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Last update: 2013-05-03

Ep 148: Zombies Part 1

2013-05-03 :: mrscienceshow@gmail.com (Marc West)

Zombies have been fodder for science fiction books and movies for years, but could we actually create one in the lab? And why indeed would you want to do this? Surely the whole "eating brains" concept would mean that making one is probably not in your best interests.

This week on the podcast, Dr Boob takes us on a journey through zombie science fiction, Haitian zombies and zombie-style animals in nature, including a fascinating scenario where ants are hijacked by a fungus. This episode is part 1 - next time we will tackle, among other things, brain parasites, eating brains (cultural, cooking and animals that do it), mad cow disease, the 'zombie' bath salts attacks (face eating), and a mathematical model of a zombie pandemic.

We have looked at zombies in the past. In the post Correlation of the Week: Zombies, Vampires, Democrats and Republicans we looked at how the political party of the US presidency seems to influence the style of science fiction movie made during their presidency. A recent upsurge in zombie films could augur well for the Republicans next time round, although there are still plenty of vampire films and TV shows around.

The song at the end of the podcast is by copperhead / CC BY-NC 3.0

Tune in to this episode here.


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Ep 149: Zombies Part 2

2013-05-03 :: mrscienceshow@gmail.com (Marc West)

In the second of a two part series on zombies, this week we go deeper in the dark world of the undead. In part one we managed, through a combination of drugs, to create zombie-like creatures who were sluggish and largely brain-dead. This week we have a shot at recreating the zombies of films such as I am Legend - creatures created through the transmission of a virus, who are filled with rage and enjoy the taste of brains. Topics covered include:
Mad cow disease and the use of prions to transmit disease, Chimpanzees who eat brains, Methamphetamines for the creation of rage, Mathematical modelling a zombie pandemic and how the zombies could do this sustainably. Somehow we ended up proposing a "Planet of the zombie apes" movie idea, and a methamphetamine-infused biodome. It might not pass an ethics committee. Tune in to this episode here.

In the podcast we use a few songs, all licensed under a Attribution Noncommercial (3.0)
I As We by Speck
Big John by copperhead 
What It All Boils Down To by texasradiofish

Above image from ABC Open Wide Bay …


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Swimming - technique, drag and strength

2013-04-03 :: mrscienceshow@gmail.com (Marc West)

The 2012 Olympics are now only days away. I put together this article for Plus Magazine - check out the original article on Plus for full coverage, and follow Plus closely during the Olympics as they will be running regular sporting articles - see their package on maths and sport.

The men's and women's 100 metre freestyle swimming races are set to be two of the most glamorous events of the London 2012 Olympic Games. Much has been made of the swimming events for London 2012 because the previous 2008 Beijing Olympics saw an unprecedented number of new world records, due to the use of controversial swimsuits. Sixty-six Olympic records were broken during the 2008 Games – indeed, in some races the first five finishers beat the old Olympic mark – and 70 world swimming records were broken in total throughout the year 2008.

The controversial swimsuits have now been banned, but the records they set have not been revoked, so the 2012 Olympics are unlikely to see many new records. This does not mean, however, that the events will be any less competitive, and indeed if records are broken, the performances will likely be exceptional.
Pumping iron or beating drag?
Broadly speaking, records in all sports are determined by two factors: the physical and mental performance of the athlete and technological influence. Pure physical performance tends to improve over time as our understanding of the scientific aspects of sport lead to improved training techniques, diets and race tactics. Technological factors, such as a more supportive shoe, aerodynamic bike or faster car can also lead to quicker times. Some sports such as Formula One car racing have an obvious reliance on technology – notwithstanding the incredible physical and mental toughness required to withstand the cockpit of the F1 car. Other sports such as long distance running may have very little to do with technology, with famous examples of Kenyan runners winning major world events bare foot.

Although at first impression swimming seems to rely little on technology, there are many factors outside a swimmer's control that influence their final time. The type of pool has a considerable influence — the first four Olympics Games were not held in pools, but in open water (1896 in the Mediterranean Sea, 1900 in the Seine River, 1904 in an artificial lake). The 1908 Games were held in a 100 metre pool, whilst the 1912 Games were held in Stockholm harbour. The 1924 Olympics were the first to use a 50 metre pool with marked lanes, and the 1936 Games saw the introduction of diving blocks. Before the 1940s male swimmers wore full body suits that were heavy and caused a lot of drag. Pool designs have also changed with pool and lane width modified to eliminate currents, and energy absorbing lane barriers used to stop waves from adjacent lanes. (See below for a chart of world records over the 100 metre freestyle event since 1904.)

There are, broadly speaking, two things you can do to reduce your swimming time:
Increase your power Reduce your drag The magnitude of the drag force acting on a swimmer moving in a fluid is given by the following equation

is the mass density of the fluid is the speed of the swimmer relative to the fluid is the swimmer's cross-sectional area, that is the area of your body as it is pushing through the water head on is the drag-coefficient, a number which depends on factors such as the exact shape of the swimmer and the hydrodynamic qualities of their skin and what they are wearing. Although it may seem like going to the gym and pumping some iron might be the obvious thing to do, reducing your drag is actually a speedier route to a quick lap time. Your power is the rate at which your body uses its energy, and when you are swimming the power you exert is proportional to the cube of your speed

Now suppose you want to increase your speed by 10%, from to . To do this solely by increasing your power, you need to exert a new power

The percentage increase in the power required is given by


we have

So to increase your speed by 10% solely by increasing your power, you need to increase the power by 33.1%.

Reducing your drag is easier. From the equation for power above we see that the drag coefficient is

Keeping your power output and cross-sectional area the same, increasing your speed by 10% requires a new drag coefficient of

The percentage decrease in drag coefficient is given by

So the 10% increase in speed requires a 25% reduction in the drag coefficient.

The exact same working can be used for cross-sectional area — a reduction of 25% will increase your speed by 10%. This is actually the key to the simplest method of reducing drag for most swimmers: improving your technique. Because human lungs are full of air, when we swim our upper body tends to rise and our lower body sinks, increasing cross-sectional area A. The drag force increases and you slow down. Keeping your feet nearer the surface is the easiest method of reducing drag for everyday swimmers.

Drugless doping
At the top end of competitive swimming nearly all swimmers already have very good techniques, so swimsuit technology comes into play. Materials have been developed that increase the swimmer's buoyancy, making it easier to keep their feet near the surface, and reduce the drag coefficient as the material glides through the water more easily than human skin does.

Full-length high-tech swimsuits were first introduced in 1999 before the 2000 Sydney Olympics, with the Speedo Fastskin suits containing V-shaped ridges, modelled on shark skin, to reduce drag. By 2008, the Speedo LZR Racer swimsuit was the most advanced. It was put through wind tunnel tests by NASA and mathematicians modelled water flow around it using a technique called computational fluid dynamics, which simulates how fluid flows around objects (see this article for more on modelling fluid flow). And this research all happened before real swimmers tested the suits in real pools. In Beijing, 89% of all swimming medals were won by swimmers wearing LZR Racer suits.
One of the ways the LZR Racer suits reduce drag is by having panels of a plastic called polyurethane on parts of the body that produce the highest drag. Other swimsuit manufacturers took note. Instead of being textile based with only patches of polyurethane, suits like the subsequent Arena X-Glide were made entirely of polyurethane. These suits were completely impermeable to water, so swimmers could conceivably complete their race without getting wet between their ankles and neck! Records continued to tumble. See more on the Speedo swimsuit technology in this article.

The governing body for swimming, FINA (Fédération Internationale de Natation – International Swimming Federation), took note of the plummeting records and the accusations of "technological doping". In March 2009 it put limits on the suits' thickness and buoyancy, affirming that "FINA wishes to recall the main and core principle that swimming is a sport essentially based on the physical performance of the athlete." They also stipulated that the suits should not cover the neck, shoulders and ankles.

This edict did not actually ban any of the new suits at the 2009 World Aquatics Championships (the "plastic games") — 38 meet records were broken. Subsequently all body-length swimsuits were banned. It was ruled that men's swimsuits may only cover the area from the waist to the knee, and women's from the shoulder to the knee. FINA also ruled that the fabric used must be a textile and not polyurethane. Despite these new rules, the records set by the now banned swimsuits were not revoked and still stand.

