What happens to all that water?

 

On Christmas Eve the wind was blowing hard from the south creating large waves on Coniston Water. If you enlarge the pictures you might see the waves. You can see the raised water level in the second picture. It made me wonder what happens to the water. If the surface water is all being pushed to the northern end of the lake, what happens? Does that mean that the water level is higher at the northern end and that the lake acts as a sort of pumped storage scheme? Or is there a counter current below the surface moving water back south in a manner akin to a convection current? I've been considering how to make lab models to check these hypotheses.

White water

 

The weather has been miserable recently - one big Atlantic storm after another. We got the edge of the awful pre-Christmas storm that battered the south. There were high winds and a lot of rain. If you enlarge the picture you'll see the prominent white water in the waterfall on this outlier of Wetherlam at Coniston. It got me thinking: why is turbulent water white? The water is full of bubbles and split into lots of drops. There are many reflecting surfaces and light is reflected in many directions, a form of scattering. White means that all colours are being reflected equally in our direction. This is a sketch of an answer - what I've been thinking about the issue.

The final quarter

 

This was the final quarter waning Moon taken on Christmas Eve at breakfast time. The evenings were much darker in the last week or so with the Moon rising after midnight. This morning we were back to the final crescent which was the first photo graph in this series, taken a month ago. I think the New Moon is New Year's Eve.

Oxford's Christmas Light Festival

Oxford was geared up for Christmas. Many religions use the metaphor of light in the darkness. So Oxford hosted what they called a "Christmas Light Festival". As a physicist I'm programmed to study things dispassionately - objectively, we like to say. But human animals are also programmed to respond to things emotionally. So in the pictures below you see scenes in which photons are travelling towards you at 300,000,000 m/s - or you might prefer to say that you are seeing the result of self-sustaining sinusoidal electric and magnetic fields that are perpendicular to each other. You might also just say that it is very pretty. I'm sure I've quoted Bertrand Russell's remarks about light already this autumn. He pointed out that someone blind from birth could experience a wave motion on a ship and learn the Physics of light waves. But they would have no idea of our experience of light.

 

Coniston Hydro-electric Power

We climbed up to Copper Mines Valley at Coniston on Christmas Day.

 

 

At the top of the stream we found the feed for the Coniston Hydro-electric Power Station. I found the details of the scheme on-line http://www.gilkes.com/case-studies/Coniston It's actually an old scheme from the 1930s which fell out of use and was then restored. 



 
 

 

The water travels 700m and falls through a height of 72m to reach turbines that generate 300kW of electrical power. It says that it takes the water 25 seconds to fall that distance. If it fell vertically in a vacuum, my calculations show that it would take only 3.8 seconds. The drag in the pipe means that it won't reach its theoretical maximum speed.  

 

Waning gibbous Moon

 

Not the world's greatest photograph but note that the whole Moon is no longer illuminated. More than half but less than whole = gibbous. It is the right hand side that fades away - or wanes. I had to wait until gone 10 o'clock to see the Moon last night and this picture was taken at 8 o'clock in the morning facing west. The waning Moon is seen late at night.

Santa in space

If you didn't see the story in the newspapers, do yourself a favour and follow this link to watch the film http://www.stratodean.co.uk/ It's very similar to the project by students from a neighbouring school up here. I love the flight data at the bottom of the screen.