Renewable electricity??

I know what we mean by a renewable energy resource but I'm struggling with the idea that electricity is renewable. Assuming it keeps raining (a fair bet in the Scottish Highlands) then Lochan na Lairige will continue to be refilled with water. That's renewable. The water flows down the pipe below the dam from an altitude of 500 metres down to a power station on Loch Tay over 300 metres below. The gravitational potential energy turns into kinetic to drive a turbine and generate electricity. I teach that renewable means "won't run out". The gravitational potential in the water at the top of the hill will continue in perpetuity. So can we say that the electricity itself, as the end product, is renewable or should the sign say "electricity generated from a renewable energy source"??

St Albans

We had a great time ringing bells in St Albans but I didn't find much Physics. The bell tower at the Cathedral was very high up giving amazing views, so there is the Physics teacher's fall back of lightning conductors. If you magnify the image you'll see that they are copper due to the green colouration when corroded. I did like the notice in the second picture.

New College Oxford

New College Oxford is not new. In fact, it is one of the oldest colleges. It is now best known for this tree which appeared in one of the Harry Potter films. I was more taken by the giant sundial. The notice says that it was put in for the Millennium. It also explains why it does not show GMT and explains how to convert to GMT.

Absorption spectrum for the Sun

The boss found some old spectroscopes on Friday afternoon. The small ones turned out to be the best. I have never seen the absorption spectrum of the Sun with my own eyes before. Here it is! You can clearly see the black lines where hydrogen atoms in the colder (on 4000C ish!) chromosphere have absorbed photons of light and re-emitted them randomly, reducing the intensity. I'm ecstatic.

Ashmolean museum

I went round the Ashmolean Museum in Oxford last month. It's just reopened after a major refit. I was amazed by the amount of Physics. Here's a piece about radioactive carbon dating!

Spectra on the windows

One of my colleagues inspired me to use colour films on my windows. It's such a brilliant idea and I can't understand why it hadn't occured to me before. Seven colours in the spectrum is a contentious idea. It is alleged that Sir Isaac Newton chose 7 as being the perfect number. He was into odd things - he was an alchemist in his spare time, I believe. So my 6 colours are not in fact wrong!

Bluebeard

Thanks to all of you who sponsored me to have my beard dyed blue in aid of Practical Action. This charity was called Intermediate Technology and was supported in the 1980s by some of my heroes. It works to use sensible technology to make life better for poor people in remote places. As such, it is a good outworking of Physics principles. I'm raising money for solar powered wells.
The dye experiment has been problematic. We put on three lots of dye but I was left with a pale turquoise "blue rinse". Beard hair is too strong. I've been told that peroxide bleaching would break up the hair allowing it to absorb more dye. I've tried the chemists but you can't buy it any more following high profile bomb plots. However I have learned a lot about Chemistry in the process. I'll keep you posted...

Water meter

It hasn't rained very much in the south for months. Funnily enough, the only day of rain coincided with our visit to Oxford! It has become common to have a water meter if you don't have many people living in your house. I was interested to note that the volume was measured in cubic metres. Note from the photograph that it measures to the nearest 1000th of a cubic metre, which is actually a litre. You are not billed to that precision though.
The booklet that came wih the metre alarmed me. The number of people is a discrete variable and so this data should really have been plotted as a bar graph. Whereabouts should one person read their typical usage volume??

All Watched Over By Machines of Loving Grace

Here is a link to a BBC programme. The warning is that it could be considered to have a left-wing bias, but if you are aware of that and think clearly, you are quite capable of making up your own mind.

What I liked was that he goes through the history of the idea of ecosystems. The Physics link is that some people modelled the feedback mechanisms using electronic circuits. Later it was discovered that the systems were far more complex than imagined. Though they didn't say in the programme, this would bring it under the topic of Chaos Theory in Physics.

http://www.bbc.co.uk/iplayer/episode/b011rbws/All_Watched_Over_by_Machines_of_Loving_Grace_The_Use_and_Abuse_of_Vegetational_Concepts/

Listen to this Guardian podcast

Matty Hoban is a former student of mine at The Becket School, Nottingham. He is currently doing a PhD in Physics in London. I have just found out that he appeared on the podcast of the Science section of the Guradian newspaper's website back in January. Amazing!

Here's the link: http://www.guardian.co.uk/science/blog/audio/2011/jan/31/science-weekly-podcast-supercomputer-ikea-archaeology

Tensioning weights for railway cables

This photograph is from the high speed line to the Channel Tunnel just north of the River Thames in Essex. You can see similar on the viaducts in Carlisle. They are to put tension into the cables to keep them taut. They are made of concrete and you put on different numbers, just like the slotted masses we use in the lab. Notice the intricate system of insulators to stop electrical conduction. And in this case you can call them weights, not masses, because gravity is pulling them down. I came across a fantastic quotation from Sir Patrick Moore: "Gravity is the force that gives weight to mass."

