Laser day

Today was my visit to the primary school to talk to the older classes about the solar system, and to supervise my Science Club class while we did experiments with laser diffraction. We measured the diffraction patterns of red, blue, and green laser light through double slits, replicating Young’s seminal experiment which established that light had the properties of waves. We ran out of time to do all of the calculations, but very quickly I got a rough figure of 620 nanometres for the wavelength of the red laser (which actually has a wavelength of 632.8 nm, so we got pretty close). Over the next while I’ll refine the measurements and calculate the other wavelengths too.

It was rainy today in Sydney. At least on the coast. It was dry as I drove towards the school, which is near the coast, and as I came down the hill from the plateau to the coastal strip, it began raining, and was really heavy by the time I got to the school. Unfortunately, we need the rain inland, where the dams are for our water supply.

New content today:

Cathedral framed

Prep for Science Club

Today I did final preparations for Science Club at the school tomorrow. I checked all the lasers, got spare batteries, and copied the dimensions of the slits in the slides to a sheet of paper so I can read them easily during the experiment, rather than having to squint at tiny print. The blue laser is cool, but it’s difficult to see the diffraction patterns after passing through the slits – I suspect because our eyes aren’t nearly as sensitive to blue as they are to green and red. Hopefully it’ll work better in the dark library at the school.

This morning I did some grocery shopping. I do almost all the cooking at home and I like browsing around the vegetables looking for interesting things to cook with. Corn cobs were on special today, so I bought a couple. Not sure what I’ll make with them yet. Probably just boil them up and eat them on the cob, with something else on the side to fill out the meal. I also bought a chicken breast, but that’s for Scully. We don’t really cook meat at home, except on very rare occasions. (I don’t cook it very rare…)

My wife had her Rock School end-of-term concert this afternoon. Normally I attend in person, but today they were live streaming the concert and she was only singing lead on three songs, so I stayed home to get some other things done while watching the stream. I had to clean up a few messy piles of stuff that I’ve had eating up space on the dining table for a while.

For dinner tonight I made pasta with pumpkin, feta, walnuts, and chilli in burnt butter. It’s one of our favourite ways to have pasta – the nuts add a nice crunch which creates the range of textures with the soft pumpkin chunks, creamy feta, and al dente pasta. (Last night I made a frittata with potatoes, broccolini, caramelised leeks with balsamic vinegar and garlic, and of course eggs. It turned out pretty good, I thought. Taking a solid half hour to caramelise the leeks before doing anything else was worth it.)

The other thing I did today was process and upload a few more photos from my trip to Portugal back in May. Going through travel photos always takes a while, since I take a lot of photos! I started going through photos after our arrival in Porto. Porto is built on very hilly terrain:

Porto is on a hill

Here’s the Igreja de Santo Ildefonso, a spectacular church with azulejo tiles on the front edifice.

Igreja de Santo Ildefonso

New content today:

Cleaning and science

Saturday is housecleaning day, and I did more than normal today, with a thorough vacuuming and dusting, which ate up most of the morning. Then I wrote up the results of the pendulum/gravity experiment I did with my primary school Science Club class a couple of weeks ago, in preparation for my next visit on Monday. I made slides to show the kids, and I also wrote it up over on 100 Proofs that the Earth is a Globe.

In the afternoon, my wife and I took Scully out for some exercise. We found a new park to try out, about 10 minutes drive away. We like going to different places, so Scully can explore. She had a good time running around the grass, meeting another dog there, and chasing a brushturkey and some ducks – I think they were Australian wood ducks.

At the park we saw an amazing cubby house that someone had in their back yard for the kids. The yard backed directly onto the park, with no fence, so we had a good view of it.

Cubby house

New content today:

Lasers!

I have lasers! Today I went to Sydney University and borrowed some of thee lab equipment from the Physics labs, for use in my primary school visit on Monday. I assured the lab technician who organised the loan that I wasn’t going to be borrowing stuff frequently, but he was delighted that I was borrowing it, and said I could have equipment whenever I wanted it. He said it was good that I was doing science with school children, and he encouraged me to get them interested in science. So that was good!

He gave me three lasers, one red, one blue, and one green, as well as a selection of slides with single slits, double slits, triple slits, apertures of various shapes, and a transmission diffraction grating. I’ll have to swot up on my interference and diffraction theory over the weekend so I can run the experiment smoothly and get the kids at school to calculate the wavelengths of the three different lasers during the lesson. It should be fun!

