## Nerdsniped

Today I started working on a new one of my “100 Proofs that the Earth is a Globe“. It’s the first one I’ve started for some time, because I’ve been distracted at home a lot with my wife working from home and haven’t been able to sit down knowing that I could work uninterrupted for several hours at a time. But today I just knuckled down and got started despite that. Normally I’d finish an article the same day I start, but I’m only about half way through, so hopefully I’ll be able to finish and post it tomorrow.

I took a break at lunch time to go do another 5k run. My fastest time for the 5k last year was 29:06, and last week I managed 29:16, so today my goal was to break 29 minutes. Unfortunately I miscounted laps and after sprinting the last couple of hundred metres and bending over exhausted to catch my breath while I checked my time on my phone, I discovered that I’d only covered 4.6 km! I still had a lap to go! I had to put the disappointment aside immediately and get the legs working again and set off on another lap…

But I managed it! My time for the full 5k today was 28:05. While running the last few laps I felt pretty exhausted and again really had to push through it mentally to avoid stopping, but now a few hours later my legs definitely don’t feel nearly as tired as last week.

I boasted to my friends on our online chat. One asked me if I was running laps of a street route, but I said no, the streets here are much too hilly for me to run, so I do laps of the nearby sports oval. And then this conversation happened:

Friend: Actually your run is consistent with orbiting a very dense object at the centre of the oval. #100ProofsGoreHillOvalIsABlackHole

Me: hmm…. I could calculate the mass, given the radius and speed… Damn, now I have to do it.

And I did. Approximating the oval as a circle and using the equation for a circular orbit: v = √(GM/r) gives the mass M of an object needed to cause me to orbit it at speed v and radius r. My speed was 5000/(28×60+5) = 2.97 m/s. I ran 11 full laps, totalling 5.14 km, so the radius of the oval is approximately (5140 m)/(11 laps)/(2π) = 74.4 m. Plugging the numbers in gives M = 9.81×1012 kg. Which is basically 1013 kg to any sensible degree of accuracy.

According to Wikipedia, 1013 kg is almost exactly the mass of comet 67P/Churyumov–Gerasimenko. Which is a little large to fit inside the oval. But never fear, for it’s also roughly the mass of two teaspoonfuls of degenerate neutron matter, which one could easily fit into the middle of a sports oval. If that much degenerate neutron matter had been in the middle of the oval, I could have stayed in orbit about it by running in a straight line. Although I suspect my orbit would decay rapidly after 5 km of running…

Friend: I’m so happy I nerdsniped you into doing this.

And just to include a photo: for dinner tonight I made a vegetable quiche, stuffed with potato, cauliflower, pumpkin, broccolini, onion, cherry tomatoes, eggs, and cheese:

New content today:

## Magic: the Gathering and the axiom of choice

After yesterday’s exertions on the golf course, I took it a bit easier today. Mostly I worked on Darths & Droids story planning, but I took a lunch break to walk up to the local shops and get a chicken burger for lunch.

I also had some interesting discussions with friends in our online chat. Some of it was Darths & Droids story planning, so I won’t go into that further. But somehow we segued into a discussion of the phasing rules in Magic: the Gathering – I think prompted by Mark Rosewater’s latest design article, in which he says:

We’re experimenting with making phasing deciduous.

Okay, this probably makes no sense if you don’t know the early history of Magic: the Gathering, but bear with me. Phasing is a rule that first appeared in the game in 1996, but which was considered too confusing and cumbersome to use again. But now they’re playing with bringing it back, at least in a limited way. (“Deciduous” in the above quote means a rule mechanic that they always consider available to include in new card sets if it makes sense for that set.)

Phasing, in essence, is an effect that makes cards in play behave as though they are not in play – they “phase out” for a turn and then reappear. While phased out, nothing can affect them, nor can the phased out card affect anything else. It’s as if they are briefly shunted to another reality.

In the ensuing discussion, I said they shouldn’t merely have one “alternate reality” – things should be able to phase into specific other realities, of which there could be several… or even infinitely many. Then if you have two infinite sets of alternate realities orthogonal to one another, and you reference them by real numbers (i.e. all the integers, rationals, algebraic irrationals, and transcendental numbers), you could phase all of your creatures in such a way that you could duplicate them using the Banach-Tarski theorem. (For a reminder on why that premise leads to that conclusion, refer to my Irregular Webcomic! annotation on the Banach-Tarski theorem.)

