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 4, 2011Continuing our countdown to Newton's birthday, let's acknowledge the contributions of one of his contemporaries and rivals with today's equation:
This is, of course, Hooke's Law for a spring, which he famously published in 1660:
ceiiinosssttuv
Clears everything right up, doesn't it? OK, maybe not. This one's not only in Latin, it's a cryptogram, unscrambling to "ut tensio sic vis," which translates roughly to "as the extension, so the force," giving the correct proportionality between the force exerted by a spring or other elastic material and the amount that material has been stretched.…
drorzel | December 4, 2011
The 45 Most Powerful Images Of 2011
The year in photojournalism.
How Beer Saved the World | Watch Free Documentary Online
Did you know that beer was critical to the birth of civilization? That's right - beer. Scientists and historians line up to tell the amazing, untold story of how beer helped create math, poetry, pyramids, modern medicine, labor laws, and America. If you think beer is just something cold and filling to drink during sporting matches or in the kind of bars that you probably shouldn't order wine in, then, boy, are you ever in the dark. It turns out beer is responsible for,…
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 | December 3, 2011
AMNH | Master of Arts in Teaching Program
Learn to teach Earth and Space science in New York City through the Master of Arts in Teaching Urban Residency Program at the American Museum of Natural History; the first urban teacher residency program offered by a museum. *Full-time 15 month program with benefits and stipend *Small class sizes and one-on-one mentoring *Science coursework at a world-class museum *Learn to teach in a supportive nurturing environment *Work alongside scientists and urban teachers *Graduate with real-world teaching experience *Ongoing professional support following…
drorzel | December 2, 2011Both Monday and Thursday were too hectic this week to get good family pictures. I got this one today, though, that I think is probably worth the wait:
The great thing about taking pictures of really little babies is that they sleep soundly enough for you to futz around changing lenses and apertures and all that sort of thing.
And so SteelyKid doesn't feel left out, here's a group shot from last week:
The Pip is a little unhappy in this, but it's the best of the shots on my camera. I think my parents might've gotten a better one on their camera.
Anyway, there's your weekly dose of cute.
drorzel | December 2, 2011We kicked off our countdown to Newton's birthday with his second law of motion, so the obvious next step is to go to his third law of motion:
This one was also originally in Latin, because that's how Ike liked to roll:
Lex III: Actioni contrariam semper et æqualem esse reactionem: sive corporum duorum actiones in se mutuo semper esse æquales et in partes contrarias dirigi.
In English, this comes out as:
Law III: To every action there is always opposed an equal reaction: or the mutual actions of two bodies upon each other are always equal, and directed to contrary parts.
That first…
drorzel | December 2, 2011
Tailgating Recipes: Puff Pastry Samosas - NYTimes.com
I'm dubious, because the texture of the outside would be way different than a real samosa. But it looks relatively simple, so maybe it'd be worth a try.
The Deepening Paradox -- KarlSchroeder.com
If the Fermi Paradox is a profound question, then this answer is equally profound. It amounts to saying that the universe provides us with a picture of the ultimate end-point of technological development. In the Great Silence, we see the future of technology, and it lies in achieving greater and greater efficiencies, until our machines approach…
drorzel | December 1, 2011It's that time of year again, when we count down the days to Isaac Newton's birthday (according to the Julian calendar, anyway), and how better to mark this than with mathematics? Thus, I'll post an equation a day until either Christmas Eve or I run out of ideas, and talk about what it means and why it's important for physics.
Since this is, after all, a celebration of Sir Isaac, let's kick things off with arguably his most famous equation:
OK, it might not look familiar in this form, but this is, in fact, the full and correct statement of Newton's Second Law (written in modern notation),…
drorzel | December 1, 2011
The 5 Best Toys of All Time | GeekDad | Wired.com
1. Stick What's brown and sticky? A Stick. This versatile toy is a real classic -- chances are your great-great-grandparents played with one, and your kids have probably discovered it for themselves as well. It's a required ingredient for Stickball, of course, but it's so much more. Stick works really well as a poker, digger and reach-extender. It can also be combined with many other toys (both from this list and otherwise) to perform even more functions.
We Are All 'Closing Time': Why Semisonic's 1998 Hit Still Resonates - Hollywood…
drorzel | November 30, 2011Yesterday's physics education post kicked off a bit of discussion in a place I can't link to about the usefulness of lectures. Something in that reminded me of an anecdote from my grad school days, that I think is useful, so I'll post it here.
When we were working on the spin-polarized collision experiment, we expected that a certain effect ought to be pretty big, but when we did the experiment, it didn't show up at all. We mentioned this in a talk or poster, and a theorist said "Oh, that's not that surprising."
