Thursday 27 May 2010

The Curious Incident again

Last December I wrote a bit about the book "The Curious Incident of the Dog in the Night-time" by Mark Haddon. It is written from the point of view of a boy with Asperger's Syndrome. He sees things from a very different point of view. I like his views on time. He explains why he needs to have timetables, so that he knows exactly what is going to happen and when it is going to happen. Not knowing scares him. He says:
"Because time is not like space. And when you put something down somewhere, ... you can have a map in your head to tell you where you left it.....And a timetable is a map of time, except that if you don't have a timetable time is not there like the landing and the garden and the route to school. Because time is only the relationship between the way different things change, like the earth around the sun ... and it is like west or nor nor-east which won't exist when the earth stops existing and falls into the sun because it is only a relationship between the North Pole and the South Pole.."
I think this is very profound physics. This is dedicted to those who write that "time slows down" when a crumple zone crushes up in a crash!

Friday 14 May 2010

Lightning conductors

One of the great things about being a bell ringer is that I get to up the church tower. You get the best view of Wigton from the top. Notice the thick metal strip running down from the spike at the top. It's a lightning conductor. It goes all the way down the outside of the tower and is then concreted into the ground. The idea is twofold:
1. If lightning does strike, the massive current is carried down the metal, which has a much lower resistance than the masonry. This stops the masonry overheating and the mortar being broken.
2. It actually deters lightning. If the cloud has a large positive charge, it attracts electrons, which are negative, up from the ground to the tip of the spike. The large concentrated charge ionises the air molecules and then repels negative ions up to the positive charge. This neutralises some of the charge, making lightning less likely.










Thursday 6 May 2010

Basalt dykes


This photograph is of an igneous dyke on Anglesey. Molten magma must have forced its way sideways between existing layers and then solidified. The way that molten magma moves under the surface of the Earth is very much to do with physics. It is due to convection cycles in the mantle. I was interested to note that in Brian Cox's series on the Solar System, he attributed the loss of atmosphere on Mars to the cooling and solidifying of its molten core.