MaxwellRainCoat

Goretex (invented by the Gores père et fils and Rowena Taylor) famously allows air and water vapour to pass through, but not liquid water.  It is a waterproof fabric that breathes.  Its trick is to sandwich a thin film of PTFE punctured by micropores in between two reinforcing sheets of conventional cloth.  The micropores allow air and vapour through, but are too small for a liquid to pass because of surface tension.

But it doesn't have a directionality.  The ideal garment would behave like Gortex, but only allow air and water vapour to pass out, not in.  That would keep you warm as well as dry, while still allowing a healthy flow of air.

The simplest one-way valve is a flap valve.  This uses the fluid medium that it is regulating as the source of power to prevent flow in one direction while allowing it in the other.  It ought to be possible to make micropores with additional microflaps over one end all out of the same material.  The flaps would not have to be perfect - we are after an aggregate effect (rather like Velcro, where not every loop catches a hook, but it still works fine).   A fabric made of such a material would allow gases to pass one way through it, but not the other and be exceptionally comfortable to wear.

Of course, if you can make the flaps small and light enough, right down at the atomic scale, then you have constructed a Maxwell's Demon...

ClockWork

If you live a blameless life, and then develop a brain tumour that turns you to violence, the law may need to restrain you, but it has no business punishing you.  This is a general legal principle that extends to pleas of insanity, diminished responsibility and so on.

In the - seemingly eternal - philosophical debate over free will a key point is often made that universalises this idea.  It is that, if there is no such thing as free will, then it makes no moral sense to punish criminals at all.  If all acts that people make are either determined or spontaneous, and people have no magic Cartesian inner pilot exercising willfulness, then every accused criminal is effectively in the same position as the tumour sufferer.  Their actions are the products of circumstances, rather than a brain lesion, but their social and moral position is indistinguishable.  Once again, restraint may be appropriate, but not punishment.  (Irrelevantly, I hold that view.  But this is not a blog about my views.)

This argument, though, contains a profound asymmetry that - as far as I have been able to find - is never pointed out.  If the criminal has no free will, and hence no moral culpability, then neither do the judge and jury.  We can't say that the criminals couldn't help robbing the bank without also saying that the jury can't help convicting them, and the judge can't help punishing them.

Either all the people in the system are clockwork, or none of them are.

FreePatent

This week, patents.

There are conservation laws for things like matter, and angular momentum.  You can't make more of either, or get rid of them.  If I have some angular momentum, and you take it, then I have less angular momentum.  But if I have an idea, then it doesn't matter who else knows about it - I still have the idea.  Information isn't a conserved quantity like the matter in my TV and my car, and the energy they use.  (And yes - I do know about the quantum Liouville theorem...)

It makes sense to prevent people stealing real physical property like TVs and energy.  But how can someone "steal" an idea?  The idea's creator is not, after all, deprived of it.

The creator is not even deprived of reasonable profit from the idea if someone else uses it.  All the creator has lost is their monopoly.  We usually consider monopolies to be a bad thing, and yet a monopoly is precisely what a patent or a copyright gives the creator of an idea.  If I want to make and to sell toothbrushes, then - quite rightly - I can't prevent your doing so too.  Why should I be able to restrict your freedom just because my idea is new?

The whole mad principle of "intellectual property" makes about as much sense as faith-based education or chiropractic, but it is entrenched.  How could we improve things without lots of lazy vested interests like drug companies and music producers bleating?

I propose the concept of a free patent (and its equivalent for copyright).  We keep patent law exactly the same, but add a "Free Patent" tick box to the patent application.  If a new idea's creator doesn't tick that box then they get their patent just like now.

If they do tick it, however, anyone else can use the creator's idea without paying any royalties.   But they have to pay tax on what they do, whereas the creator doesn't.

