Whisky Stones and Physics

Recently, for no real reason, I decided to buy myself some whisky stones.  These are little cubes of rock which you put in the freezer before adding them to a drink (usually alcoholic) which you want to be chilled.  The advantage over ice is that the rocks do not melt and dilute your expensive whisky (not that I drink that).  I have used them a few times and was quite disappointed to discover they don’t cool a drink very well at all, at least compared to ice.  The best they’ll do is stop it getting any warmer, but they are no substitute for ice cubes.  Now I’ve thought about it, I should have figured out why: a drink is cooled mainly by the process of ice cubes melting rather than their being cold, and I learned all about this in physics class at school.

There is a physics term called Specific Latent Heat which is defined as the amount of heat energy required to change the phase of a substance, i.e. turn it from a solid to a liquid, or a liquid to a gas.  This amount of heat is usually a hell of a lot more than that required simply to increase the substance’s temperature, and I remember my physics teacher telling us why you feel so cold when you step out of a shower: the heat taken from your body to evapourate the water is 2,265kJ per kg (which is, of course, why we have evolved to sweat to cool us down).  He also gave us an example of the effect in reverse: burns from steam are so much worse than those from boiling water because that 2,265kJ per kg is being transferred from the water onto the skin.

I remembered this reverse effect when I was in Sakhalin, and I noticed that the air temperature dropped right down when the snow on the ground was starting to melt.  Of course it would, because to change snow into water takes 334kJ/kg heat energy out of the air.  But somehow I’d forgotten this when I ordered the whisky stones and expected them to work like ice cubes.  My old physics teacher, wherever he may be now, would have given me a right bollocking for this.



There has been an awful lot of fuss recently about people believing in, or not being sufficiently sceptical of, creationism.  Sarah Palin has drawn huge amounts of criticism for saying she believed in creationism, and the director of education at the Royal Society has been forced to resign for stating that creationism should be discussed rather than excluded from school science lessons.

My question is: why all the fuss about creationism?

Now let me first state, I think the whole notion of creationism is barking mad and goes against a whole raft of scientific evidence not to mention basic common sense.  And I don’t think it’s a subject which should be taught in science lessons, although I think the outrage expressed at the mere suggestion that the subject should be discussed says more about creationism’s critics than its proponents.

But of all the stupid, ignorant, and unscientific ideas that are out there, creationism doesn’t strike me as being any less stupid, ignorant, or unscientific than a lot of ideas that pass for conventional wisdom.  Socialism being a viable form of economic management over market capitalism, for instance.  How many instances of teachers believing in and teaching the virtues of socialism over capitalism occur in our schools?  It’s not like there hasn’t been full-scale experimentation carried out on the subject, when we consider the Soviet Union, Mao’s China, and North Korea.  I remember being taught by a Glaswegian geography teacher that agricultural communes in China – the type which ensured Chinese never grew enough to eat – was a viable alternative to the type of farming practiced in the west.  Is this any more stupid, in the face of all the evidence, than creationism?

Sarah Palin believes in creationism, and she might one day be president.  Yet the incumbent president, and our own glorious leaders, believe in trade tariffs.  Putting all the evidence together on a table, which belief is more irrational?  And which belief causes more harm?

Sarah Palin chooses to defy scientific findings, close her ears, and believe the earth was created 6,000 years ago.  Most of the world’s leaders choose to defy an awful lot of scientific findings, close their ears, and believe the earth is heating up uncontrollably, and we the public must stump up billions in taxes to do something about it.  Which is the more irrational?  And which is most likely to cause me, you, and everyone else serious harm?

Yes, Sarah Palin is ignorant of scientific methods and findings.  As are most people.  The average Brit’s understanding of science is bordering on non-existent.  Last time I looked at a GSCE science paper, it required students to look at a picture of a thermometer and write down the temperature it read.  I believe that a requirement to balance a chemical equation disappeared from the chemistry syllabus years ago, and I have little confidence that a majority of the public would know the chemical formula of water.  Ask people how long ago they think dinosaurs lived, and calculate the variance of the answers.  Who do you know who can explain why the sky is blue?  Or leaves are green?  And what’s the difference between wavelength and frequency?

Just for fun, I’ll throw in this anecdote.  When I was staying in Owens Park hall of residence in Manchester the TV reception in my room was awful, but was okay if I dangled my small internal aerial out of the window.  One of the tutors collared me and told me to bring it inside.  Because it was dangerous.  Apparently, if it rained, sparks could come off the wire and cause a fire.  I fear that in general people’s understanding of science and engineering isn’t much more advanced than this.

So I find it a bit ironic that people who inhabit a country where scientific ignorance is rife amongst the general population and its politicians (who endorse expensive regulations to eliminate substances in quantities proven for centuries not to harm us) should castigate a vice-presidential candidate for believing in something unscientific.

But I find it baffling that it is creationism which, out of all the stupid beliefs which are out there, gets held up as the one which demonstrates unsuitability for public office.  Whereas economic idiocy is no barrier to entry.

Like I said, I’m baffled.


Carbon Confusion

Even though I suppose I’m an engineer of some description, I still consider myself to be more of a scientist than the average bloke in the street.  I feel sort of entitled to think this having sat through 2 years of the most mind-numbingly boring A-level chemistry lessons which would have made watching paint dry seem like an adrenaline sport.

At any rate, I consider myself clued up enough to spot glaring errors in Guardian articles on the environment: 

Yesterday the holiday company Airtours launched what it claims is Britain’s first round the world package holiday: a 23-day whistlestop tour of 10 countries at a cost of £4,499. Scheduled to take off from Manchester airport on February 27 next year, the Airbus will carry 329 passengers, three pilots, 10 cabin crew, 10 holiday reps and a doctor.

As environmentalists were quick to point out, they will also emit a staggering 2,289 tonnes of carbon – equivalent to the weight of 286 double-decker buses.

Sorry?  They’ll emit carbon?  As in soot?  Product of unburnt fuel?  I never knew aeroplane engines burned so rich.  Maybe they should get under the engine cowlings and play with the mixture screw a bit.

Or maybe they are on about carbon dioxide, the greenhouse gas they are all so worried about, too much of which is going to cause the earth to heat up a bit.  Sitting on Sakhalin Island watching the thermometer plumb to minus six this morning I fail to see what the problem is.  But whatever my meteorological preferences, the terms “carbon” and “carbon dioxide” are not interchangeable any more than “hydrogen” and “water” are. 

Not only are they very different substances, but the manner in which these terms are used are completely arse about face.  Contrary to the article quoted, no carbon is emitted during an aeroplane flight (a miniscule quantity of partially burned fuel notwithstanding).  The carbon is locked inside the fuel combined with other elements, chiefly hydrogen.  When the fuel is burned, the carbon and hydrogen separate and join with the oxygen in the air to form carbon dioxide and water respectively.  Carbon as a substance on its own doesn’t come into it.

So all this talk of “carbon credits”, “carbon sinks”, and “weights of carbon emitted” leaves me all rather confused.  If people are going to able to sell carbon credits, then the Yanks must be laughing all the way to the bank because they have greater coal reserves than anyone else.  And when environmentalists talk of aircraft emitting 2,289 tonnes of carbon, are they talking about large piles of graphite or are they talking about carbon dioxide gas?  Because if they cannot manage to get even the basic terminology right, why should we bother listening to anything else they say?

(via J.F.Beck)