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A Few General Questions About Special Reletivity

  1. Nov 3, 2009 #1
    I am in a freshman level Astronomy class, and we are studying special and general reletivity. I was studying for an exam last night, and I had a few questions. As I understand it, the following is true:

    1. That time is nothing more than a human conception that seperated objects from being at more than one place at one time or to seperate events from happening simultaniously.

    2. At the subatomic level, particles move at a significant fraction of the speed of light causing particles such as electrons to be in more than one place at once.

    3. Einstiens Theory of Special Reletivity accounts for this by saying that time slows down at a significant fraction of the speed of light.

    By considering these observations, I have come across some questions that I hope someone will be able to help me with.

    1. Is time slowed down at the subatomic level because the particles are moving at a significant fraction of the speed of light.

    2. If time is slowed at the subatomic level and all known matter can be broken down to the subatomic level then why isn't time slowed for everything?

    3. Is it possible that time is a force like energy or gravity? If so, the constant of time could be observed at the subatomic level, and the force of time could dissipate as it moves to the larger areas say atoms and molecules so that we experience time as "normal". This would also explain the gravitational slowing of time near massive objects as described by The Theory of General Relitivity.

    4. If time does act as a form of enery, can energy be used to slow or speed up time? In the ergoe region of a rotating black hole, there is a dissipation of time as we know it could this be due to the energy being emitted in that region?

    5. If time is slowed at the subatomic level and dissipates as it moves to larger areas, in an area of the universe where there are no massive objects, would time move infinately fast?

    I have many more questions, but I would appreciate whatever help I can get on these.
     
  2. jcsd
  3. Nov 3, 2009 #2

    dx

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    Time in special relativity means the same thing it does in pre-relativity physics. Events occur at a place and a time. The concept of time itself is not altered by SR.

    You're thinking of quantum mechanics. This has nothing to do with moving near the speed of light. Even slow moving electrons are described by wavefunctions, and can "be in more than one place at the same time".


    Time dialation occurs at all speeds. A clock moving with a speed v will tick slower by a factor of 1/√(1 - v2). This is not only at the subatomic level.

    As I explained above, time is "slowed" for all moving objects. This has nothing to do with the rate at which we experience time. An observer moving relative to you will not experience time any differently. You will see his clocks ticking slower, and he will see your clocks ticking slower.

    These questions make no sense. Energy is not a force. Time is not energy. There is no such thing as "the constant of time". Time does not "dissipate".
     
  4. Nov 3, 2009 #3
    Not true. Time is certainly NOT merely a "human conception." It is not made up. It is exactly as real as length, width, and height.

    Not true. Most electrons in most atoms do not move relativistically. A very small number of electrons in 6s states in the ground states of very heavy elements do need a small relativistic correction.

    The rate of motion is not what causes electrons to be "in more than one place at once," to the extent that that statement is accurate. All particles have quantum properties that have nothing whatsoever to do with their rate of travel.

    On the other side of the coin, moving at nearly the speed of light doesn't make a classical particle appear in two places at once. It's just moving very quickly.

    Not true. SR does not account for the quantum properties of particles. SR says that moving clocks run slow because the speed of light is c as measured by all observers.

    No. Moving particles take longer to decay because their internal clocks are running slow, but otherwise no.

    Only moving clocks run slow. Clocks at rest relative to you do not. Most everything in your world is more or less at rest relative to you.

    The rest of your questions don't make much sense in the context of accepted physics. Time isn't a force or an energy. It's a coordinate like length and width. Flights of fancy are fun, but the arbiter is observation.
     
  5. Nov 3, 2009 #4

    pervect

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    That's more of a philosophical statement that a scientific one. However, a lot of people think of it that way. I tend to think of time as what you measure with a clock though. This sounds empty at first, but it isn't - it puts the focus on the evolution of clocks, and what their properties are. One important property - even with a perfect clock, its reading won't be independent of it's motion. A moving clock won't stay synchronized with a stationary one.
    Even slow moving particles can be thought of as being in more thane one place at once - it doesn't have anything to do with speed. This is quantum mechanics, however, not relativity. And - since you never actually catch a particle at being at more than one place at a time, the observation is a bit suspect, though it's can be a useful way to think about quantum mechanics - it's the idea that particles take all possible paths, or have multiple histories due to Feynman.

    Partially true, but I sense, from experience, that you're moving off on the wrong path. The idea that time flows at some particular "rate" has some definite problems in explaining the twin paradox.

    The essence of solving this problem is to realize there's no such thing as simultaneity. But you seem to be holding onto this idea, perhaps without realizing it.

    Focusing on how, you determine which clock is moving faster will be one way of realizing the problem. When/if you realize that you can consistently consider either clock to be moving, and the other clock stationary, then you'll be on the right path.

    In general yes. But it's not quite clear which particles you are thinking of.

    Here's where you need to be clear on what particles you're thinking of. For instance, electrons in gold atoms are moving relativistic, and there are observable effects from this. Other electrons in other atoms arent' relativistically moving.

    Muons that penetrate our atmosphere are moving relativistically - and they can reach the ground, something they wouldn't be able to do if time dilation didn't exist - they wouldn't be able to live long enough.

    It's not useful to conflate (to combine in a confusing way) time with the concept of force, or with the concept of energy. Force is not time is not energy, the concepts are separate. Lets avoid arguing about whether gravity is a force for the time being :-).
     
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