Someone of course immediately pointed out that you can only use the Banach-Tarski theorem if you assume the axiom of choice to be true. (For a simple primer on the axiom of choice, see my annotation on that.)

Then someone else said that rule 722.2a of the Comprehensive Rules of Magic: the Gathering (June 1, 2020 edition) might actually imply the axiom of choice. Rules 722.2a says:

722.2a At any point in the game, the player with priority may suggest a shortcut by describing a sequence of game choices, for all players, that may be legally taken based on the current game state and the predictable results of the sequence of choices. This sequence may be a non-repetitive series of choices, a loop that repeats a specified number of times, multiple loops, or nested loops, and may even cross multiple turns. It can’t include conditional actions, where the outcome of a game event determines the next action a player takes. The ending point of this sequence must be a place where a player has priority, though it need not be the player proposing the shortcut.

Example: A player controls a creature enchanted by Presence of Gond, which grants the creature the ability “{T}: Create a 1/1 green Elf Warrior creature token,” and another player controls Intruder Alarm, which reads, in part, “Whenever a creature enters the battlefield, untap all creatures.” When the player has priority, they may suggest “I’ll create a million tokens,” indicating the sequence of activating the creature’s ability, all players passing priority, letting the creature’s ability resolve and create a token (which causes Intruder Alarm’s ability to trigger), Intruder Alarm’s controller putting that triggered ability on the stack, all players passing priority, Intruder Alarm’s triggered ability resolving, all players passing priority until the player proposing the shortcut has priority, and repeating that sequence 999,999 more times, ending just after the last token-creating ability resolves.

The argument is that it is not only possible within the rules of MtG to produce a loop of actions, but nested loops of actions, and at each loop this rule says you can specify how many times the loop is executed. If the nest of loops is infinitely deep, this means that you are effectively choosing an element from each of an infinite number of sets, where each set contains an infinite number of elements. The rules of the game say you can do this. Therefore the rules of the game say that you can apply the axiom of choice.

This is, in mathematical terms, a rather simplistic case and doesn’t (I believe) in fact rely on the axiom of choice to be doable in an actual game (although I may be wrong), but that didn’t stop us having a fun discussion about it. It was topped off by the original proposer of the example of rule 722.2a saying:

I’m not sure what it says about us that I can say “the Magic: the Gathering comprehensive rules imply the axiom of choice” as a throwaway joke, and the responses are “your rule numbering is out of date”, “no they don’t” and “actually maybe they do” (and not, for example, “ha”, “what the fuck”, or “you nerd”).

This is nowhere near the nerdiest argument we’ve ever had, by the way…

New content today:

## Flat Rock Creek walk

A friend contacted me this morning and suggested we meet up for lunch, at a Japanese place a couple of suburbs over from where I live. I walked there (3.26 km according to Strava).

I got there a bit early and was really hungry, so I ordered some gyoza to eat while I waited.

I would have taken a photo of my main dish too, but I forgot in my hunger to get started when it arrived! After lunch, my plan was to walk home the long way, via a walking track that I noticed a while ago on Google Maps, which I’ve never walked before.

And so I set off to the Flat Rock Gully Walking Track. I had a little bit of a walk to get to the starting point. The first part of the walk was paved, and seemed popular with locals out for some exercise.

After crossing under a main road, the path became more of a bushwalk.

The walk followed Flat Rock Creek downstream, which was beautiful in places.

Eventually the creek spills into this cove on Middle Harbour.

This was the ending point of the walk that I wanted to do, but I still had a long walk back home! All together, the post-lunch walk was 9.12 km, for a total walking distance of 12.38 km. I was fairly worn out by the time I got home!

In other happenings, a friend commented on our group chat that he was watching a YouTube video of “stuff that kids are taught that is wrong”, and told us that it mentioned chameleons, and that—unlike what kids are told—they don’t change colour for camouflage, but rather to communicate and find mates. Someone else pointed out that Wikipedia disagrees, as its article on chameleons says they change colour for camouflage as well as those other purposes.