And as the term "textile" is not defined, and as scientists are pretty clever folk, the ambiguity of the new rules leaves open a large area for swimsuit development.
Record history
The progression of world records over the 100 metre freestyle event is shown below. Apart from some of the pool changes mentioned earlier, records have continued to drop as we increase our understanding of our physical abilities. Other innovations which have helped reduce times include the introduction of diving blocks in 1936 – previously swimmers had just dived from the wall – and the development of the tumble turn in the 1950s.

It is interesting to note that freestyle as we know it now has not always existed. By definition, in freestyle races you can pretty much swim however you like (with some exceptions), unlike breaststroke, butterfly or backstroke which have defined methods of swimming. During the 1840s, even though they were beaten by native North Americans swimming with a front crawl style, British gentleman swimmers (in an oh so British fashion) swam only breaststroke, considering the front crawl too splashy, barbaric and un-European. In the late 1800s, the quickest (British) freestyle was the Trudgen style, named after John Arthur Trudgen, whose stroke was a combination of side stroke and front crawl. The Australian Dick Cavill modified this style to something similar to what is seen today with his Australian crawl and set a new world record for 100 yards in 1902.

The figure below shows a close-up of times from the early 1980s. You can see the decline around 1999 when the first fast-suits came in, then the sharp decline in 2008. It is difficult to predict when the next dots on the curves will occur.

At the time of writing, Australians are the favourites for both the men's and women's 100 metre freestyle events, with James Magnussen and Matt Targett having recorded the quickest men's 100 metre times in 2012, and Melanie Schlanger the quickest women's time. The UK's Francesca Halsall is 5th so far this year in the women's event, however Simon Burnett in 39th would be doing well to make it past the heats in the men's. …


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Ep 147: Time Travel and the movies part 2

2013-03-12 :: mrscienceshow@gmail.com (Marc West)

Time travel is one of the more interesting plot devices in scifi movies. In this episode and the second in the series, Dr Boob takes us on a journey through parallel universes, causal loops and the nature of time-lines. We look at Back to the Future, the Terminator series, Futurama, Looper, Red Dwarf and Twelve Monkeys. By the end, it got a bit deep and my brain hurt! There are a few spoilers in this episode, if somehow you haven't seen these classic time travel movies. And please excuse my cold!

A good reference for attempting to explain the logic of time travel in the movies is Temporal Anomalies in Time Travel Movies.

Tune in to this episode here.


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Marathon finishing times

2013-01-09 :: mrscienceshow@gmail.com (Marc West)

Statistical distributions arising from sporting events are a nerdy love of mine, so I found this chart form athlinks particularly interesting. They analysed marathon results from 2012 and found a number of invisible time barriers. You can read their original post on facebook and join their conversation.

The distributions show the psychological effects of goal times. The most striking are at 4 hours and 5 hours, with the sharp drops on the hour suggesting that a lot of runners are aiming at just beating that particular time. Indeed, if I ever ran one, I would probably be aiming at 4 hours, or more likely 4 hours 30 minutes, which is a nice round number. In my first half marathon, I beat the 2 hour mark by only 15 seconds, and if it wasn't for a sprint at the in order to pip the 2 hour mark, I wouldn't have made.

What intrigues me is whether runners are really competing to their full potential. If you took away the clock, clearly you wouldn't have these invisible barriers - you'd have a nice smooth curve. But are runners performing better than they ordinarily would, or are they pacing themselves to hit certain times? Let me know what you think.

For a description of what drives the above curve (bar the invisible barriers), see this post I put together on an ocean swim I did - you can't see the clock in an ocean swim so the invisible barriers aren't apparent. …


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Ep 146: Time Travel and Movies Part 1

2012-08-23 :: mrscienceshow@gmail.com (Marc West)

We still exist!

This week we're inhabiting the nexus of science, pop culture and science fiction. The topic of discussion is Time Travel and how it is portrayed in the movies. There's a little bit of philosophy, a little bit of physics, a dash of the paranormal, and a lot of Dr Boob, who is once again the driving force of this podcast!

If you are interested in Andrew Basiago and Project Pegasus, which is mentioned in this show, you can find more here. If you want to organise your own time traveller convention, or if you can think of a good experiment that BOOB could stand for, let us know.

This is part one of a two part series on time travel and the movies - part two will be out shortly. Tune in to this episode here.


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My Olympic Predictions

2012-07-29 :: mrscienceshow@gmail.com (Marc West)

Over at Plus Magazine, I came up with a predicted medal tally for the London 2012 Olympics. Check out my Mapping the medals article if you are interested in the maths behind it.

My top 20 predicted countries (ordered by total number of medals) are:

2012 Predicted Position2012 Predicted Medals United States1112 Great Britain279 Russia377 China476 Australia553 France642 Germany642 South Korea832 Ukraine929 Italy1028 Japan1125 Cuba1225 Belarus1321 Canada1419 Spain1419 Netherlands1617 Brazil1716 Kenya1815 Kazakhstan1815 Jamaica2012
And check out my interactive world map, where my predicted top 20 countries are coloured. If you click on each country, you will see results from previous games, a (semi-regularly) updated 2012 medal count, and some occasional comments.


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Visualising Runs

2012-07-24 :: mrscienceshow@gmail.com (Marc West)

Inspired by a recent post from Kasey Clark in which he plotted all his runkeeper runs (tracked via GPS) on a single map, I thought I'd explore my own running from the last few years and see how it might be visualised in an interesting manner.

Using his method, I exported all my runs as one big zip file of gpx files (found under your profile) then imported them all into Google Earth. Here is an image of all my runs around Sydney's inner west over the last few years. Most of the time I run along the Cooks River.

I also had a bit more fun with it, and for this you will need the Google Earth plugin for your browser - if you can see the following images you already have it, and if not then there should be a link for you to get it.

The city2surf is one of the world's biggest fun runs and I have done it the last few years. By creating a Google Earth tour, you can create an animation of your runs. I tweeked the gpx code in a text editor (and Excel) to make my 2010 and 2011 runs start at the same time, and then by using the tour gadget, you can embed the animation on your website. Perhaps over time I will add further year's runs to this animation. You'll need somewhere to host the exported kml files from Google Earth. There is a small lag at the start of the video and if it doesn't work, see the video on youtube. I'm looking to knock off that 2011 time this year in a few weeks! Edit 1: I have added a friend from 2010 and 2011.
The next tour doesn't look so great but it would look great in San Francisco or New York City. Google Earth has 3D buildings built in, and by turning these on, you can visualise your runs in 3D. The following shows my Bridge Runs across the Sydney Harbour Bridge and finishing at the Opera House. Runkeeper doesn't quite get the elevation of the bridge correct so it looks like I'm running across water. As mentioned, in cities where there are lots of rendered 3D buildings, this would look great. I haven't bothered yet to tweek the start times for each of the races to all be exactly the same as it's a bit fiddly, but you get the point. Again there is a small lag and if it doesn't work, see the video on youtube.
If you can't see the above videos, and the Google gadget seems really buggy, I have uploaded them to youtube and there you can see city2surf and bridge runs videos. …


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Broadcasting on ABC Riverina

2012-07-24 :: mrscienceshow@gmail.com (Marc West)

I have recently been doing a science segment with Chris Coleman on the morning show of ABC Riverina. If you are interested in listening to what we had to say, check out the following links:
The science behind cricket The Eurovision song contest Athletics, sleep and human achievement Quirky science funding The transit of Venus Science and the movies We also done a couple of Olympics shows, which will be online soon. Listen in at about 9.45 am each Monday. …


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Travelling Salesman - the Movie

2012-05-06 :: mrscienceshow@gmail.com (Marc West)

Science in the movies is a topic we've looked at a few times here on the blog. But this one is for the pure mathematicians. Check out this preview to the upcoming flick "Travelling Salesman".

