Relativity

Category archives for Relativity

A quick reminder: How to Teach Relativity to Your Dog (cover in the left sidebar) will be released at the end of the month. If you’d like to win a signed copy early, though, you can enter our Photoshop contest. Just edit a picture of Emmy into another picture having something to do with physics.…

It’s now officially February, and the release date for How to Teach Relativity to Your Dog is only a few weeks off– the official release date is Feb. 28. Of course, I’ve got a copy already: If you would like a copy of your very own, you can either wait until the release, or take…

End of Year Self-Promotion

I will eventually do a “Year in Blog” post with a bunch of links to top posts and so on, but not until the year is actually over. At the moment, I’m too busy prepping next term’s class to do all the link chasing. That doesn’t mean I can’t engage in a little self-promotion, though.…

A week and a half ago, when the advent calendar reached Newton’s Law of Universal Gravitation, I said that it was the first equation we had seen that wasn’t completely correct. Having done our quick swing through quantum physics, the time has come to correct that equation: If you say “Einstein equation” to a random…

Moving along in our countdown to Newton’s birthday, we start to deal with equations that Sir Isaac never would’ve seen, because they deal with more abstract quantities than he worked with. The first and in some ways most important of these is energy: This is the full and correct expression for the energy of a…

We kicked off the countdown to Newton’s birthday with his second law of motion, which is almost but not quite everything you need to understand and predict the motion of objects. The missing piece is today’s equation: This is the full and correct definition of momentum, good for any speed all the way up to…

Fast Neutrinos: Still Fast

One of the more reasonable criticisms of the OPERA result showing neutrinos apparently moving faster than light was that they were claiming 20-nanosecond resolution on the timing of a neutrino pulse that was 10000 nanoseconds long. They got their timing by doing fits to the shape of the whole pulse, as described in that link,…

I’ve been incredibly busy this term, but not so busy I couldn’t create more work for myself. Specifically, by writing an opinion piece for Physics World about the FTL neutrino business, that just went live on their web site: The result quickly turned into one of the most covered physics stories of the year, with…

In a lot of ways, the OPERA fast-neutrino business has been less a story about science than a story about the perils of the new media landscape. We went through another stage of this a day or two ago, with all sorts of people Twittering, resharing, and repeating in other ways a story that the…

If you want to know how stressed and busy I’ve been lately, you don’t have to look any farther than the fact that I’ve totally fallen down on the shameless self-promotion front: I was on a radio show, and forgot to post about it here. I know, bad blogger, no pageviews… Anyway, I talked about…