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mrbc19

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    11
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About mrbc19

  • Rank
    Quark
  • Birthday 01/09/1984

Profile Information

  • College Major/Degree
    Georgetown University
  • Favorite Area of Science
    Physics
  1. To clarify, the bleach is just the basic clorox bleach, the cheapest one you can get. It is sodium hypochlorite, and not the more expensive "bleach for colors" which my roomate said I had to buy if I wanted it to work. One more thing, I've noticed, that if you wear black pants and get bleach on them while cleaning something, like mopping a floor, it whitens the pants. So does this mean that the whitening or "bleaching" effect of bleach is not effected by temperature?
  2. I have a question regarding clorox bleach. The washer I have in my house only has a warm wash, one that is more on the cool side, and my roomate claims that the bleach I purchased will not work properly in a cool water wash. I need the bleach to whiten and remove stains, and I told him that it would still work in a cool wash, but I really have no idea or evidence to prove this. Does anyone know if it will still work the same, or if hot water actually does anything different for the bleach?
  3. Pullups would be the best thing for you. But you said no special equipment, so I dunno, you need a bar somewhere you can hang off of. Go find a playground and do it there.
  4. Movie maker is really simple, almost to the point that I find it pretty bad software. You can get a 30 day trial of Sony Vegas 5 at the sony website, and that is really top notch software. I found it very easy to learn, and you can just use its simple features, or get more in depth with key frames and color correction if thats what you want.
  5. I know that in the Elegant Universe, Greene gives a good example of how to understand more than 3 spacial dimensions, I forgot exactly what it was, but I know it enlightened me at the time I read it. If anyone has read it and remembers, could you please post it?
  6. what about shadows? Aren't they 2 dimensional? They have length and width, but because they are just a blocking of light, they have no height, there is just nothing there, but you can still see it, and its 2-d.
  7. Color constancy is a real thing, researched by psychologists for many years. Basically our perception of color is not only determined by the actual wavelengths hitting our eyes, it is also influenced by many factors such as the surrounding context of colors, what color we may expect to see from a certain object and also the relationship of the actual color of an object, and the wavelength of light that is being reflected off of it (like shining a blue light on a red wall). Generally people can retain color constancy, but it can break down in certain situations.
  8. mrbc19

    Measuring Time

    How do we know that everything slows down? Wouldn't this slowing down be measured by a clock? Additionally, the "rate" at which humans age can be varied by other mechanisms outside of time, for example through drugs or genetic alteration, and the rate of battery drainage can also be attributed to slower moving parts, or more efficient energy use, and this does provide evidence that time is slowing down, at least in my mind. Maybe I am just confused about what time relativity really is?
  9. mrbc19

    Measuring Time

    I am not very knowledgable on this subject, but from what I understand, a clock in motion at a certain velocity compared to a synchronized clock on the ground that is not in motion will "slow down" and be out of sync with the clock on the ground after the motion, and this was something predicted by special relativity. Now my question is regarding how time is actually measured, and I guess relates to the nature of time itself. Now a clock itself does not measure time by somehow tapping into whatever we call "time," it is just an arbitrary measure of intervals, using a quartz crystal, or an atom or whatever other measure you want to use. If you were to measure the velocity of a stream of water, you can literally put something into the stream, or "tap" into it to find out its velocity. Clocks do not tap into the "stream" of time do they? They are controlled and run by energy, or a battery that powers the clock. If the battery weakens, the clock may slow down or stop all together, but this does not mean that time is slowing down or stopping. So how exactly does the slowing of a clock in the above situation show that time itself is changing or slowing down. Is it not just a slowing of the physical mechanisms operating the clock? The quartz crystal is vibrating or ticking more slowly, or the atom (I dont know how atomic clocks work) is just "ticking" more slowly. If an object is travelling at a certain velocity, and then slows to a lesser velocity, that does not mean that time has slowed down. I just can't seem to grasp how a slowed clock can provide evidence for slowed time. I'm not trying to come up with a new theory about time or trying to disprove relativity at all, I am just confused on this particular issue, and any help is welcome.
  10. Thanks for the replies, but I am still a little confused after that detailed response from jakiri. So are the eqautions for earth orbits parabolic or not? I think I understand that they are parabolic, so does that mean there are no purely circular orbits around the earth?
  11. This is my first time posting here, hi to all and thanks in advance for any replies. I took highschool AP physics, and have read a little bit of new stuff like The elegant Universe, so I consider myself to have a basic uderstanding of physics. My question is about earth orbits. I know the equation for a projectile orbiting the earth is a parabolic one (I hope I am correct here, otherwise my post is unecessary.) Now in newtonian mechanics, if you fire lets say a cannonball fast enough, it will not strike the earth but will orbit it in a circle. I am confused as to how the equation for a projectile can be parabolic, yet an earth orbit can be circular, isn't a parabolic equation never going to produce a circular orbit no matter how fast an object is going? If anyone can clear this up for me, that would be great, thanks.
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