I love these kinds of films - overly melodramatic acting, a slight misrepresentation of the science behind the plot (which is OK by me as this is a movie), government conspiracies, and mysterious music. The name "Travelling Salesman" comes from the famous mathematical Travelling Salesman Problem in which a salesman needs to visit a numerous destinations and wishes to do it in the shortest time. Whilst this may seem to be a simple problem, it is one of the most studied problems in mathematics. The more destinations involved, the more difficult to solve and in general there is no algorithm that can find the best answer. Brute force methods (that is, computing every possible solution and then finding the best) are computationally difficult, and with too many destinations, impossible. Hence mathematicians often use heuristics which find good, although not necessarily optimal, solutions quickly.

The premise of the movie is that the famous P vs NP problem has been solved. I'm not a pure mathematician, so I'll do my best here... P problems are those whose solutions can be found quickly (in Polynomial time, hence the P). NP problems are those whose solutions can not be found quickly, but if somehow a solution is produced using some extra information, it is easy to check that this solution is the best one (in polynomial time). Solving these problems take Non-deterministic Polynomial time - hence NP. A good example to show this is a jigsaw puzzle - finding a solution may be very difficult (and it's probably most accurate to image a blind person doing the puzzle), but it only takes a quick glance to see if any solution is correct.

The question that mathematicians ask is whether P=NP - which means, are there algorithms out there that solve seemingly NP problems in polynomial time? We haven't found any yet and mathematicians tend to think that P does not equal NP, but there is currently no proof. Proving this one way or the other is one of the seven Millennium Prize Problems selected by the Clay Mathematics Institute and carries a US$ 1,000,000 prize for the first correct solution.

But why do we care? One of the reasons is that modern cryptography is based on the fact that P does not equal NP - this is the premise of the movie. Modern codes start with a pair of large prime numbers p1 and p2 and multiply them together to give  m=p1p2. The number m is released to the public, but p1 and p2 are kept secret. To crack the code you have to find p1 and p2, given the value of m. It turns out that finding the prime factors of large numbers (100+ digits) is exceptionally difficult, although checking an answer is very easy. It is thought to be an NP problem. But if indeed P does equal NP, this suggests that out there somewhere is an algorithm that could solve this problem in quick time, meaning that modern encryption codes are vulnerable.

They don't give too much away in the preview, but I suspect what happens is they prove P=NP, although the example of looking for something hidden in the desert seems like a P problem (you just check out under each grain of sand, which would be easy, although it's a nice illustration of the problem). We stretch the science here a bit - even if you prove P=NP, you still need to find the appropriate algorithm for the problem, which has never been done. But hey, it's a movie, and we don't pull Terminator up on its stretching of science!

There is a very good write up of the P vs NP problem over on Plus - check it out, it does a much more thorough job than I do! …


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Ep 145: Teleportation

2012-05-04 :: mrscienceshow@gmail.com (Marc West)

Is teleportation possible in the real world, or only in the world of science fiction?

In this very special episode, Dr Boob takes the reigns and leads us on a journey through teleportation, whether or not physics allows it and even if it does, can we technologically achieve it? What are the implications if we recreate someone in another spot - what about their soul? Does such a thing exist? And even if you can technologically achieve this, is it possible to reanimate a copy of someone? What do you do with their original version, if you have simply copied them? This could be considered cloning, which brings in ethical questions.

Perhaps wormholes could be a solution to this problem, but we haven't found any yet - however they are, as physicists like to say, theoretically possible.

Tune in to this very entertaining episode (and I can say this without any false modesty as Dr Boob did it all himself) here.

If you'd like to hear more of Dr Boob on this podcast, check out our past joint episodes, mostly on the science of superheroes. He's also on twitter, so come and follow him, he needs friends!


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Ep 144: Two-up - an ANZAC Tradition

2012-04-25 :: mrscienceshow@gmail.com (Marc West)

2012 update: I had a chat to Chris Coleman of ABC Riverina about the maths behind two-up. Check it out here and read on for the 2009 article on the maths.

It's an Australian tradition on ANZAC Day to take yourself down to your local pub and play Two-up - an Aussie gambling game in which you toss two coins in the air and bet on the outcome.

I'm somewhat embarrassed to say that even though I am only a month away from turning 30, this year was the first time I've ever actually gambled on two-up.

It's not a game that is played very often, despite being iconically Australian - according to the GAMBLING (TWO-UP) ACT 1998, outside of casinos it is only legal to play two-up on commemorative days like ANZAC Day (unless you're in Broken Hill, where the local council can legally arrange a two-up game any day of the year).

The rules of two-up are pretty simple. The Spinner places two coins (traditionally pennies) on a small piece of wood (the kip) and tosses the coins into the air. In the version of two-up we played at the pub, the gambling was very simple. Players standing around the Spinner either gambled on HEADS - which is where both coins come up heads - or TAILS - which is where both coins come up tails. If a head and a tail come up, the coins are tossed again and no one wins or loses. To bet, you find someone else willing to gamble the same amount but opposite to you, and then you have a one-on-one contest. If you want to bet $10 on HEADS, then you find someone willing to bet $10 on TAILS, and if you win you get their $10 - if you lose, you hand over $10. It's very simple and I love its inbuilt honour system.

The probabilities involved are simple too - you have a 50% chance of winning each time you bet. At the start of our ANZAC day down in Balmain, most people were betting $5. By the end of the day, as more beers were consumed, many were betting $50 and $100. Gambler's Ruin also started to show it's head - many people think that by doubling your bet after you lose you can get yourself back into the game. This doesn't work in this form of two-up for a couple of reasons. The first is that you need to find someone willing to bet the same amount as you, which is increasingly unlikely the larger you want to bet. And secondly, unless you have unlimited funds (or strictly speaking, more than everyone else you could bet against - or the casino if you are gambling there), it is highly unlikely that you could continually bet without going out backwards.

Two-up is also played in casinos and other gambling houses, and not just on ANZAC day. The rules, as you would expect from such institutions, are not so simple. In this expanded form of the game, there are a number of ways to bet. The South Australian Government has a good guide to two-up play, but simply put:

Players can bet in the following ways:

1) HEADS - odds of 1/1 ($1 bet pays $2, including your original $1);
2) TAILS - odds of 1/1;
3) 5 consecutive ODDS - odds of 25/1 ($1 bet pays $26).

The Spinner can bet in the following ways:

1) 3 HEADS are thrown before TAILS is thrown and before 5 consecutive ODDS are thrown - odds of 7.5/1 ($1 bet pays $8.50);
2) 3 TAILS are thrown before HEADS is thrown and before 5 consecutive ODDS are thrown - odds of 7.5/1.

This makes the game a little bit more interesting. The Wizard of Odds website for two-up sets out the probabilities for each of these outcomes - let's derive where they come from. At each toss of the kip, for this analysis it is best to think of there being 3 possible outcomes - HEADS, TAILS or 5 consecutive ODDS. We think of it this way because if a single ODDS is thrown, it is re-thrown and only makes a difference if it is one of five in a row.

Player Odds:

As you can see, the House is paying out as if the odds are better than they actually are. It's not much, but this is how they make their money.

Spinner Odds:

Again we can see, the House is not paying enough for a win - the odds should be 7.8 to 1, rather than 7.5 to 1. However, were you to back HEADS on each throw rather than as the group of three, the house would offer you odds of 7 to 1 (this is left as an exercise for the reader...), so the spinner's bet is better.

As it turns out, I came out even at the end of the day! There's some more maths to be had here - sometime soon we might take a look at some of these pay-out distributions. …


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The Big Swim

2012-02-11 :: mrscienceshow@gmail.com (Marc West)

Recently I competed in one of Australia's biggest ocean swims, The Big Swim. Now I'm not particularly good, just stupid and competitive, and the results provide a nice sporting dataset with which to play. I've wanted to teach myself some mapping / visualisation techniques for a while, so I took the opportunity to investigate this data in order to find out from where competitors for the event came, and from where they are the quickest.

I have created the following interactive chart using Google Fusion Tables. From the swim results, I extracted the competitors' times and the suburbs they came from, and then mapped the suburbs to their postcode using the aus-emaps postcode finder. From this table I worked out the average, minimum, maximum and median times for each postcode. I've only plotted New South Wales postcodes.

The tricky part was mapping the postcode boundaries. Thankfully, the Australian Bureau of Statistics has a couple of files you can use, however to use these with Google Maps, you need to convert them to the kml file type. MyGeodata Converter provide such a service. This meant we had two files - one with the swimmer statistics per postcode, and one with the boundary coordinates. It is easy to merge these tables with Google Data Fusion, and voila, you have an intensity map.

