Tag: physics

Venus in Transit

I’ve just been to a park to look through a telescope at the Sun.

Now, this isn’t safe without serious filters in place, and normally you wouldn’t expect to see much more than a big ball of light even so – but today was the transit of Venus, a twice a century or so event in which our sunward neighbour passes directly between the Earth and the Sun. (While the last famous one was in 1874 – people sailed to Australia to see it – they come in pairs: there was a transit in 2004, though most of it wasn’t visible in Australia. The next ones are in 2117 and 2125.) So today, thanks to the sterling work of Stephen Luntz and some uncharacteristic breaks in Melbourne’s cloud cover, I looked at a fairly large dot moving very slowly across the bright disc of the sun. That dot, though our nearest planet, was 41 million kilometres or so away. Blows your mind just a little, right?

To mark the occasion, Stephen gathered a small collection of poets, musicians and one comedian (guess who?) to perform to the gathered astronomy enthusiasts. Rather than do my usual gear about black holes, climate change or dinosaurs, I thought I’d share some of my favourite FUN FACTS! about Venus, and I’ve gathered them here for your pleasure.

Venus, like Mercury, has no moons, but orbitally, it’s a bit of a show off. Not only is its orbit the closest of any solar planet to a circle (they’re all elliptical, but Venus’ is the least elliptical), but it rotates on its axis in the opposite direction to its travel around the Sun. All the planets travel anti-clockwise around the Sun, but Venus and Uranus rotate clockwise. This means that on Venus, the Sun would rise in the West and set in the East – good luck for Daenerys and Drogo. A day there is incredibly long, the longest in the solar system: it rotates on its axis only once every 243 Earth days! Plus, a Venusian year is shorter than a Venusian day, at only 224.65 Earth days – and you thought Mondays at the office were long! Thanks to the backwards (astronomers say “retrograde”) rotation and shorter year, this works out to a solar day (i.e. how long the sun is in the sky) of around 116.75 Earth days, sunrise to sunset.

Venus is thus clearly the best planet for lovers, since you could hold hands and watch the sunset for weeks on end, and wouldn’t have to get up early to see it! Well…okay, you can’t. Venus has worse weather than Melbourne. Or even London. The atmosphere is incredibly dense – at the surface, the atmosphere is 92 times denser than on the surface of Earth. Not very comfortable! The cloud cover is constant, so the surface isn’t visible from orbit. Likewise, you can’t see anything in the sky; it’s like the planet of the Krikkitmen. No sunrises for you, Venusian honeymooners!

But even though you can’t get a tan, you will at least be nice and warm; with the atmosphere made up of 96.5% CO2 (the rest is mostly Nitrogen), the greenhouse effect is extreme on Venus, producing the hottest temperatures of any planet in the solar system, but with enormous range. Venus can be anything from -200°c to 420°c. That’s really hard to pack for.

On the surface, when you can see it – using special cameras from orbital missions – you can see evidence of amazing volcanic activity. Many formations are distinctive of Venus, including ones shaped like circles, stars, pancakes and spiderwebs. There’s no ocean any more – the effect of extreme global warming, which goes poles melt, seas rise, ocean evaporates – but there are two “continents” which stand taller than the surrounding plains. The larger one in the north is named Ishtar, and the southern one Aphrodite. Yes, that’s like naming a continent on Earth “Soil”, but there are rules about these things. The IAU, which oversees the naming of astronomical objects, decided that all geographic features of Venus should be named after mythological women. It’s a nice theme, but one that is broken by one of the first features to be named: Maxwell Montes, the tallest mountain on Venus, is named for Scottish physicist James Clerk Maxwell, the guy behind classic electromagnetic theory. Yes: the biggest phallic object on the planet is named after an actual man, and its surrounded by goddesses and saints and mythical heroines. (There are only two other male-named features on Venus, both named before the IAU rule was established.)

But as well as being physically interesting, Venus is also fictionally interesting. Though traditionally much less popular in science fiction than Mars, there are two distinct phases in Venusian literature. In the early days of planetary romance and pulpy science fiction, Venus was thought to be a swampy, marshy place; at the same time, the prevailing view of dinosaurs was that they were immense, slow creatures which could only live in swamps.

You can see where this is going, right?

Yes, lots of Venusian tales populated the surface with dinsosaur-like creatures. Or in some cases, actual dinosaurs. As if there was a global conspiracy and they weren’t extinguished in the KT event, but instead migrated en masse, like Adamsian dolphins, leaving fossils behind as a final message of “so long and thanks for all the cycads”. But Venus has also been populated with giant spiders, and – as usual – people who are basically human but in a weird colour (aside from the standard green, the popular colour for Venusians seems to have been blue).

But I’d like to finish with one of my favourite, and most obscure, Venusian references. During his Action Scientist! days working with UNIT, the Third Doctor (John Pertwee) was a master of a martial art he called “Venusian Aikido”. He claimed he was one of only a few beings with four limbs to master the art, but more than that, he would often tell anecdotes of his Venusian friends – who we never met or even had described. But the best bit is the lullaby he learned on Venus, which he sings to soothe Aggedor, the savage beast of Peladon:

Klokeda partha menin klatch
Haroon, haroon, haroon
Klokeda sheenah tierra natch
Haroon, haroon, haroon

It’s all a setup for a gag: when asked, the Doctor claims the first line translates roughly to “Close your eyes, my darling; well three of them at least!” (Much later, in his “Missing Adventures” novel Venusian Lullaby, Paul Leonard fleshed out the Venusian society: turns out that have fivefold radial symmetry (and thus five limbs and five eyes) and can absorb the memories of their dead by eating their brains. I love that book.)

So thanks Venus, thanks Stephen, and thanks to all the other amazing performers at the Transit of Venus event today. See you at the next one! Well, assuming we’ve all uploaded our consciousnesses in iCloud before then, anyway.

The Tweet Heard Round the World

As excitement was building the other day over the imminent announcement from CERN regarding the Higgs boson, the incomparable Simon Pampena wrote a topical tweet rewriting of a Bette Midler song: “God is watching us from a Planck distance.” I was inspired to write my own tweet:

I’ve been on Twitter for three years, I’ve gathered a modest army of followers, and I’ve had a few good gags in that time. But for some reason, this tweet really took off – it’s been tweeted over 100 times according to the Twitter site, though it’s proving quite hard to discover exactly how many people have seen fit to pass it on. I just wanted to mention it here for posterity, since Twitter is fleeting, rather than eternal – and to give Simon his due as my inspiration. He’s a funny guy. You should follow him.

Ada Lovelace Day 2011

I’ve a feeling that the average person in the street would guess that Ada Lovelace, with a name like that, must have been a cabaret singer, poet or actor. They wouldn’t be entirely off the mark, either, since she did do something beautiful and artistic to become famous: she was the world’s first computer programmer.

On Ada Lovelace Day we celebrate women working in technology and science who have inspired us. I have been definitely been inspired by women in science, from the famous like Ada herself and Marie Curie, to more recent heroes like student astrophysicist Amelia Fraser-McKelvie. But I’d like to talk about some of my friends, and in the wake of my participation in a discussion about feminism and games at Cherchez la Femme this month, specifically those working with computers and technology, like Ada did. All are inspiring to me, for their drive, their outlook, and their success, so I thought I would ask them a few questions to find about about them, and their inspiring women, in their own words.

Moran Paldi (ranpal.com.au)

Moran has over a decade of experience in the games industry; now living in Melbourne, she builds and designs video games, and teaches others to do the same. To spend even a few minutes talking games with her is to uncover an incredible depth of knowledge and passion for games in every facet of their existence, from code to controller.

How did you get into the games industry?

I studied mixed media practice at uni in London, originally planning to be an investigative journalist. I got hooked on animation at school and managed to land a job as an animator at a small indie studio when I graduated. Since then I have worked professionally as a games developer at companies like Sega and THQ,  and have now come full circle to back to my independent roots. I also teach at RMIT University on the Games Graphic Design course where I lecture in maths and games design theory.

Why video games? What do you love about this work?

I love the technical and creative challenges that making games presents. They are multilayered digital puzzles, and there’s this cycle of figuring out what you want to do, and then figuring out how to make it happen. They are fractal beasts. The more you explore them the more there is to find. Plus, the technology is always evolving, so you have to keep up with it, and that pushes you. I love exploring the boundaries of what is possible, and finding new ways to tell familiar stories. Oh, and it’s also hella fun.

