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John Cuthber

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Posts posted by John Cuthber

  1. Just a thought.

    Do you plan to make the terphthalic acid into benzene by heating it with a strong alkali to decarboxylate it?

    If so, how do you plan to ask it not to decarboxylate the first time you heat it with molten NaOH? (I think that's what UC meant)

     

    I know that there's Kolbe's method for turning acids into hydrocarbons but unless it does some clever trick, the expected product from terphthalic acid would be some biphenyl derivative.

    http://en.wikipedia.org/wiki/Kolbe_electrolysis

  2. I know it's not quite the same thing, but I once saw a TV show that said that they use biological washing powder to clean skeletal remains for forensic examination.

    Bleach will certainly kill bacteria and it may help soften up the tissue (not to mention helping get rid of any smell).

  3. If you use a streetlamp you don't have to pay for the electricity (and a lot of streetlighting uses sodium lights - the orangy yellow ones- which show the effect very well.

    A handkerchief might be easier to get than pantyhose depending on your circumstances.

     

    This page

    http://en.wikipedia.org/wiki/Double-slit_experiment

    shows roughly how it can be done with a torch bulb, some bits of cardboard and a magnifying glass.

     

    A relatively easy way to make the double slit is to get a piece of thin wire, stick it to a piece of clear glass or plastic and put two bits of black tape on either side of it so there's tape, a gap, the wire, another gap then more tape.

  4. Indeed - all the everyday applications are really pretty important, and worth learning about for anyone but the purely academic side is just that.

     

    Can anyone remember the name of the mathematician who studied number theory because he was sure the military couldn't use it? He was rather put out when they started using it to encrypt signals.

     

    As with a lot of things in science (and I don't know or care if maths is a science) today's obscure academic stuff is tomorrows everyday aplication.

     

    (This image may well be brought to you using fractal compression- 20 years ago fractals were just pretty pictures that math's geeks played with).

  5. Ah yes, monopolise the provision of a service, reduce its quality, efficiency, increase unnecessary costs and lambast your critics for denying "common good" while doing it!

     

    That's definitely socialism.

     

    I take it that you can provide evidence for that assertion.

    In particular, I'd like to see how it applies to healthcare where the US system is much more expensive but doesn't provide a better outcome (by some measures) as other "social" systems elsewhere.

  6. The rules about who can do what vary from one country to another.

    Here in the UK I could open a lab and do clinical analysis even though I am not (by any definition) a doctor. I am an analytical chemist but, strictly speaking I don't think that matters. Anyone could set up the lab if they could do the work (if they could not do the work not then it would be fraud).

    I would have a very difficult time setting up a lab because people wouldn't want to trust a lab that has not got a reputation from years of work.

  7. In zero gravity there's no convection; if you use a gas with a poor conductivity radiation might win out.

    Incidentally, monatomic gases do a really bad job of radiating energy unless they are hot enough to be electronicly excited- say 10000 degrees or so.

     

    If you wait for a cloudless night and go out to look at the stars you will observe the effect of radiant cooling- it gets cold.

    Nothing "magical" I'm afraid.

     

    (space is very cold and the stars don't add a lot of heat, so radiant cooling is a major contributor in this case.)

  8. Sadly, in 4 years, nobody even mentioned the important keywords here: Lower Explosion Limit and Higher/Upper Explosion Limit.

     

    According to the link posted above, the lower explosion limit of methane is 4.4% by volume. Any concentration higher than that and it can explode.

     

    Here's a list of explosion limits for a bunch of gases. Natural gas can be assumed to be mostly methane.

    http://www.engineeringtoolbox.com/explosive-concentration-limits-d_423.html

     

    After 4 years research it would be better to realise that there's an upper bound to flammabillity too.

    "Any concentration higher than that and it can explode"

    OK, so lets see you make 100% methane explode.

  9. Re "to say this explains all of them is just not conceivable"

    I assure you that I have no difficulty whatsoever conceiving this.

    Your assertion is, therefore, incorrect.

     

    Incidentally, I don't know if you count mathematicians as "credible scientists" but a bloke called John Allen Paulos has written a couple of books that do cover this sort of thing. He is well qualifies to explain how come coincidences happen a lot more often than people expect. Not exactly the matter in hand, but a closely related one.

  10. I look forward to the video.

    However, just in case anyone ever looks up this thread because they want some KBr and they have some bromine, here's a less "exciting" way to do it. (I have a rough idea how likely that is, but this post didn't cost much)

     

    Pass bromine over heated iron filings to produce a mixture of iron bromides. (or dissolve the Br2 in a suitable solvent and react it with iron.) Leach the Fe bromides into water and add potassium hydroxide or carbonate until all the iron is precipitated.

    filter off the Fe oxide/hydroxide/carbonate then evaporate down the solution to get KBr.

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