This began a half hour discussion over whether Wikipedia or a random YouTube video is more reliable. Rather than just haggle over it, I decided to check the literature, and quickly found:

• Stuart-Fox, D., Moussalli, A., Whiting, M. J. “Predator-specific camouflage in chameleons”, Biology Letters (2008) 4, 326–329. doi.org/10.1098/rsbl.2008.0173
• Stuart-Fox, D., Whiting, M. J., Moussalli, A. “Camouflage and colour change: antipredator responses to bird and snake predators across multiple populations in a dwarf chameleon”, Biological Journal of the Linnean Society (2006) 88, 437–446. doi.org/10.1111/j.1095-8312.2006.00631.x

These papers indicate clearly that at least some chameleons do in fact change colour for the purpose of camouflage. I was awarded the win for the conversation. Not only this, but these papers also found another very cool result. The chameleons they studied are hunted by both birds and snakes. Interestingly, when a chameleon sees a bird, it changes colour for camouflage in one way, but when it sees a snake, it changes colour in a different way. It turns out that birds and snakes have different colour vision receptors and see colour in different ways. (Bird vision is very similar to human colour vision, but snakes have less colour discrimination, similar to dogs.) So when a chameleon fears a bird, it changes colour to match its surroundings in a way that makes sense to humans. But when it fears a snake, it changes colour in a different way, which seems less well camouflaged to our human eyes (and to birds), but to a snake’s relatively colour-deficient vision it is actually better camouflaged.

This would be astonishing is it wasn’t actually just a simple consequence of evolution in action. But it’s still very cool.

New content today:

## Block experiment

I tried an experiment today. I walked out the front door with the goal of walking around the block, defined as:

• walk along the edge of a public roadway, keeping the road to one side (left as I chose) at all times, and
• never cross a public roadway.

I knew the path I would trace, but I’d never actually walked it, in 20 years of living here, for reasons which shall become clear. I tracked my walk in Strava, and the statistics of a walk around my block are:

• Distance: 2.82 km
• Minimum elevation: 48 metres
• Maximum elevation: 87 metres
• Accumulated elevation climb: +67 metres

The path I walked looks like this (I’ve hand drawn it and not provided any street names):

There are three dead end streets running into the interior of the block, so by my rules I had to walk into each one and back out along the opposite side of the street – something I’ve never done before in a single walk. The dotted lines mark pedestrian paths which provide short cuts that vehicles can’t use. Naturally, when I’m out walking I make good use of these short cuts, providing another reason why I’ve never had occasion to walk around the block like this before. The area I live in is very hilly, so there was a lot of elevation change as I traced this route.

Interestingly, I’ve long thought that if I just cross the street directly outside my place, I end up on a block of land that adjoins Sydney Harbour (as in, I can walk from that point to the shore without crossing a road – in fact have done so on many occasions). So if I tried to walk around that block by the same rules, I would end up having to walk all the way around Sydney Harbour, by a route encompassing various bridges (Fig Tree, Tarban Creek, Gladesville, Iron Cove, Anzac, and Sydney Harbour Bridges, for those counting). After doing the simpler block walk today, I checked Google Maps to see exactly what sort of route this enormous walk would take, and I realised that because of various underpasses that go beneath the bridges I was thinking of, I would actually end up either skipping some of the bridges and going even further around, further upriver (ending up crossing the river on Silverwater Bridge, of all things), or doing odd loops that cross a bridge then go around an underpass loop and then go back across the same bridge on the other side of the road.

Ultimately, I traced my path as far as the Sydney Harbour Bridge, which is the only way back to my place from the southern side of the harbour… only to realise that by my rules I would end up doing one of those underpass loops on the north side and then returning to the southern side… now with nothing to return me back to the northern side between there and the ocean. In fact, this “around the block” walk would take me all the way around the entire coastline of mainland Australia before returning to my home.

(In practice, you would be very hard pressed to actually walk this route as it encompasses several freeway sections where pedestrians are banned.)

But I was staggered by the fact that a simple rule mixed with the vagaries of the road system meant that my original assumption of merely walking around the harbour and across a few bridges was mistaken, and that instead it would lead to a grand walk around the whole continent.

If anyone else cares to try this, either with an actual walk, or tracing a route via Google Maps, please let me know your results.

