Category: adventures

An oldie, but a goodie

Last Friday, the Anarchist Guild Social Committee – a sketch comedy group of whom I was a member – celebrated their second birthday, and Nick, their leader, asked me if I’d come and contribute to the shenanigans. I said yes, he said he didn’t want a sketch, and after a while I settled on the idea of just doing a science demonstration. While I thought of a few candidates, I settled on that oldie-but-goodie, the egg in the bottle trick, made famous  here in Australia by Julius Sumner Miller; you can find a collection of clips from his most famous series, Why Is It So?, on the ABC Science web site. (They’re well worth a watch, though it’s interesting to note that the kind of interaction he has with school students is probably not allowed these days, and there’s a noticeable lack of women and girls on the program – despite his inclusive welcome of “ladies and gentlemen, boys and girls”.)

Of course Why Is It So? is quite an old vintage as television programs go, besides which the egg in the bottle experiment doesn’t appear in any of those clips. Members of my generation (X, in case you were uncertain) probably know the demonstration better from a series of Cadbury chocolate commercials in which Julius appeared in the 1980s – a cunning move, and proof that he was ready to spread the word of science in any way possible! Perhaps I should be seeking that road to success?

Anyway, it’s a classic, and I was genuinely excited to peform it again; it formed a brief part of my first solo science show, Listen to the Man in the Lab Coat in 2004, and served as an encore to my Comedy Festival debut, Science-ology, in 2007. Not having performed it for three years made it just as much a treat for me as for (hopefully) the audience – and given that some of them had never seen it before, I think I picked just the right “science trick” for the crowd. I hope to get some video of my demonstration and put it up here in the near future, but in the mean time, here’s a basic run-down.

First, you need a bottle – it used to be easy to get glass milk bottle, but now they’re a bit of a rarity in Australia. So much so I brought one back from my trip to New York, from the Milk Thistle organic dairy farm. (I’m aware that recent articles say there’s no nutritional benefit to organic farming, overturning previous research, but there are still other advantages, not least the taste. But I digress.) You can find glass milk bottles locally, though, and I recommend you do; other bottles can do the trick, but milk bottles have the perfect sized opening.

Next, you need an egg. The egg should be too big to fit in the bottle, and the larger the better; I used “XL” size (free range) eggs, about 60g each. There are some misconceptions about the egg; I’ve had a number of people complain that they always thought the egg was raw, but it’s always been a hard-boiled, shelled egg for this experiment. (You could try a raw one, and probably get a cool result, but an exploding raw egg is much messier. Actually, now I really want to try that…)

Finally, you need some paper and matches. This is the dangerous bit, so allow me to put in an obligatory warning: don’t do this at home without adult supervision, kids.

Okay, so the egg is too big to go in the bottle, right? How to get it in without mashing it? Set fire to a small strip of paper, drop it in the bottle, then put the egg back on top. After a short time, the egg will be magically “sucked” in to the bottle with a very satisfying pop! How did this happen? Or rather: why is it so?

I have to explain, of course, because that’s the primary difference between a science trick and a magic trick: there’s no scientist’s circle making sure I never explain how it’s done, and in this case, it’s all done with pressure.

(Sometimes someone claims the explanation is “Bernoulli’s principle”, and technically that’s accurate in some sense, though Bernoulli’s principle is specifically about the relationship between a fluid’s speed of flow and its pressure; an aircraft wing is a better example of that.)

So what happens to the egg? First, the flame heats up the air inside the bottle; since this causes the air to expand, there is a greater volume of air than can fit inside, and some of the air escapes by pushing past the egg. (You can often see this if you put the egg on quickly after dropping in the flame; it bounces up and down making farting noises.) Once the flame goes out – not because it has “used up all the Oxygen”, by the way – the air begins to cool, and as it cools, it condenses, decreasing in volume. There’s now a lesser volume of air in the bottle than is needed to fill it, creating an area of low pressure. The higher pressure air outside the bottle exerts a force on the lower pressure air inside – not enough to break the bottle, of course, but enough to push the egg inside until the air can get in and equalise the pressure.