Who would you be writing about for Ada Lovelace Day?

Obviously Ada! She wrote the worlds first computer program for a then theoretical analytic device. Her work is the basis of modern computing, and she deserves to be better known. Similarly, it was a group of women who built and programmed the ENIAC, which was the first electronic computer, not that you’d know that from most of the histories. Coding used to be considered women’s work, until it became high value. Now it’s perceived as a masculine pursuit. Women in tech have been made invisible for too long now. We need to break that pattern.

Leena van Deventer (grassisleena.com)

Leena is a freelance writer, both for and about games; though she only started eighteen months ago she’s already written for MMGN.com, The Age‘s Screen Play blog and a whole bunch of gaming sites, and is co-host of the GamePlayPodcast and the games correspondent for Tech Talk Radio. The first game to be released with her name in the credits will be the seventh Gamebook Adventures title for iOS, Temple of the Spider God.

How did you become a games writer?

I started with a blog, just quietly doing my own thing until people seemed interested in hiring me. I then cast out a net and worked for anyone who would let me, paid or unpaid, for the experience to then make it into a proper job. I went to as many industry events as I could find and talked to as many like-minded individuals as humanly possible. Much scotch was consumed. Oh the scotch. From there I’ve been offered amazing opportunities to work in a field I’m quickly falling head over heels in love with.

Why the love affair?

I love having an opinion. It was always a negative growing up. The over-opinionated only child stereotype was in full flight and it was always treated as a personality flaw. Once I grew up and mellowed a bit I realised I could temper it to be a powerful force – and one that could be capitalised on, at that. Taking what was once considered a flaw in my personality and turning it into a positive, constructive “thing” I had to offer was extremely rewarding, and mirrored my feelings about my favourite pastime. Playing games was always either a little bit geeky, or something only the boys in the street did, or something I was scared to talk about at school for fear of scorn. I love the fact I’m “out” now as someone who loves games so much, and that I can embrace my voice and my opinions about them. The thought of utilising those strong feelings to help make great games one day is something that inspires me immensely. Working in this industry makes me feel less broken.

Who would you write about for Ada Lovelace Day?

Brenda Braithwaite is a powerhouse of a woman – a stalwart of the games industry – who inspires me greatly. She stood up when people were saying that consoles would ruin the games industry and said “That’s bullshit”. She’s now standing up when people say games on social networks will kill the games industry and says “That’s bullshit”. She’s paving the way for many great game developers to come after her and to me that’s a lasting legacy that will stick and is something to be truly proud of. We need people to stand up and say when something is bullshit. Our industry is still in its infancy, and despite that there are many issues ingrained deeply into it. The only way we’re going to move forward and improve on our weaknesses is for people to stand up and say “That’s bullshit” and stop accepting the mediocre. She inspires me to want more from the industry and ask “Can’t we do better?”.

Catriona Wimberley

Catriona is a PhD student in medical physics at the University of Sydney, currently working at the Australian Nuclear Science and Technology Organisation (ANSTO). Though studying science, her career has been heavily entwined with technology, from computer programming to electronic engineering. She’s travelled around Australia and the world to present her work, and was featured in the Cosmos Ultimate Science Guide 2011 for prospective science students.

What are you working on for your PhD?

I’m working on kinetic modelling and parameter estimation in PET (positron emission tomography) imaging. In a nutshell, I take the images/data from scans and do some interesting mathematical modelling to find information about how the body/brain is working, or more importantly, not working, so that we can study how different neurodegenerative disorders (eg. MS or Alzheimers) progress.

How did you reach this point of your career?

A winding path where every opportunity was taken to explore exciting areas of research!

Before finally settling on the area of research I am currently in, I had worked in a biomedical engineering division (doing repair and maintenance of medical equipment), in a cardiology lab, a respiratory lab and a sleep lab (all doing clinical work). These placements helped me realise that I need more than a clinical or repair and maintenance job – I need to be able to think, create, analyse and innovate!

In final year uni, an opportunity came up to do a placement at the Bionic Ear Institute and I jumped at it. It was a great placement, gave me a taste of the research life, I was able to find out how part of the brain works using the computer and programming! But still… before I settled, I knew I needed to explore my other science love: physics.

