ID goes on: Now there is IF!
-
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!