WindPower

We all want sustainable energy these days, what with fossil-fuel-induced climate change and the need for nations not to have to rely on dodgy foreigners to sell them the gigajoules they need.

Why don't we use the power of the wind?  I don't mean the pathetic flow of air over our own planet that we already capture with giant versions of children's toy windmills.  I mean an altogether more serious wind:

And I also don't mean capturing its kinetic energy.  That would be far too difficult, and it's not the main source of energy in the solar wind anyway.  The main source of energy in the solar wind is helium-3.   This isotope of helium is particularly suited for use in fusion reactors.  Fusion reactors are attractive because they are potentially very powerful, and because anyone can make one for a few hundred dollars.  Admittedly we haven't yet made one that generates more energy out than you have to feed in, but an abundant source of helium-3 and the combined genius of lots of garden-shed tinkerers might well change all that.

There is almost no helium-3 on Earth.  It has been proposed to mine the Moon for it, as the solar wind embeds it in the lunar regolith.  But the problem with that is that the Moon is a gravity hole that you have to expend energy getting down to, and then expend more getting up from.

Why not put a solar-powered satellite that is, essentially, a big electromagnet at one of the Lagrange points?  The solar wind is ionised, and so it would stream to the satellite's poles, like a mini aurora.

Of course, helium-3 is only a minor component of the solar wind, so it needs to be separated.  But here things start playing to our advantage.  The satellite would use the same technique that mass spectrometers use to produce a clean stream: when you pass an ionised plasma through a magnetic field, the ions deflect through different angles depending on their mass.  All you have to do is to put a collector at the correct angle to the magnetic field for an atomic mass of 3, and the helium isotope you want just falls into it.

If we got everything right, we could provide thousands of amateur fusion researchers with a fuel with real potential, and leave them to collaborate and to compete in the usual crowd-source way to come up with the best design.

And, when they give us our first energy-positive fusion reactor, we would have a non-polluting power source for the entire world that, as it would have been developed on-line by a collective, would be free of patent encumbrance.

Finally consider this: people working on fusion power are, of course, working on building clean power stations.  But — in some cases without realising it — they are also building the human race's first starship engine...

NumberCounters

The number of people with autism-spectrum disorders is increasing faster than the number of those with any other single neuropsychiatric condition.  Without doubt, this is partly discovery through better diagnosis techniques.  But there is significant real growth too.

People with autism are more than twice as likely than people without to have fathers and grandfathers who are engineers.   Further, it is known that autism is strongly heritable.

The Industrial Revolution made engineering one of the most secure of human professions.  Engineers only occasionally get rich and famous, of course, but they almost always live comfortable lives.  They are often among the last to find themselves unemployed when times are hard, and economic pick-up sees them in the vanguard of those back to work.

And a comfortable life is an optimal basis for the raising of children.  Perhaps, since the Industrial Revolution, simple Darwinian selection has acted to increase the proportion of descendants of engineers in the population.

Perhaps further, a side-effect of this increase is the increase in autism-spectrum disorders that we are now seeing.

SkateSlope

Ice is flat. Or rather, to be pedantic, ice forms a surface parallel to the geoid, an approximate sphere roughly 13,000 kilometers in diameter.  This is true of both ice on rivers and lakes, and also ice in ice rinks.

Making an ice rink is fairly straightforward.  You construct a shallow dish and lay plastic pipes across the bottom.  You fill the dish a few centimeters deep with water, then pump refrigerant through the pipes.

Skateboard parks, in contrast, are anything but flat.  This allows skateboarders the freedom to play with the interchange between their kinetic and potential energy, with - in competent hands (or rather, feet) - spectacular results and  broken bones.

Skateboard parks are made by pouring concrete into formers and letting it set.

But you could do just the same thing with ice.  The formers could contain the refrigerant pipes.  You would fill them with water, not concrete, then turn on the refrigerator.

The result would be like a skateboard park, but for people wearing ice skates.

DrugBust

Pharmaceutical companies spend a lot of their time, and ill people's money, patenting medicines.  They then have a legal monopoly on those medicines, which allows them to charge a great deal for them.  For example the anti-cancer drug trastuzumab (Herceptin) costs about €30,000 per year for one breast cancer patient.

Trastuzumab is a monoclonal antibody, so it is not as easy to make as making carbon dioxide by adding sulphuric acid to chalk, but it isn't that hard either.  You fuse cancer cells and spleen cells in a mouse that has been injected with whatever substance that you want the monoclonal antibodies to bind to.  In the case of trastuzumab, that's human epidermal growth factor receptor 2, which is a protein that makes breast cancers grow.  (In that particular case, you also can't use ordinary mouse cells as people react to mouse proteins, you have to use cells that make the human version.) Finally, you clone the cells to increase their number then use them to make the antibody.

These days all this sort of messing about is done by robots with pipettes, not by the pharmaceutical company employee above with the conical flask.

How much would such a robot cost? I build robots all the time, and I estimate that such a robot might - if mass produced - cost a couple of thousand Euros at most.

Here patent law (in Europe, not America) gets interesting: any private individual can make any patented object for their own use without infringing the patent.  They can't sell it, but they can, for example, eat it or inject it.

This means that national health services could loan patients a drug-synthesizing robot that cost less than a few-months supply of some drugs.  The patients could make their own drugs and thereby treat their disease with the latest medicines.

The health services would save a fortune.

BounceFractal

One standard way to make a fractal curve is to take a straight line, cut it in half, and move its mid-point a random amount. You then do the same with the two halves, but move their midpoints by a smaller random amount. If you keep going you end up after a few times with something like the picture above.

