ID goes on: Now there is IF!
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Well, I am A Physicst so I guess I will tune in. The 'theory" that is being referenced is General Realtivity. But, I have to say this is more than just a 'theory'; it's predictions has been found reliable and repeatable often.
Jörgen Sigvardsson wrote:
How does that work? If space is curved, ought it not have been affected by some force? AFAIK,
The key concept it that 'gravatiton' is a property of all massive matter. The curvature of space-time (at least in this context) is a result due to a massive object travleing through space "dragging" it along. Think of placing a bowling ball on a mattres. You see that the mattress will 'warp' aroung the bowling ball.
Jörgen Sigvardsson wrote:
> One theory out there is that gravity might not necessarily be a 'force', but rather the result of curved space.
This is wrong. Space is curved because of the properties of massive matter. Not the other way around. May I suggest reading a light book called 'Einstein's Universe' it delves into the pedestrian aspects of The Photoelectric Effect, General & Special Realtivity, & Quantum Electro Dynamics(QED) without the pesky math :) Hey don't worry, I can handle it. I took something. I can see things no one else can see. Why are you dressed like that? - Jack Burton
Chris Austin wrote:
Well, I am A Physicst so I guess I will tune in.
Same here. What's your field?
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Er... Truth is in the eye of the beholder? Let me get this straight, the length of an object can be observed to be one length, when traveling at the same speed as the object, and another length when stationary relative to the object. In fact, the object gets shorter as it goes faster, correct? So what is the true length of the object? When you have to say, "It depends", then the truth, in this sort of a case is relative, even though it is behaviing in a predictable way based on the known velocity. Therefore, truth may be relative. Such as in the case of gravity, the true nature of gravity may be relative to whether the gravity is acting on us, or not (which is what I meant). I'm not saying you're wrong or any of the other physicists are wrong. I'm not even saying I think I'm right, or could be right. I'm just opening up question on the matter. Danny The stupidity of others amazes me!
If you look at a pencil in front of you it's length depends on it's orientation with your eyes. If someone else looks at the pencil from another vantage point they will see the pencil has a different length. The length of the pencil never changes, yet the two observers view two differrent projected views of the pencil. One of the hardest parts of learning to draw is working around your brain's tendency to translate the forshortened object so that you always percieve it to be the same length. Learning Relativity is the opposite problem. We are hard wired to view a moving pencil as shrinking and changing size when the pencil has a constant length in 4 space, the 2 observers just have different views of the same object. The mathemtatics are very similar in the 2 cases. For Euclidiean geometry a line is the shortest distance between 2 points, for space-time directions it is the longest.
bugDanny wrote:
So what is the true length of the object? When you have to say, "It depends", then the truth, in this sort of a case is relative, even though it is behaviing in a predictable way based on the known velocity.
To put it sucinctly: There is a higher truth. It is hidden from us and all we see are it's shadows. If you've read Plato it's esentialy his argument for a higher plane.
bugDanny wrote:
Therefore, truth may be relative. Such as in the case of gravity, the true nature of gravity may be relative to whether the gravity is acting on us, or not (which is what I meant). I'm not saying you're wrong or any of the other physicists are wrong. I'm not even saying I think I'm right, or could be right.
Words get in the way. The mathematics of General Relativity and Quantum Mechanics for that matter make exact predictions for how these object all interact together. Things get confusing when you translate them to everyday experience and language and then try to reason about them there. Differential geometry doesn't have a simple set of axioms like Euclidiean geometry.
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
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bugDanny wrote:
Therefore, truth may be relative.
Truth as expressed by physical, not philosphical, measurement is relative to the observer, yes. "Patriotism is the first refuge of a patriot."
Length in the space direction is changes, the points in space-time just rotate relative to each other. Whether you call the space-time points philosophical or real is philosophy. :^)
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
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Length in the space direction is changes, the points in space-time just rotate relative to each other. Whether you call the space-time points philosophical or real is philosophy. :^)
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
Well, than, I stand corrected relative to my previous post. I think... :confused: "Patriotism is the first refuge of a patriot."
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John Theal wrote:
bugDanny wrote: Did you know time goes faster in gravity that in zero-G? I think you are referring to frame dragging[^].
No, not meaning frame dragging. I mean how time actually gets slower with higher gravity (I said faster, but I meant slower), so that, for example, the closer you get to a black hole, the slower time goes. And talking about the whole Relativity thing. A person in a space ship entering a black hole would seem to hit the event horizon very fast, whereas a person looking on from a distance should see the space ship traveling slower and slower as it neared the event horizon. Isn't that right? Danny The stupidity of others amazes me!
Ah, then you are referring to time dilation.
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Richard Stringer wrote:
As a mind experiment just think of the turmoil and disarry that the discovery of extraterristral life is gonna do to organized religion. Its a matter of when not if.
I love statistics and probability. It is going to shatter some peoples fragile wrold view. Hey don't worry, I can handle it. I took something. I can see things no one else can see. Why are you dressed like that? - Jack Burton
Chris Austin wrote:
I love statistics and probability. It is going to shatter some peoples fragile wrold view.
Especially if their first message is "Repent or burn in hell, you heathens!" :laugh: "Patriotism is the first refuge of a patriot."
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Well, than, I stand corrected relative to my previous post. I think... :confused: "Patriotism is the first refuge of a patriot."
