Vector field at Spout Force, Whinlatter

 

They have felled trees at Spout Force. It reminded me of a vector field like the drawing of arrows to show compass directions for a magnetic field. The trees could be said to show magnitude by their length and also direction. Thus the field would be uniform on the right but on the left the directions vary. Perhaps it is a grad field, showing the magntitude and direction of the slope.

How wide has the contrail become?

I noticed this plane flying close to an earlier contrail that has expanded and been blown. If the plane were 50m long, then the contrail would be maybe 600 to 700m wide. I think it fair to assume the contrail and the plane might be at the same height. I wonder how long it takes to get this wide.

Bourdon Gauge at Bassenthwaite Lake Station

 The central gauge on the train at Bassenthwaite Lake Station bears the name "Bourdon".

The train is a replica built for Kenneth Brannagh's Murder on the Orient Express film. I am familiar with Bourdon gauges for pressure but I had never stopped to consider who Bourdon was. The principle is that the gas is in a flexible metal tube. When the pressure increases, the metal flexes more and that is geared to a needle which goes round a scale which can then be calibrated. Putting the name Bourdon onto the gauge is a nice touch.

Scattering on the Arran Ferry

 

The salt on the window made the scene seem misty. The particles scatter the light meaning that it looks more like white light is coming from all directions. It's a version of what goes on inside a cloud.

Another corona around the Moon

 

The Moon was shining through high cloud producing a clear corona. To my eye, there was a clear red outer edge to it but viewing the photos, you'd take some convincing. I re-read this article about the phenomenon. I'm not sure I'd noticed before that this diffraction pattern is an Airy Disc. I know the Airy Disc as the bright central view through a circular aperture such as a telescope. Unlike with the refraction halos, there is not set angular width here apparently, as it depends on the droplet size. Given that the Moon subtends 0.5 degrees at the eye, I'd say here the corona subtends 1.5 degrees.

Counterweights on a tractor

 

These iron blocks are 5cm wide and 50cm long. I'm estimating about 25cm deep. That means a volume of 6250 cubic centimetres. The density of iron is 7.9 grams per cubic centimetre. The mass of one block is therefore 49375 grams to too many sig figs. Since I'm extimating, best to say 50kg. There are 8 of them. That means 400kg. Not quite half a tonne!

What would be the mass of ATP needed to run the Basal Metabolic Rate?

 

The book is way too advanced for me but I have really enjoyed the scientific justification for the training programmes. There's a claim in the book that if we didn't recycle ATP, we'd need 60 - 70kg a day just to run the resting metabolism. ATP is C10H13N5O13P3. That means 1 mole has a mass of 504 grams. So 70kg would be 140 moles. I looked up the energy release for ATP to ADP. The two commonly quoted figures are 7300 calories per mole and 12000 calories per mole. Sources seem to say that the latter figure is for inside the body. So 140 moles x 12000 = 1680000 calories. Now the problem with calories is that when people talk about calories in food, they mean kilocalories. So that's 1680 kcal which is close to the figure of 2000 kcal that I was taught a human really needs each day. There. It works.