So that’s it! I use a big egg to get a good noise, which means it can’t be extracted easily, though you should be able to do the experiment in reverse by holding the bottle upside down with the egg near the opening and either heating the air inside (to make it expand) or blowing extra air into the bottle past the egg. My eggs are usually too big for this method to be reliable. If you want to get really fancy, you can soak the egg in vinegar without taking the shell off, which makes the shell soft; once you get the egg inside, it will eventually harden, and that’s pretty impressive. If you don’t want tell-tale signs of burnt paper inside the bottle, you can either heat up the air by immersing the bottle in really hot water, or directly reduce the pressure by immersing the bottle in really cold water, which are less reliable and less impressive, but still work.

So there you have it: the egg in the bottle. If you’d like to see me do it, along with all the witty banter I’ve developed, by all means get in touch – consider me available for weddings, parties…anything!

The Mystery of Dinosaur Island!

“Dinosaur Island” sounds like a cheap Jurassic Park rip-off, but it was a very accurate title for the presentation given last night by Professor Scott Sampson, one of the international guests for this year’s Science Week tour. Being in the upstairs function room at the Redback Brewery brought back fond memories of science activity; it’s been used as a venue by Science in the Pub, Science in Public and the Australian Science Communicators.

Scott covered a several angles of dinosaurology (you’ll be hearing more of this word from me soon), first offering a brief overview of dinosaur knowledge and how our picture of these animals has drastically changed. As you probably know dinosaurs were originally depicted as slow and dull – in both the mental and physical senses. In his words, though, dinosaurs became supercharged in a cultural nanosecond, and it’s all the raptor’s fault. That’s raptor in the “raptor-like dinosaur” sense, since he doesn’t blame Jurassic Park; rather it was the discovery of Deinonychus which originally led some palaeontologists to speculate a link between birds and dinosaurs, and when that become the majority opinion in the 1990s with the discovery of feathered dinosaurs, everything was turned on its head, graphically illustrated by the contrast between the old-school, dog-like dinosaurs in images by artists like Charles R. Knight and Heinrich Harder and those by recent dino illustrators like Greg Paul. Colour, movement, feathers…it’s all there.

From this beginning Scott made his way to his own research, mostly on dinosaurs of western North America. Around 75 million years ago what we know as North America was split into three or four pieces, and the westernmost part was a long, thin strip of coastal plains, separated from the eastern Americas by a narrow seaway – Dinosaur Island indeed! When plate tectonics allowed continental drift to be accepted by mainstream geology in the 1960s, it was no longer a mystery how dinosaurs had managed to spread across the whole, but in estern America the fossils presented a new mystery. The species found in Utah and New Mexico (in the south) were different to those in Alberta and Montana (in the north). Not only were there lots of different species, but there were lots of dinosaurs – in his sites in Utah, Scott revealed that you couldn’t walk for 15 minutes without spotting the telltale signs of dinosaur bones; he also regularly finds “bone beds” containing tens or even hundreds of specimens that died together, evidence of massive herding behaviour in herbivorous dinosaurs.

This is weird; as Scott says, there’s only one species of elephant in Africa, a much bigger area than Dinosaur Island. So how could this sliver of North America support so many individuals of so many species? Several ideas were put forth by the resident audience expert, who was of course a ten year old boy (and ginger too, which gave me a twinge of pride). Was there a huge abundance of food to support them? Did they have slower metabolisms, and require less food than modern animals? Was it easy when there weren’t human beings around to stuff things up? Or did they not really live all at the same time?

That’s what Scott set out to determine with his digs in the Grand Staircase Escalante National Monument, and he shared lots of details about how the dig is run. His “rag-tag fugitive fleet” of volunteers and students were centre-stage; as in astronomy, Scott stressed that palaeontology would get nowhere fast without these mostly unpaid workers. Not only do they spend hours in the field looking for fossils and uncovering them,  they get used as pack animals transporting them out of the inhospitable terrain – thought the biggest are airlifted by helicopter – but also spend up to two years preparing them for serious study. (He later revealed that his favourite scene in Jurassic Park is the scene at the start where they uncover a whole Velociraptor skeleton in a couple of minutes, which makes him laugh. Scott loves Jurassic Park, since it’s entertainment, but has a beef with Walking With Dinosaurs and its ilk, who present their conjecture about dinosaurs as fact.)

