Battery life

People want electric goodies battery car’s TVs, StupidPhones etc

The StupidPhones bit set me thinking – with Polonium in the battery the manufacturers could tell the users that the battery would last the users whole lifetime… (Advisory note: “may cause hair loss, or other symptoms below…”)

People want electric goodies battery car’s

I don’t want an electric car. I’m quite happy with my dinky diesel engine giving me ~300KM for €10 fuel. Especially given that throwing more fuel in will instantly give me more distance.

Battery cars? I looked at the Citroën Ami and realised that it would more or less get me to Châteaubriant and back. That’s it. If I had to go any distance, well, I pretty much can’t. I don’t think I could go to Ancenis (never mind come back). I don’t feel that battery technology is at a state that makes them a useful replacement for an engine car.

It’s the governments that seem to be wanting to push electric cars in order to meet some sort of environmental target. Which is strange actually, giving how much taxation they extract from fuel sales.
Maybe in their minds they think they can simply transfer that much taxation over to electricity? Meanwhile electric suppliers will give spot prices depending upon the time of the day, and suddenly the push for smart meters will become clear.

StupidPhones etc.

For what it’s worth, I would be perfectly willing to have a thicker stupidphone in order that I have the ability to change the battery (assuming genuine replacements exist and aren’t the sort of Chinese knockoffs polluting Amazon).

so the reactors can run their own pumps if pylons fail.

The reactors normally run their own pumps. But in an earthquake you don’t want the reactors generating power – you want to shut the fission reaction down. Which they did, of course. At that point, the reactors can no longer run their own pumps, because instead of producing 2GW (thermal), they’re suddenly down to “only” 130MW. With the external supply (which is the first line of defence) down, the next line of defence is the diesel pumps. But they were flooded.

Interesting down here at a old clay pit (Eden center) they are drilling (presumedly granite) 3 odd miles down One shaft done one to go.

Next I guess they will use explosive to join the two shafts.

Then feed in water – and get very hot water out.

See how it goes!

Yeah – they were trying that down there in the 1970s iirc. Then reckoned to be not economic, but economics change, both on the cost side and the benefit side. There’s a few places around the world where it works well – either for heating, or where the temperature and flow rate are good, for power. There’s a lot of energy down there, for sure – globally, small by comparison with wind or solar, but locally well worth exploiting.

Mrs M stopped that – Nuclear was cheaper.

Why is the center of the earth so hot after Billions of years?

Perhaps the forces from the Sun (nuclear power) squeezing twisting the earth keep the earth’s centre hot.

Iceland is tapping their underground heat – telling about running electric cables to the UK.

Mrs M stopped that – Nuclear was cheaper.

Various places in France use a scheme where there is one big central boiler and hot water is pumped around. There’s one in Châteaubriant, and they recently added solar to it. http://chateaubriant.reseau-chaleur.com/
When I went into Rennes, part of the pathway was being dug up to extend the heating network. https://rennes.reseau-chaleur.com/presentation/

This, a large central boiler (using biomass these days) is likely to be the least polluting and most effective option for heating a large number of residences, as well as functional buildings like schools and hospitals.

It is also likely a lot cheaper to install and maintain than digging deep holes in order to use geothermal heat.

Iceland is tapping their underground heat

Well, given that it’s basically a large volcano, they don’t have to dig much. ;-)

Why is the center of the earth so hot after Billions of years?

Two reasons.

Firstly, in the sense of celestial timescales, the entirety of human history doesn’t even qualify as a mere hiccup of line noise. Iceland was formed around 18 million years ago. Current estimates are that the Sun will splutter out in around 7 to 8 billion years. The first life on this planet was around 3³/₄ billion years ago (the planet itself formed around 4¹/₂ billion years ago).
Our specific species, by comparison, is estimated to have come into being around 2 to 3 hundred thousand years (the first of the Homo family, Homo habilis, is about 2¹/₂ million years old).
By contrast, the art of writing is a mere five and a half thousand years old.
So, the core is cooling down as you would expect. It’s just not doing it in any meaningful timescale compared to our own lives.
Space is like that. It would take about three years travelling at the speed of light to make it beyond the Oort Cloud. About 550 light years (or 15-20 generations of humans) and you’ve only made it to Betelgeuse in Orion. That’s the bright one on the upper left. Travelling at the sorts of speeds that our spacecraft can actually manage, and, well, Betelguise is further away in time than our primate ancestors.

Secondly, radioactive decay is keeping the core hot. So all those anti-nuclear campaigners might like to understand what’s actually going on under their feet. :-)
It doesn’t go KABOOM! for the same reason that the Sun (which is mostly a big ball of hydrogen) doesn’t.

So all those anti-nuclear campaigners might like to understand what’s actually going on under their feet.

