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Thread: Relativity.

  1. #1 Relativity. 
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    I'm a layman to the extreme so please feel free to show me just how dumb I really am. My math is pathetic but I feel I'm exceptional with just the theory of things. In any case, I present this very basic situation.

    An atom traveling closer and closer towards the true velocity of light would also increase in mass.

    Given enough time and speed incremental gain, the atom would appear to be the size of a galaxy or solar system to an outside observer.


    The theory of the big bang establishes everything radiated outwards from a specific (maybe) point in space. Starting off as simple particles and molecules, they continue their outward expansion even now. Since their path would have no friction or gravity/pulling forces (lack of better terms), they would never slow down. Assuming they generate their own energy, they would speed up into infinity, never reaching the speed of light but getting close enough (to light speed) to gain exponential mass.

    My point being... wouldn't ordinary atoms look like solar systems (or more) from our vantage point in space? Obviously they would have to be outside of our current system (and speed) in order to appear this way.


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  3. #2 Re: Relativity. 
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    Quote Originally Posted by what is science?
    I'm a layman to the extreme so please feel free to show me just how dumb I really am. My math is pathetic but I feel I'm exceptional with just the theory of things. In any case, I present this very basic situation.

    An atom traveling closer and closer towards the true velocity of light would also increase in mass.

    Given enough time and speed incremental gain, the atom would appear to be the size of a galaxy or solar system to an outside observer.


    The theory of the big bang establishes everything radiated outwards from a specific (maybe) point in space. Starting off as simple particles and molecules, they continue their outward expansion even now. Since their path would have no friction or gravity/pulling forces (lack of better terms), they would never slow down. Assuming they generate their own energy, they would speed up into infinity, never reaching the speed of light but getting close enough (to light speed) to gain exponential mass.

    My point being... wouldn't ordinary atoms look like solar systems (or more) from our vantage point in space? Obviously they would have to be outside of our current system (and speed) in order to appear this way.
    Absolutely everything that you have said is wrong. Completely and utterly wrong. So wrong that there is no fixing it.


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  4. #3 Re: Relativity. 
    Veracity Vigilante inow's Avatar
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    Quote Originally Posted by what is science?
    An atom traveling closer and closer towards the true velocity of light would also increase in mass.
    Here is the important part. The atom does not increase in REST mass, it only increases in RELATIVISTIC mass. One is the mass of an object at rest, the other is the mass of an object when its velocity is taken into account (in short, because it is moving, it has more energy, and energy equals mass... this is an extreme oversimplification, but gets the point across).

    The rest mass remains the same, and that's the part on which to focus. When we discuss mass, we are discussing rest mass. Relativistic mass is rather uncommon... It's sometimes used in special cases to describe something, but that is not what you are referring to here.


    Quote Originally Posted by what is science?
    Given enough time and speed incremental gain, the atom would appear to be the size of a galaxy or solar system to an outside observer.
    Since the atom is not gaining rest mass, it also will not increase in size. So, this is not what happens. There are some interesting effects from length contraction as the atom approaches the speed of light, but that doesn't seem to be what you're discussing... especially since such length contraction would make the atom appear smaller to outside observers.



    Quote Originally Posted by what is science?
    The theory of the big bang establishes everything radiated outwards from a specific (maybe) point in space.
    This is a common misconception, and is more of a semantic problem which hinders understanding than anything else.

    The big bang (BB) was not an expansion from a single point... It was an expansion of space itself... of the whole universe. The concept of "point" is really rather meaningless because it implies a fixed location... it implies that there was somewhere within the universe which expanded... not the universe itself. There was no spot or point which expanded... The universe in its entirety expanded.


    Quote Originally Posted by what is science?
    Starting off as simple particles and molecules, they continue their outward expansion even now. Since their path would have no friction or gravity/pulling forces (lack of better terms), they would never slow down.
    Actually, there are forces acting on them, and gravity is definitely one of them. The strength of gravity gets weaker the farther away you are from the source of it (a massive object is the source of gravity in this case), but the gravity itself is never absent. It approaches zero, but never reaches zero. In short, there absolutely is gravity no matter how far out you go.


    Quote Originally Posted by what is science?
    Assuming they generate their own energy,
    I'm not sure where you're heading with this, nor how a particle would generate its own energy, so it might be best to abandon this particular assumption.


    Quote Originally Posted by what is science?
    they would speed up into infinity, never reaching the speed of light but getting close enough (to light speed) to gain exponential mass.
    First, the speed of light is a finite value... not infinity. Second, you're correct that they would never reach the speed of light since they have mass, but they could get close to it. Third, they don't gain rest mass as I described above, only relativistic mass, so this is another assumption that rests on a misconception.


    Quote Originally Posted by what is science?
    My point being... wouldn't ordinary atoms look like solar systems (or more) from our vantage point in space?
    Nope. They don't gain rest mass, so they don't grow in size... In fact, due to length contraction the atom would appear smaller to an outside observer the closer it gets to the speed of light.
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  5. #4 Re: Relativity. 
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    Quote Originally Posted by inow
    Here is the important part. The atom does not increase in REST mass, it only increases in RELATIVISTIC mass. One is the mass of an object at rest, the other is the mass of an object when its velocity is taken into account (in short, because it is moving, it has more energy, and energy equals mass... this is an extreme oversimplification, but gets the point across).
    Alright. Sounds more reasonable then I used to think.

    The rest mass remains the same, and that's the part on which to focus. When we discuss mass, we are discussing rest mass. Relativistic mass is rather uncommon... It's sometimes used in special cases to describe something, but that is not what you are referring to here.
    Yes, I didn't understand the principle difference before. I do now though.


    Since the atom is not gaining rest mass, it also will not increase in size. So, this is not what happens. There are some interesting effects from length contraction as the atom approaches the speed of light, but that doesn't seem to be what you're discussing... especially since such length contraction would make the atom appear smaller to outside observers.
    Absurdly I still don't quite understand length contraction. It decreases in length in the direction of travel? How does that work? It seems like magic that an object would vary in size in any way just by the speed. That's like saying if you slow down atoms and molecules, the closer they reach absolute zero they lose mass and gain size (or length in the direction of ... distillation?)

    This is a common misconception, and is more of a semantic problem which hinders understanding than anything else.

    The big bang (BB) was not an expansion from a single point... It was an expansion of space itself... of the whole universe. The concept of "point" is really rather meaningless because it implies a fixed location... it implies that there was somewhere within the universe which expanded... not the universe itself. There was no spot or point which expanded... The universe in its entirety expanded.
    I understand the difference, but that would also mean things ride at the edge of the universe along with its expansion. The "edge" being its circumference of expansion. As well as there having to be "no space" for space to then occupy. More of a quibble I've never quite grasped. I understand "no space" is not just anti-space, but rather, non-existence.


    Actually, there are forces acting on them, and gravity is definitely one of them. The strength of gravity gets weaker the farther away you are from the source of it (a massive object is the source of gravity in this case), but the gravity itself is never absent. It approaches zero, but never reaches zero. In short, there absolutely is gravity no matter how far out you go.
    My intentions were gravity was present (conceptually and physically). But gravity that would affect on expansion towards collapse was not present.


    I'm not sure where you're heading with this, nor how a particle would generate its own energy, so it might be best to abandon this particular assumption.
    If particles can gain mass, they would generate increasing amounts of energy. I suppose my problem was not seeing -how- they would gain more energy. Magic big bang particles.

    First, the speed of light is a finite value... not infinity. Second, you're correct that they would never reach the speed of light since they have mass, but they could get close to it. Third, they don't gain rest mass as I described above, only relativistic mass, so this is another assumption that rests on a misconception.
    I wasn't using infinity literal, though I probably should have explained that.


    Nope. They don't gain rest mass, so they don't grow in size... In fact, due to length contraction the atom would appear smaller to an outside observer the closer it gets to the speed of light.
    Thank you for the clarification.
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  6. #5 Re: Relativity. 
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    Quote Originally Posted by what is science?
    Absurdly I still don't quite understand length contraction. It decreases in length in the direction of travel? How does that work?
    There's nothing absurd about it. It's quite a strange phenomenon, and one that is counter to our normal everyday human experiences.

    The short answer is that... from the objects own frame of reference... nothing changes. If you were the one traveling near the speed of light (ignoring for a moment the huge amounts of energy it would require to do so), you'd not notice any changes from your own frame of reference. Both length and time would appear perfectly normal to you. However, from an outside observer looking at you, they would see you as length contracted.

    It is a rough concept to wrap your head around, and to be perfectly honest I struggle with it a bit myself. A few years ago, I found these animations which really helped me to get the basics. Maybe you'll find use in them, too:

    http://faraday.physics.utoronto.ca/P...hContract.html
    http://faraday.physics.utoronto.ca/P...Invisible.html
    http://faraday.physics.utoronto.ca/P...eDilation.html



    Also, here's a good basic intro that is accessible:
    http://en.wikipedia.org/wiki/Introdu...ial_relativity


    Quote Originally Posted by what is science?
    I understand the difference, but that would also mean things ride at the edge of the universe along with its expansion. The "edge" being its circumference of expansion.
    Again, we need to be careful with words here. There is no "edge" to the universe, since the universe is (by definition) everything. If we say that there is an "edge," it implies that the universe is expanding into something, and there is no "something" into which it can expand. It's a strange concept, and to be honest, the only reason I know enough to be careful to avoid use of the words "point" and "edge" when talking about cosmological inflation is because I, myself, have been corrected so many times when I tried to use those terms in the past. 8)



    Quote Originally Posted by what is science?
    Thank you for the clarification.
    I'm glad you've found it useful.
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  7. #6  
    Forum Radioactive Isotope MagiMaster's Avatar
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    Actually, from what I've heard, while length contraction is what's actually happening, relativistic Doppler effects would make it look different, but I forgot how exactly.
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