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John Cuthber

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Everything posted by John Cuthber

  1. All "uses" are beneficial from someone's point of view. The usefulness of H bomb production is a matter of opinion and probably off-topic. Tritium is a very valuable material. The problem with the waste-water from Fukushima is that it's neither dilute enough to be "harmless", not concentrated enough to be useful. China has been very hypocritical in its criticism of Japan. China "dumps" waste with higher tritium levels than Japan is proposing to. Tritium is also one of the least problematic radioisotopes simply because, like water, it rapidly runs through the body and out. The radioactive 1/2 life may be 12 years but the biological 1/2 life is only 10 days. It also has a very low decay energy. You can get higher energy electrons in a big colour TV.
  2. You are right; the cooking times are less, but you don't know how much less. If you only have a small flame the water will heat slowly and the (for example) pasta will spend a long time in nearly boiling water- an will start cooking. If you wait until the oven is hot or the water is boiling, you eliminate the variable "run-up" time. It's not wrong, but you might be in trouble if you cook in someone else's kitchen.
  3. On a related note... https://en.wikipedia.org/wiki/Haybox
  4. Essentially, you need to heat and compress some fuel to get it to fuse. You can only focus EM radiation into a spot roughly the size of the wavelength of the radiation. So for the same output power, you can get much higher power densities (power/ area) using lasers than using masers. And that means you can get a much higher temperature and pressure. In principle, you might imagine extrapolating this and using even shorter wavelengths. But to make a laser you need a population inversion. And the shorter the life span of the upper excited state, the harder it is to fill it up before energy "leaks" out of it. And, all other things being equal, the lifespan of the upper state is inversely proportional to the cube of the energy. That's fundamentally, why it's relatively easy to make lasers for visible and very hard for X-rays. So, for a given input power you can get a lot more output power from a longer wavelength laser. (We use this all the time; our "green laser pointers" are actually IR lasers, frequency doubled to get a visible beam. the increased ease of getting an IR laser to work overcomes teh inefficiency that results from frequency doubling) And, of course, the best known property of x-rays is that they go straight through stuff. If all your input energy is in the form of x-rays, it goes right through your target without affecting it. It doesn't even warm it up. Bother! There's also the fact that we have been using light for a long time and are skilled at manipulating it. So, for us, visible light (or near visible IR/ UV), is the "sweet spot" for getting a lot of energy into a target quickly.
  5. Why don't you stop + retrain as a UPS driver?
  6. Is this the sort of data you were looking for? The average salary for Hospital Chief Executive Officer is £141,327 per year in the United Kingdom. The average additional cash compensation for a Hospital Chief Executive Officer in the United Kingdom is £43,772, with a range from £17,122 - £111,900. from https://www.glassdoor.co.uk/Salaries/hospital-chief-executive-officer-salary-SRCH_KO0,32.htm#:~:text=The average salary for Hospital,from £17%2C122 - £111%2C900.
  7. I am more used to discussions that start off about the thermodynamics of steam engines and end up discussing toilets, than the other way round. But I fear we may have strayed a bit from the topic. We pipe water to our houses at fairly high purity, and chlorinated. That's not going to grow much biology. After we use it to flush toilets, it has more "biology" in it than seawater does. So the question of maintaining free flowing water when using sea water (if one set up a pipe system to deliver it) would only relate to the inlet- the outlet would be pretty much the same (I'm assuming the mix of bugs in the water treatment works would adjust to cope with the increased salinity). If we chlorinated the infeed sea water the problem would go away. But it would take more chlorine to "sterilise" sea water than drinking water. It might not be worth the effort.
  8. The value of 0.6 volts looks a lot like a single galvanic cell. The voltage will change with temperature. I rather doubt it's doing any "collecting energy from the sun".
  9. It's remarkable to describe Hertz' work in 1886 as "recent". Anyway, if relativity only works in far-field but not near field, it's easy to test. Get a VLF radio and a short or medium wave radio and wait for a thunderstorm. Then listen for the crackle produced by lightning. Say I'm 5km from the lightning strike, listening on 5000 metres VLF and on 200 metres medium wave For the first 5 km, the long wave signal is still "near field" so it will (if the OP is correct) reach me immediately. But all but the 1st 200m of the route of the MW signal is far field. So it will be delayed by the time taken for propagation across the remaining 4800 metres at c That's about 17 microseconds. That's just about in the range where you might be able to hear it. "The normal human threshold for detection of an ITD is up to a time difference of 10μs (microseconds)." From https://en.wikipedia.org/wiki/Interaural_time_difference It's trivial to measure electronically. This is well into the range of "someone would have noticed".
  10. Why? Anyway, this would be a good plan in very limited circumstances. If you had, for example, a small island with little or no infrastructure and you were introducing a sewerage system for a small number of inhabitants then maybe it would be acceptable having a waste pipe that led out to sea with no treatment. If there was also a shortage of fresh water on the island such that pumping sea water was less "expensive" than desalinating it, then maybe it would be worth installing a separate sea water feed pipe to the village just for flushing toilets. But in almost all other situations, it's not going to work. (I'm about 300 feet above sea level, in the rather rainy North of England...) Having said all that, using "grey" water to flush the toilet is an excellent idea.