New content today:

## Science Club: water

Today was my first visit to Brookvale School for the new school year. I had a new contact teacher there, after the teacher I worked with last year moved to another school. The new teacher organised a timetable for me, giving talks to the kindergarten and Year 1 and 2 classes, and also a 1.5 hour session with the new Science Club, for which she chose the students.

With the K-2 classes I gave a talk about the many different sorts of things that scientists do, including medicine, studying animals and plants to learn how they live, looking at rocks to work out where to dig for useful minerals, measuring volcanoes, drilling in ice to study the atmosphere from hundreds of years ago, astronomy, building robots, and making computer models of things. They all seemed fascinated to see all these different things, and the talk went pretty well.

For Science Club, the teacher initially gave me a list a few weeks ago, of 12 students. Only three of them were in the Science Club last year, so she’d clearly decided to give some new children a chance to participate. Then late last week she emailed me and said there were six other kids who were super keen to be in Science Club; would it be okay with me if they joined in? I said that would be okay.

I got there today, with a print out of the initial timetable the teacher had sent me, with the names of the original 12 students, but not the new six. As the kids filed into the library after recess, I asked them all their names, wrote name tags for them to wear so I could learn them, and also wrote down the names on my list.

I told them what sorts of things we’d be doing in Science Club, and then we started on some experiments. Today we were looking at properties of water. First up was looking at surface tension. I used an eye dropper to put drops of water onto a 5 cent coin on the floor, producing a bulging bubble of water, held on by surface tension. We counted how many drops I put on, before the bubble spilled and wet the carpet.

I explained to them how water was made of molecules of hydrogen and oxygen, and how the H and O atoms like to stick together, making an elastic skin on the surface of the water. Then we repeated the experiment, but with soapy water. This time the bubble was smaller, and I added fewer drops to it before it spilled. I explained that the soap had large molecules with one end that liked to stick to the water, but the other end pushed the water away. This made the skin weaker, explaining why the drop couldn’t get as large.

Next we did another experiment to look at surface tension. I filled a plate with milk and added drops of food colouring to the middle of the milk puddle. Then I got a cotton tip and dipped it in liquid soap… and touched it to the middle of the plate. I took a video:

Satisfying!

Next I got two glasses of water, one hot and one cold. I dropped some food colouring in each one, and we watched how it mixed into the water. In the cold water, the colour sank to the bottom and formed a layer below the clear water. In the hot water, however, it mixed evenly throughout. Then I explained to the kids that hot temperatures are caused by the molecules moving faster inside the water, and the faster moving molecules mix the colouring faster.

Finally we did an experiment in which I mixed iodine solution into water to make a brown liquid, and added some baby oil to form a clear layer on top. Then I shook the bottle to mix it all up, which encouraged the iodine to move from the water to the oil, in which it is more soluble. Doing so changes the colour to a bright purple, because the iodine colour depends on which liquid it’s in.

After a full day, I went home to relax. I typed out the names of the kids who I’d written down to send to the teacher, as a roll call. Then I noticed that the other timetable sheet she’d given my first thing this morning had the extra six kids’ names on it…

And the list of names I’d written down had three names not on that larger list. There were three extra kids in the Science Club who weren’t supposed to be there! I’m not sure if there was some sort of miscommunication, the kids thought they were in Science Club when they weren’t, or what happened. So I let the teacher know, and we’ll see what happens next time!

New content today:

A couple of months ago I received an invitation from the University of Sydney to attend a celebration function for the career of my Ph.D. supervisor, Professor Richard Hunstead, as he retired. The date was to be Friday 14 February, with an afternoon of reflective talks by his colleagues, followed by an evening of drinks and canapés. I accepted the invitation.

Two weeks ago, I received another email from the University. Dick (as he was known) had suddenly fallen ill and passed away. The event would go on, now as a celebration of the life of this distinguished researcher. I felt less inclined to go to something where the mood would be so different, but yesterday afternoon I went.

I saw and spoke with many old university friends and teachers who I hadn’t seen in many years. The afternoon of talks consisted of reminiscences by several of Dick’s closest colleagues, a couple of whom had been fellow students with me back in the day. Many people who Dick had taught went on to very successful careers in astronomy – I felt a bit like the odd one out, having left astronomy and moved into a career in photographic research. But the crowd felt familiar, because during my years as an astronomy Ph.D. student I moved in the same circles as this distinguished group of people. The Australian astronomy crowd is a large family, and does some of the best astronomical research in the world.

Dick in particular had many achievements over his long career. Many I knew about, some mentioned by the speakers were new to me. In the early 1960s, radio astronomers discovered the strange radio source named CTA-102. Early observations indicated that the signal strength varied, and in 1965 Gennady Sholomitskii proposed that it might be a “beacon” set up by an advanced extraterrestrial civilisation. This was two years before Jocelyn Bell’s discovery of the first pulsar, which was also at first suspected to be an alien radio beacon – making it the first astronomical object seriously suggested as a potential sign of an alien civilisation. This caused a sensation in 1965, and The Byrds wrote a song about it, released on their 1967 album Younger Than Yesterday. Mount Palomar Observatory found an optical counterpart to the radio source, identifying it as a quasar, which removed the idea that it was an artificial radio beacon.

Dick came into this story over the next few years, when he was the first to observe CTA-102 at relatively low radio frequencies, using Sydney University’s Molonglo radio telescope. The received wisdom of the time was that variable astronomical radio sources only varied at high radio frequencies, in the GHz range. Molonglo observed at 408 MHz, well below the range that anyone thought radio variability occurred. With three years of careful observation, Dick showed that CTA-102, and three other sources, varied with time at this low frequency as well. This transformed our understanding of quasars and radiogalaxies, and laid the foundations for physical models of the processes that power these objects.

[The Molonglo Telescope (my photo, during my honours year physics project, working with Dick).]

Dick was also a pioneer in the detailed study of the Lyman-alpha forest of absorption lines in the optical spectra of quasars. This is work that I know very well, as it was the subject of my Ph.D. thesis, working under Dick’s direct supervision.

[The Anglo-Australian Telescope (my photo, where I did my observing during my Ph.D.).]

Besides his research, Dick was also passionate about education. He ran the second year undergraduate physics labs, and sometimes the first and third year labs as well, for many years, from when I was a student until fairly recently. He participated (as I learnt yesterday) in numerous education outreach programs, encouraging young people to pursue training in science, and collaborating with teachers and other groups to set up science education programs.

My last interaction with Dick was late last year, when I returned to the university for the first time in many years, to seek him out and request to borrow some lab equipment, for use in my own science education efforts with Brookvale Public School. I wanted some lasers and diffraction slits and other stuff to do experiments with my Science Club. Dick was keen to help and offered all the resources he had to give.

As I heard during yesterday’s event, this generosity of time and effort was repeated across the hundreds of students and colleagues who Dick mentored and worked with. The common theme to all the speakers was how Dick had boundless energy to share his enthusiasm for science with others and to actively encourage people, without prejudice, to develop their interest in astronomy. A good friend of mine told the story of how she, as a brand new first year undergraduate, ventured timidly into the astronomy department to ask if there was anything that she could do to participate in some sort of astronomy work. Normally only students in their fourth year are assigned research projects by the various physics departments, so a first year asking for additional work was very unusual. The first person she came across told her to go to biology because “that’s better suited to girls”. Undaunted she returned a few days later to try and find someone else. She met a professor in the corridor and asked the same question: was there some sort of astronomy project that she could possibly help out on? That professor was Dick, and he immediately gave her some real data, showed her how to book time on the computer system, and how to analyse it. That girl is now a professor in the same astronomy department.

Dick has left a huge legacy at the University of Sydney, in the Australian astronomical community, and in global research. Dozens, if not hundreds, of highly successful astronomers and scientists in other fields (e.g. me) owe their careers to Dick and his positive influence.

New content today:

## School presentation and birds

This morning was the end of year Presentation Day assembly at the primary school where I do my volunteer science teaching stuff. As in the last few years, the school invited me to present the Science Award to the best science student. I get a reserved parking spot, and a seat on the stage with other special guests – it’s pretty cool. They present a whole bunch of academic, sports, and community awards to students, and “graduation” awards to the departing Year 6 class, going on to high school next year. This was the last time I’ll visit the school before the new year starts, and I wished the kids I saw from my Science Club a good Christmas holidays.

Afterwards, I decided to take advantage of being up on the northern beaches and took a walk for about an hour and a half around the Long Reef headland, which is a good spot to do some bird watching. I opened my account today with a crested pigeon:

I got a good shot of a red wattlebird (the bird isn’t red, it has red wattles, below the eyes):

And I managed to get a decent shot of a bird I hadn’t photographed before, a nankeen kestrel. It was flying overhead and I couldn’t tell what it was, silhouetted against the sky. I boosted the exposure and shot wildly, trying to follow it across the sky:

I could go on, but rather than post all the photos here, I’ve stuck them in an Imgur album with species IDs, which you can check at your leisure if interested. (They’re also in my Flickr stream, link below.)

I had some lunch nearby, and then drove a few minutes to Warriewood Wetlands, which is another bird hostspot, and photographed some more birds (also in the album). I got home just in time to take Scully out to the park for afternoon exercise. And then I spent the rest of the evening processing and uploading bird photos. 🙂

New content today:

## Friday/Saturday Double

I missed yesterday’s post because I was out most of the day, so I’ll cover Friday and Saturday now to make up for it.

Friday morning I had a meeting at Standards Australia, chairing the committee on photography standards. I caught a train into the city, where Standards Australia has their offices in the Australian Stock Exchange building. So you have to check in and get a security pass, and the lifts have this weird operation where you swipe your visitor card and a lift comes and takes you to the floor you’re allowed access to, without you having to press any buttons – in fact the lifts have no buttons at all inside them.

We have committee members form various research and cultural institutions, as well as representatives form industry and professional photography associations. I reported on the work done at the international standards meeting in Cologne that I attended in October. One particularly interesting project is updating the formulation of visual noise measurement in photos, to revise the current international standard. Experimentally, the current definition doesn’t correlate very well with human observer opinion on how much noise is in an image. People from several countries have been doing experiments designed to derive and then verify a new formula based on image statistics – including an experiment that I ran in December 2018 (while I was still employed). The work is approaching the final stages and a revision of the standard should progress through the approval process in the next year.

After the meeting closed, I walked through the city to do some Christmas shopping. For someone I wanted to get some classic thriller movies, so I checked out a major retailer and their BluRay section. They had a bunch of Hitchcock films, and I thought I’d get Psycho and Vertigo. Both were available for \$12.95, but Psycho had a discount sticker on it saying “2 for \$20”, while Vertigo had a sticker “Buy 2, get 1 free”. I grabbed them and went to the counter and asked if they could treat the second sticker like the first and give me both titles for \$20. The person said no, the stickered items were very strictly applied, and they couldn’t change the discounts. Feeling cheated of a bargain, I walked out empty handed.

A few blocks south, there was another shop of the same retailer, so I went in to see if their stick was any different. Again Psycho and Vertigo for \$12.95, but here Vertigo had a “2 for \$20” sticker, while Psycho had no discount sticker. If I’d managed somehow to get Psycho from the first shop and Vertigo from the second, I could have had them both for \$20! But at this shop they again refused me the combo discount, so I stubbornly refused to buy either of them. If the stickers are “strictly applied”, how come the same titles are stickered differently at different shops??

Anyway, I progressed through a series of other shops, buying gifts along the way. The shopping areas were moderately crowded with Christmas shoppers, but not as bad as it’ll get in the next few weeks. Then I headed home on the train again. The sky was very grey and smoky still from the bushfires, but it seemed higher up, and not clogging the ground level with smoke like it had on Thursday.

After a brief stop at home, I set out for fortnightly Friday games night at a friend’s place. We started early, to give us an hour and a bit to write some Darths & Droids comics, at which we made good progress, writing four new strips. We’re still finishing off the Muppet storyline, and haven’t started work on The Force Awakens yet. We’re planning a group viewing of The Rise of Skywalker when it’s released in a couple of weeks, after which we’ll sit down and figure out our storyline through the final three films.

Then it was into games! We started with The Quacks of Quedlinburg, in which each player is a quack doctor, brewing magic potions in an attempt to sell them to suckers patients, in order to buy more ingredients to make more profitable potions:

This game was interrupted a bit by several of us veering off to play Magic: the Gathering games to complete the high-powered cube draft we started back in September. The final few games were completed, and Steven ended up winning, while I managed to come dead last, despite being the only person who knew in advance what cards we were going to be playing with! While this was going on, other players played hot seat in the Quacks game, taking over as other people subbed out to play Magic. I started the game in one seat, but returned later to take over another seat, from where I managed to come second in the game – while the seat I started in came last!