I also caught up with my Ph.D. supervisor while visiting the Physics Department. He’s semi-retired now, but still appears to be working virtually full time, both teaching in the labs and doing research into fast radio bursts with the Molonglo Observatory Synthesis Telescope (the telescope I used to do my Physics Honours project back in the day). He’s the author “R. W. Hunstead” on this 2017 discovery paper.

New content today:

Winter blast

Today was cold and windy. It really felt like winter for once. I went out for lunch and the sky even had clouds in it! They were pretty thick and grey in fact, and I thought it might rain, but the promise of any precipitation turned out to be false.

Besides being a very warm winter, it’s also been extremely dry. We’ve had just 3 mm of rainfall so far this August, and Sydney’s average August rainfall is 80.3 mm. In July we had 43 mm of rain, mostly loaded into the first week, while the July average is 95.7 mm. So we’ve basically had 6 weeks with almost no rain at all. The news tonight reported that Sydney’s water supply dam level is now below 50% – the last time this happened was 15 years ago.

Besides the false promise of rain, the weather was pretty wild. I took Scully out to the dog park, and even though I rugged up in a jumper (sweater for the Americans) and a windproof jacket, it was still nastily cold with the wind blowing off the harbour. While there and chatting with some of the other dog owners, we heard a big crack, and we turned to see that a branch had fallen off the huge Moreton Bay fig tree that we were sitting/standing under (there are wooden benches there for sitting, which many of the owners do). Fortunately, it was on the far side of the tree, and didn’t land on any of us or our dogs. It landed on the street beside the park, narrowly missing someone’s parked car (lucky it didn’t land on that too).

A few of us dragged the branch off the street to clear it for traffic, and I took a photo. It’s not a huge branch, but would certainly have caused an injury if it had fallen on someone, or dented the roof or smashed the windscreen of a car. You can see it’s longer than a car, and it was fairly hefty.

Fallen branch

That’s Scully on the right, with the red doggy-jumper. Next to her is Monty, a chihuahua-Jack Russell cross. Up on the street is Scout, a west highland white terrier. As you can see, all the dogs are rugged up for the winter weather!

Also today I contacted Sydney University again to arrange to borrow some lasers and diffraction slits for my next visit to the school where I teach my Science Club class. We’re going to measure the wavelengths of different colours of light! I’ll go in tomorrow to pick them up.

New content today:

Ethics of stealing

It was time for my weekly Primary Ethics class again this morning. Today we started a new topic: stealing. The discussion centred around a series of questions designed to probe the question of what exactly is stealing, and even if it’s illegal is it always morally wrong?

We started easy with: “If you borrow a book from a friend and forget to return it, does that count as stealing?” Then follow-up questions: “What if you really love the book and decide not to return it?” and: “What if you know your friend doesn’t even like the book?” The kids were pretty agreed that forgetting to return the book isn’t stealing, but keeping it if the friend asks for it back is stealing and is morally wrong, even if you know they don’t like it.

Next: “If you pick fruit from a fruit tree in your neighbour’s front garden, does that count as stealing?” Kids said yes. Follow-up: “What if your neighbour isn’t picking the fruit and it’s just going to rot?” Now some kids (but not all of them) were of the opinion that picking the fruit while technically stealing, isn’t morally wrong if it’s just going to go to waste otherwise.

Next: “Suppose it’s a very cold day and to warm up you decide to wander around a shop even though you have no money to spend. Does using the shop’s heating in this way count as stealing?” Kids said no. Follow-up: “But the shop is paying for the heating, and you’re getting the benefit, even though you have no intention to buy anything. So is it stealing, is it morally wrong?” Kids were generally no, it’s okay, because the shop invites people in.

And now the most interesting one: “You walk past a bakery and stop to smell the delicious smell of the freshly baked bread. Is that stealing?” The kids laughed at this one – of course it’s not stealing! Ah, but then: “The baker bought the flour and other ingredients, and paid for the electricity to run the ovens, so does he own the smell of the bread?” Kids laughed again – no of course not! Then: “Suppose the baker seals his shop so the smell can’t get out, and then allows people to come inside to smell the freshly baked bread, if you pay $1. Is he allowed to do that?”

Kids, a little uncertain: Yes, he’s allowed to do that.

Me: So he does own the smell? If you went inside to smell it, but didn’t pay the $1, would that be stealing?

Kids: … Yeeeeeeeessss….

Me: What if you found a crack near a window, and stuck your nose right up against it to smell the bread. Would that be stealing? Would it be morally wrong?

