We made a Gauss gun in our dining room last night.

Take a few bamboo skewers, some blue-tac, some ball-bearings and some rare-earth magnets: Put them together and shoot a ball bearing across the room.

The hardest part of this process was getting hold of ball-bearings. It turns out that hardware shops no longer sell them. You can buy made-up bearings, but not the balls. Ebay provided 40 ball-bearings for the princely sum of \$4.50 including postage from China. The magnets also came through Ebay, although they were from a shop in Queensland.

It turns out that larger balls would work better than the 8mm ones I bought, but we managed anyway. The practical problem we discovered is that the magnets hold the ball in the center of their flat surface (if you look carefully you can see that on the right of the picture). With a 10mm-diameter magnet and an 8mm ball that means the ball sits off the improvised track and so did not always follow the desired path. Adding more balls to the stack after the magnet saw the third ball in line sitting neatly on the track though. But lesson for those who might come after – try to match magnet and ball diameter.

I’m now wondering if it’s viable to 3D-print a more effective track. I’m also wondering if we could do this in a circle or, even better, hanging like a Newtons Cradle but from a center-point (and, no, I’m not envisaging perpetual motion, just a couple of rotations). Anyway, for the moment this is an excellent and simple demonstration of momentum and magnetism in action.

Even our small test-rig really accelerates the balls. We were starting the first ball with the tiniest push so it was hardly moving; the ball coming out of the third stage was flying along. The slowest-motion video we could manage (reduced down to 4-frames-per-second) still shows the moving balls hitting our second and third stages as a blur. Exciting science.

We got the idea from a nice CSIRO video that largely explains the science. My understanding is that you need to set this up so your inputs into each stage exceed the force holding the next balls in place by enough to create acceleration. So the input ball has two forces working on it: momentum from the push and the pull of the magnets. As it hits the stage, being pulled in by the magnets, the force is transferred through the magnets and the stack of ball-bearings (thank you Mr Newton). The final ball bearing has nowhere to transfer the force but into motion and is also least attracted by the magnet as it’s furthest away. It shoots off only to be captured by the next stage and the process repeats itself.

So I was at a meeting recently where someone bemoaned the costs of delivering power to iPads. This was in a school situation so they were looking potentially at the cost of charging 1000 iPads. But what would it actually cost?

Although I can’t source the original, there are many articles from last year quoting a study by the Electric Power Research Institute (eg this article from Gigacom) which says that if you were to fully recharge your iPad from empty every couple of days it would consume just under 12 kWh of electricity over the course of a year. By comparison, a plasma 42” television consumes 358 kWh.

At, say, \$0.25 per kWh that would come to \$4 pa. Most people are paying less than \$0.25 per kWh and don’t fully drain their iPad over two days – so that \$4 is probably the higher-end cost. So even allowing for variation in usage and cost that’s not a lot of money compared to the cost of purchasing an iPad in the first place.

In the specific school context it was raised you would only be charging when school was on, let’s say 280 days; so, doing some brutal rounding, that would be an annual cost of around \$3,000 always assuming schools pay something like domestic electricity rates. \$3000 is a lot of money for some schools, relatively less for others. But putting this in another perspective charging an iPad draws less power than using a compact fluorescent light-bulb.

There are many, many complex issues with the use of iPads in schools, but I’m going to say electricity is not foremost amongst them.

Your car is speeding along a bridge at fifty miles per hour when errant school bus carrying forty innocent children crosses its path. Should your car swerve, possibly risking the life of its owner (you), in order to save the children, or keep going, putting all forty kids at risk?

This is the core of a question posed in an interesting article in The New Yorker today on Moral Machines.  Google’s driver-less cars are now legal in three US States and the author points out that in a few years time driver-less cars may not just be preferred, they may be mandatory: They don’t get distracted, don’t make phone calls, don’t drink. But the interesting thing in that future scenario is that: “That moment will be significant not just because it will signal the end of one more human niche, but because it will signal the beginning of another: the era in which it will no longer be optional for machines to have ethical systems.”

