Some notes from the Oct. 4 MIAAPT meeting

Always a good meeting with these fine folks. Some notes about what happened, mainly for my safe-keeping but public in case they might help someone else. No claim is made to accuracy, they are notes!

Morning Presentations

  • Ron Schlaack of Delta College talked about a new program for middle school teachers they have where the teachers spend 54 hours shadowing an actual manufacturing job site, then attend a college class where they develop a related lesson plan for some sort of STEM education project. The motivation for the project was the realization that the picture people have in their head for “manufacturing” is actually quite old-fashioned – modern manufacturing workers are expected to be more flexible and better educated.  I believe it was also Ron that mentioned a project where students build their own speakers for under $5, then test them with a function generator. Might have to look into that online.
  • Michael LoPresto gave a talk I have mixed feelings about, involving assigning different numbers to different colors so that color subtraction and addition can be done mathematically. An article may appear in The Physics Teacher shortly. I liked his transmission graphs for colored filters.
  • Alanna Pawlak from MSU gave a talk on the “epistemic games” students play – basically, how they think about problems.
  • Michael Faleski of Delta gave a talk on the ballistic pendulum, where he pointed out that linear momentum is generally not-conserved during the collision because of forces on the pivot (but it would be for a string). Imagine a rod in space!
  • Christopher Nakamura of Saginaw Valley State talked about a math camp they run there. Two projects they do – the “energy can”, basically a rubber band and weight inside a can, more info online I’m sure, and a “chain fountain” that he said we should find on Youtube.
  • Laurence Tarini of LCC gave a talk about making the signs make sense in geometric optics.

AstroNite Workshop

I went to the AstroNite workshop, an event UofM Flint puts on once per semester involving a planetarium show, some outside telescopes, and a lot of additional activities. The additional activities include:

  • a “Mars Lander” themed egg drop;
  • pipette rockets that might make a cool SMEE event at LCC. Pipette connects to straw, and another little straw forms the rocket. Kids like to decorate them and such;
  • traditional discharge tubes spectroscopy;
  • Fun with an IR camera! Rajib pointed out that you can see shadows in IR, which he uses to do some “ghost debunking”.
  • Make your own comet using dry ice and a smattering of other ingredients. I actually am going to try this at SMEE.

They also bring in animals for AstroNite and talk about how light pollution affects them. They also do a supernova demo involving a collapsing hobermans sphere – you can see the bounce when the “core” collapses, throwing off the rest of the star. You can bounce a tiny ball on a big ball to demonstrate this momentum conservation effect. They also did the well-known can implosion demo.

Keynote Talk

The keynote speaker was Jeff McMahon of UofM, and he talked about the cosmic microwave background radiation. Some cool stuff from his talk:

  1. I liked his characterization of astrophysics as simply particle physics using bigger machines than we can construct on Earth.
  2. He said that when Hubble (the scientist) was making his measurements, many people thought our galaxy was the universe, there were no other galaxies. (“Spiral nebula” – other galaxies – were thought by many to be part of our galaxy.)  I had no idea.
  3. He had a nice “expanding graph paper” model to show how, in an expanding universe, every galaxy can see every other galaxy running away from it, without any galaxy being at the “center” of the expansion.
  4. On a related note, he criticized models of the Big Bang that portray it as a large explosion happening “over there”. The whole universe was on fire.
  5. I also liked his explanation of dark energy. Suppose you throw a baseball as fast as you can into the air. Even if you throw it with greater than escape velocity, it’s still going to slow down as it rises. If you instead observed it speeding up as it got higher, you would either conclude that you don’t understand gravity (maybe it turns repulsive at great distances, say), or that there is some other force involved here. But what we observe in the universe is an accelerating expansion – dark energy is the unknown Physics stuck in to allow that expansion.
  6. I also liked his quick justification for why there is so much dark matter in the universe – look at a galaxy and what you find is that there isn’t enough visible matter in that galaxy to keep the outer stars gravitationally confined to it. So there must be added mass we can’t see. That is all.
  7. Ah, but the exact nature of all that dark matter isn’t known. One crazy/spooky idea he threw out is that dark matter is even filling the room you’re in right now, but only interacts with normal matter gravitationally. Otherwise it could have its own parallel-universe thing going on. (Just like neutrinos are all around us but unnoticed.)
  8. The cosmic microwave background, when first measured, was thought to be exactly uniform – because it is quite nearly uniform. Inflation, then, is the unknown Physics invented to help explain this uniformity (and the large-scale mottling we do observe). If you have a mottled quilt, for example, but zoom in on any one spot of that quilt, it will look uniform. Inflation just blew those uniformities up.
  9. He had a nice graphic showing how polarization allows you to look at light coming from two different directions. Remind me to steal it when we talk about Rayleigh scattering.

Make and Take Worshop

I made some stuff with James Gell and Steve Dickie. They had an electrophorus, which we already make in PHYS200/252 at LCC, but they also added a special light so you could tell which was charge was moving when you get shocked. We also made this cute little pull tube to help students think about modeling – you’ll have to email me if you want more info about that. I also brought back a little 3-color LED bulb connected to a watch battery – though it only produces 3 colors (red, green, blue), by color mixing you get additional colors, so a great LCC PHYS120 demo. He also did a very simple demo where he had washers tied at equal spacings on a string, then dropped them into a pie pan – of course the frequency with which they hit the pan increased as they fell. He then tied them at increasing distances (5, 15, 25 apart), and then they hit the ground at equal time intervals. Fun little demo.



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