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  1. mrspeedybob

    Stronger tubes using internal structure?

    On the topic of structural tubing... It is my understanding that round tubing is stronger than square tubing, or conversely that, that round tubing is lighter for a tube of the same strength. Does it necessarily follow that the best possible use of material when making a tube, is to use it all...
  2. mrspeedybob

    General relationship between gravity and rocket design.

    I was pondering Mars missions and wondered about what kind of vehicle an astronaut on Mars would need in order to get home. My first thought was that mars gravity is .38 that of earth, so he would need a rocket about 38% as large to get off of mars as he needed to get off of earth, This of...
  3. mrspeedybob

    Temperature cycling effects on electronics durability

    I just went out to my car to retrieve my laptop. My car is at about 1 degree C, my house is at about 20 degrees C. I soon noticed condensation forming on the screen and it occured to me that condensation was probably forming inside as well on the electrical components. The combination of...
  4. mrspeedybob

    Why have I never heard of hydraulic hybrids before?

    Ran across this recently... http://www.mobilehydraulictips.com/hydraulic-hybrid-vehicles-future-driving/ Peugeot apparently has a hydraulic hybrid car in development... http://www.extremetech.com/extreme/146450-peugeot-unveils-hydraulic-air-hybrid-80-mpg-car From what I've read from Wikipedia...
  5. mrspeedybob

    Why do my newer laptops run cooler then previous laptops?

    The last 2 laptops that I've bought (both HP) run noticeably cooler then previous laptops that I've owned (Toshiba and Dell). In fact I feel no heat on my legs at all from either of them. Did some new technology come along in the last few years that allows the batteries to produce less heat or...
  6. mrspeedybob

    What is the relativistic definition of energy?

    In classical physics E=Fd and F=ma so E=mad. a=d/t2 so E=md2/t2 Measurements of d and t will get complicated by Lorentz transformation, so, is E=Fd still a correct definition of energy, or is it a Newtonian approximation which is not accurate at relativistic velocities?
  7. mrspeedybob

    Looking for resources on micro and mesoscale meteorology

    My wife got me hang gliding lessons for Christmas, which I'm going to take this summer. In preparation I'd like to learn what I can about atmospheric behavior on scales of a few meters to a few kilometers. I've found small isolated sources with tidbits of information, but nothing with any real...
  8. mrspeedybob

    Question about gravity and the shell theorem

    Consider a point in the universe I'll call X and a test particle some distance R away. For the purposes of calculating the gravitational acceleration of the test particle I'll consider all the matter within radius R of point X to be a point mass attracting the particle to X. Furthermore, all the...
  9. mrspeedybob

    Why did the Apollo spacecraft go into Earth orbit first?

    I've been playing Kerbal Space Program. I have found the simplest way to get to an outer planet is to launch straight up at dawn and the simplest way to get to an inner planet is to launch straight up at dusk, and in neither case to mess about with going into Kerbal orbit. This got me to...
  10. mrspeedybob

    How would I transmit 1 photon?

    I'm thinking about photons of low frequency as would be produced by a radio transmitter. How would a transmitter have to be set up to transmit just one photon? The smallest transmission I can think of would be to move 1 electron from one end of the antenna to the other. I would think that would...
  11. mrspeedybob

    Boiling sugar

    I have a recipe that begins with sauteing onions in boiling sugar. It occurred to be today that I don't know what the vapor is that the sugar is giving off when it boils. There is no water in the pan at that point (other then what is in the onions). Are the bubbles that I'm seeing actually...
  12. mrspeedybob

    Does uncertainty of position of particles make substances continuous?

    Ever since learning about atoms and molecules as a child I have envisioned substances (air, water, metal, etc) as being composed of discrete individual atoms and molecules. Today it occurred to me that might be an oversimplification, especially for gasses in which molecules are free to move...
  13. mrspeedybob

    A couple questions about a hot room concept.

    A couple questions about a "hot room" concept. I had an idea that I may try to implement should I ever get around to building my dream house. I think of it as a "hot room". The idea is that there is a utility room which is positioned to receive most of the wast heat generated by household...
  14. mrspeedybob

    What is the survival advantage to paralyzing fear?

    When you're getting chased through the jungle by a tiger it seems as though you would want your mind and body to be functioning at the highest possible level, and yet, sometimes in very frightening situations people freeze and cannot think clearly or act decisively. How did people without the...
  15. mrspeedybob

    How do bar code scanners read a bar code from a cell phone screen?