Governments would actually make more money in taxation - the non-idea-creator's tax bills would almost always outweigh the tax that would have been paid just by the creator alone.  The creator of the idea gets a real advantage from it - exclusively, no tax needs to be paid by them on the idea's exploitation.  And they also have no need to pursue patent infringers to keep their advantage (something individual inventors find financially impossible anyway).  So, finally, lots of lawyers have no patent infringement cases to fight and end up unemployed.

Result all round, I think.

NeuroBuster

It is notoriously the case that nobody in Hollywood has a clue what they are doing.

Specifically, nobody can tell the difference between a script that will be a blockbuster and a script that will be a turkey.  Possibly I should moderate that: maybe some scripts are definite turkeys.  One can't imagine that a script written by a six-year-old would make a fortune.  Or maybe it would...

Anyway.  From among the remainder, nobody can tell.

Perhaps it's time to take people out of the choice altogether.   I have written here before about stylometry: the battery of computational techniques used to compare the authorship of documents.  These techniques come up with a large number of statistics on a given document.  Comparing those statistics with the values from another document allows a probability to be assigned to the hypothesis that both were written by the same person.

But that's not all that one could do with such a large bunch of stats obtained from - in this case - a film script.  They could also be used as input to an artificial neural network.

Artificial neural networks are computer programs that learn to distinguish between sets of input parameters.  For example, you might want a computer program to examine CCTV footage from a road and automatically to flag up when there was a traffic jam on it.  In this case what you would do is to show the network lots of historical footage of the road when it was clear, and another lot of when it was jammed.  As the two sets of historical teaching footage have already been classified, the network can be taught to distinguish the two and to flag up one of two outputs: clear or jammed.

The stylometric measures from movie scripts are just as good a potential input to a neural network.  Hollywood has hundreds of thousands of old scripts, and of course it knows the blockbuster or turkey status of each.  You use those as the teaching input.  Once again the network has two outputs: produce this movie, or bin it.

Large numbers of expensive movie executives and their acolytes could be dismissed, and the whole problem of movie finance could be turned over to a PC.  When it lit up and rang its bell, a nearby secretary would pick up a phone and call a director from a list.  Job done.

Of course, this doesn't end with movies.  It would work just as well with TV scripts, and with novels.  Publishers would no longer have to flatter the pampered egos of their once-bestselling authors in the futile hope that they will be able to do the magic again.  All manuscripts, whether from the famous or the unknown, would go into the machine, and out would come a whittled-down but steady stream of copper-bottomed, sure-fire publishing sensations.

GolfTrap

Golf balls are denser than water.  They are also quite expensive.  Golf clubs (I understand) make a decent side income from the balls golfers lose in their course's water traps.

But that means that they have to extract them.  There are all sorts of expensive machines that attempt to fish the things off the bottom.  Alternatively, some clubs leave fine nets over the bottom of the traps.  This makes recovery simple, but it disrupts the underwater flora.

A better solution would, I think, be to make a duck-food dispenser.  This would be designed to give out a few duck pellets whenever a golf ball was dropped into it.  The birds would soon learn to retrieve the balls from the bottoms of the water traps in which they swim every day, and then to drop them in the dispenser to get their supper.

Of course they might also be tempted to steal balls from the fairways...

KinderSuperPosition

"I think I can safely say," said Richard Feynman, who understood everything, "that nobody understands quantum mechanics."

Quantum mechanics just doesn't gel in the human mind.  We can use the mathematical language of quantum mechanics simply enough, but it doesn't paint a picture in our heads.  Language only has meaning, according to Wittgenstein, to the extent that it paints a picture.  He later revised this principle (the principle itself has obvious meaning, but paints no picture), but for many physical explanations that picture is still essential.

And almost the whole of our technology depends upon quantum mechanics, in the form of electronics.  Just think what more we could achieve if we all found quantum mechanics as intuitive as we find Newtonian mechanics.

My modest proposal, therefore, is to teach quantum mechanics at primary school to everyone, starting sometime around the age of five.  Of course, not every child will get it.  But then not every child gets music, or poetry.  That doesn't stop us teaching those subjects.