At Grand Staircase Scott’s team has found a huge variety of ceratopsian, duck billed, armoured and carnivorous dinosaurs. It seems these species really did co-exist, and that there was both more vegetation to support them, and perhaps they had slower metabolisms. Crocodiles, after all, can go without food for up to two months, but top mammalian predators can’t hope to do that. (Mammals, he joked, are the SUVs of the animal world, burning up as much energy as they can get their hands on, while reptiles are more like a Prius.) His own theory, which he admits is still contoversial, is that dinosaurs occupied a “Goldilocks” state – their bodies were not too cold-blooded nor too warm-bloodied, but just at the right metabolic rate in the middle, making them quite unlike anything alive today.

Scott wound up the prepared bit of his talk with his opinions of why dinosaurs are important to science. His basic point was that they’re a great hook to start conversations about immediately relevant topics like global warming. An understanding of climate changes brought about the asteroid which probably wiped them out (correctly identified as falling in the Gulf of Mexico by our audience expert) was also used as evidence for the destructive power of a nuclear winter, leading to the (relative) end of the cold war, so as Scott says, dinosaurs have saved the earth!

Scott left time for a question and answer session, and as you might expect, he knows his stuff. None of the questions phased him, and he answered them all directly. No doubt his upcoming book, Dinosaur Odyssey, will really live up to his claim: “it’s the first time a palaeontologist of my generation has really tried to set down the current state of knowledge about dinosaurs.”

HYPOTHESIS

Friday August 14 was a pretty busy day. I was at Freeplay all day, moderating a couple of panels and checking out some others; the highlight was without doubt the international keynote address by Crayon Physics Deluxe designer, Petri Purho, whose unconventional speech included a copious amount of gameplaying (mostly Spelunky, to which he is clearly addicted, but also Enviro-Bear 2000 and ROM Check Fail, all indie games) but more importantly some of the best artistic and creative advice I’ve received in years. The man’s a genius; watch out for his next game.

As soon as that was over, though, I rushed straight down to the BMW Edge theatre at Federation Square for HYPOTHESIS, a one-night-early launch event for Science Week in Victoria. It was a big line-up; as I arrived, Teacup Tumble were midway through their circus performance as labcoated scientists, recruiting children from the audience to help do some messy experiment or other. Polarized 3D glasses were being handed out so punters could see bits of our solar system in 3D, or perhaps join a simulated party to see the effect of various choices in drug and alcohol habits. The Australian Skeptics were on hand, and in a similar but more anarchic spirit, local arts collective Tape Projects were on hand with 100 Proofs the Earth is not a Globe. (I was later challenged to name three proofs that the Earth is a globe, and was happy to find I could do this, even if a couple weren’t entirely reliable and none from personal experience. My favourite is that when there’s a lunar eclipse, the Earth’s shadow on the moon is always round, no matter where on Earth you need to be to see the eclipse – something that could only happen if the Earth is a sphere.)

I was distracted from these at the beginning of the evening, though, as I was busy catching up with some old friends who were on the scene. By the time they left for dinner, the next main event was beginning – Speed Meet a Geek. This proved to be a bit of a highlight. It’s a speed-dating take on Science Week’s successful “Invite a Scientist to Dinner” scheme, and it involved several punters sitting at a table with a scientist, talking about whatever took our fancy. After a few minutes, there’d be an announcement and music, and the scientists would get up and move to another table. The time was, of course, all too brief, but the conversation was fascinating nonetheless; I could tell that my table mates Sue (a librarian from Albury) and Gina (who produces science shows for schools) agreed.

First up we met Steve, a young man with a similar taste to me in T-shirts, and who had studied both physics and philosophy. Fittingly he is now working in the history and philosophy of science programme at Melbourne University, where he recently has been thinking about a proposed plan to fly giant kites, equipped with turbines, 10 kilometres up in the sky, where the much faster and more constant winds would both keep them aloft and generate massive amounts of pollution free electricity. This plan was of course far too expensive to test with a prototype, so Steve built a computer simulation based on Bureau of Meterology data; the simulation sadly showed that the winds just weren’t consistently high enough to keep the kites in the air, so apart from the other practical considerations, the plan doesn’t seem feasible. It’s a shame; it’s such a beautiful idea. It makes me slightly prouder of our country that, even if we’re not really all that progressive in our ideas of power generation, we’re at least considering such things. I was left in the dark, however, about why such a plan was being tested by HPS academics, and not, say, engineers.

