer represents an environmental disaster.

Let's take a Lego block as the example. My calculation is that a 2 x 1 block has about 400 cubic millimetres of plastic in it, which a 3D printer like the Up Plus can run off in a best-case 14 seconds.

The Up Plus is specified at 200 Watts, and that gives us a nice, convenient calculation: 200 Watts for 14 seconds is 2,800 joules of energy (since one watt second is one joule).

How does that compare with an extrusion process?

I don't have a number for Lego bricks, so I'll have to use public data and treat it as an “average” plastic. According to this document, from Europe's plastics industry, the whole industry produced 52 megatonnes of plastic in 2007, at an energy consumption of 3.5 million gigajoules.

That works out to 67 joules per gram of plastic produced – and if a 2 x 1 block weighs 1.6 grams, its energy budget is nearly 108 joules.

The 3D printer, on that measure, is 1/26^th as efficient as the extrusion process.

Sure, printers will get better, more efficient, quicker – but a 26 times efficiency deficit is a hell of a handicap to start with. Some things aren't subject to Moore's law – like the basic physics that a lot of the energy is needed to move the print head around, and you can't create a massless print head, so it's always going to need energy to move. It heats the plastic input mass to melting point, and heating element efficiency is capped by physics. And so on.

3D printers are interesting and exciting and they'll make huge changes out in the real world. It's just that its place in the hype world is bugging me.

Now, over to the “generate electricity walking idea, which also boils down to joules. The idea is so exciting that Adam Spencer abandoned his maths on Friday (May 3) to give it a kick along.

Whatever else it's generating, Pavegen is generating buzz. And what for? Generating real electricity, about seven joules of it, every time someone steps on a Pavegen tile.

I'm going to make two assumptions: that it takes about a kilowatt-hour to actually fabricate the tile, transport it, install it, and extract electricity out of it; and that each step generates seven watts for one second. At seven joules per step, it will take that tile about half a million steps to pay back its energy budget: if it's in a high-traffic spot, with 1,000 people stepping on it each day, that's 500 days.

After that, it's generating free electricity. At a thousand steps per day, you're getting a whole 7,000 watt-seconds out of the tile – enough to run one 11 watt compact fluoro lamp for about ten minutes. Turn the lamp off for a while and you've got the same environmental benefit as from the Pavegen tile, without the capex.

Of course, if it takes more energy to create the Pavegen, it gets worse – if it takes 10 kW to make, deliver and install the Pavegen tile, then the payback is five million steps.

And once again, I strongly suspect, physics is going to constrain the whole idea. There's only so much energy you can extract out of a footfall. Most of the available energy has to be available for the person to walk with, after all!

Confirmation bias is not journalism

The more you put in a brain, the more it holds. But you can't run a deficit: you actually need stuff to put in.

Most of the time people complaining about “mainstream media” aren't actually helping. They want journalism to stop being journalism, and instead confirm their existing world-view.

They're not actually complaining about “factual reporting”. They want a political position that agrees with theirs, and if they don't get it, they won't buy.

You idiots: all you're doing is forcing a polarisation that makes the actual newspapers worse, not better. You – both sides, left and right – are forcing an exclusion of the middle where most people actually live.

Look, you idiots: sometimes, facts can't be massaged into a political slant. Insisting that they do so is just as stupid as editors that try to do so – editors who are as easily led by the nose as asses are (but the nose-ring of the modern editor is some focus group of poor schmucks answering questionnaires in exchange for a cheese platter).

So. You're going to endorse a story because it was written in a style you enjoyed, took a position you enjoyed, slagged the right political victims, took the right position?

Really, you're an idiot. A solipsistic brain donor. Instead of wanting to know more about your world, you want to know less; you don't want information, but confirmation.

You are undermining not only the media – by encouraging their own solipsistic lock-up into arsehole-gazing, but by encouraging them to confirm your own – you're undermining democracy, by elevating Vaudeville over substance, sizzle over steak.

Sparkle is fun, but it isn't illumination.

And the stupid folly of it all is that you think that Social Media is replacing MSM when most of what it's doing is re-Tweeting MSM with the gimcrack endorsements of the worst crap MSM has to offer.

Frankly, you dills, the reason MSM has become a parody is because you endorse the parody – but only from the intellectually-crippled frame that interprets the journalist's job as endorsing your own shorthand politics.

If “bitchy to the other side” is a reason to endorse untruths, you aren't thinking. You're just knee-jerking to the idea that either Julia Gillard is Juliar or that Tony Abbot is PhoneyTony. That's slogan, you fools, and it doesn't help you.

If you endorse the offhand, one-handed ejaculations of a post-lunch editor as gold, and dismiss factual reporting as politicised, you're worse than a fool: you are engaging in the destruction not just of media, but of debate and democracy. And I have no truck with you, left or right.