It ain’t a nuclear chain reaction though, it’s just radioactive decay. Mostly U235, U238, Th232 and their daughter products, with a bit of K40 and relatively tiny amounts of other stuff. Fairly thinly distributed through rather a lot of rock and metal – at similar concentrations in fact to those in granite at the surface. Human beings get most of their radiation exposure from K40 in their bodies normally, unless they’re uranium miners, live in the vicinity of uranium mines, or spend an inordinate percentage of their time in ill-ventilated cellars in granite areas such as Cornwall, or flying about in jet aircraft (or spacecraft).

None of which is a patch on what you can get from the debris created in fission chain reactions, should you be unlucky enough to be exposed to it.

It doesn’t go KABOOM! for the same reason that the Sun (which is mostly a big ball of hydrogen) doesn’t.

Absolutely not. It doesn’t go KABOOM because the rate of heat generation per tonne is quite a few orders of magnitude smaller than the Sun’s, there being (unlike the Sun) no chain reaction, whereas the Sun doesn’t go KABOOM because of its gravity, despite its enormous heat production.

We have had simmering natural nuclear chain reactions occur in uranium ore bodies in the geological past, most famously in Gabon.

The concentration of U & Th & K in the crust is a lot higher than in the mantle, but there is a lot more mantle than crust, so that’s still a huge heat source.

there being (unlike the Sun) no chain reaction

I knew I’d read about nuclear fusion being a hypothesis for the earth’s internal heating. Took me a while to find, but…
https://www.nature.com/articles/srep37740
(warning, gets very nerdy very quickly)

because of its gravity

Which is also a factor here on earth, mind…

Gravity itself is interesting. What is this invisible force where objects with mass can affect each other by mere proximity? What is the smallest body that is liable to have observable gravity? If I was in outer space curled into a ball, could a lone Malteser orbit me?
And the bit that I like – if I pick up a large rock and drop it, the rock doesn’t just move towards the ground. The ground (the entire planet) moves towards the rock as well. However this movement is infinitely tiny because of the mass difference between the rock and the entire rest of the planet, plus the short distance of travel.

I knew I’d read about nuclear fusion being a hypothesis for the earth’s internal heating.

Yeah, I remember that. Even Nature gets fooled by the “cold fusion” pillocks sometimes. The silly thing about that is that radioactive decay fits the numbers perfectly well, well within the error bounds of the various unknown factors. We don’t know exactly how much heat is coming out of the earth; we don’t know exactly how much uranium, thorium or potassium there is in the core or the mantle. We assume it’s broadly similar to the percentages in iron meteorites, stony meteorites, and mantle rocks where they’re exposed at the surface, but those all vary quite a bit, leaving quite a wide margin of error.

…gravity… Which is also a factor here on earth, mind

Nowhere near enough to make much difference to fission (never mind fusion!)

What is the smallest body that is liable to have observable gravity?

My physics teacher at school, Philip Titchmarsh, got his PhD while I was in the sixth form – for measuring the Universal Constant of Gravitation with a clever set up in the school physics lab preparation room – with four lead spheres each weighing iirc about 5kg. The forces between the spheres were rather small. His result had, again iirc, three significant figures, which is pretty impressive – and agreed with those measured by others using other methods.

… got his PhD while I was in the sixth form – for measuring the Universal Constant of Gravitation with a clever set up in the school physics lab preparation room – with four lead spheres each weighing iirc about 5kg.

I doubt he got his PhD for that. What you describe was a fairly standard VIth form experiment. The apparatus was available from all good suppiers. ;-)

I did it in my A-levels and I last used it in my own classes in about 1986. After that the emphasis in A-levels turned away from replicating classic experiments.

This was a small version of the 18th century Cavendish experiment to “weigh the earth”. It is a torsion balance with a light beam indicator, and can give pretty good results when handled carefully.

I did it in my A-levels

When was that? Interesting…I presume this may be a confusion in my memories…I did my A-levels in 1967. Mr Titchmarsh was my physics teacher ‘64-’67, certainly got his PhD around ‘66, and I saw the apparatus which certainly looked DIY; and we certainly didn’t do it at A level.

Perhaps he made some improvement in the system? I don’t know.

When was that?

1964.

… this may be a confusion in my memories …

Or mine. Although “I remember doing it”, it may just be the analysis of the Cavendish experiment. ;-)

On the other hand, when I returned to teach in 1984 the schools I was in had the apparatus. These were ex-grammar and had cupboards full of old apparatus that had once been used for A-level.

… the apparatus which certainly looked DIY …

It did indeed, in a small box – the lamp and scale not included. Except for the size, the experiment is pretty well identical to Cavendish, so it is not original.

I do not think it was on the syllabus, so I might have been unusual in setting it.