As if to prove that good things come in pairs, our next guests was also an HPS academic, and a very pleasant surprise for me: Neil Thomason, the man who introduced me to the history and philosophy of science through his courses at Melbourne University. I was sad to hear that Neil has retired, but not too much; after all, he now does much the same thing he used to do, just for no pay! As he himself put it, he used to ask why we should believe scientists; he now asks why we should believe statisticians. I think I made rather a hash of my attempt to answer the former, but of course the general answer is that we should believe scientists because they try to only make claims which they can back up with evidence, and use techniques to try and make sure their evidence is reliable. They’re still only human, after all…

Our next visitor was Justin, who works at the 3 Giga-electron-Volt Synchrotron located out in Clayton. More specifically, he works on one of the beamlines  – streams of highly accelerated electrons fired out of the synchrotron at 14 different points – doing analysis on crystalline structures hit by the beams. His work has implications mainly for materials science – finding new types of material for construction, technology and other uses. He was the only scientist to bring gifts – big posters of the synchrotron! I keep meaning to visit the place, and now it’s further up the list. Sue made the excellent suggestion that it would get more media attention if the whole thing lit up, so you could see something happening; while this would be completely artificial, I’m not at all against the idea. People are used to seeing stuff happen thanks to sci-fi movies!

Jo Sumner came to visit us next. I’ve met met Jo before, in her capacity as Manager of Genetic Resources at Melbourne Museum; she was one of the scientists on last year’s Not the Nobel Prize, if I remember rightly. In any case, she is lovely company, and she regaled us with a story of her trip to Indonesia when her husband, also a biologist, was studying Komodo dragons. When she revealed they’d brought their very young daughter along, I was instantly reminded of Douglas Adams’ Last Chance to See…, in which he recounts stories of dragons eating small children. Jo said that when she took her daughter to see her husband catch and release a dragon, she grew bored and started making a lot of noise; when the dragon was released, instead of scuttling off, it hid in the long grass and to watch Jo’s daughter. Creepy stuff…

Our next few guests were all astrophysicists and, oddly enough, all Americans currently at Swinburne University. Lee, the first cab off the rank, is studying globular star clusters, formed in the early history of the universe, and thus able to teach us about the conditions in the first billion or two years. Charmingly he carries a photo of such a cluster in his wallet, which he brings out to show us. He uses data from one of the many optical telescopes in Hawaii, where the distance above sea level reduces the distortion caused by turbulent air currents – something that makes Australia unsuitable for optical astronomy. Asked by Sue if his research can be related to mankind, he replies “only in the sense that it gives us inspiration, and is humbling”; it’s a terribly satisfying answer.

Emily, originally from Conneticut, is working on WiggleZ, a project to map 200,000 galaxies using spectral analysis data gathered by the Anglo-Australian telescope in Coonabarabran. Emily was a stargazer as a child and clearly, deeply loves her job. Since astronomers don’t really look through telescopes any more, when Emily goes to Coonabaraban to man the ‘scope, she likes to go out on the gantry at night and look up at the Milky Way, clearly visible without the light pollution of a big city. She hasn’t been yet, but as Sue suggests, she’d love to head out to the red centre and see the stars from there, too.

Our astronomical trio is completed by Andy Green, a Colorado native, who talks less about his own work but is no less fascinating for it. We mention the light pollution survey going on as part of Science Week – 2009 being the International Year of Astronomy – and he mentions that New Zealand is currently trying to have the night sky in Tekapo Valley registered as a World Heritage Site, because there is so little light pollution there that it gives a near perfect view of the Milky Way.

Our next and final guest was Tom Rich, white haired Curator of Vertebrate Palaeontology at Musuem Victoria. He’s wearing a tie patterned with pterosaurs; when I compliment him on it, he replies that he’s only wearing a tie as he’d been to a wedding before coming to the event. I instantly liked him, and asked what kind of palaeontology he was interested in, since I know that, as awesome as they are, dinosaurs are not the obsession of every bone digger. He revealed that he was mainly interested in the mammals of the Mesozoic era, but that since he found so many dinosaurs while looking for the mammals, he’d ended up becoming “the world’s most minor authority on dinosaurs”. His background was both in physics and palaeontology, but he decided he could either be a third rate physicist or  a second rate palaeontologist, and chose the latter. (Asked by Sue if he was humble or cynical, he replied: “Both.”) Another American, Tom is married to another palaeontologist, the “Queen of Slime” (she studies the Ediacaran fauna of the late pre-Cambrian), and accompanied her to Melbourne when she undertook some research here. He decided to learn about the country by reading an issue of The Australian from front to back, and promptly found the job he has now held for many years, commuting back and forth across the Atlantic until his wife took a job at Monash University.

