Category: Physics

Proving Bethe Wrong: On Theory Inspiring Experiment

As research for the work-in-progress, I recently read Luis Alvarez‘s autobiography, Alvarez: Adventures of a Physicist, which contains a passage that I was reminded of last night while reading another book, that seems like an amusing follow-up to yesterday’s rant about theory and experiment. This is from the end of the chapter where he joined… Continue reading Proving Bethe Wrong: On Theory Inspiring Experiment

Experiments Are Not Afterthoughts

There’s been a bunch of talk recently about a poll on quantum interpretations that showed physicists badly divided between the various interpretations– Copenhagen, Many-Worlds, etc.– a result which isn’t actually very surprising. Sean Carroll declares that the summary plot is “The Most Embarrassing Graph in Modern Physics, which I think is a bit of an… Continue reading Experiments Are Not Afterthoughts

How Do You Make Negative Temperatures, Anyway?

Part of Figure 1 from the arxiv preprint of the paper discussed in the post.

Last week’s post talked about the general idea of negative temperature, with reference to this much-talked-about Science paper (which also comes in a free arxiv version from which the figures used here are taken). I didn’t go into the details of how they made a negative temperature gas, though, and as it’s both very clever… Continue reading How Do You Make Negative Temperatures, Anyway?

What Does “Negative Temperature” Mean, Anyway?

Part of Figure 1 from the arxiv preprint of the paper discussed in the post.

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?

The Psychology and Improbability of Shuffle Play

Kate and I went down to New York City (sans kids, as my parents were good enough to take SteelyKid and The Pip for the weekend) this weekend, because Kate had a case to argue this morning, and I needed a getaway before the start of classes today. We hit the Rubin Museum of Art,… Continue reading The Psychology and Improbability of Shuffle Play

The Physics of Wall Street by James Owen Weatherall

The Physics of Wall Street cover.

As I hinted obliquely a little while back, I don’t have a terribly high opinion of Wall Street or Wall Street traders. Given that, I’m not the most obvious audience for a book titled The Physics of Wall Street, and truth be told, I wouldn’t’ve picked it up on my own. The publisher sent me… Continue reading The Physics of Wall Street by James Owen Weatherall

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”

A laser (red arrow) exciting an atom. On the left, an atom with only two levels must return to the same initial state; on the right, the atom can decay into a superposition of two states.

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”

Hobbits and Prime Ministers: The Physics of Doors

Peter Jackson in the door to Bag End.

Over at Tor.com, Kate has begun a chapter-by-chapter re-read of The Hobbit, and has some thoughts on Chapter 1. It’s full of interesting commentary about characters and literary technique, but let’s get right to the important bit: Physics! Kate mentions in passing in the post that the Hobbit style round door with a knob in… Continue reading Hobbits and Prime Ministers: The Physics of Doors

Why Are Physics Classes Full of Old Stuff?

Minute Physics's open letter to the President.

Everybody and their siblings have been linking to this Minute Physics video, an “open letter” to President Obama complaining about the way that most high school and even intro college physics classes don’t teach anything remotely modern: I’m not entirely sure where the date of 1865 comes from, but it’s true, the standard intro physics… Continue reading Why Are Physics Classes Full of Old Stuff?