Superconducting sewage

One of the joys of writing a book like The Quantum Age (still just 99p on Kindle) is discovering new and interesting things - and one I particularly enjoyed was the deployment of quantum technology to deal with sewage.

Finding superconductors in powerful electronic devices and scanners may not be too much of a surprise, but a surprising example of an application of superconductivity - a totally quantum phenomenon - is a million miles away from the delicacy of Josephson junction powered SQUIDs (Superconducting Quantum Interference Devices). It is in sewage treatment. We live in a paradoxical world that is awash with water – it almost defines our planet – and yet at the same time where there is a shortage of clean drinking water. It shouldn’t be that way. The world contains around 200,000,000,000 litres of water for every living person.

If you think of that in terms of consumption, assuming a typical 5 litres a day, the water out there should last over 100 million years. And that would be if it were all used up, where we know in practice that most of the water we consume is released back into the environment in short order. Of course that 5 litres only represents our direct consumption. A typical Western water user will be responsible for up to 10,000 litres a day. In part this is due to washing, watering the garden and flushing the toilet, but also because of the indirect use in the production of the goods we buy and the foods we eat. Just one hamburger takes around 3,000 litres, while a 1 kg jar of coffee requires a massive 20,000 litres. (Though once again, most of this water will be recycled – it doesn’t remain in the product.)

The problem, of course, comes not from poor availability of water per se, but the lack of clean drinking water in the right place for those who need it. Arguably this makes any water shortage more of an energy problem than anything else –that’s the energy required to clean up the water, whether it is desalination or removing dirt and sewage, and to get the water to where it is needed. And superconductivity can play its part in overcoming this. Most existing waste water treatment – whether cleaning up sewage or cleaning water from a river to use in an industrial plant – is expensive to build and has to be on a large scale to be cost effective. There are many circumstances where a smaller, distributed system would work better and, surprisingly, superconductors offer a solution to cleaning water that is both more cost effective and compact than a conventional treatment plant. What’s more it works more quickly too.

The process makes use of a powerful superconducting magnet to separate off the suspended material in the water. This is obviously fine for magnetic metals, but it seems an unlikely solution for the rest – the typical gunk that we associate with sewage and polluted water. But by adding a substance known as a ferromagnetic adsorbent to the water this mess become accessible to magnetic fields. The suspended particles stick the adsorbent material, which is then dragged out of the water by the magnets leaving clean water behind. The only way to get a sufficiently strong magnetic field is to use superconductors. Quantum physics to the rescue.

Why I hate opera

If I'm honest, the title of this post is an exaggeration to make a point. I don't really hate opera. There are a couple of operas - notably Monteverdi's Incoranazione di Poppea and Purcell's Dido & Aeneas - that I quite like. But what I do find truly sickening is the reverence with which opera is treated, as if it were some particularly great art form. Nowhere was this more obvious than in ITV's 2010 gut-wrenchingly awful series Pop Star to Opera Star , where the likes of Alan Tichmarsh treated the real opera singers as if they were fragile pieces on Antiques Roadshow, and the music as if it were a gift of the gods. In my opinion - and I know not everyone agrees - opera is: Mediocre music Melodramatic plots Amateurishly hammy acting A forced and unpleasant singing style Ridiculously over-supported by public funds I won't even bother to go into any detail on the plots and the acting - this is just self-evident. But the other aspects need some exp

Is 5x3 the same as 3x5?

The Internet has gone mildly bonkers over a child in America who was marked down in a test because when asked to work out 5x3 by repeated addition he/she used 5+5+5 instead of 3+3+3+3+3. Those who support the teacher say that 5x3 means 'five lots of 3' where the complainants say that 'times' is commutative (reversible) so the distinction is meaningless as 5x3 and 3x5 are indistinguishable. It's certainly true that not all mathematical operations are commutative. I think we are all comfortable that 5-3 is not the same as 3-5. However. This not true of multiplication (of numbers). And so if there is to be any distinction, it has to be in the use of English to interpret the 'x' sign. Unfortunately, even here there is no logical way of coming up with a definitive answer. I suspect most primary school teachers would expands 'times' as 'lots of' as mentioned above. So we get 5 x 3 as '5 lots of 3'. Unfortunately that only wor

Why backgammon is a better game than chess

I freely admit that chess, for those who enjoy it, is a wonderful game, but I honestly believe that as a game , backgammon is better (and this isn't just because I'm a lot better at playing backgammon than chess). Having relatively recently written a book on game theory, I have given quite a lot of thought to the nature of games, and from that I'd say that chess has two significant weaknesses compared with backgammon. One is the lack of randomness. Because backgammon includes the roll of the dice, it introduces a random factor into the play. Of course, a game that is totally random provides very little enjoyment. Tossing a coin isn't at all entertaining. But the clever thing about backgammon is that the randomness is contributory without dominating - there is still plenty of room for skill (apart from very flukey dice throws, I can always be beaten by a really good backgammon player), but the introduction of a random factor makes it more life-like, with more of a sense

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