Physical Science

I’m teaching my “Brief History of Timekeeping” class again this term, and as always, I’m tweaking things a bit. This is one of our “Sophomore Research Seminar” courses, intended to introduce students to academic research, so it’s not specifically a physics class, but I’m choosing to take the statements about research outside the student’s field…

The Sun Is Red Because The Sky Is Blue

SteelyKid missed the bus this morning– she was dressed and ready, but I was talking to Kate, and if there isn’t a person at the end of the driveway when the bus comes around the corner, they won’t stop. So I drove her over to school myself (which is faster, anyway). The GE research lab…

“And you may find yourself in another part of the world. And you may find yourself behind the wheel of a large automobile. And you may find yourself in a beautiful house, with a beautiful wife. And you may ask yourself, ‘Well, how did I get here?’” -Talking Heads Well, imagine it’s happened: an apocalypse,…

Thanks, Common Core

“Daddy, ask me a math problem.” “OK. What’s 18 plus 6?” “Ummm… 24.” “Correct.” “See, I just keep the 18 and then add 2 from the 6 to get 20. That leaves 4 from the six, and 20 plus 4 is 24.” “Right. Good work.” —— “Hey, SteelyKid. What’s 120 plus 180?” “Ummm… 300.” “Very…

Dark matter in galaxies: proven! (Synopsis)

“The discrepancy between what was expected and what has been observed has grown over the years, and we’re straining harder and harder to fill the gap.” -Jeremiah Ostriker If you look at the stars in a galaxy — and then at all the different wavelengths of light that there are — you’d think you can…

When we talk about dimensions, we’re used to thinking of three: something like length, width and depth, or x, y and z. But there’s a fourth dimension as well that’s of paramount importance for our Universe, otherwise everything would simply be static: time. Our motion through time as well as space is what allows things to…

Some Follow-Up on Teaching

Yesterday’s Open Letter to Neil deGrasse Tyson struck a chord with a lot of people, and has spread a good distance on social media, which is gratifying. Given the delocalized nature of modern social media, though, it means I’m having essentially the same argument in five different places via different platforms. In the interest of…

Have you ever thought about what “nothing” truly is? We used to think about it in terms of simply removing all the particles from a given region of space, which is a pretty intuitive definition of nothing. But quantum physics is notorious for defying our intuition. When we take a look at this “empty” space,…

(When I launched the Advent Calendar of Science Stories series back in December, I had a few things in mind, but wasn’t sure I’d get through 24 days. In the end, I had more than enough material, and in fact didn’t end up using a few of my original ideas. So I’ll do a few…

Ice Breaker Card Tricks

Today was the first day of classes for the spring semester. I have a light teaching load this term, which is my reward for having an especially heavy teaching load last term. Just two classes, and they both meet in the afternoon, no less. For a night-owl like me that’s a good deal. One of…