What are wind turbine blades made of?

 

I had always assumed that the blades were made of low density metal like aeroplane wings. Turns out they are made of carbon fibre and are thus not recyclable. The Guardian ran an article about 5 years ago about the problems of recycling carbon fibre. See also https://www.latimes.com/business/story/2020-02-06/wind-turbine-blades

A weird dream about the thermometer

 I had a dream about the mis-calibrated thermometer. In it, I took the battery out and it worked again so I had a go.

I'm glad I did because I found some interesting stuff inside. The display is powered from the metal contacts at the top of the green board through the bendy piece that looks like a licorice all-sort - the pink thing with the black middle. It is flexible and slightly compressible so it makes good contact and I'm assuming that the black middle must be a conductor. When I put it all back together, itm was working correctly again - but a day later it went back to its old ways! Oh well...

Platinum Jubilee Hassock reminds me of Hofmann Voltameter

 

Mrs B made a Platinum Jubilee Hassock which was blessed today - an awful lot of work went into it! I knew platinum was ringing some bells - it is the platinum  electrodes. And I have used these in the Hofmann Voltameter. Platinum is used because it is so unreactive that it doesn't interfere with the reactions.

A badly calibrated thermometer

 

One of my students pointed out that this thermometer is reading below zero at normal room temperature. It is about 20 degrees Celsius too low. It has occurred to me that I would need to check it over a range of temperatures to see if the error remains the same each time so that there is a true systematic error. 

Something strange about the Watchtree turbine

 

Having said that the Watchree Vestas were 660kW, I noticed that the sticker on the new display turbine mechanism claims 1300kW and that it dates from November 2017. Questions to look into are 1. How long do the working parts of a wind turbine generator last? 2. Were the turbines upgraded or do you always fit a turbine with a higher spec on its name plate?

What happens when National Grid power lines cross?

 Just outside Great Orton, two sets of power lines cross each other. If you look at the pylon on the right in the picture, there are lines coming into it from behind and then they stop. The lines are sent into the ground and go underground beneath the cables shown.

They emerge later at the pylon below. There are shielding grids between the down-cables.

I've tried to find out more about these pylons but the best I have found so far is here.

A Pebble map of Geology

 This is a map of the area around Teesdale in which each pebble is of the correct rock type for the location it marks.

The slates on the left hand edge are the oldest and date from a collision of continents. That will be Scotland and England crashing into each other.

I've known about that for years but this display helped me to realise how far south of the Equator we must have been when that happened because the limestone formed on top of it in coral seas. And the Whin Sill intrusion happened before the red desert sandstone, which I understand was laid down when we had made it as far north as the Sahara is today. So the map turned out to be a bit of a gem that made sense of a set of facts I'd known but never put together.