science – Page 5 – dangermouse.net

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.

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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.

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Fire day

The main thing about today was not anything I did, but the weather and the resulting fires across the Eastern parts of Australia. We’ve had out-of-control bushfires burning in various parts of New South Wales and Queensland since the weekend, and today’s weather was very hot and windy. The combination resulted in declarations of (a) total fire bans across all of NSW and Queensland, (b) “catastrophic” fire conditions in the Sydney and surrounding regions – the first time this warning level has ever been issued for Sydney, and (c) an official state of emergency in NSW from today, for the next seven days.

Over the past few days, several hundred homes have been destroyed by fire, and a handful of people have been killed by the fires. We expected the worst today, as temperature rose to 37°C in Sydney, and hotter in some rural areas, with very low humidity and high winds. Throughout the day as the temperature climbed, I kept up with the news, hoping not to hear of further tragedies.

While this was happening, I spent the morning back at the school I went to yesterday, working with a couple of the kids in the Science Club, to prepare a short slideshow presentation of the work we’ve been doing all year. The older kids in the Science Club are going to present the experiments we’ve been doing to the whole school at an assembly in a couple of weeks. They have a 15 minute slot, so I made sure to keep things tight, and helped them write a script to read from.

I was home around lunch time, and then began work on getting a result from our solar shadow measuring experiment, that the kids have been working on since May – recording the length of a shadow each day as the sun moves.

Later I went out with my wife and Scully to the pet shop, for some exercise, since it was a much cooler option that going to the park. We walked over to the hardware store as well, and a couple of other places nearby to buy a few odds and ends. Scully enjoys going to the pet shop, as there are so many interesting things to smell. But she was getting restless again early this evening, so I braved the heat and took her to the nearest park to chase a ball around for a while until she got exhausted. While we did this, I could see the smoke from the bushfires around Sydney drifting across the sky.

(This photo was walking home, not at the park.)

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School science visit

Today was my visit to the primary school where I talk to the kids about science stuff. I had three separate session with kindergarten, Year 1, and Year 2. As mentioned on Saturday, I presented a talk on dinosaurs for the K and 1 kids. I included a bunch of photos of fossils with feathers, and showed them what feathered dinosaurs look like. The conclusion was that only some of the dinosaurs died out a long time ago, but some of them – the birds – never died out at all, and are still around us today. They really enjoyed it, so that was good.

With the Year 2 class I did a general Q&A. Some of the questions they asked included:

Where did the Earth’s water come from?
Why did the dinosaurs die out?
Where did humans come from?
Why isn’t Pluto a planet any more?
How do you make a black hole?
Does the Earth run on coal? – I talked a bit about what coal is, and how it’s used to make electricity, and how it adds carbon dioxide to the atmosphere, and how this is a bad thing because it’s causing climate change, but how hard it is to stop using it because people need the electricity.
How do potions work? – This was fun. I talked a little bit about how potions are fictional and don’t really work like in books and movies, and also a bit about alchemy and how alchemists used to believe they could make magical potions. By mixing things together and learning how they worked, they actually invented the science of chemistry instead.

Besides these three large groups, I also had Science Club with the group of 13 students I’ve been working with all year. It’s really quite a strange thing to be left in charge of 13 kids aged 7 to 10, with no other supervision, and be allowed to do science experiments with them (not on them!). Today I brewed up a pH indicator liquid by mixing hot water and shredded red cabbage. Within half an hour (during which I went over the results of our previous laser experiment), we had a rich purple liquid strained off. I gave each child a plastic cup and one of the chemicals I’d brought in. Then we added the cabbage liquid to each and watched them change colours:

From left to right around the table, the kids had: baking soda, soda water, white wine, bleach, apple juice, cream of tartar, lemonade (i.e. Sprite/7-Up for the Americans), vinegar, lemon juice, and ammonia solution. The bleach and ammonia I gave to the oldest kids, and made them wear rubber gloves for safety. And you can see the different colours they produced. Here’s a shot with them arranged in order of pH:

After establishing a sequence of colours for the chemicals, we tried mixing some of them. Adding baking soda to the vinegar made it (1) fizz up, (2) change colour, becoming a deep blue-purple. We mixed a few other things together, and the kids tried to predict the resulting colours (without much success). We established that mixing acids and bases tends to neutralise the result, making it closer to the original neutral purple colour. I made absolutely sure we didn’t mix the ammonia and bleach – I didn’t want to be generating chlorine gas!

This pretty much took up my whole day, as it took a while to drive home in the late afternoon traffic. And I was exhausted! I don’t know how school teachers do this every single day!

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Science Saturday

Besides the usual bathroom cleaning, I dedicated much of today to Science! I finished writing that 100 Proofs article I’ve been mentioning.

And I planned out what I’ll be doing with the school children on my next STEM Professionals in Schools visit on Monday. I wanted to do a Q&A session with all the classes, because it’s minimal preparation for me, but my contact said the kindergarten and Year 1 teachers requested me to do a presentation, because their kids are too young to be able to come up with sensible and meaningful questions. [It’s true – last time they got fixated on asking me “how many X are there?”, for X=(cats, animals, fish, bones, trees, etc).] SO I went through my old slides and found one I did on dinosaurs 5 years ago – so none of the younger kids will have seen that one. I refreshed myself on what was in the slides so I can talk about it on Monday.

And for Science Club I planned a new experiment. We’re going to make pH indicator using red cabbage, and then test various household chemicals. The usual suspects like lemon juice, vinegar, baking soda, etc. Which meant I had to draw up a shopping list. I’ll have to go shopping tomorrow for everything I need.

Oh, and I spent a bunch of time making tomorrow night’s Darths & Droids strip, following the writing session yesterday.

And now, it’s late… time for bed!

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Summery Friday

It was hot today: 33.5°C in Sydney. Summer has definitely arrived early. Not only is it unusually warm, but much of south-east Australia is in the worst drought in recorded history. Several towns are in imminent danger of their water supplies running completely dry. Dubbo, a large regional town announced upgrading to Level 4 water restrictions this week, which makes showers longer than 5 minutes illegal and all watering of lawns illegal. Sydney is currently on Level 1 water restrictions but it probably won’t be long before we start climbing the levels too.

Another big fear is bushfires. As the weather heats up towards summer, the dry vegetation all over south-eastern Australia is going to be at great risk. It’s been a couple of decades since the last disastrous level fires with tens of lives lost, but everyone is nervous about this summer.

I stayed in out of the heat today and tended to a stack of odd jobs I had piled up – literally – on my desk. I sorted through the pile of papers and paid some bills, filed some documents, organised things needed for my upcoming trip to Germany, and collated data collected from the laser experiment during my last school science visit. I calculated the wavelengths of the lasers we used from the interference patterns the kids traced and put it into a slideshow to show them on my next visit. It turned out that their sketching skills were not great, with some individual wavelengths being out by almost 100 nanometres, but luckily the averages of three measurements made with different slit configurations turned out to be within 9 nm (or under 2%) in each case. A good result, if honestly more by luck than careful measurement!

For dinner tonight my wife and I went to a French crepe place that we discovered recently. It’s run by four French immigrants who loved everything about Australia, except for the fact that they couldn’t find good crepes anywhere, so they decided to start their own restaurant. Both the savoury galettes and dessert crepes are really good, washed down with imported French cider. And outdoor seating, so Scully is allowed to sit with us.

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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.

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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:

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

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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.

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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.

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