  11. A+B A+C B+C A+B+C makes 4 If you consider "A + nothing" to be a mixture You have another 3 "mixtures". And You can sort of include "nothing + nothing" Which give you 8 altogether. Imagine you introduce D into the system You can either add it, or not add it, to all the previous mixtures. So that doubles the number of possibilities. So for 4 materials there are 16 possible mixtures- and in general you get 2^n mixtures of n substances. But the alchemists (and chemists) distinguish between different compounds, even when they contain the same elements, eg FeO , Fe2O3 and Fe3O4
  12. Or you can use a non-rigid container, for example, bellows- and not worry about the expansion/ contraction. You really can't beat water for heat capacity. In the other hand, if you allow phase changes, you can do even better. https://en.wikipedia.org/wiki/Sodium_sulfate#Heat_storage
  13. "What is the nature of our existence?" Ephemeral.
  14. No It couldn't be more than "about half". Granted, it could be 1% or 49%. But it does tell you that it can't be 99%. Whoope Well... its better than having to tell you that an error has been made...
  15. It tells you that an estimate has been made. It tells you what that estimate is. It tells you about the statistical power of that estimate. If the word "combination" makes an assertion meaningless, then why did you say this? Once you make it that clear that you can not even follow your own argument, it's probably time to stop, isn't it?
  16. It may seem that way to you. But when I see an estimate with a range and p value like (40–54%; p > .8) , I assume it's probably calculated from data.But... I wasn't certain. So I did something weird; I looked at the paper. And, what do you know? I found references to actual data. As for "It doesn't tell you anything" I think that, if you look carefully, it tells you that " about a half (40–54%; p > .8) of the global warming from 1901 to 1950 was forced by a combination of increasing greenhouse gases and natural forcing".
  17. OK, let's look at what you said 3 posts ago. OK, that's not going to refute anything much. That's simply wrong. We pretty much always do- as I said, sunshine, alcohol... I already said essentially the same thing. As long as you know the risk is small, you don't need to quantify it So it's fairly stupid to claim that I don't understand it. Why did you do so? Is it because you are "a person can't keep track of arguments that were already made"? I already did. But you failed to understand it. What do you think they do with the data from the yellow card scheme? Do you think they use it as some sort of lottery? Or, if I make it obvious enough, do you realise that they use it to do analyses of the risks. It's not a meta-analysis. It's better- it's an analysis of the biggest data set available- the whole uk patient cohort. And I had already made the point (see above "Actually putting a number on the first risk- say it's a 0.1234% higher relative risk- does not change clinical practice.") So you were failing to read what I had said. Which makes this really stupid, doesn't it? Do you really not understand that data- including cancer data - is kept under surveillance? Were you not aware of things like this? https://www.kingsfund.org.uk/publications/using-data-nhs-gdpr?gclid=CjwKCAjw_uGmBhBREiwAeOfsd9JFjMNx86yeyws3aIGInpt-FBc5zhgBnR_re34pl9FgvUpo3HG__hoC10gQAvD_BwE So, as I said, if it was a big enough risk to notice, it would have been noticed. On the other hand, you have failed to spot the real point I made here (presumably because you were too busy ranting). My point is that "too small to notice" is the same as "too small to notice". There's one thing which we both agree on- there's a level of risk that's "trivial". Once you know that the risk is less than some cut-off, there's no point putting the resources into measuring it. And we have systems for monitoring drug safety. Either our systems are not good enough to spot a problem which is "more than trivial" in which case there's a problem with our systems which has nothing to do with metronidazole. Or our systems are able to a problem which is "more than trivial" in which case, if the stuff is a problem, then we would spot it. Which of those conditions are you concerned about here?
  18. Here's a start. When George awoke, he felt better than he had for days. The next thing that struck him was how quiet it was; the hospital had always been such a busy place. Now, the only thing he could hear was the oxygen concentrator humming away by his bedside. He remembered the doctor saying "With luck you might not need that tomorrow morning; you had a nasty brush with death , getting poisoned like that- but your lungs are healing well." He also remembered his wife telling the doctor that he had been a professional racing cyclist in Rwanda. - the jokes about why anyone would choose it and the answers; not much competition, and the natural "altitude training" you get from a country that starts at about 950 metres above sea level, and only goes up. The doctor asked if his genetics had helped. He wasn't sure if the guy know that his dad was from Bhutan and his mother Peruvian. He knew that without those lucky strikes, the chlorine leak at the swimming pool would have killed him, like it did all others there. The next thing he noticed was two flickering lights in his darkened hospital room. One was a "low oxygen" warning on the machine and the other was more threatening...
  19. I have the book. https://www.awesomebooks.com/book/9780333248270/connections/used?gclid=Cj0KCQjwuNemBhCBARIsADp74QRYfZaxv6ZvzE_ud5NC1V6sTKAcQqAxhOyYu3aSa96MQeqH8jpp1XcaAk5YEALw_wcB
  20. Yes, Thankfully, the 1956 "keep bloody well flying" legislation ensured that all birds never to get close enough to the ground for them to be an issue for cars. Seriously, I think the best known advice in this context is "thaw the chicken".
  21. Planes don't typically have to navigate round buildings or account for children , wheelchair users, cyclists ... Essentially, there's nothing up there to hit.
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