As many of you know, I’m homeschooling my son is 8th grade science this year and so far we’ve been having lots of fun discussing science topics and this week we’re beginning to do some projects.
Lately there has been a split among the students about where they want the class to go. My son and his friend want to study cosmology while the other two want more projects and self-directed learning about whatever happens to be in their head that day.
Since I have to teach my son and his friend everyday in order to get credit for the class, I have more time with them; the other boys only come on Tuesdays and Thursdays.
Given that schedule, I’ve decided to let the class become a sort of science free-for-all on Tuesdays and Thursdays where we talk about just about anything and let the projects fall out of those discussions organically.
The other three days of the week will be spent on cosmology, at least for the next month or so.
While I was preparing a syllabus to roughly outline what topics I was going to cover, I happened to be reading Cosmic Variance, one of my favorite blogs, and I find out that Sean Carroll, one of the bloggers on Cosmic Variance and someone who has an excellent ability to teach and speak clearly in public, recently completed a DVD cosmology course, published by The Teaching Company, called “Dark Matter, Dark Energy: The Dark Side of the Universe“.
Having read his blog for a long time and seeing many of his presentations, I immediately ordered the course. It was on sale for $69.95 (regularly priced at $245.95) which made it even sweeter.
The course is composed of 24, 30 minute lectures with a very complete list of topics. I also ordered the DVD transcripts so I could refer to the material during class without having to go back and forth on the DVD.
From Sean’s post:
Even though the lectures are nominally about dark matter and dark energy, I used them as an excuse to cover lots of fun stuff about general relativity, particle physics within and beyond the Standard Model, and the early universe.
We started watching the lectures this week and I was not disappointed. It is so rare to find someone like Sean, a person able to communicate difficult science concepts effectively, and there’s nothing more counterintuitive and difficult as dark energy and an expanding universe.
The way I’m using the course is as a springboard for more detailed discussions. When Sean presents a particular concept, like redshifts or cepheid variables as standard candles for measuring distances, I pause the DVD and start asking the boys questions.
They had a hard time with the idea of redshifts and spectral lines, so we went online and I showed them examples of what a redshifted spectra look like, and in particular, looked at the data Edwin Hubble used to make his discovery that the farther a galaxy is, the faster it is moving away from us.
The DVD’s provide lots of little surprises (and jokes) too. For example, I laughed out loud at this:
This plot you’re looking at right now is Hubble’s original plot of the data. He plotted distance on the x-axis and the velocity on the y-axis and it kind of looks like a noisy plot. It kind of looks like there is a scattering of points there, but Hubble was a genius. He drew a straight line through it and he turned out to be correct.
I have seen more than my share of scatter plots with lines drawn through them. I thought that was a hilarious comment.
We also talked a length about the fact that the ideas of relativity and Hubble’s measurements are only 100 years old. Sean mentions that just 100 years ago, we thought the entire universe was the Milky Way, that there was nothing outside of our galaxy. Hubble’s measurements of cepheid variables in the Andromeda galaxy show that wasn’t true.
The kids really thought that was amazing, that just 100 years ago we had such a naive view of the cosmos. I love seeing those lights go on in their heads, and I’m continually surprised by what sparks them.
I noticed that later lectures will cover the types of galaxies that are observed and I thought that’s when I’ll introduce the boys to GalaxyZoo and we’ll start cataloguing galaxies for a few weeks.
I highly recommend this course if you are the least bit interested in cosmology, dark matter and the large scale structure of the universe. It’s absolutely brilliant, and the sale will be going on until October 11th.