Nutlessness as a service

Any tech journalist who discusses Malcolm Turnbull's "policy launch" tomorrow without quizzing him on it acting in the service of politics without the chance to examine the policy-maker, and is a fool.

Whatever else we know about Malcolm Turnbull's broadband plans, they represent brains without balls.

Brains tells us that everything you say about broadband in Australia is an attack launched on a government that can't take a trick, even with fourteen trumps in its hand.

Balls?

There once was a man from Devizes

Whose testes were two different sizes

The one was so small

It was no ball at all

The other won several prizes.

When it comes to a broadband policy launch, is Malcolm Turnbull winning prizes?

Don't make me laugh: he's keeping the gig to the morons, partisans, gourmands, time-servers, place-seekers, and dyspeptic dipsomaniac brain-donors of the press gallery.

Having handed a gift of a policy that's already risible – virtue of its red-handkerchief $90 billion – to a witless goon at the Daily Telegraph, Mr Turnbull is now ignoring every approach to journalists with, you know, experience in the telecommunications market.

He's quite free with his advice, criticism and public denigration of journalists that don't agree with him. I've had “why won't you call British Telecom?” (answer: I did) and is happy to tell me what I've misunderstood, forgotten or added up wrong, should I dare to run a spreadsheet over the NBN or any similar project, anywhere else in the world.

I've offered to quiz him at any public press forum he chooses, and never once received a reply.

With 25 years experience in writing about the telecommunications industry, and – if I include my original training at the Overseas Telecommunications Commission – close to 30 years all up around telecommunications, I'm not on the invite list for Malcolm's Great Broadband Policy Launch.

Because, unlike the lazy shit-for-brains that infest the gallery, for whom all politics is reduced to “the government said / the opposition hit back” or “the opposition said / the government hit back”, I am both numerate and familiar with all of the technologies that are proposed for modern broadband.

In other words, people like me – and I have – need to suffer his lame lectures about journalistic technique if we don't agree with him. He'll sit at the door, scratching and whining like last decade's hound that we're not going to the original source (that is, sources that agree with him). But we're not permitted to quiz him in a public forum.

In his broadband launch, Malcolm is going to be an original source – but only if he can share his fleas with other superannuated hounds.

What a lame joke: and this is the best brain in the alternative party of government.

What a joke.

Work that “$90 billion” figure, printed without question, query or even the simplest mathematics by the Daily Telegraph, the utter suckhole of journalistic suckholes in Australia, a place even facts won't use as their hospice because it's better to die in the gutter than have your brains sucked out by News Limited lizard-people with skull-drills and straws.

On today's number of households in Australia, that's well past $10,000 per household.

That number is so stupid – strike that, so utterly stupid – that any journalist worth the price of the headline and a Starbuck's coffee should have asked even one question:

“Since British Telecom is only asking a couple of thousand per kilometre for individual node-to-home connections, on the most inefficient model that human ingenuity can devise, what idiot gave you a convincing estimate of $10k per household for FTTH?”

Or even better: “Why did you believe an estimate that is many times every available international benchmark for FTTH rollouts, based on what's already been spent?”

Or even better: “This is a naked political lie. Put up or shut up.”

News Limited doesn't work that way. Its game is this: we will only run with the naked, unadorned press release, if we get it first. Go off to its IT pages and tell me I'm wrong: but only if you first poll the PR companies who know how the game is played. Give News a 24-hour break; that's all you need.

And it can even be utter drivel as ran in the Telegraph today.

Which is why experts aren't going to be welcome at Malcolm's little piece of theatre. It only took a few seconds with a spreadsheet – but the brain donors don't do numbers, they do “he said / he hit back”. Which is exactly the wank-and-dribble level of intellect Malcolm Turnbull wants covering his policy launch.

The one was so small, it was no ball at all

Poor of Australia: Stand Behind Broggers!

Thanks, John Brogden, for defining the problem.

There you were on the ABC show 730, valiantly toiling in your paid occupation as apologist for Porsche Cayenne buyers the nation over, the negative-gearing doctors'-wives of Double Bay, and so on …

Doing quite well until you had to try and convince people, whose superannuation won't buy a second-hand Honda Postie and whose entire wardrobe is worth less than your damn pinstripes, should grab pitchforks and torches to defend the interests of your clients.

Against what?

Against the old, poor, sick, the cancer patients with no private cover, the desperates trying to work four jobs to pay both the mortgage and the chemist bills, the staggering Alzheimer patients who can manage to get a prescription filled if there's a friend to help them, the single parents who somehow manage to get a couple of hours cash-in-hand at a cafe without either super or leave.

John, I won't even try to make this nice: your egregious, patronising, insulting and offensive plea to egalitarianism, that superannuation policy should be about “all Australians” – like hearing a Tsarist serf-owner of the 19^th century say “it's about all of Russia!” – is beyond crapulous.

