Recent content by salamander

  1. S

    Goedels Incompleteness Theorem

    Don't know anything about Goedels theorem. However I can't help getting the feeling that you are impling this: if Goedels theorem is right, it would mean the theorem had to be either inaccurate or inconsistent or else it would be the only complete theorem, and thus violating itself... how does...
  2. S

    Photons hitting the metal of the bike

    Bah. I had toy cars with that type of paint when I was a kid. I used to have them in my mouth and that made them change colour, don't know how smart that was concidering the possible hazards of the involved chemicals... I for one wouldn't like to have marks after my ass on my motorcycle an hour...
  3. S

    Falling Objects Puzzle: Find Ratio of Heights

    Most questions like these end up with squares. I use to think that since the vertical distance is a quadratic function of time, "2 times the time" must mean 2^2 times the distance. If the stone from the taller building flew three times the distance of the other stone, height ratio would be...
  4. S

    Falling Objects Puzzle: Find Ratio of Heights

    Tip: Horisontal velocity is constant. distance = velocity * time As the second stone travel twice the distance of the first one, it must bee falling for twice the time: d=v*t(1) 2*d=v*t(2) Hope that helped. Cheers. J.
  5. S

    Free Fall Acceleration: Better Term?

    In a books on s. relativity by John A. Wheeler (Spacetime Physics, Freeman) the frame in which no gravitational acceleration is experienced is referred to as the "free float frame". I think the frame is officially called inertial or Lorentz frame, but free float is pretty good. Why not call...
  6. S

    MDI's Compressed Air Technology Systems: C.A.T's ©(*).

    And it is a pretty ugly car too! I think electric cars have more potential, are more efficient, practical and perhaps even better from a enviromental point of wiev, if good fuel cells are developed. However there must come something good out of this research too. Perhaps in a couple of years...
  7. S

    Speed of light squared got to do with the production of energy

    Special relativity is the result of measuring and combining space and time in the same unit of distance. (One second in meters is the distance a light pulse covers in one second, 299792458 meters.) In special relativity energy is easiest expressed in units of mass, like kilograms. What the...
  8. S

    What Happens to a Person at the Center of a Hollow Earth?

    krab: Yeah that stuf seems logical. I can probably find the integral proof if I do some thinking, hell I think I will, haven't much else things to do these days. My problem was that I was assumiung that the hole would be made just at the place where the person was, and just big enough to fit...
  9. S

    What Happens to a Person at the Center of a Hollow Earth?

    Cool. Maths are amazing. Can somebody show me a proof? I'm really interested. Cheers.
  10. S

    Is Nitrogen in the Atmosphere Really in the Gas Phase?

    I'm quite sure critical pressure is the pressure it takes to liqudize a gas at a certain temperature. It can also be seen as the pressure at which a liquid will vaporize at a given temperature... I think that's it, but just don't listen to me if you're about to conduct some experimentation...
  11. S

    What Happens to a Person at the Center of a Hollow Earth?

    Gravity does not orgin from some mythic central point in the middle of the Earth, that is a missinterpretation of the term "centre of gravity". Gravity depend on mass and distance alone. The formula g=GM/r^2 is a generalisation assuming that you are located outside the massive body, IE, the body...
  12. S

    What Are Some Common Physics Mistakes in Textbooks?

    I think it is 5.9 m (along the incline). But hell, what do I know? JohnDubYa, enlighten us!
  13. S

    Is Nitrogen in the Atmosphere Really in the Gas Phase?

    I believe critical temprature is the temperature above which a gas cannot become liquid, whatever pressure you apply to it. I hope I'm right. Cheers.
  14. S

    Graphing Calculator for Physics Major - Need Hi-Tech or Not?

    Hi! I'm in third year high school. I got a voyager just so that my classmates would think I'm insane. I'ts quite a good calculator, symbol handling, has lots of memory, very programable, 3D graphing, diffeq. solver, eq. systems solver, usb cable and not to forget: it's got a built in watch and a...
  15. S

    Exploring 3D Laser Imagery & How It Works

    I've seen a 3D screen in a popular science magazine. Basicly it was continously projecting slices of the image on a rapidly rotating mirror in a glass ball... pretty simple technique. The smallest one was $30 000, and I doubt there are many 3D DVDs in the market... compared to a hologram of the...
Back
Top