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John Cuthber

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Posts posted by John Cuthber

  1. "Hydrogen molecules can create intense heat [3200F] and water by exothermic reaction with oxides in crustal layers. "

    What oxides? For iron oxide (as an example) the reaction generally goes the other way; passing steam over hot iron produces hydrogen and iron oxide. For any element more reactive than iron (Al, Si, Mg, Ca etc) the story is even less likely. The reaction may be forced the other way at very high pressures so the idea isn't utterly absurd but I'd like some sort of evidence rather than being asked to take it on trust.

     

    It hardly matters anyway, Edtharan's point about density renders the idea "highly speculative". Oh, I almost forgot, the laws of thermodynamics would make the system about as stable as a baked Alaska.

  2. #2 might technically be tricky (though I don't see why) but I'd include it in the answer anyway because it's the traditional way of doing things. Strictly, it gives the equivalent mass rather than the molar mass. Something like a freezing point depression measurement would give a rough value for the molar mass and you can use that, together with the equivalent mass to get the true molecular weight.

    An accurate molecular weight will probably give a very good idea what the compound is.

    #1 only works if the sample is pure, doesn't decompose on heating and is in the table when you look it up.

    If you do #2 properly you can get #3 "for free".

  3. "How I can measure the fluorescence curve obtained from my machine?"

    "Lefthandedly" would be one possible, but completely unhelpful, answer.

    What curve?

    Absorbtion spectrum? quantum yeild vs temperature...?

  4. "Our organisms characteristics do not make that possible "

    Please don't say things are impossible after someone has pointed out that they have been done.

     

    Odd as it may seem, it's likely that you could fly on the "high gravity" planet too.

    The atmosphere would be denser so the lift (and bouyancy) would be greater.

    Since (at least some very fit athletic) people can fly on earth "DIY flying" might be a useful tourist atraction for a heavy planet.

  5. I used to think the logo was just rubbish until someone pointed out that it looked a bit like "Lisa Simpson performing an obscene act". Now I think its almost worth the cost (about $0.8 million. Yes, really, about £400000), just for the comedy value

  6. "Searching google on [tetrahydrofuran methanol hypochlorite] points me towards the production of hexanitrostilbene (2,2',4,4',6,6'-hexanitrostilbene). "

    That's odd, because it looks to me like someone trying to make GHB- at best a recreational drug. I'm not commenting on the morallity of this, but runaway oxidations of organic compounds are a good way to get dead in a hurry.

     

    If you don't know the chemistry I think you should probably leave it to someone who does, or just leave it.

  7. Is there a competition for the weirdest and least plausible theory on this site?

     

    This thread seems to be a challenge to what I for one thought was the leading contender there. I'm sure many of you remember having a real laugh at the idea that nuclear explosions were a coonspiracy theory. http://www.scienceforums.net/forum/showthread.php?t=29808&highlight=nuclear

     

    Now that theory just required a lot of people to be very gullible and a lot more people to be exceptionally good liars for half a century or so.

    This one about the earth being full of supercold hydrogen not only strains belief on the "surely someone would have noticed" front, but it also drives a coach and horses through the laws of thermodynamics.

    Are there any other contenders for this "honour" that I have missed?

  8. "And if I do? Do you dispute the law of cause and effect?"

    Yes.

    I say that, while some people might be uncomfortable with it, nuclear decay is truly random. Pinning it on quantum fluctuations lending the energy to the nucleus to get it to decay just moves the random bit from the nucleus to empty space.

     

    The other interpretation is that it is "caused by empty space" ie by nothing. It has no cause.

     

    God plays dice.

  9. "The electroweak interaction only happens during certain circumstances."

     

    What circumstances? (And how does the nucleus "sample" the external world to find out if these circumstances apply?)

     

    Anyway, I'm still waiting for someone to explain what caused God. If the theists are permitted an uncaused God that breaches the laws of cause and effect (but without having to produce any evidence for Him) then I don't see why I can't say that the big bang has no cause. Perhaps it was similar to (albeit unimaginably bigger and longer lasting than ) the real observable popping into existence of particles.

    The Casimir effect shows us that things flit into existence briefly. The spontaneous, uncaused, existence of particles is a real property of the universe. All it takes is one phenomenally large example and you have a big bang.

    Putting God into this just adds to the difficulty. It's easier to come up with a big bang than a thinking, deliberately acting, God; just look at the relative complexity of the 2 ideas.

  10. Just for the record and as a clue as to the overall plausibility of this idea. When asked to come up with one simple paragraph that explained the (strange) idea that the middle would stay colder than the outside notwithstanding the laws of physics the proponent started with "All heat pump cycles work by compression and decompression. "

     

    Simply flat wrong, ask anyone using a Peltier cooler.

     

    BTW, hydrogen has a really anoying habit of leaking out of containers because the molecules are small.

    The idea that it's just sat there in the middle of the earth is untennable.

  11. The question looks OK to me. With the tube horizontal the air column is at one atmosphere and is 50mm long. With the sealed end downwards the mercury squashes the air to 45mm long so the pressure must have risen to 50/45 atmospheres when you added the pressure due to the mercury.

  12. One person can lift the car. He just has to stand next to it (he may need to jump if his CoG is lower than that of the car, but that seems unlikely). Gravity will atract the car towards his CoG; provided that's above the car's, the car wil rise on its springs.

    Just don't ask me how to measure the extent to which this stretches the car's suspension.

  13. I have wondered about the idea of vacuum baloon before too. It clearly needs a rigid shell.

    I also wondered if you could make the rigid shell by putting two balloons together one inside the other, tying the two together with (radial) threads then inflating the space between the 2 "skins".

    I think that all designs of balloons become more efficient as they get larger (the weight of the "skin" gets bigger as the square of the radius but the lift ges bigger as the cube, so the net lifting power increases with the size). If that's right then, for a big enough balloon, it should work.

  14. Are we talking about monkeys, some of which are not that bright (however you measure that) or apes, some of which are possibly bright enough to have an opinion on the matter?

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