The tricky thing of course is a combination of choosing an ethical system and actually managing to program it in. Whose ethics do you use and how do you formulate them into a coherent set of rules. Asimov’s three laws are the usual starting point. But any analysis of even the first law “A robot may not injure a human being or, through inaction, allow a human being to come to harm.” reveals a morass of tortuous ethical conundrums. How much damage is harm, how consequent must the harm be – would a robot stop me having a drink or eating a doughnut because it’s not good for me and will lead to eventual harm? How do you judge the trade-off in the school bus question?

Programming a car to make a decision between the school bus or you is tough. It’s tough enough for humans to make those judgement calls. Just this week there was an awful accident north of Sydney when a car swerved to avoid hitting a dog and ended up causing an accident that saw several people lose their lives. In retrospect hitting the dog would probably have been the better call; but weighing the issue in a split second and balancing out practicalities and the ethics is something we’re simply not that good at on the fly.

Having spent all of this year teaching ethics to primary school kids immediately before I teach them programming and robotics and I’m only too aware of the contrast between the disciplines. I keep telling my technology groups that “the computer will do exactly what you tell it to” – if something is not working it’s because of the way you programmed or built it; it’s an entirely black and white issue. Ethics on the other hand is a field of not just 50, but thousands of subtle shades of grey.

This question gets even more pointed when you start talking not about cars but about robotic soldiers. That doesn’t have to mean some fanciful Robocop or Terminator – just an autonomous drone making it’s own decision about when to drop its bomb. That’s not even fanciful, it’s with us today. How do you build ethics into a situation like that?

Gary Marcus, in The New Yorker,  doesn’t provide an answer to these dilemmas but he does clearly point to the need for more time, effort and money to be spent on finding those answers.

The New Yorker article is here. There’s also a good Economist article on the same topic here.

You know all those wonderful Youtube videos and TV programs about launching helium balloons to space? You didn’t think it was a matter of just grabbing a few party balloons and letting them go did you? Of course not. But beyond the obvious need for some more serious kit in the way of appropriate balloons and tracking devices there’s also the issue of the rules.

Luckily the high-flying Robert Brand has a website dedicated to his space exploits and detailing what’s required for a lift-off from NSW. Brand’s website, wotzup.com, is a treasure trove of local practical information on balloons into space. Importantly this includes how to get permission from the Civil Aviation Authority for a launch.

In addition he’s just taken it upon himself to solve one of the key problems faced by local space-balloon-o-nauts – namely where to buy weather balloons. Brand is now selling 350gram Totex Balloons for \$45 including shipping.

It’s like a replicator on Star Trek when you think about it. You push a button on a computer and a real object appears. That’s what the dream of 3D printing is all about. Of course the reality remains a lot more clunky and expensive than that. But, if you are prepared to insert some waiting time into the process, Ponoko can make the whole thing seem seamless and easy.

Ponoko has been running since 2007; it started in New Zealand. Originally it involved laser cutting items but more recently it has upgraded to include 3D printing and CNC routing services. The idea is about as simple as it gets – you upload your design and a few days later you get a real-world version of it back in the post. So, yes, that’s not quite the Star Trek replicator but… There’s a lot to Ponoko’s claim to be ”the world’s easiest making system.” A key feature of the Ponoko system is that it gives you an instant online price for making your creation come to life – the entire process is automated.

Of course one of the tricks to all this is that you have to come up with the ideas in the first place and then draw them out using some 3D modeling software. Neither of those things is necessarily as easy as it sounds. If you have inspiration or a need for a particular widget, the first part is covered. The drawing up part is getting progressively easier as software develops; but is still tricky – especially in an environment where the computer is unforgiving, it will print out what you tell it to, mistakes and all. Ponoko is trying to address this by working with software developers and creating apps for specific design types but there’s still a way to go until it becomes easy.

If you are short on inspiration Ponoko has taken things a step further. You can browse through other people’s designs and have them made up for you – paying the designer for the privilege. At this level Ponoko is really just a market for designers. That’s a good thing, but it’s not the 3D printing dream.

