Inconstant Constants: “Probing fundamental constant evolution with redshifted conjugate-satellite OH lines”

Via Jennifer Ouellette on Twitter, I ran across a Discovery News story touting a recent arxiv preprint claiming to see variation in the fine-structure constant. It’s a basically OK story, but garbles a few details, so I thought it would be worth giving it the ResearchBlogging treatment, in the now-traditional Q&A format. What did they… Continue reading Inconstant Constants: “Probing fundamental constant evolution with redshifted conjugate-satellite OH lines”

Measuring the Angular Momentum of Light

I’m teaching a junior/senior level elective this term on quantum mechanics. We’re using Townsend’s A Modern Approach to Quantum Mechanics, which starts with spin-1/2 and develops the whole theory in terms of state vectors and matrices. This is kind of an uneasy fit for me, as I’m very much a swashbuckling experimentalist, and not as… Continue reading Measuring the Angular Momentum of Light

Cooling a “Macroscopic” Object to Its Quantum Ground State

Several people have sent me links to news stories about last week’s Nature paper, “Quantum ground state and single-phonon control of a mechanical resonator.” (It was also presented at the March Meeting, but I didn’t go to that session). This is billed as the first observation of quantum phenomena with a “macroscopic” or “naked eye… Continue reading Cooling a “Macroscopic” Object to Its Quantum Ground State