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    IPhone on space.

    http://www.wired.com/wiredscience/2011/06/iphone-space-shuttle/" [Broken]. Anyways, it says that it will look for radiation effects with "single bit upsets", is memory really that sensible to radiation?
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    Missing matter found by Monash student.

    Is this paper trying to say that dark matter is actually baryonic mass?
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    Learning to read schematics

    Allaboutcircuits.com has a great E-book, and very good forums on the topic, check it out.
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    Just curious how electric motors work, specifically DC motors.

    Re: motors There are many DC-AC converters designed specially to run from a 12v car battery. I find it really usefull to have 110v AC outlets in my car. It costed me around $30 for a 400W inverter.
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    Ideas for inventions

    There are a few companies developing Exo-skeleton suits. I've seen the Raytheon (named XOS) suit in a few videos.
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    What is it exactly about an explosion that pushes the piston in an engine?

    Besides the Temperature increase, there is a very high increase in the 'n' of the equation -number of moles-. The gasoline enters as liquid and changes into gas.
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    Newton's 2nd Law conceptual problem

    Expanding cjl's post: 30000N=15000kg*2m/s^2 is wrong; while F=15000kg*(2m/s^2 + 9.8m/s^2) is the right expression.
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    Electron schwarzchild radius problem

    Anyways, applying the concept of Schwarzchild radius to an electron seems pointless. EDIT: It appears it's not entirely pointless. There's even http://en.wikipedia.org/wiki/Black_hole_electron" [Broken]
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    Photons reflecting off mirrors, wheres the flaw?

    Maybe when considering a single photon one would have to consider solid state physics and phonons? (I'm just thinking out loud)
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    Movement In Space

    1. "...in contact with an equal and opposite force" to what? the object won't stop unless a there is a force that causes it to decelerate until it stops. 2. No, it will keep moving at a constant 100km/h. Remember that acceleration involves work and energy, so nothing accelerates unless...
  11. S

    Photons reflecting off mirrors, wheres the flaw?

    When you say de Broglie you mean the 'simple' \lambda = \frac{h}{p}?
  12. S

    Photons reflecting off mirrors, wheres the flaw?

    So to resolve this scenario one needs complex math with Hamiltonians? Isn't there some simple math for it? I was expecting a very straightforward solution.
  13. S

    Photons reflecting off mirrors, wheres the flaw?

    Hello. Consider 2 spacecraft isolated in space, with a mirror on their back, facing each other. One light pulse is shot between them. The photons reflect off the first one, transferring a momentum off 2p, travels in the opposite directions, reflects off the second spacecraft, giving it 2p...
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    HELP pounds to kcal

    Re: HELP!!! pounds to kcal You are trying to add apples and oranges. Kcal is a unit of energy, while pound is a unit of mass. For determining how much weight in the long run a person will gain after consuming X kcal you would need precise data on his energy consumption.
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    Isolated system

    Open system exchanges matter and energy with its surrounding. Closed systems exchanges just energy with its surroudings; e.g a Thermos An isolated system doesnt exchange anything with its surroundings. Its like if it were alone in the universe.
  16. S

    Extreme Pressure and Organic Molecules

    You'll get very impure diamonds.
  17. S

    Earth Mass Increasing? Photons and Photosynthesis making more matter on earth?

    It's reradiated, but with a lower frequency, meaning less energy and so the Earth gained this energy difference as mass.
  18. S

    Parachute for Weather Balloon

    Talking about the temperature in the probe, be sure to have a moderate temp and to test it out. Too much insulation might fry up the electronics.
  19. S

    Utilizing light

    Fresnel lenses maybe? That would still require the same ammount of space, but maybe its more comfortable for him using the space outside instead of windows.
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    I can't figure out why this happens with pure substances. My book is a

    Re: Sublimation As far as enthalpies of fusion and vaporization, they're different for different temps and pressures, so I'm sure that the calculations go right if you use the enthalpies of the below-triple-point pressure and not the STP enthalpies.
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    Earth Mass Increasing? Photons and Photosynthesis making more matter on earth?

    Actually, plants gets most of their mass from water and CO2, they just get a little ammount of nutrient from the soil. Jan Baptist van Helmont did this experiment long ago, weighing the soil before planting a tree, and a couple years later, the soil weighed almost exactly the same. Plants use...
  22. S

    Parachute for Weather Balloon

    The only way it would deploy early is if the system is compeltely upside down (i.e balloon below payload). Your tape idea sounds goo too but as you said, the stretching of the balloon might deploy it earlier.
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    Parachute for Weather Balloon

    Thats what I meant with the high center of gravity, so it pops and the center of gravity has to be lower, so it turns around. With some aerodynamics you can maintain it that way without flipping (I think so).
  24. S

    Parachute for Weather Balloon

    How about using a high center of mass, so when the balloon pops the probe will turn upside down, and use a simple air-drag-deployed parachute?
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    Need a website that explains general physics 2 (electricity and magnetism)

    www.khanacademy.org is a great website with hundreds of online lessons. Try it out.
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    Volume of a graduated cylinder

    I cant think of anything not involving Bernoulli's. What have you been learning in class?
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    Question about Force (I think)

    Many think that F=ma is the equation of force, but it is actually F=(change in momentum)/time, when you jump, your muscles do force in order to get you high, then when you fall you have that same energy in the form of kinetic energy. The time it takes your body to come to a stop is inversely...
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    How to make a remote control on / off switch

    Once I needed a remote controlled circuit, and I bought a $2.99 R/C car and hacked it. It was way easier than making one from scratch. Just avoid parks and place with kids or be prepared for many undesired triggerings.
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    Reactivity of a Proton

    To achieve that I think high temperatures are required and some form of plasma will form. Ionized hydrogen is a fancy way of saying protons. I think it's highly corrosive.
  30. S

    Help me win a bet

    Take a look at this similar thread. https://www.physicsforums.com/showthread.php?t=423839"
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