We had been pretty surprised, so I was sent off to talk to Paul Julienne, one of…
drorzel | November 30, 2011
Science Experiments for Unimpressed Kids: Surface Tension | Live Granades
How to Demonstrate Surface Tension This easy and fun experiment will be sure to captivate absolutely no one. Equipment Glass of water Needle A piece of toilet paper One or more kids who will be unimpressed by your experiment
Coilhouse » Blog Archive » Mr. Mead's Menagerie
"Edward Gorey doing The Fantastic Mr. Fox" was the first description that entered my head when I saw these, but that's not quite right. Maybe if The Fantastic Mr. Fox had been the book written by HP Lovecraft instead of The Dream-Quest of Unknown…
drorzel | November 29, 2011
"They've traded more for cigarettes / than I've managed to express"; or, Dives, Lazarus, and Alice
"Let us consider a simple economy with three individuals. Alice is a restaurateur; she has fed herself, and has just prepared a delicious turkey dinner, at some cost in materials, fuel, and her time. Dives is a wealthy conceptual artist, who has eaten and is not hungry, but would like to buy the turkey dinner so he can "feed" it to the transparent machine he has built, and film it being "digested" and eventually excreted. To achieve this, he is willing and able to spend up to $5000. ... Huddled…
drorzel | November 29, 2011As I said last week, I recently wrapped up a term experimenting with "active learning" techniques in the two intro courses I was teaching. The diagnostic test results were a mixed bag-- one section showed really good improvement in their scores, the other was no better than the same class with traditional methods-- and the exam scores weren't really any different. There was probably some slight improvement in the multiple choice-- fewer students got trapped by the Newton's First Law questions than usual-- but in the free-response problems, they did about the same as usual.
So, having turned…
drorzel | November 28, 2011One of the many things I wish I had had time to blog about during the just-completed term was the big New York Times article on attrition in science majors. This generated enough commentary at the time that people are probably sick of it, but I haven't seen anything that exactly matches my take, so I'll belatedly throw this out there.
The big point of the article is that lots of students who enter college planning to major in Science, Technology, Engineering or Math (the "STEM" fields, in an awkward but now inescapable acronym) end up graduating with degrees in something else:
But, it turns…
drorzel | November 24, 2011This has been an exhausting and exasperating fall, but my classes are done, and my grades are in. And, more importantly, The Pip is out and about, SteelyKid is super excited to be a big sister, and everybody in Chateau Steelypips is healthy and happy. (Well, OK, Emmy's a little disgruntled that I didn't drop either the turkey or the sausage for the stuffing on the floor where she could get at it, but she'll get over it...).
We've got plenty to be thankful for around here, and we have a turkey in the oven and family on the way to help us celebrate. I hope this is a happy Thanksgiving for you…
drorzel | November 22, 2011A few months back, I did a post about estimating the time required for the different routes I take to work, looking at the question of whether it's better to take a shorter route with a small number of slow traffic lights, or a longer route with a bunch of stop signs. This was primarily conceived as a way to frame a kinematics problem, but I got a bunch of comments of the form "Aren't you an experimentalist? Where's the data?"
Well, here it is:
This is a histogram plot showing the number of times my morning commute fell into a given ten-second bin over the last couple of months. The blue…
drorzel | November 21, 2011SteelyKid's away at Grandma and Grandpa's for a few days, to give us a little more time to acclimate to The Pip, which means you get a very traditional baby blogging picture:
It's not the greatest angle for comparing his size to Appa, but you get the idea.
The Pip is settling in nicely. His rate of growth met with medical approval last week, and he won't need to be checked again until his one-month birthday, which is nice. He's settling into a fairly reasonable routine of eating, sleeping, and excreting, with occasional periods of cute-and-awake. And he's much calmer about the small…
drorzel | November 21, 2011As noted in previous posts, I've been trying something radically different with this term's classes, working to minimize the time I spend lecturing, and replace it with in-class discussion and "clicker questions." I'm typing this while proctoring the final exam for the second of the two classes I'm teaching, so it's not exactly the end, but nearly everything is in but for the student evaluations, so here are some semi-final thoughts on this experiment:
-- On the whole, I think it went reasonably well, though things definitely flagged toward the end, particularly in the regular mechanics class…
drorzel | November 20, 2011Including pretty much anybody wearing a helmet in this video from UC-Davis:
That's just disgraceful, all the way around (with the possible exception of the chubby hatless cop in the first part of the video, who appears to be behaving in a more reasonable manner than his armored colleagues). I feel a tiny bit bad for the fact that the pepper-spray-wielding officer now has his name and contact information splashed all over the Internet, and the resulting world of shit that will crash down upon him. After all, as Alexis Madrgial notes, he's the product of a terrible system. But then again,…