Late Friday catch-up

I missed Friday’s entry last night, because my wife and I went out for a nice dinner, and then when I got home my friends were keen to play skribbl.io and I spent the rest of the evening doing that. Our custom word list is working well – we’re getting more interesting and tricky things to draw, and the results are even more hilarious than the default word list.

I forgot to mention yesterday that on Wednesday night when I took Scully out for her pre-bedtime toilet, I was standing with her out on the grass and looking up at the stars, and I saw a meteor streak across the sky. Almost directly overhead, and heading south-west. Not particularly bright or noticeable – I was just lucky to be looking in the right spot at the right second. It’s not the first meteor I’ve seen when out with Scully at night either – this is about the third in a couple of years. As an astronomer I know that meteors are actually very common, and if you sit outside for half an hour or so just looking up at the night sky, you’re likely to see some – it’s just that most people never do this. But I have a habit now of looking up whenever I take Scully out (and the sky is clear), so I’ve been spending a significant amount of time doing this added up over the year.

Another thing I accomplished this week is finishing off reading book 6 of the Diary of a Wimpy Kid series in Italian: Si Salvi Chi Può (“everyone for themselves”, which is how they titled the Italian version of Cabin Fever). So that’s six complete books I’ve read in Italian now. They’re definitely getting easier and faster to get through as my vocabulary and grammar skills are improving. When I began, every page I’d have to stop and look up several words. Now I can often get through a page without needing to look up anything, except perhaps to confirm the meaning of a word which I can figure out by context. On to book 7!

New content today:

Filming a video for Science Week

It was mostly a lazy Saturday today. The main thing I accomplished was filming a short video for the school where I do my volunteer science visits. I haven’t been able to visit the school to talk to the kids in person since March or so due to COVID. I wrote to my teacher contact and said I’d be happy to do something remotely, like a Q&A session via Zoom or something. She suggested that with Science Week coming up next week maybe I could record a short video to introduce the week to the students.

The theme of Science Week this year is “Deep Blue” – basically looking at the science of the oceans and how to use them sustainably rather than damaging them. So today I drove out to the coast, specifically to the rock shelf at Freshwater, where I could set up a tripod and camera with the ocean as a backdrop.

My wife came to help me do the recording, and she did a great job of directing as well. My first take was very flat and lifeless, and she got me to add more movement and gestures and voice inflection, which really helped in the later takes. I ended up with just over 4 minutes of video, and although not super professional I thought it turned out pretty good. After getting home I checked the result and it was good to go with no editing. So I sent it to the teacher and hopefully it’ll be a hit with the kids on Monday.

New content today:

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:

Vegetable quiche

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).

Sushi Taro

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

Gyoza

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.

IMG_4313

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

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

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Eventually the creek spills into this cove on Middle Harbour.

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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):

block walk path

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:

In memoriam: Richard Hunstead

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.

Molonglo Observatory Synthesis Telescope, east arm

[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.

AAT Dome

[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:

Crested pigeon

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

Red wattlebird

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:

Nankeen kestrel

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:

The Quacks of Quedlinburg

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.

Wingspan

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:

Wingspan

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: