Relativity

Category archives for Relativity

General Relativity With Toddler Toys

A couple of times last week, I mentioned on Twitter that I was going to demonstrate relativity with toddler toys and string. This was an inspiration that hit late on Thursday, when I was trying to think of a better way to explain embedding diagrams (the technical term for those stretched-rubber-sheet pictures that everybody uses…

Quick Interstellar Thoughts

I’m teaching a Gen Ed course on relativity this term, which means I’m spending the last few weeks of the term discussing black holes. Which, in turn, means there was no way I couldn’t use that story about Kip Thorne calculating the appearance of a black hole for the movie. Especially since I have the…

Relativity and Baseball

It’s baseball playoff time, so sport shows are full of one of the great mysteries of the season, exemplified by this .gif (from SBNation): No, not “Raul Ibanez, really?” but “How can he make the ball go that far?” After all, even very good outfielders are lucky to reach home plate with a throw from…

Trains of Clocks

My Gen Ed relativity course has mostly been me lecturing about stuff to this point, so on Wednesday I decided to shake things up a bit and convert a chapter of David Mermin’s It’s About Time. The idea was to get students up and moving around a bit, and actually making some measurements of stuff.…

New Year, New Class: Gen Ed Relativity

The new academic year starts this week– first day of classes is Wednesday– and I’m dealing with the usual chaos associated with the influx of a new class of students. Who now look to me only a tiny bit older than SteelyKid and the Pip in the above picture (and if you think that sharing…

This coming fall term, I’ll be teaching Astronomy 052, “Relativity, Black Holes, and Quasars,” because the guy who has traditionally taught it (a radio astronomer who studies active galactic nuclei) has to do other courses instead. But I said “Well, hell, I’ve written a popular audience book explaining relativity. I can teach that.” And since…

Last week’s talks were using sci-fi space travel as a hook to talk about relativity, and my original idea for the talk was to explain how faster-than-light travel ultimately ends up violating causality. Some observers will see effects happening before the events that cause them, and that’s just weird. In How to Teach Relativity to…

Space Travel, Einstein, and GPS

Below you’ll find the slides from my Physics Day presentations at Space Center Houston, embedded via SlideShare. I was doing the TED-style minimal text thing, so they’re probably not all that comprehensible on their own. The event was supposed to have a pop-culture connection, so I decided to use space travel and extrasolar planets as…

SteelyKid Demonstrates Relativity

Before going to the playground Saturday to investigate non-intertial frames, SteelyKid and I went over to campus to do some experiments in relativity. Galileian relativity, that is: What you see here is SteelyKid sitting on a rolling lab cart with a camera bolted to it. She throws a ball up in the air a couple…

Cosmos F*$&ing Loves Science

The fourth episode of the Cosmos reboot aired last night, and as I said on Twitter it was a beautiful demonstration of why I’m finding this show intensely frustrating. There were flashes of brilliance, but also quite a few bits that left me shaking my head. Thus fitting the pattern of the previous episodes– I…