The map below is coloured by the number of competitors from each postcode - red is the most and green the least. The most swimmers came from postcode 2026, which is Bondi and surrounds. Many postcodes, including my own, only had one competitor. If you click on a postcode, it will give you that postcode's statistics - note that the times are in decimal (Google Data Fusion has some issues with data type, so it was easiest to treat the times as decimals, rather than date/time format). So 51.58 minutes means 51 minutes 35 seconds.

The quickest postcode (that had over 10 competitors) was 2075 (St. Ives and surrounds). The slowest with over 10 competitors was 2153 (Baulkham Hills and surrounds). One might postulate that Baulkham Hills is too far from the beach, and that everyone in St. Ives has a private swimming coach. Or it could just be random, as there really aren't enough swimmers per postcode to draw too many conclusions.

The biggest bug in this is the "Sydney" postcode which is, I'm fairly sure, way over populated due to people putting "Sydney" down instead of their suburb in their swim registration. Not that many people live in the city.

The following chart shows the distribution of times, which looks quite like a normal distribution with a slight right skew due to the fact that there is a hard limit on the quickest you can possibly complete the swim, whilst you can take as long as you like to finish. Large public sporting events tend to have a long tail as people may come out once a year and jump in the ocean without particularly caring how quickly they go. This is especially true for running events where you often have people dressed up as Snoopy out the back. Ocean swim events tend to have less of this as, unlike running, if you stop, you drown! So without a very long tail, the Central Limit Theorem kicks in and gives you a normal-ish (or log-normal distribution) distribution.

The results come from the Ocean Swims website (which is an excellent source of information for ocean swimming in Australia) - the Ocean Swim Series website is also a good data source. Make your own tables and maps at Google Fusion Tables. The postcode information came from the Australian Bureau of Statistics and aus-emaps. I converted the ABS data to a kml file using MyGeodata Converter. All Things Spatial is a great resource for data mapping …


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Correlation of the year: Drinking encourages unsafe sex

2011-12-22 :: mrscienceshow@gmail.com (Marc West)

If you thought the biggest science stories of 2011 concerned faster-than-light neutrinos, the Higgs Boson or the discovery of ever more exoplanets, you would be wrong.

Researchers at the Centre for Addiction and Mental Health in Toronto, Canada have performed a meta-analysis of 12 previously conducted experiments and found that drinking alcohol makes people want to have unsafe sex. Their paper, Alcohol consumption and the intention to engage in unprotected sex: systematic review and meta-analysis of experimental studies, published in the journal Addiction, showed that alcohol consumption directly impacts a person’s intention to have unsafe sex. That is, the more you drink, the stronger becomes your intention to engage in unsafe sex.

Well I never. Generations of children owe their lives to this phenomenon!

The researchers were actually testing something a little more subtle than this appears. They wanted to test whether alcohol consumption influenced the contraction of HIV via unsafe sex, or whether certain personality traits, such as a disposition to risky behaviour, would lead to both alcohol use and unsafe sex - that is, if the unsafe sex would have happened anyway, regardless of alcohol.

They found that the more people drank, the worse the decisions they made. An increase in blood alcohol level of 0.1 mg/mL led to a 5% increase in the likelihood of unprotected sex.

"Drinking has a causal effect on the likelihood to engage in unsafe sex, and thus should be included as a major factor in preventive efforts for HIV," said principal investigator Juergen Rehm in a statement. "This result also helps explain why people at risk often show this behaviour despite better knowledge: alcohol is influencing their decision processes."

So remember this over the holidays at your work Christmas parties when your boss starts to look good after 8 beers. And at your family gatherings, your second cousin is still related....

Rehm, J., Shield, K., Joharchi, N., & Shuper, P. (2012). Alcohol consumption and the intention to engage in unprotected sex: systematic review and meta-analysis of experimental studies Addiction, 107 (1), 51-59 DOI: 10.1111/j.1360-0443.2011.03621.x


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My favourite Sesame Street science videos

2011-11-25 :: mrscienceshow@gmail.com (Marc West)

I'm stranded at Adelaide airport with my flight delayed for four hours, so what better way to get back onto the blog than by sharing my favourite Sesame Street science videos (Sesame Street having recently resumed it's exalted position in my life). The other day they were using the scientific method to deconstruct fairy tales - how would you tell the difference between the Big Bad Wolf and Grandma? Those videos aren't up online yet, but let's kick this off with comedian Craig Ferguson helping to define the word "experiment".

Here's Elmo and a Justin Bieber look-alike singing "Measure, Yeah, Measure," to the tune of Bieber's song "Never Say Never." I like his hair flicks. Elmo measured it, yo.

This is pretty cool, a Cookie Monster interactive video teaching us about experiments and things that float:

In this one, Emma Stone balances stuff on her head:

Here's Ernie showing all the curiosity of a good scientist:

And this is not sciencey, but it's the best Sesame Street video. Cutest thing you will ever see!


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The 27 Club

2011-07-29 :: mrscienceshow@gmail.com (Marc West)

Brian Jones, Jimi Hendrix, Janis Joplin, Jim Morrison, Kurt Cobain, and this week tragically Amy Winehouse, all died at the age of 27. This coincidence has spawned the notion of the 27 Club - a club whose members are influential musicians who died at the age of 27. But is there anything statistically significant about this club? Should musicians fear turning 27?

There are a few things that we should note before starting this investigation:
It's quite clear that it is not true to say that more influential musicians die at the age of 27 than at any other age. If this were true, musicians would be dying all the time, and the facts that our radios are filled with golden oldies and John Farnham keeps touring are testament to this.  We will never find enough data to fully test out any theory we come up with. For example, what defines an "influential" musician? One approach might be to scour wikipedia and find the death dates of every artist who had a top ten hit in the last 50 years. I leave this as an exercise for the reader. What we will do for this article is redefine the club to be for musicians who have died through misadventures with drugs. And what do you know, wikipedia has an article dedicated to just this topic - a list of celebrities who had drug-related deaths. Looking at just the 100 musicians in the list, we get the following distribution for lifespans of musicians who died through drug misadventure.

This distribution has an average of 36, a median of 34 and a mode of 28. All pretty close to 27. Maybe there's more to this than we thought. This can be compared to Australian Bureau of Statistics data for Australian males between 2007 and 2009. It's clear that musicians who have drug-related deaths are dying at a much younger age than Australian males. Note the caveat here, the musicians aren't dying of old age - these are only musicians who have drug-related deaths.

It's easy enough to come up with a theory for this. Musicians - indeed society at large - are most likely to start being exposed to drugs at the age of 20. In any case, before this time there aren't many musicians popular enough to have a wikipedia page or a public influence strong enough to be accepted into the 27-Club. The number of deaths seems to drop off after about the age of 40, but this is not because they are all becoming family oriented and leading a clean life. The number drops because there are less musicians alive at 40 to die. This is the same explanation for why less people in the general population die at the age of 95 than do at 80 - not that many people live long enough to die at 95.

The following chart displays the probability of dying within the next five years given that you have survived to now. For example, if you are currently in the 60-64 year age range, this chart shows the probability of dying in the 65-69 year age range. For musicians who have drug-related deaths, between the ages of 20 and 65, the chance of dying in the next 5 years is between 25-50%. Within the noise of the small sample set, its about the same for each 5 year category between 20 and 65, perhaps increasing slightly with age. This suggests that for influential musicians, if they are going to die through drug use, they have roughly the same chance of dying within the next 5 years no matter how old they currently are, perhaps a little higher if they're older. The probability of death doesn't peak at 27, and conversely, just because you have survived till now doesn't mean you have a greater chance of surviving the next five years. This is similar to the distribution of cricket batting scores, for those interested.

The peak at 25-29 in the previous chart occurs only because the musicians have not died before that age and suggests there is nothing supernatural about the number 27 (despite the curse of 27). Note that for Australian males, the data stops at 100 so the 100+ bar represents dying above this age. For the musicians, the data stops at 70-74, hence its peak at 100%.