    A quick google search found that there are 2 kinds of bar code scanners. One uses ambient light and a CCD device, these obviously would have no problem with a bar code on a screen since it is essentially just taking a picture. The other kind sweeps a laser over the bar code and reads the...
  16. mrspeedybob

    How do intelectual property rights apply to scientific discoveries?

    Say for example I discovered how to unify General Relativity with Quantum Mechanics and then someone else uses this improved understanding of physics to engineer a new product which would have been impossible without it. Am I entitled to a portion of the revenue generated by the new product...
  17. mrspeedybob

    Question about extreemly large black holes.

    If we define the density of a black hole to be it's mass divided by the volume within it's event horizon then as the mass of a black hole increases it's density decreases. At some point the density would be equal to the ambient mass density of the universe. Can we correctly consider ourselves to...
  18. mrspeedybob

    What happens to meteors after they vaporize?

    meteorites that are not large enough to reach the ground vaporize in the atmosphere (as do large portions of the ones that are). What happens to the vaporized material in the atmosphere? A little bit of internet research indicates meteorites are composed primarily of iron, nickel, and...
  19. mrspeedybob

    WW2 airplane submarine

    This question may be impossible to answer without specific knowledge of vintage aircraft engines but maybe not. How does this airplane... come out of the wave running? It seems like running a piston engine underwater would result in ingestion of water and hydro-lock. I'm not an...
  20. mrspeedybob

    Multiple parallel plate capacitor question.

    Consider a capacitor with 4 parallel plates and 3 dielectric insulators arranged like this...+I-I+I- The insulator in the center has an equal amount of + and - charge on each side of it so shouldn't the electric field across this insulator be almost zero? If I constructed this capacitor with...
  21. mrspeedybob

    Is the space-like distance to a black holes event horizon infinite?

    From a distant frame of reference a falling object never reaches the event horizon due to time dilation. If I drop a meter stick into a black hole lengthwise I should see both ends of the stick getting asymptotically closer and closer but never reaching the horizon, thus the stick should appear...
  22. mrspeedybob

    Antimater anhilation rate on macroscopic scales

    I'm sure we've all envisioned bombs made by allowing macroscopic quantities of antimatter to react with ambient matter thereby releasing vast quantities of energy in very short time scales. I'm wondering how realistic this actually is. Suppose I have a 1 kg chunk of anti-iron in the middle of...
  23. mrspeedybob

    Magic trick: how was it done?

    The trick in question starts at 13:30 and goes through 19:00 Begin with the premises that this is trick wasn't produced strictly for television and could be performed live, and that the audience participants were not plants. Any theories about how it could have done?
  24. mrspeedybob

    Transparency via destructive interferance.

    Suppose I have 2 lasers. 1 emits light of exactly 500 THz and the second emits light of a frequency exactly 1 hertz higher. A semitransparent mirror is used to superimpose the 2 beams and create a composite beam. The beam is directed to a detector which detects the intensity of the beam...
  25. mrspeedybob

    Stargazing Question about reflecting telescope design.

    Error in title. I meant refracting. At every transition between air and glass it seems to me like there would be some reflection. Each photon it seems would have a certain probability of entering a lens and reflecting off of both of the lenses interior surfaces and then continuing on into the...
  26. mrspeedybob

    Adding subluminal and superluminal velocities.

    Suppose we have a long row of rods, each of which is equipped with a clock and a solenoid which can raise and lower the rod. All the clocks are synchronized. Each rod is programed to raise and lower at a slightly different time so that in the rest frame of the apparatus the rods rise and fall in...
  27. mrspeedybob

    Applications of new physics which may be discovered at the LHC

    First off let me say that I am not interested in discussing whether the LHC is a worth while project. I believe human beings are curious by nature and that learning new things to satisfy that curiosity fulfills a human need just as real as any other. What I am interested in is discussing...
  28. mrspeedybob

    Is there a reason to believe in a limited variety of dark matter?

    "Normal" matter makes up about 5% of the mass/energy content of the universe. From studying this 5% we have discovered 4 fundamental forces and numerous fundamental particles. When I read things about dark matter and dark energy it seems that each is assumed to be a single class of phenomena...
  29. mrspeedybob

    Why doesn't dark matter clump together?

    I understand there are no friction forces to slow it down but there are other means of dissipating kinetic energy. Every time 2 dark matter particles come close enough to interact gravitationally there should be some exchange of momentum. If there is a cloud of dark matter particles, such as...
  30. mrspeedybob

    Question about a black hole formation scenerio.

    This scenario is described by Lenard Susskind in a lecture on general relativity starting at time stamp 44:23 in the following video. The scenario is that a spherical shell of radiation is directed inward to a point. The shell contains enough energy to form a black hole. He states that...
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