## School prep

Saturday is housecleaning day at Chez DMM. After the weekly chores, I spent much of the day preparing for my school science visit on Monday, putting together slides for my talk on the solar system, and calculating what size balls I need to have ready to show the kids the comparative sizes of the sun and planets. I’m borrowing a 600 mm exercise ball from a friend. If the Earth is that size, I need a 160 mm diameter ball to represent the moon – I think the styrofoam ball I used for this 100 Proofs that the Earth is a Globe post will work nicely. It’s 150 mm, but close enough. And then to show the relativedistance between the Earth and moon I need to put the balls 18 m apart, which I think I can just about manage in the school library where I do my presentations.

And if the sun is represented by the exercise ball, then the Earth needs to be a 5 mm bead, and it needs to be 64 metres away! And Neptune needs to be 19 kilometres away! Hopefully this will impress on the kids just how big space is.

On a different topic, I noticed a disturbing thing today. I made a post to the Irregular Webcomic! Facebook page, and as I was doing it I noticed that Facebook was advertising some groups that it thought I “should join to increase your audience”. What sort of groups were these? Let’s take a look at them:

• FOR THE BOYS – a group whose icon is a bunch of bikini models
• Over 18 PEEP SHOW – icon is a silhouette of a woman
• Holden Haters – icon is a Ford logo
• Have a laugh Australia – icon is an “R over 18s” logo

So, Facebook, I’d like to know (a) why do you think people in these groups might be interested in my comics, and (b) why is there no feedback mechanism to let you know that these groups are not appropriate, or to hide them as suggestions?

## School science prep

Today I did further preparation for my school science visit on Monday. I’ve been trying to contact a nearby high school to borrow some of their lab equipment, but they kept not returning my calls. So this morning I decided to try Sydney University, where I studied for several years, and know some of the staff in the physics department. I called up and got onto the first year lab coordinator (who I hadn’t met before) and asked her if I could borrow some stuff. She put me onto the lab technician, but he wasn’t in yet, so I sent an email.

Then I was planning to go do some grocery shopping, but I didn’t want to be out driving the car when he phoned back, so instead i stayed home in that sort of anticipatory state that makes it hard to concentrate on anything. He emailed back at 11:00, saying to meet him in the physics labs at 11:45.

Now, I was at home, and the university is on the other side of the harbour… I mailed back saying I might be a few minutes late, and jumped in the car. Fortunately traffic wasn’t bad and I managed to find a parking spot right next to the university gate closest to the physics building, so I was actually on time. I borrowed a retort stand and clamps, and a brass mass carrier with a stack of brass weights. Pretty simple stuff, but it would have been tricky to improvise adequately for Monday.

And I spent some time trying (in vain mostly) to help solve puzzles for the MUMS Puzzle Hunt. I don’t know where the rest of the day went!

Oh! I queued up a bunch of new comic submissions for Lightning Made of Owls. We had a bit of a slump in submissions for a while, but now there are several comics in the queue. If you want to make a simple gag comic and have it published, send it in!

## Colour naming

I spent all day today doing science! If you weren’t aware, I do volunteer work with a primary school, going in to teach science stuff to kids from kindergarten to year 6. I talk to all of the kids at the school, but this year I’m also running a Science Club for 13 of the very keen science students, ranging from years 2 to 5.

A couple of months ago I ran a colour naming experiment with them, to explore the psychophysics of what colours we see and deciding what names they should have. I won’t go into gory detail here, because I described the experiment in detail in a previous post over on my science blog, 100 Proofs that the Earth is a Globe. Today I spent all day (about 10 hours of work as I type this) analysing the results and preparing slides to present to the students next time I see them (on Monday next week). Again, I’ve written a detailed post about it over on 100 Proofs. But here’s a sneak preview of the results:

Besides showing the kids the results and talking about them on Monday, we’re going to do another new experiment: measure the acceleration due to Earth’s gravity! I’ll write that up over on 100 Proofs too.