Posted on 10/09/2005 2:43:18 PM PDT by Southack
All physics requires empirical parameters as inputs. The point is that it works - the structural model has legitimacy. The point is, EM theory without quantum mechanics CAN'T calculate hyperfine splitting to 13 orders of magnitude.
Couldn't the same be said of standard electromagnetic theory?
Not at all. Shortcomings of classical EM theory are why we have QM.
Yet, you don't believe that EM theory is a correct description of nature ...
EM theory describes a lot of what we see in nature quite well. So do Newton's Laws, for that matter.
...you can either believe QM or EM, not both
Why not? QM reduces to EM in the limit h-->0. In many cases, the classical EM approximation works fine. In many, however, it doesn't.
I see QM as engineering, not physics, in that it gives you the endpoints and calculational tools but not the gory details. For example, I can analyze circuits using Laplace or Fourier transforms but that glosses over all the important details.
QM isn't physics because is doesn't give closed-form solutions? That doesn't make much sense. Numerical solutions are often the best we can do. Classical EM theory does not suffice to describe all of nature. We live in a manifestly non-linear universe, I'm afraid.
Anyway, QM appears to me (or, at least, some of its proponents claim) that it is actually *invalid* to ask what happens at a lower level. As if QM was the end and the rest unknowable.
You can *ask* all you want; QM does say there are fundamental limits upon our ability to measure, because of the fact that you have to use a QM "object" to do the measurement. I don't see what this has to do with any underlying reality.
I also don't like lack of burden when it comes to "proving" QM.
There are 100 years worth of papers in Physical Review Letters and other journals that have addressed this "burden" - I'm not quite sure what you mean by this.
Of course, all this isn't to say that em theory is the be-all, end-all theory of Nature. It clearly isn't. It has serious flaws, ie. no physical model.
I still don't see what you mean by a "physical model". If it makes measurements and predictions within a consistent framework it's a physical model, isn't it? If not, I don't see what classical EM has over QM at all, even from an aesthetic viewpoint. Why do physics at all, then?
Also, why does the energy density in an em wave always seem to go as frequency cubed when interactions with electrons are concerned?
I have no idea. This problem sounds like it would take me a lot of work to answer. Could be an interesting problem to look at if I have the time. One day I've vowed to go back and review E&M more carefully (time is short in grad school to do these things, though).
It's as if qE is just a low frequency approximation to the force on an electron.
This statement sounds, oddly enough, a bit quantum mechanical to me...as if you're talking about classical E&M to be a limiting approximation of a deeper underlying theory...
You sound like a pretty bright person who has taken the time to learn quite a bit of physics. I don't know if you have an advanced degree in it or not - if not, have you considered pursuing one? If so, have you considered actually submitting work and working within the framework of the physics community? You won't get very far doing work in isolation, that's all I'm saying - you could be, in many cases, spending time reinventing what is already out there. Assuming you keep advancing your knowledge, you might have something to contribute to the insight we already have into these fields of knowledge. You won't do it, however, by saying we should "throw out" successful theories though.
If our view of QM is laden with misconceptions (as it might well be), why not work through legit. channels to try to collaborate to improve our understanding of it? You might well have some good insights, but unless you get involved in the process of having it reviewed, any good insights you may have will be lost amidst the superfluous side of your work and your errors (which we all make, as I did a good job demonstrating) will never be clarified.
I'm referring to the difference between a high-level, statistical theory like QM versus a deterministic, low-level theory like EM. EM has to handle the ugly details of fields interacting with charges over time while QM basically takes a "sh*t happens" approach.
I still don't see what you mean by a "physical model". If it makes measurements and predictions within a consistent framework it's a physical model, isn't it.
Not in my opinion. That's engineering. Physics, imho, is coming up with a deterministic physical model of some phenomena and then finding the equations that describe the physical model. Statistics has absolutely *no place* in the physical model, it would only come in when applying the model to a complex situation where the experimental details contain unknowns.
I have no idea. This problem sounds like it would take me a lot of work to answer. Could be an interesting problem to look at if I have the time. One day I've vowed to go back and review E&M more carefully (time is short in grad school to do these things, though).
The frequency-cubed relationship comes in whenever you use EM to solve problems where QM applies. You can see this in my classical Compton Effect paper. I believe it's due to fact that relativistic effects become dominant in EM when high frequencies are involved. The reason why QM works, imho, is three things: 1) nonlinear EM due to relativistic effects, 2) the fact that a smooth, time-bounded em wave cannot transfer net energy or momentum to a free charge, and 3) due to #2, a charge must interact with a third party in order to react to bounded em wave. Point #1 is what gives the appearance of quantized interaction between em waves and charges. Point #3 is what creates the statistical nature of QM.
You sound like a pretty bright person who has taken the time to learn quite a bit of physics. I don't know if you have an advanced degree in it or not - if not, have you considered pursuing one? If so, have you considered actually submitting work and working within the framework of the physics community?
Actually, I have no degree at all. I became obsessed with EM and physics in my third year in EE and dropped/flunked out (had a short paper published in Proc IEEE on transmission line theory a few months later, so it wasn't all for naught :). Got caught up in the Wild West world of PC software in the mid-80s and now have some free time on my hands.
Anyway, my interests are too narrow to really get into physics. I just want to figure out what an electron is, to my own satisfaction. It makes no sense that it's quantized, for example. EM waves must be highly non-linear at strong field strengths and this nonlinearity must be due to the medium's characteristics. Heaviside figured this out but was too old to fully explore the implications. He found that high field strengths "compressed" space so that the speed of light was significantly reduced. It doesn't take much imagination to see that this varying speed of light could lead to stable configurations of EM waves without introducing the concept of charge (charge would be related to the gradient of the density of speed, ie. not a real thing). Unfortunately, I'm not smart enough to juggle the intense equations, even in the idealized cases...