There is a philisophical question of the existance of mathematical objects. The Platonic view is that these objects exist outside of our universe and are intependent of reality. Other philosophers believe that they are just abstract constructs based on our universe. If our reality ceased to exist then they would disappear along with us. The invariants of relativity are 4 vectors and 4 dimensional length. We are incapable of physically observing them, just like we cannot observe a quantum mechanical wave function. If these objects exist they only exist in the mathematical models that we use to model our physical observations. I try to ignore all this as much as possible since it doesn't affect the mathematics or science any more then imagining some unobservable designer.
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
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There is a philisophical question of the existance of mathematical objects. The Platonic view is that these objects exist outside of our universe and are intependent of reality. Other philosophers believe that they are just abstract constructs based on our universe. If our reality ceased to exist then they would disappear along with us. The invariants of relativity are 4 vectors and 4 dimensional length. We are incapable of physically observing them, just like we cannot observe a quantum mechanical wave function. If these objects exist they only exist in the mathematical models that we use to model our physical observations. I try to ignore all this as much as possible since it doesn't affect the mathematics or science any more then imagining some unobservable designer.
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
Still, its a bit of stretch to suggest that philosophy itself is relative in the sense of General Relativity isn't it? That is all I was trying to say. I mean, obviously you could say that the observer is going to use philosophy to translate his observations and that since the observations are relative so are the philosophies behind them, but, honestly, at that point, my brain starts to hurt. It has been a long time since I read Plato, though. :-D "Patriotism is the first refuge of a patriot."
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Still, its a bit of stretch to suggest that philosophy itself is relative in the sense of General Relativity isn't it? That is all I was trying to say. I mean, obviously you could say that the observer is going to use philosophy to translate his observations and that since the observations are relative so are the philosophies behind them, but, honestly, at that point, my brain starts to hurt. It has been a long time since I read Plato, though. :-D "Patriotism is the first refuge of a patriot."
Stan Shannon wrote:
Still, its a bit of stretch to suggest that philosophy itself is relative in the sense of General Relativity isn't it?
Wasn't that the whole point of Decarte's "Cogito Ergo Sum" statement? I think therefore I am. The only validation of your existence is your own internal dialog with yourself. I wasn't actually trying to imply that philosophy is relative like length observations in Relativity. Only that there are abstract mathematical objects which are preserved in Special Relativity. These objects have an existence which is debated in philosophy. No one will ever see a four-dimensional vector directly, but we deal with 3 dimensional projections of them all the time. It's akin to asking what is the reality of a computer simulation. It exists in some sense, but is it real. There are much more abstract physical concepts like Entropy, which is even more dependent on an observer. And I don't even claim to understand anything beyond how to apply the formulas for wave-function colapse. That is the biggest mystery in modern physics as far as I'm concerned.
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
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If you look at a pencil in front of you it's length depends on it's orientation with your eyes. If someone else looks at the pencil from another vantage point they will see the pencil has a different length. The length of the pencil never changes, yet the two observers view two differrent projected views of the pencil. One of the hardest parts of learning to draw is working around your brain's tendency to translate the forshortened object so that you always percieve it to be the same length. Learning Relativity is the opposite problem. We are hard wired to view a moving pencil as shrinking and changing size when the pencil has a constant length in 4 space, the 2 observers just have different views of the same object. The mathemtatics are very similar in the 2 cases. For Euclidiean geometry a line is the shortest distance between 2 points, for space-time directions it is the longest.
bugDanny wrote:
So what is the true length of the object? When you have to say, "It depends", then the truth, in this sort of a case is relative, even though it is behaviing in a predictable way based on the known velocity.
To put it sucinctly: There is a higher truth. It is hidden from us and all we see are it's shadows. If you've read Plato it's esentialy his argument for a higher plane.
bugDanny wrote:
Therefore, truth may be relative. Such as in the case of gravity, the true nature of gravity may be relative to whether the gravity is acting on us, or not (which is what I meant). I'm not saying you're wrong or any of the other physicists are wrong. I'm not even saying I think I'm right, or could be right.
Words get in the way. The mathematics of General Relativity and Quantum Mechanics for that matter make exact predictions for how these object all interact together. Things get confusing when you translate them to everyday experience and language and then try to reason about them there. Differential geometry doesn't have a simple set of axioms like Euclidiean geometry.
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
I like your succinct reasoning comments here. A few things I picked up on.
andy brummer wrote:
To put it sucinctly: There is a higher truth. It is hidden from us and all we see are it's shadows. If you've read Plato it's esentialy his argument for a higher plane.
I don't know whether you're saying this in the philosophical sense, or the physical sense, but as far as Quantum Mechanics goes, you're right. I know this is grossly simplifying it, but in Quantum Mechanics, the thing being observed is affected by the observer. For example, you can't measure an electron's location and velocity, because by measuring the location, you change its velocity. In Relativity, the measurement depends upon your relative location and speed. Okay, the pencil might have a constant length in 4-dimensional space-time, but at speed the pencil would shrink in 3-dimensional space, to an outside observer. But if you could be in the pencil, it wouldn't seem to be changing. So we're affected by gravity. It's "hidden from us" because we can't become outside observers. Kind of the point I was trying to make. I'm sorry, I guess we were just reaching the same conclusion. Danny The stupidity of others amazes me!