Our time with the scientists over, the rest of the evening was given over to conversation with old friends, new friends, and entertainment, mainly in the form of another friend, Simon Pampena. He performed a truncated teaser version of his show Super Mega Maths Battle for Planet Earth, now touring for Science Week. I took a break after that for some food, returning for Science: fact or fiction?!, a sort of revamped version of Not the Nobel Prize. I wasn’t on the panel this year, but it was stacked with people I knew: local comedians Rob Lloyd, Tegan Higginbotham, Jason Geary and Xavier Michaelides, plus Melbourne Museum’s Rolf Schmidt, who I’d worked with on Not the Nobel Prize. I must confess I missed most of the panel as I was talking with some of the Science Week volunteers and the girls from Tape Projects, but I did enjoy Rolf’s introduction to the nigh-indestructable life forms known as tardigrades, or “water bears”, and Tegan’s subsequent impression of one.

Hypothesis was a big night, and a stirling kick off to the Victoria Science Week calendar. Let’s hope we see something similar next year!

H. P. Lovecraft’s “Melbourne Aquarium”

May 22 is the International Day for Biological Diversity, and what better excuse could I have to tell you about my trip to Melbourne Aquarium?

The tickets were part of my birthday gift from my beloved, and we went together. I hadn’t been since they’d expanded the place and added the penguins, and if you haven’t seen them, go. These aren’t local penguins; these are Antarctic penguins, of two species, the King and the Gentoo.

King Penguins (Aptenodytes patagonicus) are, as you might guess from the name, like Emperor Penguins, but a bit smaller. They’re not truly an Antarctic species, living instead on sub-Antarctic islands. They’re no wusses when it comes to the cold, though; there are millions of them on the icier side of the Antarctic Polar Front, the circle around the continent where cold Antarctic waters meet the warmer ones of the sub-Anatarcic area. They certainly look right at home in the icy enclosure at the Aquarium. It’s not hard to see how they get their name: they have quite an impressive, regal bearing, with their distinctive yellow markings, patience (they never seem in a hurry), and towering stature compared to the smaller Gentoos. They’re in pretty good shape for a species – they have a “Least Concern” rating on the conservation “Red list” maintained by the International Union for Conservation of Nature (IUCN). The ones in the Aquarium, like the Gentoos, are from a breeding programme in New Zealand.

Gentoo Penguins (Pygoscelis papua) – the least populous species in Antarctica (though more populous in the Aquarium), and one rung worse (Near Threatened) on the IUCN list – are easily distinguished by the white marking on their heads, a band which runs from one eye to the other, almost suggesting a pair of flying goggles. They’re described on the informational plaques as “cheeky”. (Penguins are especially easy to anthropomorphise – it’s probably the way they walk upright, with flippers held out like arms.) The ones in the Aquarium certainly seem inquisitive; while we were there a staff member was cleaning the tank in diving gear, and the Gentoos were constantly biting and probing his wetsuit and breathing hose. They also seemed quite entranced by anything held up to the glass by visitors – programmes, watches, even just a finger. The pool for the penguins has glass on two sides, and two different Gentoo Penguins quite energetically followed my beloved’s finger as she traced patterns on the glass, never tiring of the game.

Next to the pool is where we spent most of our penguin watching time: penguins underwater are truly amazing. The Gentoos couldn’t get enough of it, shooting around the water like planes in a dogfight. Like seals, they’re almost comical on land, but sleek and perfect in the sea. Even the King Penguins, so much larger and more ponderous, were graceful in the water, if slower. (Let’s call it a kingly reserve.)

Those King Penguins are big, though, and I couldn’t help but recall the giant albino penguins of classic horror writer H.P. Lovecraft’s story At the Mountains of Madness (in which the remains of an ancient pre-human civilisation are discovered in Antarctica, to the horror of the protagonists). Antarctica is one of the few places on Earth that still holds some kind of mystery; it’s difficult to imagine unknown “things” hidden in most places on the planet, but the white centre of Antarctica (though by now thoroughly mapped) is still a popular place to find hidden aliens and monsters in fiction. Followers in Lovecraft’s shoes include The Thing (most famously John Carpenter’s 1982 film version), the Doctor Who story The Seeds of Doom, and even Aliens vs Predator (don’t watch it).