By now the kids were realising this topic isn’t as easy as they thought, and they’re giving really thoughtful answers across a spectrum of responses. It was a good class! And after it was over and the kids left to go back to the regular classrooms, I walked out past the other classes, and overheard one kid telling a friend who hadn’t been in my class about the bread smell example. So I consider that a success! Getting the children talking about the topics outside the classroom is basically the measure of success for my classes.

New content today:

Stranger Things!

Here are some photos as promised yesterday of the Stranger Things Lego set that I finished building.

Stranger Things: Where's Will?

Stranger Things: The Upside Down

Stranger Things: Byers House

Stranger Things: Christmas lights

It’s incredibly cool. The whole set can be turned upside down, to display either the real word or the Upside Down more prominently. And there’s a light that projects onto the Christmas Lights. There’s a whole lot of other wonderful detail that you probably can’t see very well in the photos. This is the definitely biggest and possibly the coolest Lego set that I’ve ever owned.

Today I spent most of the day writing another one of the 100 Proofs that the Earth is a Globe, this time about walking around the world in a straight line. And a bit of time doing more prep for my Very Special Magic Draft. Oh, and I decided to remove the “latest posts” thing in the sidebar of this blog and replace it with a tag cloud, now that I have an interesting number of tags that I use for posts.

New content today:

Magpie attack!

Monday! I spent much of today finishing off the build of the Lego Stranger Things set. It’s a big set and took several hours of building over the past couple of days to finish. I’ve only just finished it late this evening. I was planning to take a photo to show it off, but honestly I’m mentally exhausted and want to head to bed soon, so I’ll do it tomorrow.

I took a break at lunch time to walk up the street to get some fish & chips. I took them to my usual fish & chips eating spot, on a hill overlooking the harbour. It’s lovely eating outdoors with a view. But today a couple of magpies decided that they also liked the looks of my lunch, and came threateningly close – within striking distance to steal a chip or a chunk of fish if I wasn’t careful. At one point one tried to land right on my meal, and I barely managed to fend it off without letting it touch any of the food. And within a minute or so another two magpies arrived, looming ominously from the tree branches not far above me like something out of Hitchcock’s The Birds.

I didn’t fancy the sharp beaks on the birds and the fact that they looked keen to strike, so I packed up my lunch and walked to a different location to eat in peace. It’s a shame. I’ve had birds hover around me at that spot before, but never so aggressively or dangerously close. I fear that spot may be lost for good, because magpies are highly territorial and maintain their behaviour over several years.

New content today:

Sunday walking

Today was mostly a day spent with wife and Scully. We took a couple of long walks to exercise Scully, around the neighbourhood. The council has laid poison fox baits in one of the bushland areas that we like to walk through, so we gave that a wide berth, taking a detour up a very steep hill to avoid them. Here’s Scully at the marina this morning:

Scully at the marina

On the afternoon walk we want a different way. There’s a street lined with cherry blossom trees, and they’re all in flower at the moment, so it’s very pretty. It’s rather early in the year for this, but our winter has been so warm that the plants obviously think it’s spring already.

Cherry blossoms in August

At home in between and then this evening, I’ve been shuffling between two thing: building the Stranger Things Lego set that I got the other day, and working some more on my secret Magic: the Gathering project. The date for the Magic draft event with my friends is set for Friday 27 September – it’s the earliest date that we can all make. So we have a bit over a month of anticipation. When it happens I’ll definitely report on it!

New content today:

Slow Saturday

Housework day! The bathroom is sparkling clean once more, groceries have been shopped, and… I finalised the sale of my old computer to a buyer through a local classifieds website. All very domestic.

In more fun activities, today saw the assembling of tomorrow’s Darths & Droids strip, which was written just last night at Games Night, as reported in my previous post. And I now have RSVPs from everyone I invited to my Very Special Magic: the Gathering Draft event Secret Project that I told you about on Wednesday. Even though I saw some of the guys last night at Games Night, we didn’t talk about it, so I don’t know what sort of thing they’re expecting. But the emailed RSVPs have expressed curiosity and intrigue.

To round out the day, wife, Scully, and myself went out for dinner at a nice restaurant a few suburbs away – from which we’ve just returned home this fine winter evening. It’s always nice to not have to cook! Their dessert menu had a “deconstructed cheesecake” on it, which I had to try because it reminds me of some of the things at mezzacotta Café. It was delicious, actually.

New content tonight: