It’s Thanksgiving here in the US, so blogging will be light to nonexistent. For the sake of those looking for a quick escape from the chaos of a family gathering, or, you know, those poor benighted souls in other countries for whom this is just another Thursday, here’s a thematically appropriate poll about science: What… Continue reading Dorky Poll: Gratitude
Category: Science
Seeing Exoplanets Sideways
Given that I’m currently working on a book about relativity, I’m spending a lot of time idly thinking about various relativistic effects. Many of these won’t end up in the final book, but they’re fun to think about. One thing that occurred to be earlier, while thinking about something else entirely, is the Doppler shift.… Continue reading Seeing Exoplanets Sideways
Interference of Independent Photon Beams: The Pfleegor-Mandel Experiment
Earlier this week, I talked about the technical requirements for taking a picture of an interference pattern from two independent lasers, and mentioned in passing that a 1967 experiment by Pfleegor and Mandel had already shown the interference effect. Their experiment was clever enough to deserve the ResearchBlogging Q&A treatment, though, so here we go:… Continue reading Interference of Independent Photon Beams: The Pfleegor-Mandel Experiment
Poll: Significant Figures
I’m grading a big backlog of homeworks today, so I don’t have time to do any really lengthy posts this morning. Thus, a poll question inspired by going through these homeworks: You are doing a physics homework problem. How many significant figures do you report?survey software While the class in question uses some quantum ideas,… Continue reading Poll: Significant Figures
Trapped Antihydrogen
The big physics-y news story of the moment is the trapping of antihydrogen by the ALPHA collaboration at CERN. The article itself is paywalled, because this is Nature, but one of the press offices at one of the institutions involved was kind enough to send me an advance version of the article. This seems like… Continue reading Trapped Antihydrogen
Rock Stars of Science
So, if you look at this picture: You might be asking yourself “Why does Debbie Harry rate Secret Service protection?” But no, this isn’t a photo from some alternate universe where the lead singer of Blondie went on to become leader of the free world, it’s part of the Rock Stars of Science campaign by… Continue reading Rock Stars of Science
Writing Relativity vs. Writing Quantum
Fall term classes ended yesterday, officially– my last class was Friday– so I’m shifting over to spend more time working on the sequel to How to Teach Physics to Your Dog, which involves talking to Emmy about relativity. Progress has been slower than last time, largely because the previous book was written while I was… Continue reading Writing Relativity vs. Writing Quantum
How Do You See Interference Between Independent Lasers?
This is adapted from an answer to a question at the Physics Stack Exchange site. The questioner asked: It seems that if the coherence length of a laser is big enough, it is possible to observe a (moving) interference picture by combining them. Is it true? How fast should photo-detectors be for observing of the… Continue reading How Do You See Interference Between Independent Lasers?
Relativity on a Human Scale: “Optical Clocks and Relativity”
As mentioned in yesterday’s post on
Crowd-Source Your Physics Questions
There’s a new physics Q&A site from the folks at Stack Exchange, this one on physics. If you’re not familiar with the format, it’s a bulletin-board style site where you can post questions to be answered by other users, and people vote the answers up and down, so you can get a decent feel for… Continue reading Crowd-Source Your Physics Questions