The curious incident

"The Curious Incident of the Dog in the Night-time" is a marvellous book by Mark Haddon. It is murder mystery book as done by a character with Asperger's Syndrome. He is obsessed with maths and physics.
Musing about his love for prime numbers, he says "Prime numbers are what is left when you have taken all the patterns away. I think prime numbers are like life. They are very logical but you could never work out the rules, even if you spent all your time thinking about them."
Later he discusses Occam's razor. This is a philosophical concept from several centuries ago. It states that you should always go for the simplest possible explanation of the evidence. Overcomplicated explanations are far less likely to be true. An example is what they did with the observed movement of the Sun. Yes, it looks as though it goes round the Earth, but that would mean that the planets would have to perform little spirals and loops in their orbits. Far simpler to have the Earth and all the planets going round the Sun.
Ican't recommend the book highly enough! It's brilliant. (parental advisory: lots of strong language when he reports what his parents and other adults say.)

The shortest day

Today's the shortest day of the year, the winter equinox. You'd expect that it is because sunrise is later than on any other day and sunset is earlier. This isn't quite true. For the next week, sunrise will get later and later, but sunset will also get later, by a little bit more, so overall the day length will increase. The reason is that whilst day length is a result of the tilt of the Earth's axis, day and night is caused by the rotation of the Earth around that axis. As the Earth travels a little further around the Sun, the Earth has to travel slightly more than 360 degrees to get back to the same point. This causes both sunrise and sunset to seem slightly later. After a week or so, the effect of the tilt of the Earth will have swamped thie effect.
It was put to me that this is why the mornings seem darker in January, but it's over by then anyway. And you'd be struggling to notice the effect against variations in weather due to cloud cover.

Revision blogs

The Lower Sixth can find archive postings on revision issues at http://www.brockbankrevision.blogspot.com/

The Upper Sixth will find similar at http://www.brockostressline.blogspot.com/

In both cases, you'll have to ratch around to find the stuff that applies to the topics that we have done this term.

Solar panels

We went to the RSPB's nature reserve at Leighton Moss in Lancashire. They have this display up about the solar panels on the roof. They have generated 8749 kWh of electricity in about six and a half years. At, say, 10 pence per kWh that's saved them over £800. I wonder how much they cost to install? The power is very low: 0.13kW on a bright day in December would do some low energy light bulbs. I'm also wondering how this system works. Does it mix with the mains electricity or does it run on a separate circuit?

A controversial book

I had my letter published in the Cumberland News suggesting that people read David MacKay's book "Sustainable Energy: Without Hot Air". It's his opinion so it's become a controversial book.

The letter next to mine suggested another book: "The Real Global Warming Disaster" by Christopher Booker. I have bought the book and am reading it. He is a climate change skeptic. ie he thinks that even if there is any global warming, it is not caused by humans. He does bring up some evidence that is hard to argue against. As far as I can tell, historically, rises in carbon dioxide actually follow rises in temperature, so it would be hard to say that carbon dioxide causes the rise.
At present, I am with the consensus blaming humans for global warming at the moment. But I've always believed that science is like a court case. You should listen to arguments from both sides and decide on the basis of the evidence. Hence it's always possible that new evidence might make me rethink my position. I'll let you know how the book goes.

Alan Guth Lecture

Alan Guth is a big name in astrophysics. He solved a problem to do with the Big Bang Theory. The problem was that the time since the Big Bang (roughly 15,000 million years) is not long enough for galaxies to form and for space to seem flat. Stars form when the gravitational forces between hydrogen atoms start to pull them inwards into large balls. Think about it - the gravitational attraction between atoms in piddly small so it should take forever. Then the stars have to be attracted together to form galaxies. What Guth proposed is called inflation. Early in its life, there was a massive expansion of the universe. That magnified the clumps of matter and let them pull in faster. It also stretched out the curved up ball of space-time so that it appeared flat.
Alan Guth has done this year's Isaac Newton lecture for the Institute of Physics. They have put the lecture up on the internet. I haven't had time to watch it yet, so of course it might boring but there's only one way to find out:
http://www.iop.org/activity/awards/International%20Award/newton09/page_37514.html

Lorn!

Fans of natural logarithms (Ln) will realise that they now seem to have been rebranded as "lorns". I think we've agreed on that spelling instead of "Lawn", which is a suburb of Swindon. Well, at least it's better than the class who used to refer to it as the "in" button on the calculator. So imagine my pleasure to discover that my Scottish holiday was to the region of Lorn. I want to be MacDougall of Lorn when I grow up. (NB1 some of you might take this as evidence that it will be a long time before I do grow up) (NB2 the carving is in the marvellous church of St Conan - not the barbarian- which is very close to the Ben Cruachan pumped storage facility at Loch Awe)
Logarithms (ordinary Log on a calculator) are a great way of working out how to express any number to the power of 10. I'm not fond of the number 3. To avoid using it, I can do Log3, which is 0.477. So instead of saying 3, I can just say "10 to the power 0.477" instead, because they mean the same thing.
Natural logarithms are based on the number "e", which is another fantastic irrational number like pi. It helps you to work out a way to write any number as a power of e. We use it a lot in physics to analyse exponential decay in radioactivity and in capacitors. It helps us turn curved graphs into straight lines. (Now Ln3 = 1.099, so I could avoid saying 3 by calling it "e to the power 1.099" instead.)