Note again that this analysis is for musicians who die drug related deaths. It doesn't suggest that musicians have shorter lifespans than the average Australian male - it does however suggest that musicians who die via drugs have shorter lifespans. This could be because if you are going to die a drug-related death you are likely to die young because taking drugs is a risky endeavour, or it could be because by the age of 75 you have probably stopped doing drugs and so your death doesn't appear in the chart.

So is there anything to the 27 club? Not really. We've shown (albeit with just one rather incomplete article on wikipedia) there is nothing magical about the age of 27 - indeed 28 seems more interesting - and the peak in drug-related deaths around this age is quite predictable. Far more musicians die at an older age of other causes just like the rest of us, and somehow Keith Richards is still alive. The club exists because humans like to associate meaning to patterns. We're very good at pattern recognition. Our ability to associate the seasons with animal migrations, and the stars in the sky with when to plant vegetables, gave us an advantage throughout evolution. However, false pattern recognition doesn't get us killed and so we often spot patterns where they don't exist - for example, we see faces in the World Trade Center disaster, or the Virgin Mary at the beach. Some even believe that because of this, we have created religion to explain patterns we can't explain.

A nod here to the like-minded Bespoke Blog and its article Morbid Statistics & The 27 Club which I found quite coincidentally as I was finishing up this article.  …


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Ep 143: TedxSydney - Bryan Gaensler

2011-07-17 :: mrscienceshow@gmail.com (Marc West)

TED is a US based not-for-profit enterprise devoted to the propagation of Ideas Worth Spreading. TED started out in 1984 as a conference bringing together people from three worlds: Technology, Entertainment and Design. TedxSydney was a Sydney-based TED event, bringing people together to share a TED-like experience. I ducked out to Carriage Works to catch some of the event, and you can see all the talks over at the TedxSydney youtube channel. Many of these talks were science based, so I'm going to put up some of my favourites over the next few posts.
The following video is from Bryan Gaensler, former Young Australian of the Year, NASA Hubble Fellow and Harvard professor, Australian Laureate Fellow at The University of Sydney, and Director of the Centre of Excellence for All-sky Astrophysics. His talk was entitled A new way of looking at the sky.

Ted Copyright
TEDTalks are distributed under a Creative Commons (CC) license. Anyone is free to download the videos from TED.com; share them with friends; republish or embed them on their website or blog. But this use must be made within the terms of the CC license "Attribution -- NonCommercial -- NonDerivative."


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Ep 142: Beyond Zero Emissions

2011-06-13 :: mrscienceshow@gmail.com (Marc West)

Beyond Zero Emissions is a not-for-profit, volunteer run organisation whose core goal is to develop blueprints for the implementation of climate change solutions. In partnership with the University of Melbourne's Energy Research Institute, BZE are undertaking the Zero Carbon Australia 2020 Project, which puts together fully costed transition plans for getting Australia to zero emissions in ten years using commercially available technology.

Last year I attended their launch event for the Zero Carbon Australia Stationary Energy Plan which goes into detail about how Australia can reach 100% renewable energy within a decade. Speakers at the launch included former NSW premier Bob Carr, member for Wentworth Malcolm Turnbull, Greens Senator Scott Ludlam and Matthew Wright, Executive Director of BZE. The event was hosted by journalist Quentin Dempster.

In this podcast, with permission from Matthew Wright, I bring you Matthew's speech at this launch which details the science behind their proposal. I also chatted to BZE volunteer Petra Liverani at the recent Say yes to a price on carbon pollution rally in Sydney.

Click play below or listen to this show here:

If you'd like to hear what Turnbull, Carr and Ludlam had to say, check out the full video of the launch below, reproduced here with permission. Turnbull, for all his climate change activism, might have some difficulty convincing his electorate, as we found out with this video last year.


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Total lunar eclipse across Australia (or what is a syzygy)

2011-06-08 :: mrscienceshow@gmail.com (Marc West)

Today I learnt a new word.


A syzygy is a straight line configuration of three celestial bodies (such as the Earth, Sun, and Moon), and on Thursday 16 June, if you can get yourself up before dawn, you will witness a syzygy - in this case a total lunar eclipse - above the western horizon as the Moon passes through Earth’s shadow. This syzygy ends at sunrise in all states but Western Australia. It has been something of a star and planet watcher's dream recently, with four planets having lined up in the sky during May.

The eclipse begins at 3:25am AEST and enters its darkest phase at 05:22am AEST when the transformation to a blood-red Moon should begin. The colour of the eclipse depends on the amount of dust in the Earth's atmosphere. The red colour comes about because sunlight reaching the Moon passes through the Earth’s atmosphere where it is scattered. Shorter wavelengths (blue) are scattered more by  air molecules and dust particles than longer wavelengths (red), and so by the time the light has passed through the atmosphere, the light is mainly red. In extra-solar planets - planets in other solar systems - lunar eclipses can be used to determine the content of the planetary atmosphere. You might remember back to 2009 when Sydney was covered in dust and turned red to gauge a feeling for what the colour could be like - check out that article for a fuller description of the physics involved as it is similar.

If you are keen enough to not only get out of bed but to leave your house, Sydney Observatory is hosting a special breakfast viewing which includes tea, coffee, croissants and “blood-red” jam. Book at the Sydney Observatory website.

This material came from the Sydney Observatory. …


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There is more kicking in Union than League (and other misconceptions)

2011-06-01 :: mrscienceshow@gmail.com (Marc West)

If you listened to the crowd at a Waratahs (Rugby Union) game, apart from wondering which side the so-called fans were barracking for, you'd think that the Waratahs kicked the ball too much. If you have ever listened to a Rugby League fan wax lyrical about how Union teams keep kicking the ball away and how League teams know how to cross the try line, you might start to become convinced that Union teams really do kick too much. But as we like to do here, let's put these popular notions to the test. Is there really more kicking in Union than League?

The question originated at my work, where most Mondays - indeed most days of the week - we debate the relative merits of the two rugby codes. So if for no other reason than to prove my own hunch, I compiled the data for the current season of the Australian National Rugby League (after round 12) and the three nation Super Rugby (after round 15) tournaments. The following chart shows the distribution of the number of times each game a team kicks the ball.

We can conclude:
This year in the NRL, each team averages 19.05 kicks per game. In Super Rugby, each team averages 19.07 kicks per game - there is essentially no difference between the average number of kicks in a Union game and a League game in 2011. The difference of 0.02 is well below what we need for statistical significance; Both sets of data look pretty-much bell shaped - that is, they are close to normal distributions (probably as a result of the Central Limit Theorem). The League distribution is thin and tall - there is only a small distribution about the mean (standard deviation of 3.8) - whilst the Union distribution is fatter (standard deviation of 6.2). This suggests that in a League game, most of the time teams will kick somewhere near this average number of times (19), whilst in a Union game you are more likely to see a game with not many kicks or a game with a lot of kicks. This is a result of the fact that in League, after the 5th tackle, you don't have many other options but to kick, whilst in Union, with an unlimited tackle count and continual contest for the ball, you have more options for when and how often you wish to kick. The notion that it's the boring teams that kick too much take another hit when you look at the teams who actually do kick the most. The Reds, lauded this year for playing running rugby, are top of the kick table, whilst the Brumbies, who can't beat anyone, are stuck at the bottom of the kick and Super Rugby tables. In the NRL, the top three kicking teams are 3 of the top teams in the competition. Check out Green and Gold Rugby for more on the Super Rugby kicking stats.
table.tableizer-table {border: 1px solid #CCC; font-family: Arial, Helvetica, sans-serif; font-size: 10px;} .tableizer-table td {padding: 4px; margin: 3px; border: 1px solid #ccc;} .tableizer-table th {background-color: #104E8B; color: #FFF; font-weight: bold
Super 15NRL Reds23.8Dragons21.9 Waratahs22.8Storm20.6 Cheetahs21.1Broncos20.5 Rebels20.7Eels20.4 Stormers20.1Sea Eagles20.2 Bulls19.9Warriors19.4 Sharks18.9Raiders19.4 Force18.7Rabbitohs19.4 Blues18.6Sharks19.2 Chiefs18.6Knights19.2 Crusaders17.4Cowboys18.6 Hurricanes17.2Panthers18.2 Lions16.5Bulldogs18.2 Highlanders16.4Titans17.7 Brumbies14.5Roosters16.5 Wests Tigers15.6   I find it fascinating that the averages come out so close. It's over 100 years since the codes split from their common ancestor, and despite numerous law changes and evolutionary paths, teams in League and Union seem to want to hold onto the ball, on average, for about the same amount of time. In league, you are limited to 6 tackles, so could it be that the law-makers of League, when devising the 6 tackle rule, knew instinctively that this is the right balance of attack and defence? Does this balance give the players just the right amount of rest during a game? Or is it all a coincidence? And while we're on the topic of maths and sport, it's important when doing statistical analysis on sport that you analyse the right thing and take note of statistical significance. Despite the popular saying, statistics don't lie, but poor use and interpretation of them does. I think this comic from xkcd sums up how I feel when I listen to ex-professional sportsmen commentating on sport...