This is a way to generate artificial coastlines. If you do it with a triangle instead of a line and move the midpoints of its edges out of the plane of the triangle, you make an artificial fractal landscape (shown here flooded):


Here's a new way to do this sort of thing.

Take a box (blue) with a single diagonal line in it (black). Split the line in half and move it as far as you can without a disc on the split-point hitting anything. You get this:

Then repeat this on the two halves, with the exclusion disc reducing in radius at each stage and being imagined to be on every vertex of the curve:

That's it after six steps. Note that, although it looks random, it is entirely deterministic and its shape is set by that simple rule: split, and move as far as you can without the straight lines overlapping the discs.

Here it is after splitting ten times.

If you start with the four edges of a square (filled in red here so you can see what happens):


And let it run you get this:

For more on this idea see here.

SweatShirt

We sweat to dump excess body heat.

Sweating is an elegantly efficient mechanism that takes advantage of the fact that our most readily available liquid - water - carries an exceptionally large quantity of energy away when it evaporates. The enthalpy of vaporization of water is 2257 kilojoules per kilogram. This means that if you are exercising at 500 watts for half an hour (which is a good aerobic workout) you only need to evaporate 400 grams of sweat to carry away all the heat you generate. That's one large glass of water.

In practice, it works even better than that because you also lose heat by radiation and convection as well. But just because something marvelous has evolved, it doesn't mean that we can't improve on it.

As anyone caught in a rainstorm in light clothing knows, a wet shirt is very cold indeed, especially when the wind blows. It is sweating for you when you don't need it to.

We also deliberately get our clothes wet once each time we wear them: we wash them afterwards.

Poly-(N-IsoPropyl-AcrylAmide) is hydrophobic above 37^oC and hydrophilic below 32^oC. This means that at low temperatures it holds onto water, and at high temperatures it expels it. There are other materials with similar properties.

Suppose we were to make clothing incorporating these materials? If we were to wash them on a warm wash, they would absorb some of the final rinse water and then retain it when cold, feeling dry to the touch. But when we exercised in them, or simply found ourselves in the warm sun, they would start to give up their stored water.

Our clothing would keep us warm and dry when it was cold, then sweat for us when it was hot.

EPlane

Most electric aeroplanes tend to look like this. Make no mistake, the achievements of electric aero researchers are impressive. But the results always tend to look a bit fiddly and - both more importantly and more understandably - lightweight.

That example (Helios) is solar powered. Sunlight has a density of about 1 Kw per square meter, and conversion efficiencies don't get much above 30%. This means that you don't have a lot of power to spare, given a reasonable wing area. That is why the plane looks like it does.

The obvious solution - replace the sun with batteries - stumbles because batteries don't give a lot of power either. Worse, they are heavy.

Suppose we want to carry 300 people like this:


The source of power here (oil) has a specific energy of about 45 megajoules per kilogram. But the battery in your car only has about 0.15 megajoules per kilogram.

However, the battery in your car is 100-year-old technology. The specific energy of batteries has been increasing, and increasing more rapidly in recent years. The best we have today (lithium ion nanowire) gives about 2.5 megajoules per kilogram.

And batteries don't have to get to the energy density of oil to compete in aircraft propulsion. This is because electric motors are much more efficient than gas turbines. Typically, you can't get more than about 40% out of a gas turbine, but you can easily get 80% from an electric motor.

So when batteries get to ten times the energy density of the best now, it will start to make sense to power aircraft with them. And with the rate of progress in battery development that will probably take less time than most would imagine.

But there is a research gap. As far as I can find out, no one is trying to develop an electric aircraft turbine for passenger aircraft. Given the lead times for this sort of technology, this seems short-sighted to me. We are in danger of having the batteries for planes, and then having to take ten years to make engines to go with them. Engine development doesn't need to have the batteries available, as all the testing can be done on the ground.

A final point. At half the energy consumption of an equivalent gas turbine, an electric turbine will generate half the heat. This will have to be got rid of in the airflow, where it can be put to good use expanding the air and generating extra thrust.

PictureFrame

Having a picture framed is an expensive business - if the frame is going round a print it can cost three or four times as much as the print itself. And even if the frame is for an original painting it can cost a significant fraction of what the painting cost (unless you are the sort of person who needs to re-frame a Caravaggio).

It's also a difficult job to do yourself. Even the most careful amateur carpenter can have trouble mitering the corner of the moulding to get a perfect 45^o cut.


My father was a painter, and he would frame his own pictures for sale. The machine on the right used to live in our kitchen when I was a child. It is a Morsø mitering machine, and it makes the cutting of a perfect 45^o miter easy; anyone can get a good result with one of these. It guillotines the moulding to form two mitres simultaneously.

But it obviously makes no sense for everyone to have such a machine for themselves for use on the one occasion every two years when they want to frame a picture.

There are many products that are designed to break once cleanly. Think of the perforations around postage stamps, or of the ring pull on a Coke can. Why not make picture frame mouldings that have a series of 45^o indentations along the back every few millimeters designed to snap cleanly? The indentations would have to be symmetrical about the middle of a length of moulding with -45^o to the left and +45^o to the right. You could then buy two lengths a little too long for the width of your picture, and another two a little too long for the height, and make your own frame of any size you liked.

It ought to be possible to do the design with added clips that would fit into the remaining indentations to hold the corners together, so you wouldn't even have to use a hammer and nails.