John Cuthber

OK, here's the picture from the site I cited earlier. The picture is a plan view of light coming in from the left, hitting the grating and then spreading out from the holes in that grating as a series of circles (in green) The green circles represent the peaks of the waves as they spread out. The distance between the circles is the wavelength of the light. The centres of the circles are the gaps in the grating. In reality the grating have thousands of lines and they are separated by something like a thousandth of a millimetre. Does that make sense so far?

Nevertheless, they are linked. Are you aware of this way to measure the wavelength? http://www.schoolphysics.co.uk/age16-19/Wave properties/Interference/text/Wedge_fringes/index.html

OK, I have a mercury lamp. It emits light of a number of different colours. If I let the light shine through a piece of green glass then only the green light gets through. If I pass it through a prism it doesn't split into different wavelengths - it's pretty nearly monochromatic. How do I go about measuring the wavelength? There are a couple of options reasonably easily available It's a lot easier to work with beams of light if hey are nice parallel beams. So I will start by passing the green light through a pinhole. Then I can use a lens for make the light into a parallel beam. Does that make sense so far?

That's further use of the wrong language. You should try to avoid it.

If you choose light of a single colour, the wavelength of all the light is the same. Do you understand how the angle between the diffracted rays depends on the wavelength? http://www.cyberphysics.co.uk/topics/light/A_level/difraction.htm

Does this help clarify things? https://www.khanacademy.org/science/physics/light-waves/interference-of-light-waves/v/diffraction-grating

Not really. It's perfectly possible it started with something else which subsequently evolved into DNA /RNA or with something that was overtaken by DNA/RNA

As you say; not even superhuman hearing would help here. So it's not a valid test. A better test would be so see if you can discriminate sounds better than your friend with good vision. Having said that, there is some truth in what you say. The best known example of the idea of blind children having better hearing was to get a person in a dark room to point to the source of a sound- say a bell- as it was moved round the room. The expected response was that blind people would do this more accurately than those who could see. It turned out that the blind volunteers did slightly worse than the sighted ones (remember, this experiment is done in a dark room- sight couldn't help). It's assumed that the blind people didn't have the same opportunity to practice linking sound to location. But, in many cases- blind piano tuners are the folk-lore version- people do compensate and there are functional MRI scanning experiments that show that blind people use the parts of the brain usually reserved for vision to process auditory data. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0173064

In general, men often have more variability in a lot of parameters. It's usually put down to the fact that the Y chromosome doesn't carry spare copies of genes that the X chromosome may carry. There may, of course, be a whole lot of other factors; in particular, the IQ test is skewed every which way but loose.

Who generally sees this? The data suggests that women also live longer if they are married. In any event, how would you demonstrate causation? Is it that people who marry live longer, or is it that healthy people are more likely to marry?

The magnetic field from a coil is governed by the current through it. A CRT supply certainly won't deliver much current. You would probably do better with a torch battery.

Since red blood cells don't reproduce they fail to meet the criteria that define "life". "the condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional activity, and continual change preceding death." All cells that are known to reproduce do so via DNA so the answer to the OP's question "How long can a Cell live without DNA???..." is "They can't".

Is anyone else struck by the irony of needing to tell someone that in this thread?

Conservatives do not seem interested in "decent".

Actually, there are differences. https://www.huffingtonpost.com/2013/02/20/republican-democrat-brain-politics-fmri-study_n_2717731.html So, it's perfectly possible that both sides have been shafted by big business, but their perceptions of the experience differ. It hardly matters in this contest- Trump is a very poor businessman (as you might expect from someone with poor analytical and social skills). He's been repeatedly bankrupted and if he has invested that legendary "small loan of a million dollars" from his father in the stock market, he would be much richer than he is. If he had relied on other people's brains (via the stock market) rather than his own, he would have made more money.

It seems that the UK's increasingly insane government has legislated to increase animal suffering by removing EU restrictions on it. http://www.independent.co.uk/voices/brexit-government-vote-animal-sentience-cant-feel-pain-eu-withdrawal-bill-anti-science-tory-mps-a8065161.html

It's also possible that it won't. Bacteria, like humans, have defences against UV. https://www.biotecharticles.com/Applications-Article/Colorful-Bacteria-612.html Someone has exploited this in an interesting way. https://www.nature.com/articles/n-12302488

Well, yes it is. But not in the way you think. Trump claimed that more people were at his parade. That claim was " spin and misinformation " spouted by Trump. And what underlies the claims that Trump is a liar are his " spin and misinformation" . He's called liar because he keeps lying.

Fundamentally, human cells are very much like bacterial cells. Things that kill one will generally kill the other. Lasers and microwaves are not going to discriminate well between the two cell types.

It shows Or, we can start off with a small loan of a million bucks from Daddy and then buy influence in politics in order to make sure that we win, and the other guy loses. There's a lot of money to be had, relatively easily, by cheating and lying. And one side is doing most of the lying. Marginal rates are certainly interesting. Consider 3 people: my boss; some rich bloke and his cleaner. The Rich guy first- he's a millionaire. Because his investments (which supply his income) are offshore, he doesn't pay tax on them, but lets assume he's "one of the good guys". As a higher (income) tax payer, he gets charged 28% capital gains tax - rather than 40% income tax which he would pay if he had the same income as a salary (and, of course, he benefits from the tax free and low tax parts of his income- but that's not the marginal rate.) His marginal rate is the higher capital gains rate of 28% My boss, who is just well enough paid (together with his wife) to get caught in the higher tax bracket pays a marginal rate of 40% Next lets look at Mr Rich's cleaner. He's on income support so, if he earns money he loses income from dole. The amount depends a bit on his circumstances, but it's typically 50 to 100 % of what he earns So the cleaner's marginal tax rate is somewhere between 50 and 100 % Are you going to say that is just "luck" or did Mr Rich (who inherited his money) "make his own luck" Or did the Mr Richs of the world get together and rig the system?

Would you like me to find the research on it? The problem is that you are on record as not accepting those arguments. You said so yesterday in this very thread. Did you forget?

Nonsense. People still manage to do that in countries where there's a dictator in charge. The fact that you found it easy to do shows that you had the good luck to be born in a relatively free country. When, exactly, did you choose to be born in the US?

A plasma composed of just H+ and OH- ions would be a very weird plasma. It's a very long way from any equilibrium.

Light often goes through stuff, air, windows, whatever. The alternatives are that it gets absorbed or that it gets reflected. Polaroid filters don't reflect much so we can focus on absorption. The nature of light- especially polarised light is that it is composed of a magnetic component and an electrical one at right angles to eachother and also to the direction of propagation. If you put a metal wire in an electric field the electrons in it will respond to the field and move along the wire. The field due to the displaced electrons tends to oppose the original field. If you do that with a field that changes with time the field drags the electrons up and down the wire. But that movement is a current. And a current flowing in a wire will encounter resistance and that transfers energy from the field and converts it to heat. So a set of conductive wires like a polariser will tend to tend to convert the light energy into heat; that's absorption. If the wires are mounted at right angles to the field the electrons are not moved so far and so there's a lot less absorption.

Actually, once they bounce of something they are not (usually) parallel. They get reflected in all directions.