Successes and failures

Well, The Cumberland News didn't print my letter. Oh well.

However, we climbed Schiehallion yesterday - photos next week when I've got broadband again. There's a large plaque at the bottom commemorating Nevill Maskelyne's gravity experiment in 1774. I've collected some rocks so we can check the mass of the mountain by a density and map method in the lab. The cloud clearer when we were on the summit and we could see half of Scotland.

The nearest village has one of the oldest trees in Europe and claims to be the birthplace of Pontius Pilate. How weird.

The musical stones in church last Thursday were entertaining. They have been made up into a xylophone and were nowhere near as big as I'd expected. I've seen photos of Sigur Ros playing a much bigger stone xylophone. Still, I now want to know why you can get a note out of the metamorphosed hornfels but not the original slate country rock.

Letter to The Cumberland News

If you trawl through the older posts, you'll notice that I am a big fan of Professor David MacKay's book Sustainable Energy: Without the Hot Air. He has since been appointed as a government advisor. I'm pleased because he believes in a no-nonsense approach to working things out. I'm in favour of numbers. They make a debate more precise. He's good at providing figures. I've checked a lot of my own consumption figures to test his claims.

In the farming supplement of the The Cumberland News 16 October 2009, Austen Davies lays into Professor MacKay in his View from the Trough column. The article starts really well - I agree with a lot of the commentary. Nor does it bother me that Austen Davies is vehemently against wind farms. I'm not sure where I stand on that issue. I love the mountains and the way I read the book is that Mackay thinks too much land would be needed so it's not really feasible.

But I don't like a level of debate that descends to personal attacks. "Wildly staring eyes of Vulcan-looking Professor David MacKay". So I've written a letter in defence of the book! Let's see if it gets published. Now is this citizenship?

Skiddaw musical stones performance

Further to yesterday's post, it is at 6pm on Thursday. Word on the street is that it will be packed out.

Skiddaw musical stones

On Thursday, the local primary schools will be playing the Skiddaw musical stones in Wigton parish church. It is 6pm for the final performance.

The stones are normally kept in Keswick museum and I think that they are like a giant xylophone.

There is a bridge in the valley between Blencathra and Skiddaw, which has, according to my guidebook, similar slabs. It said that if you tap them gently with a hammer, the slabs should ring. Trouble is, they have been cemented in, which is damping the vibrations.

The physics goes like this: When you hammer them, a sound wave travels through the stone. It travels very fast in the solid because the atoms are close and joined. It cannot travel fast in the air, so when the vibration hits the end of the stone, very little escapes into the air and the rest is reflected. If the dimensions are such that the reflected waves are in phase with the outgoing waves, then a standing wave is set up and that is what you hear. Damping removes energy from the vibrations.

Searching for radon gas

I got this plastic in the summer called Tastrak. It is supposed to get scarred by alpha particles when radon gas is released from rocks underground. It turns out that the limestone rocks around Sandale and Caldbeck are supposed to be medium bad for radon, so I gave a piece to someone I knew to test it. Nothing!

So last Saturday I hid a piece at Sandale Quarry. I'll collect it in a couple of weeks. You need a microscope to see the marks.

Electric field lines

I have used a petri dish of sunflower oil with semolina floating in it to see the field lines for an electric field. It's similar to doing the iron filings experiment for magnetic fields. I made the metal contacts from a coat hanger and connected it up to 3000 Volts. I projected the result onto the board and you can see the semolina lining up between the contacts. The parallel lines show a uniform field, which will have a constant field strength throughout.

Don't look back into the sun

This week I've started looking for sunspots. You musn't look at the sun directly. You'll seriously damage your retina. To look at it, block off one side of the binoculars and shine the sunlight through the other side onto a piece of paper. The second picture shows the image of the sun thus obtained. Sunspots are slightly colder areas on the surface of the sun. There are none in view at the moment. The sun rotates on its axis every 25 days. Maybe in a couple of weeks ...

Sunspot activity goes in 11 year cycles. I thought it was supposed to be good at the moment, but maybe I've picked a bad time to start.

To undefined and beyond...

OK, so maths have rebranded infinity as undefined. I think this gets us back to the essential difference between physics and maths - that physics is measurable. So in physics, we need to be clear that infinity will mean something different. In the case of infinite resistance, what we actually mean is that it is UNMEASURABLY BIG. Remember, maths like their perfect fractions like 2/7. That won't do in physics. We use decimal fractions to show the precision of the measurement. It DOES matter whether you write it down as 0.29, 0.286 or 0.2857. So there.

My geiger counter

Sounds rather grand, "my geiger counter". Actually, it's a datalogger with a geiger muller tube. It's portable so I took it on tour in the summer.

The watch belonged to my father-in-law. He bought it in 1951. In those days the luminous paint on the hands was made of a radioactive material. The final photo showa the geiger counter reading. The "safe" background reading that I took was less than 1 count per second. You can judge for yourself how dangerous a watch like this might be.