After this, we split into two groups to play two different games. I ended up playing Wingspan, which I’d never played before. It’s a game of collecting different birds, using food to gather them, and then they lay eggs, and various other things happen that score points.

This was two rounds in; I was playing the board at the bottom with the red cubes, and I thought I was going rather poorly. But by the end of the game:

I had a lot of birds, with a lot of eggs. My birds were not worth many points compared to the other players, but I had so many eggs that I won the game by 3 points! (89 on the score sheet in the photo.) It was a fun game, and I’m definitely keen to try it again.

The other guys were all ribbing me during the game, saying I’d find factual errors or stuff on the bird cards, since I’m interested in birds. I don’t recall the details, but I certainly made some erudite bird comments during the game, which only served to prove their point!

I got home late, so didn’t make a post last night. Today, Saturday, I spent the morning cleaning the bathroom and then making one of the new Darths & Droids strips that we write last night. And then after lunch my wife and I went out with Scully to a market, to meet her mum and sister there. Scully got to chase ducks and geese, which I don’t think she’s seen before. The geese were three times her size, but she was keen to chase them! The market ate up the afternoon, and then this evening we went out for dinner at a Greek place near us – that was established in 1969, so is celebrating its 50th anniversary this year.

Today was warmer, and the sky a smoky grey all day. This smoke is really starting to get to people, me included. It feels like we haven’t seen blue sky for weeks. And the outlook isn’t good either, with forecasters saying it will most likely hang around Sydney for weeks, if not months. Blah.

New content yesterday:

New content today:

## Man 0 – Nature 3

Remember last Tuesday, when we had that incredibly intense but short storm? And it blew over my chilli plant, and I spent hours cleaning up the mess and repotting the plant?

This morning I woke up, and the chilli had been blown over again by strong wind during the night, spraying the new soil all over balcony. I quickly collected as much as I could with a dustpan and broom, and returned it to the pot. The plant is now leaning over again, so I’ll have to re-insert the stake and tie it up to hold it vertical again. But I didn’t have time to do that in the morning, because I had to leave to go the school where I talk to the kids about science, and run the Science Club.

Today I had the older classes, from year 3 to year 6, and I did a general Q&A session with them. They had a lot of good questions today, on a variety of topics, covering astronomy, chemistry, biology, physics, and geology. I talked through most of the answers, but a couple I had to admit I didn’t know the answer to and suggested they look it up later. The session with the Year 6 class, one boy asked the very first question: “How big is Uranus?” – setting off a lot of giggling. I quickly said something factual about the planet and then moved on. Only afterwards did I realise I should have answered: “Not big enough to be sat-urn. Next question.”

After the group sessions (and the recess break) I had Science Club with my 13 students who I’ve been working with all year. As this was our final session, I didn’t have time to run another experiment, so we just sat and had a discussion about what we learnt this year, about science in general, about what sort of jobs you can get in science, and then I let them ask any questions they had, and tried to answer those. Here’s the whiteboard we were using, at the end of the session:

I cam home mid-afternoon. I went out on the balcony to assess the leftover mess from the chilli plant blowing over. And then, as I was standing out there, another gust of wind blew over the basil plant I’m growing for use in cooking! Soil went everywhere, and because the balcony door was open, including inside, on the carpet, and even on the dining table!

Today was really windy. I had a late lunch out, after finishing Science Club, sitting by the beach, and the wind was blowing wildly, making trees sway violently, generating huge whitecaps on the ocean. It was really awful conditions. Oh, and as I was driving to and from the school, I passed some of those areas where the power lines were still down today, 6 days after the storm last week. A friend of mine had no power from last Tuesday to Sunday night – 5 full days.

Anyway, with the wind still blowing strongly, I just quickly swept up the largest piles of soil, righted the basil, and placed the plants in sheltered positions against a wall, so hopefully they won’t blow over again.

I also decided not to take Scully out to the dog park where we meet other people and dogs, as it’s down by the water and it gets windy there even on calmer days, so today would be intolerable. Instead I took her downstairs, intending to cross the road to the nearby park which is a lot more sheltered, and let her just chase a ball for a while. As we were coming out of our property, Scully pulled up lame, favouring a rear leg. I thought she must have a burr or something stuck on her paw, as she was trying to get something off. I grabbed her leg and brushed the base of the paw, finding a sticky lump, which I pulled off…

It was a bee.

