John Cuthber

Here is a page from Peter Atkins' book "Physical Chemistry" which refers to a particle in a box. The purpose of the box is to exclude the environment. It's as close to a free body diagram as anything else. He was a good lecturer, but his habit of producing new editions of the book was annoyingly good at dropping their re-sale value. That's why I still have mine from '84. When I was there, Oxon had the largest chemistry department in the Western world.

I am curious. Studiot, when you got a hat pump installed, did you also upgrade the insulation?

Not really. This circuit generates a distorted sine wave in which the phase of the distortion is arbitrary WRT the sine wave. https://en.wikipedia.org/wiki/Phase-fired_controller Obviously, you can resolve any arbitrary phase into a sin and cosine component. In that case, you only need two phases, as long as you don't mind one of the amplitudes being negative.

How do I distinguish that from being fat? Also, it may have escaped your notice but essentially everyone is "peasant stock". However, that's enough time wasted on a random number generator.

BMI is a system by which a doctor can tell a patient "You are too fat" while causing less offense. Reading anything more into it is fishy. It's a bit like IQ.

Because it didn't make sense. BS1363 was introduced in 1947. It predates any EU standard. The UK BS1363 plug is wired with brown, blue and green/ yellow wires. The BRown wire goes to the Bottom Right pin. The BLue wire goes to the Bottom Left pin. Remarkably few people seem to understand this. There was a very old standard BS546 where the wires were black and red, but there's no good reason to revert to that . It went at about the same time as round-pin plugs. There was a relatively recent change of standard for wiring the socket that goes with that plug. Previously the house wiring was done with red, black and bare T&E cable. This was changed to match the colours used in the flex from the cable to the equipment. This was done deliberately; it was brought in at the same time as a requirement that any new installations needed to be verified by a competent electrician. Before that change, the "householder" could do their own work on the system. If you think about it you will see how they needed to change the wiring somehow in order to distinguish old wiring (which doesn't need a certificate) from new wiring (which does). The "old colours" cable is still available on eBay etc- it's not clear why...

And if that dot is not in a direct straight line from the source and through the slit, then there's obviously diffraction happening. So we know that the single electron diffracts. So we know it's a wavelike thing.

The Earth's rotation slows slightly when I go upstairs and rises again when I come back down. But the point remains that apart from the tiny effect of lifting some mass- that of the turbine and tower- using a wind turbine won't stop the earth rotating. Building the tower makes a difference, using it doesn't. If the wind didn't hit the tower then it would be slowed down by drag against the earth anyway. The rotation of the rock we are stood on changes. The rotation of the atmosphere also changes. But the rotation of the whole earth- including the geosphere and atmosphere pretty nearly doesn't. There's a tiny effect because, when the earth is nearer the sun, it warms and the atmosphere expands. The reason you can't use the rotation of the earth as a much better clock is that you only measure the rotation of part of it. If you could include the air as well, the whole earth would keep much better time.

No. Not "tends to cancel" but "absolutely has to cancel". The Earth is pretty much isolated so the angular momentum is conserved. (Ignoring tidal coupling to the moon etc) Since the moment of inertia is also unchanged the rate of rotation can not change. Yes, the wind provides a torque on the turbine, but only because the planet provided a torque on the wind in the first place.

There is a fundamental difference between the dam and a wind turbine. The dam moves a huge mass slightly further from the centre of the Earth; this changes the moment of inertia of the earth and therefore affects the rate of rotation because the angular momentum is fixed. The wind turbine doesn't. So it won't affect the rotation rate.

Stagnant water is a great way to encourage rot.

Like whether your uncle loves your aunt.

In what circumstances?

Unless you don't. The distinction between white and colourless is a bit unclear (if you forgive the pun). Resins used in varnish making are classified by their colour. The clearest (and thus the most expensive are called "water white". By the way, the word "albumen" comes from the Latin "albus" meaning "white".

It might breach this or indeed. My solution would probably stop me being weightless.

I presume that is considered cheating.

The chemical and microbiological specifications for tap water are generally more stringent than for bottled water.

Among other things, it could be describes as Mt Putin's dream come true.

Actually, those processes are (by the laws of thermodynamics) driven by a net reduction in organisation in the universe. It's true that trees grow, but it's also true (and a necessary part of evolution) that trees die. The expectation is that the universe will end up cold dull and empty. Your problem is only looking at yourself and the things near, and like, you. We may be getting more complex; so is life. But the universe isn't.

Long ago, at school I really pissed off the metalwork teacher. He had just finished explaining to the class about pickling copper after annealing it. You wash it in 10% sulphuric acid to remove the oxide film. They also pointed out that you had to use the special brass tongs because the acid would damage the (usual) steel ones. And, of course, he made a big song and dance about being careful with the acid. It undermined his authority when i just took stuff out of the bath with my hands and rinsed it under the tap. Dilute sulphuric acid does attack normal human skin, but slowly. Washing your hands in it is stupid bravado (and yes, that applies to me doing it when I was a school kid) but it doesn't imply any superhero skills. I doubt I ever got through a gallon of coffee in a day, but when I was a student I was getting through half a dozen caffeine tablets with my breakfast. Lethal doses of caffeine taken rapidly- are of the order of 5 grams. A cup of coffee is of the order of 0.1 grams. So, 50 cups of coffee at once would kill you . But a gallon over the course of a day is just an expensive (and unhealthy) choice of drinks. One obvious effect would be an extra gallon of piss every day. That's rather a lot. Enough, for example, to wash out a lot of any medical drugs you took before they had time to work. So the idea that it takes 4 times as much medicine to have an effect isn't a miracle either. There's nothing here to investigate.

In what way?

"What is the best political direction?" Neither- if you go too far.

Most of the people in the UK didn't vote for him or his party.

I once got asked to analyse the stuff found on the inside of a burst gas cylinder. They were trying to work out what had happened. There had been a witness- very very briefly- but he wasn't telling us anything anymore. (re)filling high pressure cylinders isn't as easy as people thing. It's also often illegal. This is not the sort of thing to do with "string and sealing wax" as the phrase goes https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10309/1030908/Whatever-happened-to-the-string-and-sealing-wax/10.1117/12.2283713.short?SSO=1

I think they value it; they just don't recognise it. To be fair, they have seen few examples.