We talked about waves today down at the creek. The water was fairly calm so we could make some nice surface waves using floating leaves to show the up-down/side-to-side motion as the waves passed. I gave them 10 minutes to “play”, and more than one team tried to make a tsunami.
Since it’s allergy season, one student who could not go outside, read the chapter on the characteristics of waves and prepared a short–5 minutes–presentation for the rest of the class when we came back in.
As of this Saturday, we have two bee hives. With bees. Ms. Mertz and Mr. Deitrich received a pair of nukes (bees with a queen in a box) that were driven up, overnight, from Louisiana. They let them acclimatize for a few hours, with the nukes sitting on top of their respective hives, before putting them in. The nukes seem healthy; we were able to identify two queens and the bees were out foraging immediately. Ms. Mertz is happy.
It’s possible to be precise but not accurate. It’s also possible to be accurate but not precise. These ideas are summarized very nicely in this diagram.
A long winter is coming to an emphatic end with a series of dramatic spring storms. This hailstorm from April 3rd was one of the most remarkable I’ve experienced.
There was a bit of discussion about just how big the hailstones were. After all, could we say that the hail was the size of golf balls if only the largest were? Or would it be more honest to go with some sort of median or modal size.
Mrs. F. brought out the calipers and a rule for a few of the larger stones.
And I will report that the hail was large enough to put small dents in the roof of my car.
The infra-red satellite image below shows the frontal system that dumped the hail on St. Louis.
RadioLab has an excellent podcast featuring Jay Melosh, a geophysicist who specializes in impact craters, and who advocates the hypothesis that the entire extinction event that killed off the dinosaurs at the boundary between the Cretaceous and Tertiary (the K-T boundary) took place over a period of two hours. The asteroid impact vaporized the crust of the Earth where it hit (near the Yucatan peninsula) and blasted this rock gas into space. There it cooled down to create little glass particles that reentered the atmosphere. On reentry the glass burned up, but there was so much of it that it raised the temperature of the atmosphere by several hundred degrees Celsius. Anything near the surface (mostly the dinosaurs) was cooked, but anything living just beneath the surface could have survived.
The trailer for a documentary about what it’s like to live as a single parent, working on a single close-to-minimum wage paycheck, in the United States.