Relativity
drorzel | February 13, 2012So, the big How to Teach Physics to Your Dog Photoshop contest concluded on Friday. We got five really good entries, and the judges (me and Kate) had a hard time reaching a decision. After long deliberation, though, we've come up with a solution.
But first, the entries:
Jane Di Giuseppe has Emmy as the dog pulling Einstein's strings:
John Pearce has Emmy playing with Einstein as well:
And Joseph Roith tells Maxwell's Demon to respect Emmy's authoritah!:
But in the end, it came down to two pictures: Tristan Croll's take on the famous chalkboard photo:
It's a little-known fact that not…
drorzel | February 8, 2012Through a weird quirk of scheduling, I haven't actually taught the intro modern physics course since I started writing pop-science books about modern physics. So, this week has been the first chance I've really had to use material I generated for the books to introduce topics in class.
In the approximately chronological ordering of the course, we're now up to the late 1800's, and the next book we're talking about is Einstein's Clocks, Poincar$eacute;'s Maps, which talks about how Einstein and Henri Poincaré were (arguably) influenced by developments in timekeeping as they looked for the…
drorzel | February 7, 2012A 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. Like this:
(See the transcript here for the source of this comment.)
The deadline for entering is this Friday. We've already got some quality entries, but the more the merrier.
drorzel | February 2, 2012It'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 part in this shameless publicity stunt: The second-ever Dog Physics Photo Contest!
Last time around, we did a LOLEmmy contest for a bound galley proof of the first book. This time, I'm giving away a signed copy of the finished book, so we'll go for something a little trickier: I've picked three pictures from my…
drorzel | December 30, 2011I 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. After all, my second book, How to Teach Relativity to Your Dog will be out at the end of February. And the first pre-publication review is in, from Publishers Weekly:
Physics professor Orzel follows his How to Teach Physics to Your Dog with a compact and instructive walk through Einstein's theory of relativity,…
drorzel | December 23, 2011A 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 person on the street, odds are they'll immediatley think of "E=mc2." If you ask a physicist to think of the Einstein equation, though, this is the one they'll think of. This is the Einstein field equation from general relativity, and while it's not as well known as E=mc2, it's…
drorzel | December 5, 2011Moving 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 particle with mass m moving at speed v. The notion of energy traces back to Newton's contemporary and rival Gottfried Wilhelm Leibniz, but this particular equation involves the same square-root factor as Saturday's definition of momentum. That tells you for sure that this particular…
drorzel | December 3, 2011We 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 the speed of light. Newton's second law tells us how the momentum changes in response to a force, but in order to use that to predict the future, you need to know what momentum is, and that's where this equation comes in.
(Wouldn't it make more sense to do this first, and the second law…
drorzel | November 18, 2011One 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, and there's always a little bit of alchemy in that sort of process, but they had big long pulses because that's what the accelerator at CERN that served as the source of the neutrino beam provided.
After the original annoucnement, they got the neutrino beam reconfigured…
drorzel | November 10, 2011I'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 numerous articles in magazines, newspapers and on television asking whether "Einstein was wrong". Just as quickly came numerous physicists denouncing the media frenzy, with Lawrence Krauss from Arizona State University and Cambridge University cosmologist Martin Rees both calling the…
drorzel | October 16, 2011In 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 whole thing has been explained as a relativistic effect due to the motion of GPS satellites. So, relativity itself has overthrown an attack on relativity. Huzzah, Einstein! Right?
Well, maybe. I'm not quite ready to call the story closed, though, for several reasons. First and foremost is the fact that…
drorzel | October 5, 2011If 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 the fast neutrino experiment on the phone to Clay Naff, who runs the Science Odyssey show on KZUM in Nebraska, and he used it as part of this past weekend's show. My interview is in Part 1, and Part 2 is Alan Kostelecky, who is an actual expert on this sort of thing.
For some odd reason, it…
drorzel | September 24, 2011There 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 {theorist, journalist} so hearing about experimental details gives me the vapors" (a snarky paraphrase, obviously). This suggests that there's still room for a canine-level write-up going into a bit more depth about what they did and where it might be wrong.
So, what did those jokers at CERN pull this time?…
drorzel | September 23, 2011The 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; et hypotheses seu metaphysicae, seu physicae, seu qualitatum occultarum, seu mechanicae, in philosophia experimentali locum non habent. In hac philosophia Propositiones deducuntur ex phaenomenis, et redduntur…
drorzel | September 20, 2011I'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, fine, it's the cover for our new book. Anyway, what do you think?"
"Hey, that's not bad. I'm way better than that dog, though."
"Yeah, well, they didn't want to make the owners of inferior dogs jealous."
"Oooh. Good point. See, this is why I could never make it in marketing."
"It's Madison Avenue's loss, I'm…
drorzel | June 23, 2011A 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 to sell wacky general relativity-based schemes to people.
Until now, anyway-- recent advances in atomic clocks have made it possible to see relativistic effects on a human scale. There was a really nice talk on this experiment in the fundamental symmetry…
drorzel | June 13, 2011Right 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 a wind-down read to pass up.
Like other books in the series, this sets up a manga-type plot that just happens to require introducing relativity. In this case, on the last day of school at Taigai Academy, headmaster Rase Iyaga makes a surprise announcement: that he will throw a dart at…
drorzel | May 5, 2011NASA held a big press conference yesterday to announce that the Gravity Probe B experiment had confirmed a prediction of General Relativity that spacetime near Earth should be "twisted" by the Earth's rotation. A lot of the coverage has focused on the troubled history of the mission (as did the press conference, apparently), but scientifically it's very impressive.
The shift measured is very, very small-- 0.04 arcseconds over the course of a year, or 0.000011 degrees-- but agrees nicely with the predictions of relativity. I'm not sure whether to try to work this into the book-in-progress as I…
drorzel | April 15, 2011Regular blogging has been interrupted this week not only because I jetted off to southern MD but because this week was the due date for the manuscript of the book-in-progress. It's now been sent off to my editor, and thus begins my favorite part of the process, the waiting-to-see-what-other-people-think part.
I'm pretty happy with it, though it's a bit longer than it was originally supposed to be. This is no doubt partly due to the fact that I'm too close to the thing at the moment, and can't see the obvious places where I could cut material, but that's why professional editors get the big…
drorzel | March 1, 2011Blogging will continue to be minimal, as I'm buried in grading, and feeling significant time pressure regarding the book-in-progress. I thought I'd pop up briefly, though, to provide a look at the current status of the book-in-progress.
The way this process works (or at least has worked for me) is that I write up a proposal describing what I plan to write about and giving some samples. For both books, this has included one full chapter worth of prospective text, plus a bunch of dog dialogues for other chapters. My agent then shops this around to publishers, one of whom buys it and sets a…