Forum members, This comment is, as per the subject line, [off-topic]^2, so only proceed if you have spare time and are very bored.
The original thread which I labeled "off-topic" was an off-shoot from a thread about someone slowing the speed of light in some medium down to 38 mph. This precipitated the off-topic discussion about whether General Relativity was violated. Several members opined on the subject, and Mr. Woodgate in particular, but others as well, stated that "General Relativity is surely wrong." At this point my curiosity was piqued, and I entered the thread and asked why that statement was made. I caveated my comment by saying I had no more than a layman's knowledge of General Relativity, and I wish to emphasize that once again here. Mr. Woodgate (and possible others) replied to the effect that General Relativity didn't agree with quantum mechanics, and also that General Relativity made some predictions about singularities in black holes with which some scientists are uncomfortable. That's where things stand, and I very much wish to rebut the contention that "General Relativity is surely wrong." Not on the basis of the science, which I have noted I am incompetent to discuss, but on philosophical (epistemological) grounds. Epistemology being the study of "how we know what we know," or how we think and gain knowledge. First, the idea that a scientific theory is wrong implies that the theory doesn't explain or predict empirical observations of reality. But a theory can make very good predictions under some conditions, but fail under others. In those circumstances, we can say that a theory is a good model of reality under certain conditions, where it applies, but outside of those boundary conditions, its accuracy decreases, and it cannot be trusted, or cannot be trusted to yield the same degree of accuracy as when the boundary conditions are met. So for instance we know that the Newtonian theory of gravitation works well in our own solar system, as long as we are calculating ballistics and orbital mechanics and the like. After all, we sent men to the moon and returned them safely to earth using nothing but Newtonian physics. Even while we knew that Newtonian mechanics doesn't explain light bending around a massive object like the sun, and other anomalies. It is philosophically incorrect to make a global statement like, "Newtonian mechanics is wrong," even though we know it doesn't explain all observed phenomena. Newtonian mechanics makes adequate predictions under certain boundary conditions, and given the acceptance of those conditions, Newtonian mechanics is a useful approximation to reality, a useful model. The same line of reasoning can be applied to General Relativity. Every experiment of which I know (recall the caveat) that was designed to test GR has shown GR to be correct within experimental accuracy. If GR appears to conflict with quantum mechanics, it isn't obvious to me at least, that QM is RIGHT and GR is WRONG. Now also notice that GR reduces to Newtonian mechanics when the right boundary conditions are observed. This is a statement of fact, not opinion. So it can be seen that Newtonian mechanics is a special case of GR, correct under certain conditions, but outside those conditions, the full GR theory must be invoked to properly model reality. It may come to pass (may have already happened?) that some phenomenon will be observed that is poorly explained by GR theory. When/if that happens, GR theory will have to be adjusted or augmented to explain the newly observed phenomenon. At that point, GR will occupy a place relative to the new theory that Newtonian mechanics occupies relative to GR - a subset. Given that eventuality, I am saying it will not be correct to state globally that "GR is wrong" - only that GR will no longer be held to apply globally under all conditions, but only under some conditions. The history of science is a succession of better and more finely tuned models of reality. Each successive model builds on the previous model, as more data comes in. The old model is not discarded as wrong, it is augmented as needed. Note that classical mechanics works extremely well where it applies, but quantum mechanics has supplanted CM where CM failed. And just to forestall the inevitable discussion of the Copernican revolution relative to the Ptolemaic universe, that was science vs. empirical observation, not science vs. science. One final example that is closer to home for most of us than General Relativity - Maxwell's equations. There is an asymmetry in Maxwell's laws because the fundamental unit of electric charge is a monopole, while the fundamental unit of magnetic "charge" is a dipole. Ever since Maxwell gave us the four laws of electromagnetics, which explain every electromagnetic phenomenon yet observed, people have been looking for a magnetic monopole to "balance" the asymmetry. None has been found to date. Let us imagine that at some point in the future, an experiment in a yet to be built cyclotron or similar device, or perhaps an observation of some astronomical event, reveals the existence, perhaps only momentary, of a magnetic monopole. At that point in time, Maxwell's equations will be rewritten, this time with full symmetry. Will people then say that Maxwell was wrong? Some may, but that just means I phrased the question incorrectly. Will Maxwell have been wrong in some absolute sense? The answer is no. Maxwell's asymmetric equations as he wrote them will still apply to the known universe below a certain temperature, and/or above or below some pressure, or under a host of other boundary conditions. Under those conditions where the monopole can exist, the augmented symmetric equations will apply. Maxwell's asymmetric equations will be seen to be a subset of the symmetric set, true under certain conditions, but not true under all conditions. Saying that a theory is absolutely wrong because it is not universally applicable is epistemologically incorrect. Some small minority of the forum waded through this long post, and maybe many of them are asking, "What is the point of all the verbosity?" The point is this: If science is viewed as a succession of theories, each of which was found to be false and replaced by another theory, which may also be found to be false, it casts doubt on man's very ability to comprehend the world in which we live. But if instead we understand that man's view of the universe is a constantly evolving and ever more accurate gauge of reality, not a final destination but a journey, then that understanding yields a proper and accurate appreciation of how man perceives and understands the world in which we live. It may be apocryphal, but Einstein is said to have said that all his efforts were an attempt to read God's mind. That is a poetic way of condensing the previous paragraph. For the small minority of you that waded through all this, I appreciate your fortitude! Ken Javor Phone: (256) 650-5261 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
