Beautifully clear here last night, just a small smudge through x20 binoculars. Sounds like it may brighten over the next couple of weeks, just in time for the Moon to pop up and ensure it remains a smudge!
You never know though, best of luck peering through the fog!
Mind was sent into overdrive this morning whilst on way to a little job.
Thing on Radio 4 about 9am discussing superconductors and all the associated fucking weirdness thereof.
They behave like an atom. An actual atom. Insanity.
I realise I haven’t really sold it in the description above 
How is your understanding of the Bardeen-Cooper-Schrieffer theory after listening to that?
Ha! Did you listen to it too?
Regularly appeared at Hartlepool Town Hall in the fifties, usually supported by Wilson, Kepple and Betty.
Nah, Graeme mentioned it in the what are you watching thread. Might have a listen on Sounds, quite enjoy it when Bragg can’t disguise his bafflement.
#Freeman Hardy Willis have got your shoes…
One guy had a go at explaining it, in a qualitative way (negative electrons moving through a slightly flexible lattice of positive ions, each electron draws some positive charge towards itself and that clump of positive charge attracts other electrons - so two electrons can be drawn to the same place and will appear to have ‘paired up’ as long as everything’s cold enough that thermal vibrations don’t jostle them apart).
I think Bragg’s response consisted of the two words “Oh, God” 
.
Fuller, Smith and Turner for the win
Yeah. That’s kinda what I was alluding to.
Old people are mutants!
One for @Valvebloke i think.
Chatting to a friend today who was spinning dits about the work he undertook with Rumic to survey the 2 windscale reactors some 20 plus years ago, fantastic take it was.
There was one element they surveyed, the purpose of which he still didn’t know other than it was a scientific experiment.
Running through both reactors were 6 small vertical channels for this experiment, that’s some effort to build that into the graphite blocks, must have been an important experiment at the time, late 40s really 50s design.
What they found in the channels was a device that held sheets of gold leaf which could be open to exposure at any depth and retreived. Any ideas what this could be for? I was wondering if they were developing new sensors for the forthcoming nuclear bomb tests or the like. The channels were 1.5 inch and full depth of the two piles.
Almost certainly neutron dosimetry. It’s way off my patch (the radiation sources I worked with all produced X-rays) but it’s the case that radiation in general can transmute one element into another. Some transmutations are hard to achieve, others are easier. It turns out that if you irradiate the stable isotope of gold (Au197) with neutrons you can make a different isotope (Au198) which decays in a couple of days to mercury (Hg198) with the emission of a 0.4MeV gamma ray. The cross-section for the Au,n reaction is large so you can measure small neutron fluxes. Gold is an easy material to work with (solid, thermally stable, can be made very pure, can be shaped very easily e.g. into thin foils). 0.4MeV gamma rays are easy to detect. The Au198 half-life is long enough for measurements on the activated foil to be conveniently made but short enough that you don’t have hideous radioactivity hanging around for decades. So gold has become, it seems, a standard for neutron flux measurements
file:///C:/Users/Authorised%20User/Downloads/lana25803enn.pdf
It’s just a shame that there are no high cross-section reactions going the other way. So the transmutation of anything into Au197 is a bugger. Sorry, alchemists.
As well as academic experiements on the neutron flux in reactors, the Au197,n reaction has also been used for accident dosimetry. The Japanese had a bad criticality accident in 1999. Two workers died and people living beyond the plant perimeter were irradiated. One way they assessed the dose received by those people was by checking the neutron activation of the gold in their jewellery and teeth fillings as well as of coins left in their houses after they were all evacuated.
What you’ve made, if indeed it has a name, is some green.
Cheers, appreciated. I’ll let my mate know, he’ll be chuffed with that.
Cosmology - one damn thing after another (dark matter, dark energy, now this …)