Indeed, the only other place it seems credible to find monsters is under the sea, another theme explored by Lovecraft. Several of his creatures dwell there, waiting in the impenetrable depths. His most famous creature, Cthulhu, lies waiting in his hidden city on the sea floor, and is usually depicted as a giant humanoid figure with an octopus for a head; alien eyes and a mass of tentacles where a mouth should be.

Which brings me to my other favourite things in the Aquarium. I love octopi and cuttlefish and squid…the cephalopods. The cuttlefish in the Aquarium, right at the start of the main circuit through the exhibits, change colour in real time to match their environment. This all involves five different kinds of cells, packed densely under the skin – around 200 per square millimetre!

The changes don’t rely on the cuttlefish’s eyesight – which, though excellent, doesn’t perceive colour! They can, however, sense polarisation of light, which gives them an excellent sense of contrast. I’m fascinated by cephalopod eyes, too – they’re among the most advanced in the animal kingdom, similar to our own but quite different (one of the best examples of convergent evolution). Cuttlefish have “W” shaped pupils and two foveae – areas richer in light receptors providing excellent vision, and of which humans have only one.

Cuttlefish share many things in common with squid and octopus – three hearts, copper-based oxygen-carrying molecules in their blood giving it a green colour, a doughnut shaped brain… They’re more alien than anything the Doctor Who production team has come up with in the last four years! (They seem limited to sticking animal heads and “hands” on human beings: Cat people, Rhino people and, most recently, Fly people. As I recently discussed, this is dull and incredibly unrealistic.) Fittingly, for me, the last tank in the main round – it’s on the way out past the Sharks Alive exhibit – had an octopus.

A sign above the creature’s tank proclaimed that octopus are among the smartest creatures on Earth; that a logic puzzle that could confound a primate could be completed in six seconds by an octopus. I imagined for a second an octopus sitting on the tram completing an entire book of Sudoku puzzles while someone next to her struggled with the easy one in the mx, but it’s a much deeper statement than that. I found an excellent (if old) article from Discover magazine, Through the Eye of an Octopus, which goes into the research around octopus cognition. Research has suggested that they play, communicate, deceive, use tools, have personalities and  even sleep in ways they are startlingly like so-called “higher vertebrates” like us. I’ve often thought I’d like to have an octopus for a friend, rather than as a pet, and I think I’ve just talked myself into giving up one of my favourite dishes – salt and pepper squid.

Significantly for me, octopus have very small brains – something which challenges a long held prejudice against dinosaurs, and my favourite dinosaur especially. Stegosaurus had a brain the size of a walnut, very small for its body size, and is generally regarded as among the stupidest of dinosaurs. But the common octopus brain is the same size; albeit a very different shape, and it evolved to its current state over a much longer period, but still, it brings me hope. Perhaps a Stegosaurus could have managed a Sudoku as well.

I feel the earth move…

The Earth is, of course, always moving, but sometimes bits of it move relative to the rest of it. That just happened right here in inner suburban Melbourne – an earth tremor, I’m guessing nor more than 1 or 2 on the Richter scale, which lasted for less than half a minute. Reports via web 2.0 – Twitter, Facebook status, that sort of thing – indicate it hit a reasonably wide area centred on the inner northern suburbs.

It’s not the first time Melbourne has felt such a thing; a tremor hit the eastern suburbs in October 2006, much further out of the city. I was hoping to read up on it and tell you all about the plate tectonics of Victoria, but unfortunately the Geoscience Australia web site isn’t responding (let’s hope it’s just because they’re busy analysing the new data!). I’ll update with more info when I can.

UPDATE: Well, my estimate was way off: turns out the quake was rated 4.6 (much lower and we’d have hardly noticed it), and occured 8 kilometres down near Korumburra. No, I didn’t know where that is either; turns out it’s in South Gippsland, near the Strzelecki Ranges. You can find the lattitude and longitude on the Geoscience Australia web site, in the list of recent earthquakes (we have a lot of them!). With thanks to the ever-reliable and always interesting Clem Bastow, who shared knowledge via Twitter. Hard to imagine not knowing more about this sort of thing instantly via the Internet, these days!