Your threat to take up arms of advertising against the government is just odious, and completely out of touch. So here's a quick sample of the life of people who you're happy to have take the kicks on your behalf.

1. Can they skip the trip to the chemist? Before the safety net level, even familiar prescriptions can cost a bomb. Does the asthma feel okay, or do they head for the discount butcher to buy the preventer?
2. Darn. Need to register the car. That means the insurance, four tyres, and plastic that's already maxed. Wonder if the parents can lend a grand to tide things over?
3. Can't call mum to ask, because the phone got cut off and there's not the spare cash to buy a $20 prepaid voucher. Bugger.
4. “Hang on, why the final demand? I paid that bill” “No dear, that was the previous one.”
5. “I hate porridge!” “I know dear, but until Dad's working again, we really can't lay out $7 a box for Nutri-Grain. It won't be long.”

In among all this, I can just imagine the unsuperannuated rising in outrage at the unfair treatment that you and your peers might suffer – not will suffer, because we don't actually know what's in the budget until it arrives – not because the government will raid your superannuation accounts, but merely because they'll remove a tax break.

And there they will be: risking the sack for sneaking away from work early, losing benefits because Stand Behind Broggers is more important than turning up at Centrelink for ritual humiliation, laying out three nights' dinner-money on burgers to join the rally.

You can be sure that Jones will deliver a foam-flecked rant; instead of naff hand-drawn signs, someone from an ad agency has kindly thrown in a couple of hours for a nifty new Witch logo, and there's always a mate who runs a printing company so that things can be done properly.

And there they will be: the poor, the starving, the broke and the huddling, holding your signs and chanting your slogans to make sure that no Australian has to start retirement living without at least a Princess Crusies trip of some kind or other.

I can just see it. Can't you?

Greg Sheridan: stop it

Yeah, I know. He's A Serious Foreign Correspondent.

He's also a shameless fear-monger.

You see, Mister Sheridan, I'm of A Certain Age – when I was young, your predecessors in fear-spreading would find an excuse about once a year to draw maps of “nuclear devastation”. You know the kind: Vaporised at X kilometres, killed by the blast at Y kilometres, dead in the firestorm at Z kilometres, everyone in the last circle to die horribly from radiation sickness, and so on.

I have no way to assess how many kids got how depressed at this constant You-Will-Die theme.

The prophets of doom have been utterly miserable since the end of the Cold War. Oh, they try to stir up a good head of steam about Islam's Ultimate Plans for A Worldwide Caliphate, but their heart isn't in it. What satisfaction is there in frightening people who are already nuts enough to believe that Al Qaeda can take over the world?

North Korea is a gift from Rupert: nuclear-armed, belligerent and insane, and the belligerent howlers want us to all return to the appropriate state of atavistic fear that we abandoned when the Berlin Wall fell.

Take it from an old hand: don't fall for it.

I have no idea what motivates the Greg Sheridans of the world. Whatever makes someone want to see other people fearful, miserable and blighted is a disorder too deep for me to even discuss. The same bleak, hellfire Calvanist heart beats underneath the chest of the cyber-war fear-monger, the “here comes the Great Depression of three months from now”, the End-is-Nigh sandwich-board wearers, and on and miserably on.

So I'm calling this out. Greg, people are not “right” to be afraid of North Korea, no more than they're “right” to fear that they're going to get MRSA tomorrow and lose limbs, die in a crashing Qantas airliner, or be hit by a meteor.

What if North Korea launches a nuclear strike against the USA?

That ends North Korea as a problem. Is China going to go to international thermonuclear war over Pyong Yang? One that involves bombing, say, Sydney – just because there are a few spare missiles hanging around?

Don't be ridiculous.

If it did happen, what on Earth can you or I do about it? Worry? Oh, well, there's the cure for Dear Leader's mental malady right there?

Teach my children to worry, like I did when the odious, unprincipled bastards of another era scored sales by spreading misery?

I refuse.

What's the point of worrying about whether Pyong Yang is insane?

Save your worries, your concerns, your sleepless nights – save them for things that matter. The people around you, since you can't guarantee that your lives and loves will last the next 24 hours, with or without North Korea or Cassandra Sheridan. Worry about the mortgage or the business, the boss or the kids' HSC, not missing the next episode of Game of Thrones, what to have for dinner – the small, the close, the personal, the things you can hold and trust and love.

Don't listen to Sheridan: if you do, it won't improve either your life or your epitaph.

And anyhow, North Korea isn't about to bomb Sydney.

Payback for a 2,000 litre water tank: about four years

Update: I have a crow to eat. Playing citation hide-and-seek I find that the original benchmark included purchase, a pump, plumbing and installation. It's here: http://www.marsdenjacob.com.au/cms/index.php?option=com_content&task=view&id=53&Itemid=63 Thanks to Stilgherrian for getting the ball rolling (below). I have added other thoughts at the end of the post. 