I think we've found coal

We went to stay at the highest pub in Britain, set in bleak moorland just over the county boundary into Yorkshire. As you can see from the photograph, it was a mining inn. What was odd was that they were mining coal. I am struggling to think of a coal mine that high up. We walked along the Pennine Way for a couple of miles and found this black outcrop of rocks. I guess it must be coal. Closer inspection revealed poor shale not really good enough for burning, but look at the think layers of sandstone between the shales. This would suggest episodes of flooding washing sand across the swamps that would have provided the mud and vegetation for the black shales. Not really physics, I know, but I love geology too.

Cairngorm Mountain

We drove through the night on Friday to see rare wildlife in the woods at dawn. Mid-morning we were up watching the skiers on Cairngorm Mountain. They get them up the mountain with a funicular railway. You can see it snaking upm to the ski station on the second picture. In fact, there are two trains that are strung together on a long cable. One goes up whilst the other comes down. Hence gravity is doing a lot of the work of lifting the lower train as the upper train falls. The falling train gives its gravitational potential energy to the rising train. It is a single track but there is a short section of double track half way. There is no other place where they will meet because they are tied by a cable.

Sk8r Boi

We've bought two skateboards for the Physics Department to help us to demonstrate Newton's 3rd Law and the conservation of linear momentum. If you'd been in Silloth this afternoon you'd have seen Mrs B and me having our first ever goes on a skateboard. Deprived childhoods, I'm afraid. I want to learn to skateboard...can anyone help? The picture shows the bottom of one of the boards: 1. Another mess up with mass and weight. Oh dear. 2. I'm 65kg. This surely can't be right.

Not Brian Cox

The Brian Cox Wonders of the Universe programmes on Sunday nights have been brilliant. The second programme Stardust was probably the best documentary on Physics I've ever seen.
http://www.bbc.co.uk/iplayer/episode/b00zm833/Wonders_of_the_Universe_Stardust/
But you might have missed JimAl-Khalili on BBC4 on Monday night. He did a brilliant programme about why the sky is black at night even though the Universe is infinite in size. You should watch it! http://www.bbc.co.uk/iplayer/episode/b00yb59m/Everything_and_Nothing_Everything/

Estimation

There haven't been many posts recently. I've been very busy. Further to the last post - the estimation went like this:

We thought that there might be 100 trees per row and 100 rows, meaning that 10,000 trees had been cut down. It seems a lot.

Next estimate the height of the turbine in the picture and the length of one blade. This turbine is at Watchtree.

Estimating

My friend spotted this area of felled trees in the forest above Ennerdale. He challenged his children to estimate how many trees had been felled. Estimating is a particularly important skill in Engineering, but also in Physics. Have a go using the second, more detailed, picture. Let me know what you think.

Physics students write on windows

The window of the students cafe in the Particle Physics building at Oxford was covered in equations. I've been experimenting with board pens in my lab - but don't try this at home (or at school).

Ice at the bottom

We went up to Bowscale Tarn. There was a real oddity - ice on the BOTTOM of the lake near the outflow. Everyone knows that ice is less dense than water and should float. So what happened here? We had several theories but most likely is that in this shallow water, it froze from top to bottom. Then the water at the top was the first to thaw, leaving this oddity.

The tarn used to be a very popular tourist attraction in Victorian times. In one of his worst poems (my opinion), Wordsworth quoted a legend of there being two immortal fish in the lake. If it's true, they must still be there...

If you want to read the poem, here's the link http://www.everypoet.com/archive/poetry/William_Wordsworth/william_wordsworth_340.htm

Museum of the History of Science

The Museum of the History of Science on Broad Street in Oxford occupies a building constructed for the original Asmolean Collection - the world's first public museum. It is next to the Sheldonian Theatre, designed by Sir Christopher Wren. It is surrounded by the sculptured heads of Greek philosophers. Inside the museum, I found Einstein's chalk board - he delivered a lecture at the university many years ago. They preserved the board. Sorry about the pictures - no camera flash allowed. More to follow about this trip.

Roberts Boyle and Hooke

During the blizzard in Oxford, I went down the High Street to find the memorial on the wall of University College. Boyle's Law for gases now comes towards the end of the Upper Sixth. I didn't know that Robert Hooke was his assistant. Hooke was Newton's bitter rival, best known in physics and engineering for Hooke's Law: the extension of a spring is directly proportional to the applied force as far as the limit of proportionality.