That dream really has to encompass household objects. I break a cup and can get another almost instantly. Perhaps every household doesn’t have to have their own replicator in the wall, but there needs to be one on every corner, or within a couple of hours delivery time. Until then it is Ponoko and some patience.

Ponoko’s holiday gift guide is now on their website; It’s full of interesting things. My personal whimsical favourite is the 3D-printed flower-pot for your bike.

Sydney’s hoverbike maker is in search of a partner to get things moving along; or should that be ‘moving up’?

I was reminded of the Malloy Hoverbike by the news that American company, Aerofex, has conducted flight tests on its own version. Aerofex seems to have jumped ahead of Malloy who, thus far, has only managed tethered tests of his dual-propeller bike. Not an enormous surprise as Aerofex has resources not available to our local pioneer.

Malloy is based in Hornsby, in Sydney’s north, and is seeking a partner:

A real partner in the project, this includes helping with design and fabrication, revenue sourcing and testing.  You would need to be capable of mechanical design and  fabrication - aluminium and carbon fibre (carbon fibre not necessary as long as you have the fabrication skills – I can show you the rest)

I need to make parts test etc, and just do not have the time nor money to outsource.  I work on this almost entirely by myself, so it would be good to have another person working side by side, if even just for the motivation it provides.  I cannot pay you, but depending on what you can bring to the project, appropriate shares in the company.

Malloy is also looking for funding. He’s showing \$75,000 in donations at the moment – which has him a long way to go to reach his \$1.1M funding goal.

The whole hoverbike thing looks so cool and it’s possible we’re seeing a Wright brothers moment in personal flying in our own Sydney backyard. If you’ve ever seen the Star Wars scene where they fly hoverbikes through the forests of Endor you can only think this looks like fun. Whether it is practical is a whole different kettle of fish. In spite of the obvious press about hoverbikes replacing cars, Malloy’s own site lists the fare more practical applications of:

• Aerial Cattle mustering
• Search and Rescue
• Aerial Survey
• Wildlife and Parks
• Film
• Power-line Inspection

Without having to worry about fitting the bike into a car lane, I do wonder why the designs are not more like the fabulous Parrrot Drone toys, which seem amazingly stable and versatile with their four propellers: I’m sure there are reasons. There are also, probably, reasons why a bike that’s estimated to reach a ceiling of 10,000 feet doesn’t have a seatbelt as far as I can see: Makes my acrophobia kick in just to think about it.

If you are a daredevil with a head for heights, or an interest in this sort of engineering, full details on the hoverbike, and how to get involved, are on hover-bike.com.

Image credit: Malloy Hoverbike.

In many adrenalin sports the line between serene heart-pumping wonderfulness and sheer gut-wrenching madness is hard to spot. No matter how many times I look at Trike Drifters videos I’m still not sure where the line lies.

I hadn’t even heard of trike drifting before I came across this local Sydney operation whose aim is to “change Drift Triking forever”. I can’t say I know enough to be able to say if that’s a good thing, but given they are going about it through some pretty lovely engineering and production I applaud them. As I understand it ‘traditional’ drift trike’s basically start at the top of a hill and run down it, with the real skill being in sliding the back wheels around corners (thank you Wikipedia). They generally operate at speeds between 20 and 35km/h.

This Sydney team of industrial and electrical engineers have added a motor and now we’re talking about racing on the flat at 70km/h with the back wheels drifting you around corners. Or spinning on the spot at a speed which makes me dizzy just watching them. The team is also trying to get powered trike drifting recognised as a sport.

Regardless of your interest in motor sports (which for me is minimal) you have to appreciate a local team having the vision and skills to produce such a lovely bit of engineering. Even as a beta, their beast looks pretty cool. The renderings of the finished product are just stunning. And hurling yourself about a track at 70km/h on one of these things with the back wheels sliding out just looks both terrifying and glorious.

One thing is for sure I’ll never look at a toddler’s tricycle the same way again.