Why do I let myself get sucked in like this? I could ignore this stuff on a Sunday, then someone points me at a dodgy statistic swallowed without chewing by an uncritical journalist, and away I go.

The dodgy statistic in question is this:

“Restrictions could also encourage ''inefficient'' measures such as rainwater tanks, which cost up to $2000 but held only $4 worth of water at 2011 prices, the report said.”

It's in this story about water pricing, and because the Sydney Morning Herald doesn't practice source-linking, you have to do a bit of Googling to find out that the report in question is this one, from the Productivity Commission (the quote is on page 184):

“For instance, a common 2000 litre household rainwater tank costing about $1500 to $2000 holds about $4 worth of water at current mains water prices.”

It's a very misleading statistic in two ways. First, I can't find any 2,000 litre water tank that costs that much – even an expensive under-deck tank can be had for about $1,300. Second, it assumes that the water in the tank is a static resource – hence the snitty crack about it containing $4 worth of water.

Sydney's price of water in 2011 was $2.103 per kilolitre (hence “about $4 worth”). If I run a fairly simple model, and use a $640 purchase price for the tank (from here), it's not a bad deal.

Here are my unrealistic assumptions:

1. The turnover of the tank is sufficient that each “fill” gets used.
2. The catchment is 8 meters x 8 meters (the roof area above my head right now).
3. 1mm of rain on 1sqm is 1 litre (this is assumed by every online calculator I see).
4. I used the Bureau of Meteorology Observatory Hill average rainfall here.

Under those conditions, that tank would deliver about $163 worth of water each year – paying for itself in around four years. And it's this that the Productivity Commission dismisses (with unsourced data and zero analysis) as “inefficient”.

Let's reverse the calculation. What do you have to get out of a $640, 2kl tank for it to achieve payback in five years? About 5 Kl per month – which means filling and emptying the tank 2½ times each month, or the equivalent of six days with better than 10mm rainfall per month.

Sure, there are other on-costs. Sure, this isn't a complete study. But even if I'm out by fifty percent, we get six-to-eight years of payback time for a water tank.

Addendum: As noted, the cost includes installation. However:

1. It's still silly for the PC to treat a water tank as $4 worth of static water.
2. Payback doesn't happen overnight, but it does happen.

I'd be interested to see what a better model would show!

Different privacies

The thing Google Glass enthusiasts don't get is this: it's quite possible for privacy to be specific to the medium.

There are things, for example, that someone is prepared to discuss in words, or even publish in text, that they would never, ever wish to reveal in images or live video.

If you read this and know me already, you know that my wife, Ms T, has an immune system disorder that requires heavy chemotherapy. And that chemotherapy has unpleasant side-effects.

Now, she's brave: she gave me permission to blog about the real world of chemotherapy, to try and counteract the images of smiling people with no hair that sell charity gim-gams, and the glamorous world of movie-chemotherapy of Noble Suffering. Chemotherapy, among other things, leads to copious vomiting and bowel incontinence, and it's a living hell when the planets align against you.

But that's text, Sergie. The worst of it – the real-world cleanups, the unscheduled showers, the extra loads of washing, the reassurance that someone isn't repulsive just because they've been injected with a drug that's two steps removed from mustard gas – remains private.

And then there's the Google obsession with its new cargo-cult, the not-yet-released Google Glass, a way to capture everything that happens to everyone if one psychotic company can just sell enough product.

Now imagine yourself in a situation: That someone you loved with nothing more than a disease is caught short during a shopping trip; that she makes a desperate dash to the public toilet, while you head in a different direction to buy underwear; and that some creep decides that this is going to get them a handful of YouTube hits.

Yeah, I can easily imagine that such creeps exist. I've had to deal with creeps with smartphones who thought that “this is the junkie getting to the doctor ahead of me” was a legitimate Tweet (Ms T isn't a junkie; the marks on her arms are symptoms of her disease, and she was at the time 35 kg because she was near death).

I can easily imagine men using video-glasses to upskirt women on stairs or escalators or any other chance that presents itself. Hell, I'm a man: Ms T, discussing this subject said “If you stop looking at women, I'll bury you. If you video them, I'll kill you, then bury you.”

But there are too many people, too vulnerable, who have to be in public. They all have to work, shop, visit the doctor, the dentist, the library, the butcher. They don't need some smug, solipsistic smart-arse with camera-glasses to publish their misery worldwide.

The humiliation of the helpless is the endless preoccupation of the nutless: and with Google Glass, all those guys with no balls will have their perfect humiliation to practise on everyone with more misery than they have.

So I will make this pronouncement: not on my patch. At least on those parts of the world that are my property, I will never permit anything that looks like Google Glass. Go elsewhere, you sad losers, and leave people to their unaugmented reality, with its imperfections and loves and privacy.