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Radical Edward

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Everything posted by Radical Edward

  1. when you consider the volume of matter needed to account for gravitational phenomena such as the lack of falloff in rotation speeds, it would be very very visible. If it were normal electromagnetically interacting matter, then it would have a spectroscopic signature that we could observe. The fact of the matter is that there is no spectroscopic signature. What is more, from our understanding of the Big Bang, it simply could not produce enough baryons to account for this amount of matter without severe implications for what we do see. Whilst I do see reason for cynicism as regards WIMPS, suggesting baryonic matter isn't a solution either.
  2. well some people just enjoy debating - that's pretty much the only reason that people would get involved in a debate of that kind. After all, debating is primarily about winning, rather than discussing. I find that I rarely learn much from them, so I don't bother. (that forum has a complex history... most of the members used to post on one of the biggest freethought fora, IIDB, until there was some meltdown and they split off and made a new one - it's more of a community forum now more than anything else)
  3. that depends entirely on the wave function you are talking about. Waves on water (obviously) have a wave function for example. In this case it is a surface amplitude related to distance and time. Light has a wave function which describes the electric and magnetic fields as a function of position and time. In essence it is a deviation from the average value (height, field strength or whatever) with distance and time. In the case of QM it is a deviation on the complex plane.
  4. nice answer here: http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970412e.html
  5. manual is also more fuel efficient, makes it easier to drive up and down hills, and is bloody easy anyway.
  6. what are your variables there? It's been a while since I worked with that sort of stuff. lambda I guess is wavelength, v, velocity, t and to are time, rhos are density, but what about a and z?
  7. It's a nice idea, but even with large numbers of members it can be a pain to get debates together. I'm one of the admins over here http://talkrational.org/ and you can see how often we have formal debates despite having a pretty large member base with a lot of diverse opinions. One mechanism we came up which worked fairly well for a bit was "exclusive engagement threads" which were discussion threads limited to two or three members. Those were better for when you had one person (usually a creationist or some complete moron) who got piled on by dozens of other members and spent most of their time ignoring other people. one-on-ones stopped them from being ignorant. Perhaps the best thing would be to have a method of running debates here which is posted in the forum announcements/rules or whatever and have ad-hoc debates in the relevant forums.
  8. The main elements of the big bang theory; that the whole universe was extremely small about 13.7 billion years ago, expanded rapidly, and has been expanding since, is pretty much as certain as we can be certain of things. There are questions of course, relating to the structures of the universe and other things like why is everything matter... when we would expect a 50:50 matter antimatter split, how much mass was there in the original universe, what is the ultimate fate of the universe, and is there a cosmological constant. Dark matter and Dark energy go some way to explaining some of those questions. Dark Matter was really first hypothesized from galaxy rotation curves. When we look at the orbital velocity of objects, their velocity decreases as their orbit gets larger (so Jupiter orbits more slowly than the earth). For the galaxies it is a little more complex as the matter is dispersed, but once we get away from the core we expect the velocity to drop off like with planets, but oddly it doesn't: A is the expected velocity with distance, and B is the measured velocity. That means there is a load of mass there that we can't see.
  9. I'd start everything in 1859, the year we truly began to understand our place as humans in the world.
  10. infinity - 1 is infinity, for any infinity.
  11. it would be infinitely easier to just pick up radio signals and things like that, than actually try to resolve something on a planet. Another thing you have to remember is that not only do you have to resolve the image, but you also have to know where to look, and when you are light years away, there are an awful lot of earth sized spots to look at, and they are all very difficult to focus on (moving targets, very narrow focal plane) Merged post follows: Consecutive posts merged what if they have never found another planet with life on it? they would be very interested then, I'm sure. And they could be exploring like we do. We have lots of technologies to see stars, galaxies, and yes, even planets, and we're not doing it all to look for threats to our civilisation.
  12. entropy isn't a force that does stuff, it is a numerical quantity that is measured as an outcome to various interactions - the higher the entropy, the less energy there is available to do useful work. In the early universe, the entropy was very low - the universe consisted mostly of hydrogen, helium (very low binding energies) and mostly high frequency radiation (we'll put dark matter aside for now). As gravity pulled things together into stars and galaxies, fusion began to occur, which released energy and made higher mass atoms (up to iron) - increasing the entropy of the universe.
  13. a quick and dirty guess might be that the sum of the kinetic and potential energies would be less than the potential energy of the object at infinity wrt the larger object.
  14. you'd have a bit less trouble if you put your ring in geostationary orbit though
  15. assuming it were strong enough to take the stresses on the structure, then it would be incredibly unstable, since any slight deviation from perfect coincidence of the centers of gravity would pull the thing down somewhere. Such deviations are inevitable, for example the moon as mentioned in the post above. It would not however be strong enough to take the stresses and strains, for the same reason that arches can only be built so big.
  16. Salamanders determine sex using ZZ/ZW combinations - and in this system, ZZ are male and ZW are female. Now salamanders can reverse sex, and this can be induced by hormones, particularly steroids - no doubt there will be environmental triggers for this. if we have a sex-reversed (ZW) male and a normal (ZW) female, then we have the following combinations for the offspring (just do the punnet square) ZZ, ZW, ZW and WW. I would expect that much like you cannot have a y-y offspring in humans (but you can have XX, XY) because essential genes are missing on the y chromosome, the situation is the same with the ZW combination - WW is simply not viable, so the only offspring that are born are the ZZ (male) ZW and ZW (both female), explaining the 2/3 - 1/3 ratio.
  17. If God created everything, including morality, and morality is objective in nature, then God can simply define anything he does as good. The problem of course is arguing that morality is objective. It is subjective by it's very nature, and the only way that God wins is by a might-makes-right approach.
  18. I agree. Sentience is more important than anything else, be it DNA or whatever. I would consider it just as immoral to turn off a sentient computer as I would to kill a person.
  19. The font is called HandelGotD light. It's freely available online as a ttf just google it.
  20. what has fusion got to do with this? And yes, I know it is not the same thing as decay, but my point was to illustrate that the amount of energy released can be adjusted by appropriate shaping of the nuclear material in some cases.
  21. to add to my submission, the concept is to unify sciences. So we have some physics in the atom on the left, blending into the DNA double helix, and the placement of the n makes it look like an nth power, symbolizing mathematics.
  22. there is no problem at all, because what you are actually looking at is an airy disk (or more accurately a point spread function, since the eye is not a perfect lens). The object does not need to be above a certain size to be seen, since anything with a subtended angle less than the diffraction limit of 1.22 lambda/d will look the same anyway. Merged post follows: Consecutive posts merged actually this is a really cool thing about the eye. The distances between rods and cones are pretty much the same as the diffraction limit of the eye. Merged post follows: Consecutive posts merged well the reason we don't see stars on earth in daylight is because all the scattered light obscures them. On the moon though it is a different story, because there is no scattered light. If the astronauts on the moon couldn't see the stars though (and I say if, because I have no idea) it would be for the same reason that you can't see stars if you go out at night, and shine a torch into your eyes while looking at the sky.
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