John Cuthber
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The human body weight force on human body joints
John Cuthber replied to awaterpon's topic in Speculations
I presume he's rehashing this tripe. -
Ditto Irish- so I understand. So you get exchanges like "Are you going for lunch?" "I am". This stuff about language may be the most useful bit of the thread.
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Did we need more?
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UV will not kill microbes which are hidden in dirt, because the dirt is opaque. So you would need to start by washing things.
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Commercial washing powder surfactants v NaHCO₃
John Cuthber replied to Erina's topic in Inorganic Chemistry
What's wrong with using soap? I realise it's rather old fashioned- Roman technology- but it works and it's cheap. -
Commercial washing powder surfactants v NaHCO₃
John Cuthber replied to Erina's topic in Inorganic Chemistry
Yes it is. It's generally a better cleaning agent than the bicarbonate. And it's cheaper. -
Commercial washing powder surfactants v NaHCO₃
John Cuthber replied to Erina's topic in Inorganic Chemistry
The idea of a "surfactant" is interesting. One of the oldest is soap. And that's the sodium salts of fatty acids. But part of the residue left on clothing is a mixture of fatty acids- the lower molecular weight ones are responsible for part of the bad odour. So adding dirty clothes to a weak alkali like bicarbonate will generate a very small amount of soap. And it will also remove some of the material that's responsible for the smell of stale sweat. Hypothetically, the stuff will also hydrolyse fats but that reaction is very slow. To make soap, you normally use a fairly concentrated solution of sodium hydroxide and heat it to nearly boiling so it's about a hundred million times more alkaline and also hotter. Fundamentally, washing soda is cheaper and more alkaline. Hence the name... Drying kills most bacteria. If they didn't kill you when you wore the shirt, they probably won't kill you after they got washed off and then dried. One valuable reason to add glycerine to soap is that it absorbs water- which is marvelously cheap. Also, if you make soap, the by-product is glycerine. So you can save yourself the trouble of removing it by leaving it in the soap, and calling it an ingredient. It's very soluble in water so it will rinse off at least as easily as the soap. There won't be any left on your skin. The water you wash it off with is actually quite good at hydrating; glycerine, on the other hand, is a dehydrating agent. -
Climate change; it seems we avoid it like the plague.
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Cutting / treating glass to refract specific colours ?
John Cuthber replied to Erina's topic in Engineering
https://en.wikipedia.org/wiki/Dichroic_filter -
It may have been. https://www.bbc.co.uk/news/magazine-14374296
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And that Cp/Cv is 7/5 or whatever.
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I think you are in this territory. https://en.wikipedia.org/wiki/Adiabatic_process#Ideal_gas_(reversible_process)
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The 7 squares in that picture shoe the effects of All 3 sets of dots on my screen illuminated, Just red and green Blue and green Red and blue; and then the 3 primary colours on their own. Since all 3 lights are on in the white square, I see it as brightest. My eye is most sensitive to green, and least sensitive to blue So the mixtures with blue in them are going to be perceived as relatively dark. Thus the mixture without blue, (to which the eye is relatively insensitive) and containing green (at the peak of sensitivity) will be seen as lightest. And that's yellow. It looks lighter than the green for the simple reason that it is. It has the green light and it has the red as well.