With regards to cricket, we have shown here on the blog that a batsman's cricketing scores over his career fit the exponential distribution very well, suggesting that many notions of cricketing form, and discussions of it, are quite troublesome - that is, it's not form creating the fluctuations in a batsman's career, but the very nature of the game itself. Deep.

Kicking images courtesy State of Union address - Tom Bradshaw's rugby blog. Yes I support the Waratahs and believe wholeheartedly that Rugby Union is a much better game than League. And unlike other Waratahs fans, I think they're actually pretty good!


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Four planets align over Sydney at dawn Friday 13 May

2011-05-15 :: mrscienceshow@gmail.com (Marc West)

When the moon is in the Seventh House
And Jupiter aligns with Mars
Then peace will guide the planets
And love will steer the stars.

The age of Aquarius has arrived! Well, it will, this Friday 13th May.

In a rare planetary event, Mercury, Venus, Mars and Jupiter, will appear together (within around 2 degrees of each other) in the eastern sky just before dawn this Friday. The event will be particularly spectacular for Sydneysiders. From 5am, the four planets will be clearly seen just above the horizon in the east. The brightest planet will be Venus sitting in the middle of the group. Just above and to the left of Venus and almost as bright is Jupiter. To the right of Jupiter and slightly fainter will be Mercury. Sitting below these three planets and fainter again will be Mars. The four planets are quite bright, so if you are up early enough, you will see them over city lights.

If you have been up early recently (I had the pleasure of a 5am start today for work...) you will have already noticed Venus and Jupiter together. The last time these four planets came together was in 1910, but the planets were too close to the Sun to observe. The next close grouping of these planets will not be until 2056.

“The close grouping of these particular four planets only happens every 50 to 100 years. We are hoping for a clear autumn morning for this unique sight in the southern sky,” said Sydney Observatory’s acting curator, Andrew Jacob. The event will be visible to the naked eye and Sydney Observatory is holding a breakfast viewing. If you are interested in getting along, there is more information at www.sydneyobservatory.com.au, and check out the Observatory's blog.

The last cool astrological event that we've seen in Sydney was back in 2008 when the Moon, Venus and Jupiter aligned to form a smiley face in the sky. I was a bit late for the happy face but managed to capture a grainy celestial sad face. Time will tell whether I manage to drag myself out of bed at 5am for this latest viewing - with a new born bub, you never know...

Addendum: Here's an explanation of how the alignment gave such a great view from Earth, and why my car is more likely to influence your personality - astrologically speaking - than this rare alignment. …


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How the planet alignment worked (and why astrology does not)

2011-05-15 :: mrscienceshow@gmail.com (Marc West)

Did you get up at 5am and brave the cold to see the planets align? If you had, you would have seen something like this. Venus and Jupiter were very bright, Mercury was fainter and eventually fell behind some clouds, and I couldn't see Mars at all with the naked eye. It was only with this long exposure shot that I could see what I think to be Mars. I've put up a bunch of photos on flickr.

The reason we were treated to this early morning light show was because of a rare alignment of the planets. It's not rare due to being unexpected - it's completely predictable - it just doesn't happen all that often. The next time these four planets will get together will be in 2056.

The following images have been made using the excellent Solar System Live by John Walker. The site shows the positions of the planets around the Sun, and in the sky, either live or at a time of your choosing. On May 13, the four inner planets were all in a straight line and from Earth you could view the other three clumped together in the sky. The images show the solar system from above, with the orbits spaced equally for ease of viewing. From this viewpoint, the Earth spins counter-clockwise on its axis, and counter-clockwise around the Sun. The alignment of planets is not seen until just before dawn, however as the Earth continues to rotate and the Sun comes into view, the light from the Sun becomes too strong to see the planets (you rarely see stars or planets during the day). Unseen, they continue to track overhead during the day. By the end of May, as the various planets move at different orbital speeds around the Sun (a year is different on each planet), they will be in different parts of the sky and the light show over.

If you take a closer look at the figure below, you'll notice that besides the aligned planets, there are actually six planets visible in the dawn sky - all planets except Saturn can be spotted if you find a dark enough area, although you'll need binoculars to see Uranus and Neptune. Even Pluto, if you still maintain it to be a planet, might be found with a small telescope - the Solar System live site still has Pluto in its diagrams. A crescent Moon will reappear near the end of May to add to the scenery.

For more information, this video from ScienceCasts gives a great overview of the phenomenon, showing how the planets move in the sky throughout May. It's also a geometry lesson before breakfast. Check out science.nasa.gov for more.

The alignment of the planets has various meanings in astrology and some astrologists maintain that there is science behind their beliefs, often claiming the precise positioning of the planets and stars at your birth effects you through gravity. Whilst these effects may be small, some claim they're enough to influence your developing brain and therefore your personality. Let's test the theory. To find out the gravitational force between two masses, we use Newton's law of universal gravitation:

F is the force between the masses, G is the gravitational constant, m1 is the first mass, m2 is the second mass, and r is the distance between the masses. We can use this to examine the gravitational force between a one kilogram mass on the surface of the Earth and the distant planets. The distances the planets were from Earth on May 13 were obtained from Solar System Live, and their masses from NASA. I've also included the gravitational effect of my car if you were standing 50 cm from it.

As you can see, the gravitational effect of my 1.5 tonne car is greater than all the planets put together.

It is also important to note that on May 13, the pull of the Moon on our 1kg object was 199 times bigger than that of Jupiter's at the Earth's surface. The Sun's pull was 178 times bigger than the Moon's, and the pull of the Earth itself was 1656 times bigger than the Sun's. Essentially, the pull of the planets on an object at the Earth's surface is negligible. The calculations can be explored in this spreadsheet. Read more over at Bad Astronomy debunking the claims of astronomy, especially with regards to gravity and the tides.

So, don't blame Jupiter if luck doesn't favour you this month - blame my car. Oh Marc, that is such a Taurian thing to say... …


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Are NSW players over-represented in the Australian cricket team?

2011-05-01 :: mrscienceshow@gmail.com (Marc West)

In every sports competition in the world, fans of one team will claim another team gets more favourable treatment than their own, whether it’s selection in representative teams, concessions regarding player salaries or favourable refereeing decisions. Cricket in Australia is no different. The dawn of summer is almost inevitably accompanied by bleating, generally from Victorian fans, about how players from New South Wales are more likely to be selected in the national team than players from other states. This opinion found a voice in David Hookes, who claimed:

"When they give out the baggy blue cap in New South Wales, they give you a baggy green one in a brown paper bag as well to save making two presentations."

