In which Rhett and I chat about the hot new discovery of primordial gravitational waves (maybe) very briefly before segueing into talking about LIGO, and Cosmos, and why “theory” is a terrible word, and the memorization of constants, and standardized tests, and time-lapse videos. You know, as one does. Miscellaneous items: — I’m a little […]
Category: Experiment
What Is the Resistance of an Instek GDM 396 Current Meter?
Last week, we looked at the resistance of a voltage sensor by using the discharge of a capacitor, getting a value that was a bit high, but not wildly out of line with the specs. This time out, we’re going to look at the resistance of a current meter, because some students asked about it […]
What Is the Resistance of a PASCO 750 Interface Box?
For the latest in our ongoing series of post where I overthink simple questions, I’d like to present the longest single continuous experiment in Uncertain Principles history, which took six and a half hours yesterday. All to answer the question in the post title. This may seem like a waste, given that I could download […]
Computers and Shades
In comments to the post on computer display colors, Will Slaton notes that Mac displays emit polarized light. And, indeed, this is an inherent part of the backlit LCD technology– the individual pixels are bits of liquid crystal between two polarizers, and an applied voltage causes the liquid crystal molecules to flip between a state […]
On Computer Color
This year’s “Flame Challenge” is to explain color in terms an 11-year-old can follow. I have opinions on this subject, a background in AMO physics, and access to scientific equipment, so I’m putting something together. In the course of this, though, it occurred to me to wonder how my different portable computing devices process color. […]
Old Thesis Club: A Specific Effect of X-Rays on Bacteria, by Thomas J. Dietz, 1934
Back in the fall, I did a bunch of write-ups of old Master’s theses that we found when clearing some space in a storage room. I got away from this because I was busy working on the book, but I have a few more that I pulled out to look at, and since all the […]
Small College, Exotic Particles
Topping the looooong list of things I would give a full ResearchBlogging write-up if I had time is this new paper on a ultra-cold atom realization of “Dirac Monopoles”. This is really cool stuff, but there are a lot of intricacies that I don’t fully understand, so writing it up isn’t a simple matter. The […]
Sticky Tape: The Final Chapter
I realize people are getting sick of reading me talk about this charged-tape business, which has run to one, two, three, four posts at this point. Truth be told, I’m losing enthusiasm for it myself. So this will be the final post, at least for now… As I mentioned on Twitter, as I type this […]
Simulated Tape and Universal Behavior
Having spent a lot of time solving equations related to sticky tape models, including trying to work solutions in my head while driving to Grandma and Grandpa’s with the kids, and making some measurements of real tapes, there was only one thing left to do: try simulating this problem in VPython. Because I’m a physics […]
Atomic Physics with Sticky Tape
In addition to making a toy model to show the tipping-point behavior of charged pieces of sticky tape, I spent some time on Tuesday trying to do something quantitative with this. Of course, Tuesday is the one day of the week that I don’t teach, and I didn’t want to go to campus to do […]