Relativity

Category archives for Relativity

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…

There have been a lot of pixels spilled over this faster-than-light neutrino business, so it might not seem like something I should take time away from pressing work to write up. It is the story of the moment, though, and too much of the commentary I’ve seen has been of the form “I am a…

Neutrino Hypotheses Non Fingo

The final sentence of the neutrino paper that everybody is buzzing about: We deliberately do not attempt any theoretical or phenomenological interpretation of the results. From a somewhat older work in physics: Rationem vero harum gravitatis proprietatum ex phænomenis nondum potui deducere, et hypotheses non fingo. Quicquid enim ex phænomenis non deducitur, hypothesis vocanda est;…

I’m looking at an email from my editor when Emmy wanders by the computer, sniffing around just in case a crumb of food has fallen on the floor in the last five minutes. “Hey,” I say, “Come here and look at this.” “Look at what?” “This:” “It’s the cover for my new book.” “A-hem.” “OK,…

A scientific theory hasn’t really arrived until the cynical and unscrupulous find a way to use it to extract money from the credulous and gullible. This has posed a significant obstacle for general relativity, dealing as it does with gravity, which requires really gigantic masses to produce measurable effects. That makes it a little difficult…

Right around the time I sent in the manuscript for my own book explaining relativity to Emmy, I got an email offering me a review copy of The Manga Guide to Relativity, part of a series of English translations of Japanese comic books explaining complicated concepts in a friendly way. That was clearly too good…