It’s about time we put this idea to the test. Since the 1977/78 season, all 6 Australian states have played in the Sheffield Shield, Australia’s domestic first-class cricket competition. Since 1982/83, the season has culminated in a grand final (previous to this the winner was determined league style by whoever won the most throughout the season). I will use data from 1982/83 till now for consistency and so that all states are represented. The following table shows the players who have debuted for Australia since the start of the 1982/83 season, the state they were playing for at the time of their debut, and the number of Tests they played throughout their career.
table.tableizer-table {border: 1px solid #CCC; font-family: Arial, Helvetica, sans-serif; font-size: 10px;} .tableizer-table td {padding: 4px; margin: 3px; border: 1px solid #ccc;} .tableizer-table th {background-color: #104E8B; color: #FFF; font-weight: bold;}
PlayerYearsTestsStatePlayerYearsTestsState Carl Rackemann 1982–9112QldMatthew Elliott 1996–200421Vic Kepler Wessels 1982–8524QldMichael Kasprowicz 1996–200638Qld Tom Hogan 1983–847WAJason Gillespie 1996–200671SA Roger Woolley 1983–842TasAndy Bichel 1997–200319Qld Wayne B. Phillips 1983–8627SAShaun Young 19971Tas John Maguire 1983–843QldSimon Cook 19972NSW Greg Matthews 1983–9333NSWStuart MacGill 1998–200844NSW Steve Smith 19843NSWGavin Robertson 19984NSW Dean Jones 1984–9252VicPaul Wilson 19981SA David Boon 1984–96107TasAdam Dale 1998–992Qld Bob Holland 1984–8611NSWDarren Lehmann 1998–200427SA Murray Bennett 1984–853NSWColin Miller 1998–200118Tas Craig McDermott 1984–9671QldMatthew Nicholson 19981WA Simon O'Donnell 19856VicAdam Gilchrist 1999–200896WA Dave Gilbert 1985–869NSWScott Muller 19992Qld Robbie Kerr 19852QldBrett Lee 1999–201076NSW Merv Hughes 1985–9453VicSimon Katich 2001–56WA Geoff Marsh 1985–9250WAMartin Love 2002–035Qld Bruce Reid 1985–9227WABrad Williams 2003–044WA Steve Waugh 1985–2004168NSWNathan Bracken 2003–055NSW Simon Davis 19861VicAndrew Symonds 2004–0926Qld Tim Zoehrer 1986–8710WAMichael Clarke 2004–67NSW Chris Matthews 1986–883WANathan Hauritz 2004–17Qld Greg Dyer 1986–886NSWShane Watson 2005–25Qld Peter Taylor 1987–9113NSWShaun Tait 2005–083SA Mike Veletta 1987–908WAMichael Hussey 2005–57WA Tim May 1987–9524SABrad Hodge 2005-086Vic Tony Dodemaide 1987–9210VicPhil Jaques 2005–0811NSW Ian Healy 1988–99119QldStuart Clark 2006–0924NSW Trevor Hohns 19897QldDan Cullen 20061SA Mark Taylor 1989–99104NSWMitchell Johnson 2007–40Qld Greg Campbell 1989–904TasChris Rogers 20081WA Tom Moody 1989–928WABrad Haddin 2008–30NSW Mark Waugh 1991–2002128NSWBeau Casson 20081NSW Shane Warne 1992–2007145VicCameron White 2008–094Vic Wayne N. Phillips 19921VicPeter Siddle 2008–20Vic Paul Reiffel 1992–9835VicJason Krejza 20082Tas Damien Martyn 1992–200667WADoug Bollinger 2009–12NSW Justin Langer 1993–2007105WAAndrew McDonald 20094Vic Jo Angel 1993–954WABen Hilfenhaus 2009–15Tas Michael Slater 1993–200174NSWPhillip Hughes 2009–8NSW Brendon Julian 1993–957WAMarcus North 2009–21WA Glenn McGrath 1993–2007124NSWBryce McGain 20091Vic Matthew Hayden 1994–2009103QldGraham Manou 20091SA Michael Bevan 1994–9818NSWClint McKay 20091Vic Damien Fleming 1994–200120VicRyan Harris 2010–4SA Phil Emery 19941NSWTim Paine 20104Tas Greg Blewett 1995–200046SASteven Smith 2010–3NSW Peter McIntyre 1995–962SAPeter George 2010–1SA Stuart Law 19951QldXavier Doherty 20102Tas Ricky Ponting 1995–151TasMichael Beer 2011–1WA Brad Hogg 1996–20087WAUsman Khawaja 2011–1NSW
Of the 104 players who debuted after 1982/83, 28 were playing for NSW when they were first picked for Australia (27% of the new players).

PlayersPercentage NSW2827% WA2019% Qld1817% Vic1615% Tas1010% SA1212%
Clearly NSW players have played more Tests. But is this unreasonable? There are two measures we can look at here. Sheffield Shield results and state populations. The following shows the results of the Shield since 1982/83.

Season Winner Second Third Fourth Fifth SixthSeason Winner Second Third Fourth Fifth Sixth 1982–83 NSWWASATasQldVic1997–98 WATasQldNSWVicSA 1983–84 WAQldTasNSWSAVic1998–99 WAQldVicSATasNSW 1984–85 NSWQldSAWAVicTas1999-00 QldVicWASATasNSW 1985–86 NSWQldVicWASATas2000–01 QldVicNSWTasWASA 1986–87 WAVicQldSANSWTas2001–02 QldTasWASAVicNSW 1987–88 WAQldNSWVicSATas2002–03 NSWQldVicSAWATas 1988–89 WASAQldNSWTasVic2003–04 VicQldTasWANSWSA 1989–90 NSWQldSATasWAVic2004–05 NSWQldWAVicSATas 1990–91 VicNSWQldWASATas2005–06 QldVicSATasWANSW 1991–92 WANSWVicQldSATas2006–07 TasNSWVicQldWASA 1992–93 NSWQldWASATasVic2007–08 NSWVicWATasSAQld 1993–94 NSWTasWAVicSAQld2008–09 VicQldSATasWANSW 1994–95 QldSAVicWANSWTas2009–10 VicQldNSWWATasSA 1995–96 SAWAQldTasNSWVic2001–11 TasNSWQldWAVicSA 1996–97 QldWANSWTasVicSA
NSW has won 9 Shields, ahead of WA’s 7. If you look at the percentage of Shield wins per state and compare this to the number of players picked for Australia from that state, you will notice that these results are remarkably similar. Is it any surprise that the most successful team over this time has more players picked for representative honours? If you look at all the Tests played since 82/83, 34% of the Test positions up for grabs were occupied by NSW players, and the order of states is exactly the same as the order for number of Shield wins. This is strong evidence that rather than a selection bias, players are being picked either because they are the best players or because they have been a part of successful teams.

PlayersTestsShield wins NSW2827%98334%931% WA2019%54018%724% Qld1817%51618%621% Vic1615%38013%414% Tas1010%30610%27% SA1212%2087%13%
The second way to look at this is by state population. I don’t particularly like this method because sportsmen, especially in this professional age, move teams for many reasons, including for better opportunities and more pay, and don’t necessarily play for the state of their birth. The most populous state is not necessarily going to have the best team. But because this is often the first measure people look to when analysing team results (for example, Olympic results), and because arguably a larger population means a bigger economy and therefore more money flowing through the team, we shall include some analysis. Since 1982, NSW (+ACT) has averaged 36% of the total population of the states (excluding Northern Territory). Again, this matches quite closely the number of players picked for Australia – indeed, you might argue that more players from NSW should have been picked. It would be by this measure that Victorians may claim some bias.

PopulationShield Wins NSW + ACT36%31% Vic25%14% Qld18%21% WA10%24% Tas3%7% SA8%3%
Finally, let’s look at the one-test wonders – the players who only played one test.

One Test wonders NSW3 WA3 Qld1 Vic4 Tas1 SA4
Victoria and SA share this honour with 4 one-test wonders – and this is possibly why David Hookes, of SA stock and coach of Victoria after his retirement, was cranky. In the case of SA, this is a third of their players who have made their debut since 1982/83 – indeed, 7 of their 12 Test players did not play more than 4 Tests. Tasmanian players also fair poorly in this regard, with 6 of their 10 players playing no more than 4 Tests – Tasmanian results are severely skewed by Ponting’s 151 and Boon’s 107 Tests.

No matter what state a Test player is from, he has roughly the same chance of playing 15 or more Tests. Thus the data does not support the idea that selectors are more likely to stick with NSW players through a patch of poor form.

Percentage of state Test players (15+ Tests) NSW43% WA40% Qld56% Vic44% Tas40% SA42%
I would be interested to hear your thoughts regarding this – I know it can stir some passions. But the data would suggest that there is no unfair bias towards NSW.

