drorzel | January 6, 2010Today's lecture in intro mechanics is a whirlwind survey of vectors. While I struggle to clear my head enough to be able to teach this stuff, here's a Dorky Poll to pass the time:
What's your favorite three-dimensional coordinate system?(survey)
This is a strictly classical subject, so please choose only one.
drorzel | January 6, 2010Not a whole lot new, but it's been a few days. Also, it's a challenge to remain ambulatory at the moment, thanks to this cursed cold, so I'm not really prepared to turn out Significant Blogging.
-- This morning's vanity search (why yes, I am searching for "How to Teach Physics to Your Dog" on a daily basis. Aren't you?) turned up this Current Geek podcast, which talks about the book. They haven't read it yet, but picked up the BoingBoing mention, and are enthusiastic about the idea. They pretty well nail the thinking behind the book.
-- The vanity search also turned up this discussion of my…
drorzel | January 6, 2010
Owl City and the Slow Earth : Built on Facts
"Does planet Earth turns slowly? It depends on how you look at it. At the equator it's roaring along at more than 1000 miles per hour. This is pretty fast by terrestrial standards, and perhaps what Owl City had in mind. But on the other hand its angular velocity is just one rotation per day, or a very sedate 0.000694 RPM. Kids sometime imagine the earth as a spinning basketball and wonder why we don't fly off, and that's pretty much why: spin a basketball at 0.000694 RPM and I bet any ants on its surface will keep their grip just fine."
(tags:…
drorzel | January 5, 2010"Slow light" is in the news again. The popular descriptions of the process usually leave a lot to be desired, so let's see if we can't do a slightly better job of explaining what's going on. The key idea is using one light beam to control the transmission of another.
Let's say you have a bunch of atoms in a gas and a laser. The laser happens to be at exactly the right frequency to be absorbed by the atoms, meaning that if you try to shine the laser through the gas, it'll be absorbed, and won't make it out the other side. This is traditionally represented by a diagram like to one to the right…
drorzel | January 5, 2010Over at Cosmic Variance, Sean's been taking a beating over his negative comments on an atheist anti-Christmas sign. There's no small irony in this, given that Sean is a vocal atheist. His sentiments, which basically boil down to "it's good to promote atheism, but there's no need to be a dick about it" strike me as perfectly unobjectionable, but as he's learning first-hand, that's not enough for a lot of people on the Internet.
The difference between an unjustly accused "accommodationist" like Sean and a real one like myself is here:
The problem with accommodationism isn't that its adherents…
drorzel | January 5, 2010
America: Too Stupid To Cook | Ruhlman.com
"That one sentence crystallized the issue for me, turned my frustration from a wall into a lens. Americans are being taught that we're too stupid to cook. That cooking is so hard we need to let other people do it for us. The messages are everywhere. Boxed cake mix. Why is it there? Because a real cake is too hard! You can't bake a cake! Takes too long, you can't do it, you're gonna fail!
Look at all those rotisserie chickens stacked in the warming bin at the grocery store. Why? Because roasting a chicken is too hard, takes FOREVER. An…
drorzel | January 4, 2010I spent most of Saturday in the lab, swapping out a turbopump that was starting to die. How could I tell? Well, for one thing, it made an awful noise, even more than usual for a noisy pump. But after it was stopped and unmounted from the chamber, there was a simple test: comparing the rotation to a second pump that I knew was in better shape:
The pump on the left (with the copper gasket stuck to it) is the old one; the pump on the right is the one that I replaced it with. As you can tell, even with a bearing starting to go, it's a pretty damn good rotor, but clearly worse than the…
drorzel | January 4, 2010Let's say you have some liquid that you want to contain without leaks, say, milk for a baby. What do you do?
Well, you put it in something like a baby bottle, the components of which are shown here:
You have a hard plastic bottle, a soft silicone nipple, and a hard plastic ring that screws onto the bottle. When you put it together and screw the cap down tight, it compresses the silicone between the two plastic bits, squeezing it into the small gaps, and plugging any leaks. Done properly, this will ensure that milk doesn't leak out of the bottle except through the whole in the nipple.
Now,…
drorzel | January 4, 2010Today is the first day of classes, and to celebrate, I've come down with the Martian death virus that Kate and SteelyKid have had the last few weeks. Joy.
This calls for a How to Teach Physics to Your Dog update, to distract myself from the cotton balls and vacuum pump oil that have apparently been stuffed into my sinuses:
The primary news is that Peter Woit has posted a review, in which he says mostly good things:
While Brian Greene in his Elegant Universe Nova special introduced general relativity by trying to discuss it with a dog, concluding that "No matter how hard you try, you can't…
drorzel | January 4, 2010
Remembering the giddy futurism of Omni magazine. - By Paul Collins - Slate Magazine
"The magazine was a lushly airbrushed, sans-serif, and silver-paged vision dreamed up by Penthouse publisher Bob Guccione and his wife, Kathy Keeton. It split the difference between the consumerist Popular Science--which always seemed to cover hypersonic travel and AMC carburetors in the same page--and the lofty Scientific American, whose rigor was alluring but still impenetrable to me. But with equal parts sci-fi, feature reporting, and meaty interviews with Freeman Dyson and Edward O. Wilson, Omni's…
drorzel | January 3, 2010OK, they're not that tiny. Here's your cute baby video for the weekend: Kate blowing bubbles for SteelyKid and Emmy:
I really don't need to say any more than that, do I?
