Everyday
drorzel | February 2, 2012As I keep saying in various posts, I'm teaching a class on timekeeping this term, which has included discussion of really primitive timekeeping devices like sundials, as well as a discussion of the importance of timekeeping for navigation. To give students an idea of how this works, I arranged an experimental demonstration, coordinated with Rhett at Dot Physics. We've been trying to do this literally for months, but the weather wouldn't cooperate. Until this past weekend, when we finally managed to make measurements that allow us to do some cutting-edge science. For 200 BC, anyway...
So, what…
drorzel | January 20, 2012While clearing the cars of frost Thursday morning, I was reminded of a difference of opinion Kate and I have about the best approach to a cold car. I tend to start the car up, and immediately turn the defrost on full blast; she prefers to let the car warm up for a while first, because it just blows cold air for a while. My feeling is that while the air from the defrost is not warm in an absolute sense, it's still passed over the engine on the way in, and thus is warmer than the outside air. Which means that it's going to increase the temperature inside the car somewhat, and thus will heat the…
drorzel | January 2, 2012My class this term is a "Scholars Research Seminar" with the title "A Brief History of Timekeeping," looking at the science and technology of timekeeping from prehistory through modern atomic clocks. This is nominally an introduction to "research methods," though the class operates under a lot of constraints that fully justify the scare quotes, at least for scientists. As I am a scientist, though, I want the class to include at least one original measurement and the reporting thereof, so I've been thinking of really simple measurements that I can have them do independently and write up. I've…
drorzel | December 13, 2011And what happened then?
Well, in Who-ville they say
That the Grinch's small heart
Grew three sizes that day.
And then the true meaning
Of Christmas came through
And the Grinch found the strength
Of ten Grinches, plus two
-- Dr. Seuss's How the Grinch Stole Christmas
It's nearly Christmas, so SteelyKid keeps demanding to watch the two classic Christmas specials we have recorded, Dr. Seuss's How the Grinch Stole Christmas and Rudolph the Red-Nosed Reindeer. Watching these over and over again, my thoughts naturally turn to physics, and what sort of physics you could do with these shows.
The…
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 | August 19, 2011As a follow up to Wednesday's sad balloon post, the repair that lofted it back to the ceiling was a temporary reprieve, unsurprisingly. After 24 hours, more or less, it had sunk back down to the point where the ribbon was just barely touching the floor.
On the one hand, it looks kind of pathetic again. On the other hand, though, this is a chance to do some more physics. See, I know how much ribbon I clipped off the end to get it to lift off again, and if it's fallen back to where it's just touching the floor, that means that the buoyant force due to the displaced air has decreased by an…
drorzel | August 17, 2011My birthday was two months ago, and SteelyKid's was the weekend before last, so we've had balloons running around the house for a good while now. Meaning that when I came into the library yesterday, I saw the sad little image on the right: a half-deflated Mylar balloon floating at about chest height.
Now, the first thought of a normal person on seeing this would be "Why didn't we throw this away a while ago?" My thought, since I've been on a bit of an everyday physics kick for a little while now, was "Hey, physics!"
"What do you mean?," you ask. "What physics is there in the sad balloon? It…