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On the myth that it was leftists who were "anti-vax"
John Cuthber replied to ScienceNostalgia101's topic in Politics
It's one of the things that grinds my gears. Another related one is the media's idea of "balance".Stuff like this "In todays show we will be talking about covid. On one hand, we will talk to Dr Bloggs- a professor of immunology and, by way of balance we will talk to Mr jones whose last job was at the back half of a pantomime horse prior to his sacking for incompetence." And then they give equal weight to the views of the failed horses' arse. (And you can guess which one agrees with the Republicans) It's a deliberate policy to undermine the importance of truth because, as someone pointed out "Reality has a well known Left wing bias". -
On the myth that it was leftists who were "anti-vax"
John Cuthber replied to ScienceNostalgia101's topic in Politics
Sorry, it's one of those subjects that winds me up. -
On the myth that it was leftists who were "anti-vax"
John Cuthber replied to ScienceNostalgia101's topic in Politics
Guess. Here's what might be considered a hint. Jeremy Corbyn, while repeatedly described as "unelectable" was rather successful in elections. Notably, in the 2019 general election, in the only vote where his name was actually on the ballot paper, he got 64% of the votes. He was, for a while, the leader of a mainstream, left wing party. And I also said So, can you work out if I think he's an outlier? The point I was making was that the Right try to claim "false equivalence" You have people saying, "Yes, Trump said that the virus would just disappear when Spring arrived, but look at this cartoon Leftie from 10 years ago saying something silly. That proves that the Left is obviously just as bad!". And that's just a lie; there's no way round it. -
On the myth that it was leftists who were "anti-vax"
John Cuthber replied to ScienceNostalgia101's topic in Politics
No, there isn't- not among politicians who actually get elected. Did you read the thread I linked to? I kept on asking for examples of the Left wing nutcases. Nobody was able to provide any. It's not that left wing nuts don't exist- Piers Corbyn is a fine example. But the point is that, unlike the Right wing, these people are never given a role in any mainstream party. There really is a big difference. No. It belongs in the "fake" category. That picture is "old". Someone has just written the new words (the leftie antivaxxer meme text) over a old picture. "She" does not exist. She was invented by someone to discredit the Left. https://knowyourmeme.com/memes/college-liberal So, at best, you have an example of a college student who is a hypocrite. Well, the thing about students is they are still learning... Are there any instances of any credible Left wing politicians saying that the vaccines don't work or that the virus is a fake- you know- like Trump did...? -
OK, this is the flu virus, not covid but... "This study focussed on the effectiveness of surgical masks against a range of airborne particles. Using separate tests to measure levels of inert particles and live aerosolised influenza virus, our findings show that surgical masks provide around a 6-fold reduction in exposure. Live viruses could be detected in the air behind all surgical masks tested. By contrast, properly fitted respirators could provide at least a 100-fold reduction". from https://www.hse.gov.uk/research/rrpdf/rr619.pdf The maths isn't really this simple but, if the R value is 3 and your mask reduces exposure by a factor of 6 it might get the R value down to 0.5- i.e. below 1- which would be good. That's not a thermal image video.
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On the myth that it was leftists who were "anti-vax"
John Cuthber replied to ScienceNostalgia101's topic in Politics
I see two points to it. First it shows which "side" actually has a grasp of reality and secondly, it's hilarious. Who remembers this oldie-but-goodie? One of the more interesting traits is that 10 years back, a guy called Rigney perpetually saying that Biden was mad, without offering aby actual evidence of it. -
Much better than Elo, Glicko, and Trueskill
John Cuthber replied to Theodoros Kiriakopoulos's topic in Applied Mathematics
Fred is the worst player on the team. To be honest, it was a mistake recruiting him. We only put him in to play when there's no choice - we really only do that when we are up against a team who we are sure we can beat. So Fred only gets to play in matches where he is actually likely to win even though he's a bit rubbish. So, he's usually on the winning side What is Fred's score based on the OP's ranking system method? -
Will the pandemic cause major shakeup of capitalist economies?
John Cuthber replied to Peterkin's topic in The Lounge
Given that the trains have not been public for about quarter of a century, I think we can largely discount your view on the matter. -
Origin of COVID (hijack from Rand Paul Called Fauci a Liar)
John Cuthber replied to Alex_Krycek's topic in Biology
If a sovereign country like China (or the US or UK) chooses to do GoF research clandestinely then there's nothing that another country can do about it. So, if we were magically able to prove that China had been doing it (And it seems unlikely that they would be stupid enough to do it essentially on an open lab bench) there's nothing we could do about it. So there's not much point wasting time on trying to find out. -
Origin of COVID (hijack from Rand Paul Called Fauci a Liar)
John Cuthber replied to Alex_Krycek's topic in Biology
Are you saying that, if it turns out to have escaped from a lab we do not need to worry abort wet markets? Are you saying it it escaped from the wet market we do not need to worry about labs? Or are you, as I am, saying that we actually need to look carefully at both of those because, whichever one was the source this time, that doesn't mean the other won't be the cause of the next outbreak? If both look like plausible sources we need to reassess both. -
Will the pandemic cause major shakeup of capitalist economies?
John Cuthber replied to Peterkin's topic in The Lounge
Which?