But for many children the principles and ideas of quantum mechanics will sink into their subconsciouses, which will work their usual magic, making the ideas instinctive when some of those children, as adults, encounter them again.

Then we will have a whole generation the physicists and engineers who will both understand the mathematics of quantum mechanics, and also find that it chimes with their subconscious idea painter.

LiquidSolid

Liquid fuel rockets are good because you can turn the engines on, and - more importantly - off.

Solid fuel rockets are good because they are a lot simpler and cheaper, plus fuel storage is not a problem.

Liquid fuel has a higher specific impulse than solid fuel (typically 500 seconds rather than 250), but this is - in part - because of the necessarily inefficient design of a solid-fuel rocket: the entire rocket body is the combustion chamber.

The usual solid rocket fuel is a mixture of ammonium perchlorate, aluminium, and polybutadiene acrylonitrile, which is a synthetic rubber.  The latter is the binder, but it burns along with the aluminium in the oxygen from the ammonium perchlorate, of course.

Thermites (like copper oxide mixed with aluminium) would make lousy rocket fuels on their own.  They are very stable until you set fire to them, and they create a lot of heat, and both these are good.  But they give off very little gas, and so there is nothing actually to eject stuff out the back end of the rocket.  You just end up melting its casing.

But suppose you were to mix thermite with a binder?  That would decompose to gas to give an exhaust, and the exhaust would carry the metals from the thermite along with it out of the nozzle.  And, because copper has a high atomic weight, the exhaust gas velocity needed to carry a given momentum would be low and easy to control.   Lead oxide and aluminium should work even better in this regard, though it might not be a good idea to get downwind of the exhaust...

But we still haven't solved the control problems for a solid fuel rocket.  How do you turn it off, and then on again?

Instead of making the entire rocket body one solid lump of fuel, lighting it at the bottom end, and then running away as fast as your legs can carry you, why not wind a filament of rubberised solid fuel into a reel?

The reel would fill the entire body of the rocket, except for a liquid-fuel-sized engine at the bottom.  You would unwind the reel and feed the filament into the engine, where it would be ignited.  If you match the filament feed rate to the rate of burn, the thing would run steadily.  To shut the motor down, simply guillotine the filament then stop the feed.  To start it again, start the feed and re-ignite.

It ought even to be possible to arrange things so that, as the filament unwinds, the reel moves slowly inside the rocket body to keep its centre of gravity in the same place, making flight control much simpler and the rocket more stable.

PhotoCrawl

At a party in Washington in November 1954 a general confided in Richard Feynman that what the army needed was a tank that ran on sand...

The entire global capacity to generate electricity is about 5 TW.

To give you some idea of how big that is, if you were to weigh all the electricity humans generate in a year (we're talking E = mc² here) it would come in at about two tonnes.  A year of the world's electricity weighs about as much as a small truck.

To give you some idea of how small that is, if you were to cover a 200 kilometre square of one of the world's deserts near the equator with solar photovoltaic cells, they would comfortably generate more than 5 TW, at least in the daytime.  That's an area slightly bigger than Devon and Cornwall, or Greater Los Angeles.  A square metre of PV cells costs less than a square metre of Los Angeles.

But we don't want to plod about in deserts laying down PV cells that we've made in factories on a different continent.  It's expensive and, worse, it's hard sweaty work.

PV cells are made of silicon.  A desert (to a first approximation) is also made of silicon.  Getting that silicon out and turning it into PV cells needs energy, of course.  But if you have some PV cells to start you off, you have some energy.

So.  Let's build an autonomous robot that crawls slowly over a desert shovelling up the ground and refining it into solar cells.  These it connects up and lays down behind it as it goes, keeping its own connection to them to power the refining process.

After many years the PV cells will lose efficiency as they get scratched by sandstorms and the like.  The robot could work in a continuous cycle, like painting the Forth Bridge, going back to its start point then grinding up the worn old cells and re-refining them back to brand new ones in its wake.

Free green electricity for everyone for ever...