Is this a ratio?

 

I've always held with the idea that physicists use division as ratio; well, as a way of trying to explain to classes that it doesn't have to have a colun in the middle to be a ratio. But I found myself writing that resistance is the ratio of potential difference to current. Is this a ratio? A bit of chasing references on the Internet suggests that mathematicians would want a ratio to be unitless ie both quantities to be divided would have the same units as in the turns ratio for a transformer. That is not the case here. However there is support for the idea that it is a ratio at http://hyperphysics.phy-astr.gsu.edu/hbase/electric/ohmlaw.html which encourages me that it is an acceptable usage in physics.

Amending my Covid model

 

The R number is definitely falling in the UK. Using my model, I think it might have fallen to 0.7 this week. Last week I was wondering how to incorporate this fall into my model. I used data I had from earlier in the month and modelled the far in R as linear. I think this might be unrealistic. It puts R to zero after 150 days but has it down to 1 case in the entire UK in about 40 days. I will have to think about how to refine it.

Microstates 3

This was quite a complicated one for working out the microstates. I hope I've got it right.

I started by doing Level 2 as 123, 124, 125, 126, then 134, 135, 136, because anything with 2 in it would repeat, then 145, 146, finally 156 which is 10 cominations all containing particle 1 on Level 1.

Now I needed to do the combinations that didn't have particle 1 in them.

Start 234, 235, 236, then 245, 246, then 256. Next 345, 346, 356 Finally 456. That gives a grand total of 20. I've instinctively missed out many combinations as being repeats of earlier ones (number order doesn't matter here) but I hope I've not been careless.

Microstates 2

 This is my third possible overall pattern or macrostate to investigate.

Here are two further possible versions of it:

It can easily be seen that with particle 1 on Level 5, there will be 5 microstates possible, corresponding to 2, 3, 4, 5 and then 6 on Level 1. It retains a total of 6 quanta throughout. By putting 2, 3, 4, 5 and then 6 on Level 5 in turn, it gives a total of 30 possible microstates for this macrostate.

The same applies to this other macrostate:

Microstates and macrostates

 I have been working on my energy level analysis following the wording I got from a set of lecture notes I was given. We started with 6 particles on Level 1

I understand that this would be a macrostate. All six particles are on this one level and there is no other way to achieve this state. There are six quanta of energy.

Here's a second macrostate. It is possibe to have one particle on Level 6 and the rest on Level 0. There are still six quanta of energy.

But this time is is possible to have different numbered particles as the one on Level 6, for example:

These are wqhat I am taking to be microstates, different ways of ordering the same particles into the same larger overall pattern. There will be 6 microstates for this macrostate.

Why are metals shiny?

 The gilded cross on the top of the horse fountain was catching the light. I realised I'd never really thought about why metal reflect. Obviously they must absorb and reemit the photons that come towards them, but why shiny rather than dull. Even dull white surfaces are reflecting something - though that is diffuse reflection. I was interested in these answers https://www.quora.com/Why-are-metals-shinier-and-more-lustrous-than-non-metal-elements especially the one that links it to the layer of metal oxide. But I am also wondering if it is because the layers in the metal allow for a smoother surface and thus more specular reflection - the firing of the photons back in a more unified direction.

A ghost shadow

 

I spotted a strange white shadow in a field. It is longer than the current dark shadow. My best guess is that it was sunny earlier in the day for long enough to melt the frost in the field except where the shadow was at that time. Then the sun went in so that the unmelted strip remained white long enough for me to arrive.