Why Do We Have Stuff? Hints from Fermilab

There’s a Dennis Overbye article in the Times today with the Web headline “From Fermilab, a New Clue to Explain Human Existence?” which I like to think of as a back-handed tribute to the person who linked to an interview with Sean Carroll by calling him “The cosmologist, not the scientist.” This is the secret… Continue reading Why Do We Have Stuff? Hints from Fermilab

Through a (Noble) Gas, Darkly

There’s a minor kerfuffle at the moment over the XENON experiment’s early data (arxiv paper) which did not detect any dark matter in 11 days of data acquisition. This conflicts with earlier claims by the DAMA experiment and recent maybe-kinda-sorta detections by the CoGeNT and CDMA experiments. As a result, a couple of members of… Continue reading Through a (Noble) Gas, Darkly

The Most Amazing Laser Application of All Time Is…

Voting has closed on the Laser Smackdown poll, with 772 people recording their opinion on the most amazing of the many things that have been done with lasers in the fifty years since the invention of the first working laser (see the Laserfest web site for more on the history and applications of lasers). The… Continue reading The Most Amazing Laser Application of All Time Is…

Last Call for Laser Smackdown Voting

With over 700 votes cast in the Laser Smackdown poll in honor of the 50th anniversary of the laser, laser cooling has opened a commanding 20-vote lead in the race to be the Most Amazing Laser Application of All Time. If you prefer one of the other options, you have only six hours left to… Continue reading Last Call for Laser Smackdown Voting

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

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!