I posted my utter disgust with press releases masquerading as science, pointing out that it is well-known that the earth is NOT a perfectly round sphere. Therefore a satellite orbiting above the earth (and a few hundred miles is nothing compared to the size of the earth, infinitissemal), will be subject to a NON-uniform gravitational field.
Thus this experiment is absurd. The attempt to measure the tiniest variation in the pointing of the satellite towards a guidestar will be swamped by the non-uniform effects of gravity as the satellite orbits the earth thousands of times.
My point is not to challenge relativity, per se, but the sloppy and careless mentality that science has fallen into. I don't care whether relativity is true or not. But I do care that we learn to use the scientific method on all subjects, whether testing for relativity or not.
To that someone responded:
To: Moseley
If the experimental telescope drifts away from the guidestar all it will prove is that the NON-uniform gravitational field of the LUMPY earth has caused it to drift off axis.
I'm going to hazard a guess that they've corrected for that.
-------> How? One would have to map with incredible detail every irregularity in the shape of the earth (which is considerable). Furthermore, the gravity of an object is NOT concentrated at the center unless the object is perfectly uniform in mass and the distribution of mass. Therefore, the irregularity of composition, just between the seas and the continents (like the Himalayas) makes gravity an inconsistent force upon the test satellite.
As a result, the attempts to compensate would swamp the tiny change being "measured." If the artificial effects of compensation are far greater than the effect being measured, the signal is lost in the noise, and no reliable result can be measured. Mistakes in the compensation process become a far greater cause for the "measured" variation than any relativistic effect.
Furthermore, the reaction of many is revealing. Relativity has been proven again and again in press releases and pop science articles, but almost never using the 8 step scientific method that distinguishes voodoo and alchemy from modern science. Observing a general consistency is NOT science. Science requires TESTING under rigorous conditions. Relativity might (accidentally) be true. But that is no excuse for sloppy science.
No, the atom bomb is not proof of relativity. The convertibility between mass and energy was quantified by the same Einstein, as well as by other scientists. But despite the press releases, it is not part of the Theory of Relativity. THe fact that the THeory of Relativity might borrow its terms and wrap itself in things proven does not make those things "part of" the Theory of Relativity. One can refer to things while talking about Relativity, but that does not mean they prove Relativity.
Preliminary results of Gravity Probe B will be presented at a special session during the American Physical Society (APS) meeting, 14 to 17 April 2007.
http://einstein.stanford.edu/highlights/hl_polhode_story.html
Editor’s Note
I have often mentioned the term “polhode” in these status updates, with a parenthetical reference to the motion of our gyroscope rotors. Typically, a few days later I then receive a number of email messages, asking for more information about this exotic word—what is the polhode motion of the gyro rotors, and why is it important to the GP-B experiment? In this month’s GP-B Mission News story, I will attempt to answer these questions in more detail. I am most grateful to our GP-B science team for their time and invaluable assistance in writing this story. —Bob Kahn
Time to bone up on this Gravity Probe B. It's going to be controversial and lead to countless FR threads.
You heard it here first, and we're just 2 weeks away from the payoff pitch (Jacksonville, Florida for those of you who want to hear the above prediction played out live).
Inasmuch as modern cosmology, relativity, and statistical mechanics are still young and in rapid evolution they provide excellent opportunities for the young physicist to make his mark. Expect much controversy and disputation especially between the older and the younger participants. Pay attention to those who mention Clifford algebras since even the sage Dirac was unaware of them and didn't know how to do a cross product above three dimensions.
Was Einstein right? First look at Gravity Probe B results
GP-B NEWS RELEASE
GP-B scientists expect to announce the final results of the experiment in December 2007, following eight months of further data analysis and refinement. Saturday, Everitt and his team shared what they have found so far-namely that the data from the GP-B gyroscopes clearly confirm Einstein’s predicted geodetic effect to a precision of better than 1 percent. However, the frame-dragging effect is 170 times smaller than the geodetic effect, and Stanford scientists are still extracting its signature from the spacecraft data. The GP-B instrument has ample resolution to measure the frame-dragging effect precisely, but the team has discovered small torque and sensor effects that must be accurately modeled and removed from the result.
“We anticipate that it will take about eight more months of detailed data analysis to realize the full accuracy of the instrument and to reduce the measurement uncertainty from the 0.1 to 0.05 arc-seconds per year that we’ve achieved to date down to the expected final accuracy of better than 0.005 arc-seconds per year,” said William Bencze, GP-B program manager. “Understanding the details of this science data is a bit like an archeological dig. A scientist starts with a bulldozer, follows with a shovel, and then finally uses dental picks and toothbrushes to clear the dust away from the treasure. We are passing out the toothbrushes now.”
IF Einstein is correct, then a gyroscope in polar orbit at 400 miles should turn away from its initial “pointing direction” by an angle amounting after one year to 42 milliarc-seconds, due to frame-dragging (Theory of Relativity’s math behind space-time warping near a large body such as the Earth).
GP-B was in orbit longer than 1 year, however, so the directional change should be larger. Likewise, all of GP-B’s gyroscopes should agree on the change, especially direction and scale.
Modeling is problematic.
Lets see the directional change data raw, without "modeling" (a polite way of saying that data quantities are going to be changed for publication).
We're looking for a directional change larger than 42 mili-arc-seconds.
Why then would the non-relativistic sensor effects of 1/3 of 1 milli-arc-second require 7 more months of "modeling" to rule it out?!
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