|
|
Forums:
Community:
Campground:
Re: [rrradam] two parallel lines can cross!!!:
Edit Log
|
|
petsfed
Jan 20, 2007, 7:58 PM
Views: 957
Registered: Sep 25, 2002
Posts: 8599
|
rrradam wrote: Have you read QED ??? Are you familiar with it ??? Theoretical physics is a vastly different field from Astronomy and basic physics, as I am sure you know. Even Cosmology and Astrophysics are only briefly covered in a general physics degree, unless you are working toward a graduate degree in those areas. Would you not agree ???
I'm in a physics heavy astro-department. And most simply put, most of the research I do in astrophysics is described by QED, but we don't use that formulation because its unwieldy.
Also, you misunderstand the progression of sciences. Maxwell's equations showed that light travels at the same speed regardless of the observer's velocity relative to the light source. This caused Einstein to formulate a theory of relativity that allowed for a constant speed of light from any "rest" frame. Concurrently, he worked on explaining the photo-electric effect (and also Brownian motion), which led (eventually) to quantum mechanics, which led (eventually) to Feynman and others reformulating classical electro- and magneto-dynamics to fit the quantum world view. However, what remains is a melding of relativity and QED (and later a quantum-relativistic theory of gravitation) into the grand unified field theory.
However, to claim that astronomy and theoretical physics are different fields is an error of confusing the methods for the explanation. Like I said, over macroscopic distances, QED doesn't really apply, and for low masses and low velocities, relativity doesn't really apply, so we go back to the classical equations, which are themselves still very complex.
For instance, I've done some work with semi-hot plasma clouds that radiate in the visible because of energy released via gravitational compression. They radiate in a way that we can't reproduce in a laboratory, but is still predicted by QM. The reason for this phenomenon is that the density of the gas clouds in question is lower than the best lab vacuum available. Its only in that situation that special "forbidden" energy transitions can happen.
Another example is the preliminary finding that time is not quantatized because that would have a measurable effect on the appearance of very distant quasars. That it doesn't have that effect implies that time itself is not quantatized like distance seems to be.
Finally, the cosmic microwave background radiation has its explanations firmly rooted in quantum processes. Its effect on the large scale structure of the universe (a research interest of mine) is obvious, but obscured by complexity all the same.
Something you have to realize is that while Feynman is a brilliant teacher, he is only one source. I suggest looking into Weinberg as well, and maybe some of Hawking's work, although the latter should be taken with a grain of salt. Anybody locked in their own mind as long as Hawking can be characterised as at least a little bit crazy.
I have not had the opportunity to read much of Feynman's work (Six Easy Pieces is all that I've read, a book you should read as well) because I've been a bit too wrapped up in my course work. However, it should say something that my courses these last 2 years have been Electro- & Magneto-dynamics, Quantum Mechanics, Mathematical and Computational Physics, and Thermodynamics & Statistical Mechanics. By the time I graduate, I'll have taken 2 astronomy courses.
(This post was edited by petsfed on Jan 20, 2007, 8:02 PM)
|
|
|
Edit Log:
|
|
Post edited by petsfed
() on Jan 20, 2007, 8:00 PM
|
|
Post edited by petsfed
() on Jan 20, 2007, 8:02 PM
|
|
|
|
|
|