drorzel | January 3, 2010Over at Faraday's Cage, Cherish has a very nice post on Fourier series, following on an earlier post on Fourier transforms in the Transformers movie. She gives a nice definition of the process in the earlier post:
A Fourier Transform takes a signal and looks at the waves and then shows us the frequencies of all the waves. If we only have a single sine wave, like above, we will have a frequency that is zero everywhere except for the frequency of that sine wave. More complicated signals will be made up of several of these different frequencies and thus will have several peaks. The idea is that…
drorzel | January 3, 2010It's a new year, so that means it's time to take a look back at the previous year. In graphical form, it looks like this:
Clears it all up, doesn't it? That's the past year in blog traffic, showing pageviews per day. Integrate it all up, and it comes to 717,254 pageviews. That's kind of mind-boggling, really. Even more mind-boggling is the fact that there have been 2,465,829 pageviews here since the move to ScienceBlogs in January 2006.
So, what drew eyeballs this year? There were a total of 14 posts that drew more than 2,000 pageviews according to Google Analytics. In order, they were:
29,…
drorzel | January 3, 2010
Ringing in Kepler's Year : Built on Facts
"Happy new year! While we're thinking about years, why don't we think about one of the first guys to explore the physical reason behind the year?"
(tags: science astronomy planets education math blogs built-on-facts)
The Universe within 12.5 Light Years - The Nearest stars
A handy reference for interstellar tourism.
(tags: astronomy space maps science planets)
BOOK VIEW CAFE BLOG » Ways to Trash Your Writing Career: The Wall of Books
"If you've been to a science fiction convention you have likely encountered The Wall of Books. You go into a…
drorzel | January 2, 2010In talking to a reporter about How to Teach Physics to Your Dog on Wednesday, I learned of a mistake in the text of the book-- a footnote on page 71 says that Scientific American published an article on how to make your own "quantum eraser" in April 2007, when in fact it was May 2007.
If that's the worst mistake in the published book, I'll be very happy. It is a mistake, though, and needs to be corrected. This also reminded me that I never did post the scholarly references that go with the book, so maximizing the birds killed per stone, I have added a References and Errata page to DogPhysics.…
drorzel | January 2, 2010Most of my fiction reading at the moment is done while rocking SteelyKid to sleep at night, using a Palm as an e-book reader. This does not really lend itself to the reading of weighty Literary Novels, but rather lightweight genre trash. Which means I've been reading a bunch of "urban fantasy," because that is the default mode of trashy genre fiction at the moment.
I'm kind of souring on the (sub)genre at the moment, though. I've read a bunch of Patricia Briggs's Mercy Thompson novels, whose "My Awesome Werewolf Boyfriend" interludes are really beginning to grate. I barely made it through the…
drorzel | January 2, 2010
Interstellar Cyclers -- KarlSchroeder.com
"To me, the idea that you should expend billions or trillions of dollars to accelerate a starship, only to decelerate it again, is pure lunacy. 90% of the ship's mass is support structures--either power or life support systems. The key to viable interstellar transport, in my view, is simple: if you've got it all in motion, keep it in motion and re-use it. The only thing you want to decelerate at your destination is your cargo."
(tags: space sf astronomy physics relativity energy books)
How to Teach Physics to Your Dog at Barnes & Noble -…
drorzel | January 1, 2010There isn't all that much news for a real obsessive update, so I'll lump in a few writing-related items of possible interest to people who read books other than mine.
A real obsessive update item: BradDeLong doubts my book can help his dog.
How to Teach Physics to Your Dog gets four out of five stars as part of a good books round-up in the Timmins Daily Press in Ontario. (Google News search is nifty).
A fortuitous discovery thanks to, of all things, an ad in GMail: QM for cat lovers, part of an old blog of imaginary conversations with Einstein. I doubt this will change anybody's mind about…
drorzel | January 1, 2010
Giro.org » Grace, Internets. Internets, Grace.
"Grace is snoozing away in Anne's arms while our lunch (rice and dumplings) and dinner (roast chicken with pesto) cook away. This will be the first non-hospital food we've had in two days, though I recall us sneaking in a patty melt and milkshake from Izzy's the night she was born. Really, this is all a blur of plastic bassinets, rotating nurses, and a tiny, tiny person with a mighty grip."
(tags: kid-stuff blogs)
Tell me what to agree with, and I'll agree § Unqualified Offerings
"Indeed, even if we restrict ourselves to hypothesizing that…
drorzel | December 31, 2009SteelyKid says "You know what? Forget Appa-- take a picture of me next to Mommy:"
"I'm half Mommy's height already!"
And, if you think about it, that's a pretty good accomplishment for 2009. Happy New Year, everybody.