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John Cuthber

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Everything posted by John Cuthber

  1. So, you do realise that the Right are just less well informed, don't you? Maybe you should listen to those who learned to think and to express those thoughts. Just "thinking" isn't good enough. You need to study how the world really works. You need evidence.
  2. Russia invaded another country. Are you saying they can be trusted?
  3. https://en.wikipedia.org/wiki/Oxford_Electric_Bell https://en.wikipedia.org/wiki/Zamboni_pile Or balance some KCl in a dish exposed to the air against a counterweight. As the humidity (+ temperature) changes the stuff will gain + lose moisture and will tip back and to. In principle, you can use that motion to drive a mechanical clock. Good luck KCl would be a poor choice for this (unless you live somewhere with a humidity that's about 85%). Magnesium nitrate would be better near 50% RH This is a better bet https://en.wikipedia.org/wiki/Atmos_clock
  4. https://en.wikipedia.org/wiki/Photoacoustic_spectroscopy
  5. Lightning involves currents of something like 10,000 amps (it's very variable) The circuit breakers at your fuse box probably limit the current your house can draw to less than (about) 100 amps. So the lightning only draws the same as about 100 houses (if they were all "maxed out") probably more like 1000 houses most of the time. However, if you want to compare power, you have to take the voltage into account, and lightning has a much higher voltage- something like a million times higher than that supplied to your house. A lightning strike would power about a billion households. But not for long. If you try to measure very very small currents say, less than 10^-15 of an amp, you don't get a steady current. The effect of each electron passing becomes "noticeable". If the average current is only 1000 electrons per second, then the variability is quite large- about 32 electrons per second on average. This is one source of "noise" in electronic systems.
  6. Without a good indication of scale, it's very hard to identify things. (I know you say 400 and 1000 magnification, but is that on my phone or on my widescreen telly?) Comparison with a hair at the same magnification might be informative.
  7. Mankind was using fire and breathings smoke before broccoli was bred. On the other hand, Broccoli, like other brassicas is actually toxic. https://en.wikipedia.org/wiki/Goitrin To a good approximation, sweat is water; and anything that can be carried out of the body in solution in water will be excreted in the urine, much more than in sweat simply because we don't normally sweat that much.
  8. It's "barely" true. While some toxic material will be lost that way, it's nor very effective. No, that's because they either (1) like saunas or (2) have been conned into thinking it's a "detox". (Possibly by videos like that one)
  9. Yes. And I can do it with only one field.
  10. I think there's some misunderstanding(s) here. Irises (both the flower and the coloured bit of the eye); iridium and iridescence all get their names from ίριδα the Greek for rainbow. Iridium was named after the fact that many of its compounds are strongly coloured. Chromium was similarly named (from χρώμα) But iridescent minerals do not typically contain much iridium (and nor do irises). Iridium is rather rarer than gold.
  11. It doesn't matter who says what. The constitution can be, in fact, be changed.
  12. In what way? The bits of that which made any sense seemed to be saying that the best approach is defeatism.
  13. Only by amendment. Amendments can be revoked. And the constitution can be amended. Pretending that the constitution is Holy writ is one of America's problems here.
  14. If the V2 at 5760 km/h was above about 15000 feet (depending slightly on the weather) it would be hypersonic. https://www.fighter-planes.com/jetmach1.htm
  15. I have used PEEK fittings at 5000 PSI and above.
  16. It's still "sort of " right. Brown goggles will not protect you against a brown laser beam- because it doesn't exist. UV blocking goggles are likely to be yellow. IR blocking ones are likely to be blue/ green. If they block by reflection they (1) are not a good idea and (2) they look really shiny/ mirrored . It's not a good idea because reflective coatings are typically thin and easily damaged. In general it's not a great idea to judge the goggles by their colour.
  17. According to this, you should be able to find "moon dust" with enough potash to grow plants. But without combined nitrogen you are stuffed. https://sites.wustl.edu/meteoritesite/items/the-chemical-composition-of-lunar-soil/
  18. The range of frequencies we can see is (just) less than an octave. We could possibly just about see 400 THz. 401THz and 801THz. The closest thing to relevant that I can think of is that both getting the sum of two frequencies, and the photochemistry of photosynthesis rely on 2 photons. A single visible photon doesn't have enough energy to split water.
  19. Anyway, lets be a bit more clear. The action spectrum for photosynthesis has been measured. https://ib.bioninja.com.au/standard-level/topic-2-molecular-biology/29-photosynthesis/action-spectrum.html There's a big trough for green light- which is, at best, poorly absorbed (even with the help of the carotenoids). So it makes sense to focus your efforts into making red + blue light. The most likely fate of a green photon near the bottom of the graph is that it will be wasted as heat. If you were making coloured light by starting with white light, and filtering it there would be no point (except that taking out the IR might prevent overheating). But with LED lighting, you can selectively generate the colours that work best. Also, none of this has anything to do with heterodyning light.
  20. Plats are, in general, green. They reflect green light so they can't absorb it. So any green light emitted by your LEDs is wasted on the plants. As you say, you need a lot of light to get plants to grow well. But there's no point shining green light on them. So it makes sense to produce lights that only have the blue and red bits of the spectrum. People (generally) have three different colour sensors so colour rendering for people is different to efficient illumination of plants.
  21. Cow manure. Seriously- The farmers used crushed old plasterboard as "bedding" for cattle. (It was cheap) That led to a dangerous enhanced production of hydrogen sulphide in slurry pits.
  22. You can use sulphates as oxidisers, if the fuel is a strong enough reductant. The reaction of calcium sulphate and aluminium is well documented. I should probably say something like "don't try this at home" but
  23. What do you mean by "react"?

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