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Everything posted by Skye

  1. Could possibly be a fragment of a tin foil hat.
  2. Hydrogen vehicles are fine, there are already small numbers operating in areas like public transport. This is probably where the growth over the next decade or two will be limited to though. The infrastructure based around petroleum is huge. It will take many years to replace it. With things like bus services, long distance trucking and rail, there isn't the need for the huge infrastructure that private vehicles rely on. They have planned, predictable routes, so you just need a limited number of depots. It will still rely on incentives though, unless oil prices go crazy.
  3. Norman, yes, the dominant phase in low carbon steels (ferrite) has a body centred cubic (bcc) structure. This refers to the arrangement of atoms in the crystal. All metals display increasing brittle behaviour at lower temperatures, but there is often a dramatic change over a small temperature range. This is called the brittle-ductile transition. This is more of an issue with bcc metals, as the transition occurs at higher temperatures and it is more pronounced. An interesting application of this was that the ship steels used a century ago had higher brittle-ductile transition temperatures, which has been put forward as contributing to the Titanic sinking: http://www.tms.org/pubs/journals/JOM/9801/Felkins-9801.html
  4. The metal that is used is important too, because at the temperatures you are talking about they may behave in a more brittle manner, and fail unexpectedly. Metals that have a body centred cubic crystal structure, such as some steels, will do this. Copper pipe though, probably wouldn't, at least it's more likely to be predictable.
  5. Polystyrene foam concrete is good for construction in remote areas. The main components can be prefabricated, they are light so transport is easier, and the construction time on site can be really short. I could see this sort of thing becoming big in the future, centralised mass production of housing. With modern CAD/CAM, robotics, etc., the house designs could be individual, so it wouldn't have the stigma of mass housing currently, where every house looks the same. Instead, design the house, have the robots make it, truck it out and have put up in a day or so. Would save huge amounts of time in housing development.
  6. If space is infinite, and matter is distributed evenly within it, then matter will be infinite too. Imagine that there is one hydrogen atom every meter throughout space. Then you travel through space, every meter hitting a hydrogen atom. Since space is infinite you would hit an infinite number of atoms if you traveled along a path for long enough (infinitely long time). The only difference with solid matter is that the atoms are a little closer together, but it is still a matter of hitting an atom every few Angstroms along an infinite path.
  7. YT, I think you are intuitively doing algebra using infinities, and that's not really possible.
  8. Except that lawyer may being paid by the other party in the legal dispute.
  9. Skye

    It's a Drag

    Err yeah, thinking about what actually stops the boat running aground is a force created by the boat travelling at an angle of attack, which is maintained by the rudder. Same way that lift is generated by a aeroplane. But probably not that relevent to the question.
  10. Skye

    It's a Drag

    In practice, a rudder. It's not important to the question though, since you know what the velocity is anyway. You could break it down into it's component forces like swansont says and work out just how drag would be required though, if that's your thing.
  11. Septicemia is where you have bacteria in the blood. It generally happens through wounds, so any serious injury to the colon could result result in septicemia. This then leads to sepsis, where the white blood cells go nuts and your organs start failing. I'm not sure about the other part of your question. The useful functions of bacteria are generally essential for their survival too, so I'm not sure that they can malfunction and survive.
  12. By infecting the germ line cells (eggs and sperm). Only certain retroviruses do this, and they have to be lucky enough to infect the cells that get passed on.
  13. Yeah, I'd had about ten beers so I was having enough trouble keeping my own CoM above the floor, let alone making any sense. But I meant the second way of reading it. It's more noticeable with other balls though, like the really cheap plastic inflated balls. If you really want to see it happen get a beach ball with a little water in it.
  14. Yeah, you're right. The CoM will move through it's roughly parabolic path. So the ball itself would move about the CoM as it was travelling along this path. And that's what makes it difficult to track the ball, as it would be oscillating around that CoM, that is moving along this path.
  15. I'm not sure air resistance is that important. What's important is that the ball is like a spring and oscilates when you hit it. Hitting the valve is like hitting a mass on the end of a spring, so there are going to be effects due to the momentum of that. But overall the ball will move about because of the changing CoM.
  16. Meh, that isn't anything new. It's just another example of middle class people supporting liberalism and lower class people supporting socialism. That's classical liberalism mind you, that tends to straddle the political divide.
  17. While increasing troop number from roughly 150,000 to 170,000 troops in Iraq doesn't sound like much of a difference, the number of combat brigades has increased from 15 to 20. That's a third more combat troops in the country, most of which have gone into the capital. So the surge is deceptively large when in comes to the numbers of combat troops in Baghdad, where the conflict is now centred, and that's a pretty simple reason why it has been effective.
  18. The main problem with wood in alternate engineering structures is that it is not nearly as good at handling dynamic loads as other materials are, most notably steel.
  19. Maybe it would be more accurate to call everyone involved here corporatists. A fair, living wage is more the rhetoric of socialists, and I don't see anyone suggesting a nationalisation of the entertainment industry.
  20. 'Michael Charles Smith Richard Michael Smith' is a drinking game waiting to happen.
  21. I wasn't talking about the evolution of brain size. I was commenting on Sisyphus' last sentence, and so I was saying that K-selection is the main reproductive strategy in developed countries, which is I guess what this thread is about.
  22. Why is asking for the ultimate cause of things, so obviously a why question assumes there's an ultimate cause for things. If there isn't, then why questions don't have any meaning (but why does that turtle support all the turtles above it?). A purely materialistic philosophy isn't necessarily going to be devoid of an ultimate cause for things though, so why questions can be asked here as well, though you can draw a line between philosophy and science if you want.
  23. I don't think it's a matter of intelligence verses number of children. It's about reproductive strategy, either a small number of children with a large amount of resources allocated to each, or a larger number of children with a smaller amount of resources each. When it comes to humans, our intelligence is quite dependent on resource allocation. Obviously there is an underlying genetic basis for our big noggins and that, but a modern big noggin is probably no better than a stone age big noggin, just the stuff filling it is more sophisticated. Also, humans haven't suddenly evolved in the last few hundred years to have gone from half a dozen kids a woman to a deuce. Just that a higher resource allocation probably pays more dividends when you don't have things like the plague and cholera cutting a swathe through the kids regardless of education. There are competing reproduction strategies though, but hey, that's evolution for you.
  24. Clearly she's humble yet wise. The use of "US Americans" is a long overdue attempt to end the arrogance of assuming the "Americans" refers those people from the USA (but one of many nations in the Americas).
  25. The thing about Dawkins is that he is good at analogy, perhaps the best popular science writer at analogy. He is not particualarly original, Huxley and Popper had many of his ideas before he did. I still like his books though.
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