russ_watters said:
So, QM makes testable predictions that ar accurate. But that's not good enough? What more can we ask of any theory? (in fact, based on that, scientists consider QM to be the most thoroughly tested and verified theory ever).
That can be but the theory seems not always confirming the results. Ooeps. Of course then you just adapt the theory. Why not? QM is not about a concept, it's about results. Being the "good" guys everything is allowed. Right?
Russ, next to my cynic remarks ... this is a nice article.
Snapshot Yields Inside Look at Molecular Movement
http://www.lbl.gov/Science-Articles/Archive/CSD-molecular-movement.html
BERKELEY, CA – The secret lives of molecules are now less secret. Using the U.S. Department of Energy’s Advanced Light Source at Lawrence Berkeley National Laboratory, an international team of physicists has obtained the clearest snapshot yet of the simultaneous behavior of all the electrons and nuclei inside a molecule. Their work, in which they broke apart a deuterium molecule and measured the momenta of its particles, opens the door for a more basic understanding of molecules and the everyday processes they drive, from breathing to rust to photosynthesis.
(snip)
The combined momenta of a molecule’s electrons and nuclei dictate its geometry and how it binds with other molecules — in other words, what makes the molecule tick. But pinning down all of the particles’ momenta at the same time has proven extremely elusive. Theoreticians, relying on quantum mechanics, can only predict the probability that an electron will possesses a given position or momentum.
To get an inside look at all the particles’ dynamics, experimental physicists are developing ways to fragment a molecule in a manner that preserves at least some of its internal motion, which is no easy task. Hit a molecule with an ion, for example, and the ion’s momentum transfers to the electrons and nuclei, which clouds physicists’ ability to determine their true momenta at the time of impact. As Weber explains, it’s like cutting a stretched rubber band with a hammer. The rubber band breaks, but the set-up is ruined.
(snip) But bombard a molecule with a photon, which has no mass and no charge, and the photon mainly deposits its energy and kick-starts the fragmentation process. It’s like cutting the rubber band with a scalpel instead of a hammer. With a scalpel, an observer can watch the band explode into two fragments and, more importantly, get a feel for the tension present in the band before it was cut.
(snip)
“We experimentalists are ahead right now. Calculating such a few-particle break-up is a big challenge for state-of-the-art quantum mechanics,” says Weber. “The forces, charges, and angular momenta of a molecule’s particles are known. We know the ingredients, but when we observe all of the particles moving together in a few-particle system, an image appears that doesn’t match theoretical predictions.”
