Laser Smackdown: Final Days of Voting for the Most Amazing Laser Application

We’re just over 600 votes in the Laser Smackdown poll in honor of the 50th anniversary of the laser, as of early Friday morning. I notice that it has moved off the front page of the blog, though, so here’s another signal-boosting repost, just so we have as many votes as possible, to establish maximum… Continue reading Laser Smackdown: Final Days of Voting for the Most Amazing Laser Application

On the Quantum Physics of Whiteboards

I’m teaching Physics 350: Quantum Mechanics this term, which is a junior/senior level elective course using Townsend’s book which deals with quantum mechanics in the state vector formalism. The room in which the class meets is the only one in the department that contains a whiteboard (using dry-erase markers) rather than a blackboard (using chalk).… Continue reading On the Quantum Physics of Whiteboards

Reminder: Vote for the Most Amazing Laser Application of All Time

As of 1:45 Monday, 217 people have cast votes in the Laser Smackdown poll. That’s not bad, but it’s currently being handily beaten by the 271 people who have voted for a favorite system of units. The nice thing about using actual poll services for this sort of thing, though, is that I can re-post… Continue reading Reminder: Vote for the Most Amazing Laser Application of All Time

Laser Smackdown: Vote for the Most Amazing Laser Application

In 1960, the first working laser was demonstrated, and promptly dubbed “a solution looking for a problem.” In the ensuing fifty years, lasers have found lots of problems to solve, but there has been no consensus about which of the many amazing applications of lasers is the most amazing. Now, in 2010, as we celebrate… Continue reading Laser Smackdown: Vote for the Most Amazing Laser Application

Amazing Laser Application 11: Frequency Combs!

What’s the application? An optical frequency comb is a short-duration pulsed laser whose output can be viewed as a regularly spaced series of different frequencies. If the pulses are short enough, this can span the entire visible spectrum, giving a “comb” of colored lines on a traditional spectrometer. This can be used for a wide… Continue reading Amazing Laser Application 11: Frequency Combs!

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

Amazing Laser Application 6: LIGO!

What’s the application? LIGO stands for Laser Interferometer Graviitational Wave Observatory, because (astro)physicists feel free to drop inconvenient words when making up cute acronyms. This is an experiment to look for disturbances in space-time caused by massive objects, which would manifest as a slight stretching and compression of space itself. What problem(s) is it the… Continue reading Amazing Laser Application 6: LIGO!

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

Sketchy March Meeting Notes: Monday

I’m terrible about taking notes on conference talks, especially when I’m jet-lagged and was sleep deprived even before I got on the plane. I do jot down the occasional paper reference, though, so here are the things I wrote down, and the talks they were associated with. This should give you some vague idea of… Continue reading Sketchy March Meeting Notes: Monday

Entanglement Happens

There have been a bunch of stories recently talking about quantum effects at room temperature– one, about coherent transport in photosynthesis , even escaped the science blogosphere. They’ve mostly said similar things, but Thursday’s ArxivBlog entry had a particular description of a paper about entanglement effects that is worth unpacking: Entanglement is a strange and… Continue reading Entanglement Happens