The most talked-about physics paper last week was probably Negative Absolute Temperature for Motional Degrees of Freedom (that link goes to the paywalled journal; there’s also a free arxiv preprint from which the above figure is taken). It’s a catchy but easily misinterpreted title– Negative absolute temperature! Below Absolute Zero! Thermodynamics is wrong!– that obscures… Continue reading What Does “Negative Temperature” Mean, Anyway?
Category: Experiment
Top Physics Breakthroughs of the 13th Baktun
We’re at that time of year where people publish lists of top stories of the year, but as many crazy people will be happy to remind you, this Friday marks the end of another calendrical period, in the Mayan calendar. So, I’m going to steal an idea from a college classmate on Facebook, who wrote:… Continue reading Top Physics Breakthroughs of the 13th Baktun
Using Light to Put a Mirror in the Dark: “Optomechanical Dark Mode”
In which I unpack a cryptic paper title and explain how quantum superposition lets you use light to keep things from interacting with light. ————- I joined AAAS a couple of years ago to get a break on the registration fee for their meeting, and I’ve kept up the membership mostly because I like having… Continue reading Using Light to Put a Mirror in the Dark: “Optomechanical Dark Mode”
The “Ballistic” Story
Last week, in the post about fermion conduction, I left a reference hanging: There’s nothing physically blocking the atoms from flying right through the channel– in fact, an atom that enters the channel will always exit the other side without slowing down along the way. This is termed “ballistic,” a term that will always have… Continue reading The “Ballistic” Story
Simulating Wires with Atoms and Light: “Conduction of Ultracold Fermions Through a Mesoscopic Channel”
So, it’s been a while, but let’s see if we can’t hit the ground running with a good physics post. There have been a few notable physics events since I went on hiatus, but for a return to physics ResearchBlogging, we’ll go with something near and dear to my heart, ultracold atoms. Specifically, this Science… Continue reading Simulating Wires with Atoms and Light: “Conduction of Ultracold Fermions Through a Mesoscopic Channel”
Higgs Rumors Are the Price of Success
In which celebrity culture comes to particle physics. ———— It’s been about six months since we had a big flurry of Higgs Boson stories, and as enjoyable as the relative quiet has been, it means we’re due for another run. And, predictably enough, the usual suspects are stoking speculation about what, exactly, will be officially… Continue reading Higgs Rumors Are the Price of Success
Single Photons Are Still Photons: “Wave-particle dualism and complementarity unraveled by a different mode”
In which we do a little ResearchBlogging, taking a look at a slightly confusing paper putting a new twist on the double-slit experiment. ———— I’m off to California this afternoon, spending the rest of the week at DAMOP in Pasadena (not presenting this year, just hanging out to see the coolest new stuff in Atomic,… Continue reading Single Photons Are Still Photons: “Wave-particle dualism and complementarity unraveled by a different mode”
Excellent Approximations and Lying to Children
In which I talk about the common complaint that we teach students physics that “isn’t true,” and the limits on that statement. ———— Frequent commenter Ron sent me an email pointing to this post by David Reed on “What we “know” that t’aint so…. and insist on teaching to kids!”: he science we teach is… Continue reading Excellent Approximations and Lying to Children
Entangled In the Past: “Experimental delayed-choice entanglement swapping”
Enough slagging of beloved popularizers– how about some hard-core physics. The second of three extremely cool papers published last week is this Nature Physics paper from the Zeilinger group in Vienna, producers of many awesome papers about quantum mechanics. Ordinarily, this would be a hard paper to write up, becase Nature Physics are utter bastards,… Continue reading Entangled In the Past: “Experimental delayed-choice entanglement swapping”
Clock Synchronization Done Right: “A 920-Kilometer Optical Fiber Link for Frequency Metrology at the 19th Decimal Place”
I’ve been busily working on something new, but I’m beginning to think I’ve been letting the perfect be the enemy of the good-enough-for-this-stage, so I’m setting it aside for a bit, and trying to get caught up with some of the huge number of things that have been slipping. Which includes getting the oil changed… Continue reading Clock Synchronization Done Right: “A 920-Kilometer Optical Fiber Link for Frequency Metrology at the 19th Decimal Place”