The other day, I made a suggestion to one of my research students of an experiment to try. When I checked back a day later, she told me it hadn’t worked, and I immediately realized that what I had told her to do was very stupid. As penance, then, I’ll explain the underlying physics, which… Continue reading Reflecting, Totally; or Why the Pool Looks Shiny from Underwater
Category: My Lab
DonorsChoose Payoff: Where Do Ideas Come From?
As promised, an answer to a question from a donor to this year’s DonorsChoose Blogger Challenge. Sarah asks: Chad, can I get a post about how you (or scientists in general) come up with ideas for experiments? You’ve covered some of the gory detail with the lab info posts, but I think it would be… Continue reading DonorsChoose Payoff: Where Do Ideas Come From?
Teaching, Research, and Teaching Research
Melissa at Confused at a Higher Level has a nice post on the tension between faculty research and teaching: Malachowski writes, “We all know that working with undergraduates is time consuming and in some cases it slows down our research output, but work with undergraduates should be supported, celebrated, and compensated at a high level.… Continue reading Teaching, Research, and Teaching Research
The ABC’s of AMO Physics
Over at Confused at a Higher Level, Melissa offers an alphabetical list of essential supplies for a condensed matter experimentalist at a small college. This is a fun idea for back-to-school time, so I’ll steal it, and offer the following alphabetical list of essentials for Atomic, Molecular, and Optical physics at a small college, kind… Continue reading The ABC’s of AMO Physics
Technical Request: Gas Cell Filling
I doubt that this will actually work, but then the Web has brought me some improbable successes before, so it’s worth a shot: I have a sealed glass cell (Pyrex, I think, if it matters) that I would like to get re-filled with a mix of rare gases– partial pressures of 100mT Ne, 30mT Ar,… Continue reading Technical Request: Gas Cell Filling
What Do You Need to Make Cold Atoms? Part 3: Test and Measurement
The third category in our look at lab apparatus, after vacuum hardware and lasers and optics is the huge collection of electronic gear that we use to control the experiments. I’ll borrow the sales term “test and measurement” as a catch-all description, though this is really broader than what you’ll usually find in that category.… Continue reading What Do You Need to Make Cold Atoms? Part 3: Test and Measurement
What Do You Need to Make Cold Atoms? Part 2: Lasers and Optics
Following on yesterday’s discussion of the vacuum hardware needed for cooling atoms, let’s talk about the other main component of the apparatus: the optical system. The primary technique used for making cold atoms is laser cooling, and I’m sure it will come as no surprise that this requires lasers, and where there are lasers, there… Continue reading What Do You Need to Make Cold Atoms? Part 2: Lasers and Optics
What Do You Need to Make Cold Atoms? Part 1: Vacuum Hardware
Over in the reader request thread, Richard asks for experimental details: I’d be interested in (probably a series) of posts on how people practically actually do cold atoms experiments because I don’t really know. I needed to take some new publicity photos of the lab anyway, so this is a good excuse to bust out… Continue reading What Do You Need to Make Cold Atoms? Part 1: Vacuum Hardware
A Tale of Two Turbos
I spent most of Saturday in the lab, swapping out a turbopump that was starting to die. How could I tell? Well, for one thing, it made an awful noise, even more than usual for a noisy pump. But after it was stopped and unmounted from the chamber, there was a simple test: comparing the… Continue reading A Tale of Two Turbos
A Stainless Steel Baby Bottle
Let’s say you have some liquid that you want to contain without leaks, say, milk for a baby. What do you do? Well, you put it in something like a baby bottle, the components of which are shown here: You have a hard plastic bottle, a soft silicone nipple, and a hard plastic ring that… Continue reading A Stainless Steel Baby Bottle