Next thing I knew, I had a shooting pain in my thumb. It stung me right on the pad of my thumb. I’ve never been stung by a bee before, so my lifetime record is now trashed. The bee fell to the ground, but the sting was stuck in my thumb. I scraped it out with a fingernail. It hurt a lot – but honestly nowhere near the pain I got from a jack jumper ant sting a couple of years ago. Given a choice, I’d take the bee sting any day. Anyway, I aborted the park trip and went back inside with Scully to wash the sting area and apply ice for a while.

Ten minutes later I was fine and resumed taking Scully out for exercise. (The jack jumper ant sting throbbed for months.) We played in the park a while. Then, just as we were turning to head home, a huge gust of wind blew into my face from the south, bringing a strong smell of smoke.

The bushfires around Sydney have been burning for a couple of weeks now, and every few days the winds bring the smoke into the city. Some days it’s been really terrible – horrible choking smoke everywhere. Today had been okay, up until that moment. As we walked home, I could see clouds of smoke, made orange by the late sun, wafting across the sky.

Here’s a photo someone posted to reddit as the smoke drifted in: [photo]

And another photo from nearby shortly afterwards: [photo]

In the endless struggle of Man versus Nature, today Nature won.

New content today:

## Science assembly presentation

Today was the presentation by my Science Club kids at their school assembly, in front of the whole school. (I wrote about the preparation for this here.) Since it was at 2 o’clock, I decided to head out and get some lunch somewhere nearby, and then head to the school after that.

I went to a Spanish tapas place at Dee Why, a beach suburb. Here’s the view from my lunch table:

The meal was pretty good! I’ll have to come back some time with my wife and Scully. After eating, I went for a brief walk along the beach:

And then back to the ocean pool at the southern end of the beach:

There were a lot of people out for a Thursday lunchtime, enjoying the warm but not-too-hot late spring day. There’s still a bit of bushfire smoke in the air, which you can see in the photos, but it didn’t smell particularly bad today. Far out to see I saw a giant yacht on the horizon (a racing yacht, not a motor yacht). It must be out there with the crew practising for the Sydney to Hobart Yacht Race, which begins on Boxing Day.

The extra wide lens on my new phone camera is pretty cool:

I drove over to the school and checked in with the science coordinator. She said that the preparation I’d done, writing a script for the kids to read along with the slides, couldn’t be found because the girl I’d written it with had been away for a week and hadn’t told anyone where she saved the file! So the other kids had had to write their own script from scratch!

At the school hall, there were a couple of rows of seats in the back for parents, although there were only a handful there. A woman came up to me and introduced herself as Belle’s mother, Belle being one of the girls in the Science Club. She thanked me for volunteering my time at the school and helping out with the kids’ science education, and said Belle was really keen on science. I said I enjoyed doing it, and especially showing the kids that if they like science then it’s possible to have a career doing it. We chatted for a bit before the kids filed into the hall.

There was some preliminary with kids getting weekly merit awards, and then the Science Club kids gave their presentation using the slides I’d prepared. Their script was a little bit wrong in places, but I don’t think it mattered much. It was great to see the kids on stage talking about all the experiments we’ve done this year.

Afterwards I chatted some more with Belle’s parents, until the bell rang and classes were dismissed, and Belle arrived. Her mother took a photo of me with Belle! Although I didn’t really do much at the school today, it was good seeing the presentation, and meeting Belle’s parents.

Then I had to drive home… On the drive out there, I’d seen just how much devastation there was from the storm on Tuesday. One road I drove along had trees down every hundred metres or so, in some cases with power lines still down and safety tape around the site. Some of these had power company workers busy clearing the trees and restoring the power lines, but others were completely unattended. Clearly they don’t have enough workers to get to all of the downed lines at once. I heard on the radio news while driving that the job is so large that they expect up to 20,000 homes to remain without power over the weekend. It was incredible seeing so many destroyed trees.

At home I’ve been working on a new 100 Proofs that the Earth is a Globe post, but it won’t be ready today – hopefully tomorrow.

New content today: