Copasetic Flow

In my research this morning, I came across a collection of interesting articles from the 1970s where researchers observed a shift in the phase of a neutron's quantum wave function because of a change in the gravitational potential. This is similar to the Aharanov-Bohm effect, but using a gravitational rather than an electromagnetic potential. If you're a university student like myself, all the journal links below should be accessible via your university's library. The experiment design is described in Experimental Test of Gravitationally Induced Quantum Interference The results of the experiment are presented in: Observation of Gravitationally Induced Quantum Interference Another similar experiment by the same researchers was described in: Observation of a Phase Shift of a Neutron Due to Precession in a Magnetic Field For a nice primer of all things Aharanov-Bohm with reference to the above mentioned experiments, see Reviews of Modern Physics: The quantum effe...

I'm doing a presentation later this year on the role Agnew Hunter Bahnson Jr. played in founding the Institute of Field Physics at the University of North Carolina at Chapel Hill. On a recent trip to the Philadelphia Museum of Art, I lucked onto a painting, ("The Agnew Clinic" by Thomas Eakins), of Bahnson's namesake, Dr. David Hayes Agnew . Dr. Agnew was the long time friend of Bahnson's grandfather and performed the excision of his elbow joint. Thomas Eakins is a famous American painter who lived in the Philadelphia area. The "Agnew Clinic" was his largest painting. The picture below is of another painting by Thomas Eakins.

We're covering tunneling in my quantum mechanics class. I did a little bit of research and was surprised to find out that Gurney and Condon made one of the first practical application of quantum tunneling to accurately predict alpha decay of various radioactive elements. They describe alpha decay as alpha particles tunneling through the attractive potential barrier of the nucleus. I found three very interesting journal articles on the subject. The first is a historical summary by Condon. The second and third are the initial journal articles by Gurney and Condon in Nature and Physical Review. All three of these articles can be accessed for free from most university libraries. EU Condon, Tunneling - How it all Started, Am. J. Phys., 46, 319, (1978) Gurney and Condon, Wave Mechanics and Radioactive Disintegration, Nature, 122, 439, (1928) Gurney and Condon, Quantum Mechanics and Radioactive Disintegration, Phys. Rev., 33, 127, (1929)

This little, (kinda big actually), guy was hanging out at the gas station today.

Why is Boulder, CO cast in the part of Washington D.C. in Scarecrow and Mrs. King, Season 3, Episode 19, "The Boy Who Could Be King"? 11:32 into the episode a panning shot that is supposed to be in downtown DC is actually the Pearl St. mall, in Boulder, CO. Here's the shot from the episode, (scroll down for the same view of the Pearl St. mall in Google Earth): Here's the view of the Pearl St. mall in Google Earth. Google Earth is a bit strange, you may have to reload the page to get the correct picture, (or click the 'View Larger Map' link below: View Larger Map Later at 23:14 an assay report is shown from the Stagler Mining Co. of Bolder Colorado. Anybody know if there was any rhyme or reason to all this?

I'm still studying for quals. I got stuck for awhile on problem 2.11 of Griffith's Introduction to Quantum Mechanics first edition. The problem involves manipulating raising and lowering operators to perform a normalization. The problem I was having was doing too much of the math too early. I tried to expand all the operators and got stuck. I tried to apply integration by parts as the book suggests and applied it to the wrong term the first time, and carried the operation too far on a second try. The series of conservative steps that finally did the trick is shown in the video below.

After seeing Jeri Ellsworth's videos on software defined radios, it looks like something that'd be fun to try. This post is just an easy access point for the reference materials I'm using. It starts with the Element14/Jeri Ellsworth video outlining her SDR project followed by her 7 vlog entries on the project. Following that are links to the FB papers on SDR from AC5OG, and a few references to parts from Sparkfun that look like they'd be handy. vlog part 1 vlog part 2 vlog part 3 vlog part 4 vlog part 5 vlog part 6 vlog part 7 AC5OG SDR Paper part 1 AC5OG SDR Paper part 2 AC5OG SDR Paper part 3 AC5OG SDR Paper part 4 Sparkfun analog mux board Winrad software from I2PHD