I applied for the Nuclear Futures graduate program at ANSTO and was accepted into it. This program was what helped me decide that I truly did want to be a researcher. It was a rotational program so I got to work in an engineering project management role creating devices and upgrading safety systems, in the maintenance team for the OPAL research reactor; I wrote computer programs for physicists to interpret their data, I wrote reports about nuclear power for the Australian Government, I designed equipment to improve the quality of medical imaging – and from all of these adventures, I decided I wanted to specialise in medical physics – where else do you get the combination of physics, computing, maths and the end result is figuring out how the brain works?

What drives your passion for science?

I do it because I love finding patterns and meaning in data. I do it because I love programming and I love making programs that work and make life easier for people or elicit information. I do it because I get to think and discover new things about how the world works. I do it because it is fascinating and I couldn’t not do it.

I do it because I am curious and I need to figure things out. I love that I can lose myself in thinking and designing and analysing and interpreting.

Who would you write about for Ada Lovelace Day?

Marie Curie, for her ideas, her hard work and her drive to never give up. My PhD lineage can be traced back to her! Marie’s daughter Irene Joliot-Curie was also a chemist, and won a Nobel prize in 1935. Irene’s son Pierre Joliot is a biologist and was the PhD supervisor of Marie-Claude Gregoire, who is supervising me.

Also Elizabeth Blackburn [winner of the 2009 Nobel Prize for Medicine], for showing people that it is possible to have a highly successful science career and have a family.

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!

It belonged in a museum

…and thankfully, that’s exactly where the original Foucault’s Pendulum was: the Musee des Arts et Metiers (the Museum of Arts and Industry) in Paris. It’s still there, only in mid-May its cable snapped, sending the weight crashing through the floor of the museum.

It was only about 160 years ago that many people were still not convinced the Earth rotates on its own axis. After all, we don’t feel the motion; the Sun, Moon and stars seem to wheel around us, we don’t spin around like a top. Otherwise we’d get seasick on land, surely? Even when it became fairly common belief that the Earth orbited the Sun, the idea that the Earth also spun didn’t have much going for it. What’s to keep us from flying off?

We can be all superior about it now and talk about how the attractive force of the Earth’s gravity is far stronger than any angular momentum we might experience from it’s spin, or about frames of reference, or anything else, but we wouldn’t all have such concrete knowledge of these ideas without the work of Léon Foucault.

No relation to the philosopher and historian Michel Foucault, the physicist Jean Bernard Léon Foucault achieved all manner of great things: he measured the speed of light (with pretty good accuracy, much better than his predecessors), vastly improved the quality of telescopes, and named the gyroscope. But his most famous invention was a large, free-rotating pendulum, suspended in the Panthéon, which slowly changed the direction of its oscillation as the Earth rotated.

Many other such pendulums have been built, and I saw one when I was a boy, set up in the Queen Victoria Building in Sydney. I remember being quite obsessed with it at the time, reading up about its significance, enjoying the rich history of the same experiement being carried out over more than a century and across vast distances. I didn’t know it was only a temporary exhibit until I tried to find it on a trip back to Sydney in 2008, but I relived the joy when I saw another one in operation late last year at the Boston Museum of Science – suspended over a Mayan calendar!

Even the pendulum in the Panthéon was not Foucault’s first, but it was this one that caused a sensation in both scientific and lay circles – and which was irreparably damaged in May. Imagine it in the context of the time: a definite, physical demonstration of the Earth’s rotation! Today, a comparable feat would be to set up a simple demonstration  showing direct evidence of anthropogenic global warming. It’s easily possible to show that even a small amount of CO2 causes an increase in temperature – the wonderful Intelligent Life Magazine recently ran a great article showing you how – and perhaps building such a demonstration in public would silence some of the critics, but it’s hard to imagine it having quite the same impact as Foucault’s simple and elegant experiment did back in 1851.

There’s still a pendulum in the the Panthéon, a replica of the original, and given that party-goers at the Musee des Arts et Metiers had previously pushed the pendulum around, perhaps it’s better to go see the replica. That’s the wonderful thing about science – and indeed art: you might destroy the artefact, but the idea lives on. And if you really want to see a pendulum in action, you can find them all over the world.