Further thoughts:
I have made no attempt to look at players moving state during their careers. Simon Katich, for instance, had a career revival when playing for NSW, even though he was originally picked for Australia when playing for WA. Nathan Hauritz similarly had his fortunes revived when playing for NSW, even though he debuted when playing for Queensland. There are also many examples of this working the other way – Jason Krejza moved to Tasmania, and Adam Gilchrist to WA, both from NSW and then made their debut. Even Don Bradman first played for NSW before an ongoing career with SA. You could do the same analysis if you have time and patience on your hands for one-day and Twenty20 cricket. It was quite difficult in some cases to track which state a player was playing for when they made their Australian debut, especially if they moved state soon after. I have put the data here (some of the array formulae don't work in Google docs, and I have stripped out the macros, but you can redo them). If I have made a mistake, let me know! …


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Ep 141: Science of Superheroes - Harry Potter

2011-04-29 :: mrscienceshow@gmail.com (Marc West)

And we're back! It's been a while, but finally it's time for another podcast, so we've made it a long one. Take this episode on a long train ride or car trip, as Dr Boob and I explore the science of the spells of Harry Potter.

Attempting to find scientific and engineering solutions to Harry Potter spells is probably the most difficult task we have set ourselves yet, so we would be very interested to hear how you would made the Harry Potter spells a reality. The spells dealt with in this episode are:
Lumos - Producing light from the end of a wand (A voice activated torch seems a logical solution), Aguamenti - Shooting water from the end of the wand, Alohomora - Picking a lock at a distance, Expecto Patronum - Protection against evil dementors in the form of some virtual creature, Sectumsempra - Slicing your opponent open, Aparecium - Reading invisible ink, Accio - Summoning things to you, Expelliarmus - Disarming your opposition of their wand, Confundo - Confusing the victim, Stupefy - Stunning the victim, Invisibility cloak - Covering yourself in a cloak to make yourself invisible, Imperio - Forcing your victims to obey your commands, Obliviate - Erasing the memories of the victim, Legilimens - Telepathy. Although some of these are quite clearly impossible at the moment, in every case we have come up with a scientific or engineering solution to take us at least part of the way there. Listen in to find out what we came up with, and please write in and let us know where we have gone wrong or what you would do.

Click play below or listen to this show here.

Santos, V., Paula, W., & Kalapothakis, E. (2009). Influence of the luminol chemiluminescence reaction on the confirmatory tests for the detection and characterization of bloodstains in forensic analysis Forensic Science International: Genetics Supplement Series, 2 (1), 196-197 DOI: 10.1016/j.fsigss.2009.09.008 A.J. Barnier and D.A. Oakley (2009). Hypnosis and Suggestion Encyclopedia of Consciousness DOI: 10.1016/B978-012373873-8.00038-4 T.C. Jerram (1982). Hypnotics and sedatives Side Effects of Drugs Annual DOI: 10.1016/S0378-6080(82)80009-3 Wood, B. (2009). Metamaterials and invisibility Comptes Rendus Physique, 10 (5), 379-390 DOI: 10.1016/j.crhy.2009.01.002


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Search Traffic in Egypt

2011-02-13 :: mrscienceshow@gmail.com (Marc West)

The Egyptian Revolution of 2011 was a series of street demonstrations that demanded the overthrow of the Egyptian President Hosni Mubarak. One of the government retaliations to the protests was to shut down the Internet. Imagine you're a youth in Egypt and all of a sudden you don't have access to the Internet with its social networks, games and unlimited porn. You'd protest too! Great strategy guys...

Here is the Google search traffic in Egypt normalised against world-wide Internet traffic, created through Google Transparency Report. As you can see, it took a little less than a week for the government to realise their folly.


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Science events for February, and a little bit of Valentine love

2011-02-08 :: mrscienceshow@gmail.com (Marc West)

February is a big month for science, and a big month for love. Here are a couple of events that caught my eye.


The Global Google Science Fair is an online science competition open to all students aged 13 to 18 from around the world. Unfortunately, I'm now way too old to enter, but were I still at school, this would be a fantastic opportunity to have some fun with science and technology. Scientific American, Lego, National Geographic and CERN are partners in the science fair, whose winner will receive a $50,000 scholarship, a 10-day trip to the Galápagos Islands and a virtual internship at Lego or a three-day site visit to CERN, Google or Scientific American.

The idea behind the show is that it is a chance for participants to showcase their ideas and experiments. Entrants are required to submit their work either as a video or slide show on their website (using Google products of course), and the works can fall into the following categories:
Computer Science & Math Earth & Environmental Sciences Behavioral & Social Sciences Flora & Fauna Energy & Space Inventions & Innovation Physics Biology Chemistry Food Science Electricity & Electronics Check out the Official Rules carefully and watch the video below for an introduction:


The Powerhouse Museum is opening three new exhibitions in February and March 2011. The exhibitions, Engineering Excellence (open now), designTECH (opens 19 February) and Student Fashion (opens 12 March), showcase emerging innovators and designers in New South Wales.

Six local and international contemporary engineering projects that recently received industry awards are on display in Engineering Excellence. They include a spectacular, fully-glazed building, design-engineered to a complex geometry with a unique waste collection and removal system, in one of the Middle East’s biggest developments in Abu Dhabi; an articulated head featuring a robotic arm attached to the image of a human face that ‘chats’ with the visitor; an internet laboratory for engineering students living and working remotely; new technology for producing renewable energy for electricity generators; a new optical device for microscopes that lights up hard-to-detect bacteria; and a new track safety system for a 350km per hour China Fast Train project.

Furniture, fashion, technology and leisure products are among more than twenty HSC student works in designTECH.  Humanitarian concerns such as the 2010 Haiti earthquake and the use of child labour in manufacturing, and health and safety issues such as 2009 swine flu and pool drownings were just a few of the motivating factors that inspired the student works. Some of the unique ideas on show include a homeless shelter designed for natural disasters; a brake device for runaway prams; a supermarket trolley aid for the elderly; a learner driver log iPhone app; and a pool fence alarm system.

Adelaide (and the world):

We've blogged and podcast about the science of love and sex many times, and with Valentine's Day coming up, the Royal Institute in Adelaide is putting on a special love themed event, Seven Deadly Sins: 'Lust' - Is Love Blind? Running the show will be Rob Brooks, who we spoke to at the end of last year in Ep 136: Sexual Selection about how evolution not only favours animals with the ability to survive, but also those who are attractive to the opposite sex and therefore more likely to reproduce. If you can't make the Adelaide event, it will streamed live on their site.

While we're on the topic of love and Valentine's Day, if you are looking to get the attention of that one special person, check out the Science of Speed-Dating, and our Scientific Dating Tips. If you are lucky enough to be waist deep in romance, then check out the reasons why we fall in love, and how love is simply a chemical process in the brain. And if you simply just want to get lucky, then check out:
Can you recycle condoms? And can you make them out of cocoa? Should you have sex before sport? Here is what the phone hotline 118118 thinks, Perhaps you're interested in older ladies, Or maybe risky sex is your thing.... If you think this whole love and sex thing is just one big joke, then perhaps the idea that those who are more sexually appealing may be dumber might be up your alley. Or talk sex over a beer with the Beer Drinking Scientists. …


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Ep 140: The Redback Spider invasion of New Zealand

2011-01-24 :: mrscienceshow@gmail.com (Marc West)

Research published in Biological Invasions shows that Australian redback spiders are invading New Zealand and could become established in many urban areas around major ports.

The paper, The invasive Australian redback spider, Latrodectus hasseltii Thorell 1870 (Araneae: Theridiidae): current and potential distributions, and likely impacts, details recorded sightings of redback spiders in New Zealand, then used biological and climatic information to reveal where redbacks could establish. Warm, dry conditions in some eastern areas of New Zealand are suitable for redback spiders to become established, and they are likely to spread further as they are surviving in places with relatively high rainfall. Urban areas, for example, provide shelter from the rain. The spread of redbacks is likely to have arisen from the establishment of new invasions through New Zealand's ports.

There is genetic evidence that redbacks have interbred with the protected, endemic katipo and there is a danger that redbacks could competitively displace katipo or cause extinction by interbreeding. Redbacks are also a public health issue as they have the potential to become established in areas close to urban populations. Successful border control already produces regular interceptions of the redback as well the invasive brown widow and the western black widow. Both these species are related to the redback and have similar habitat and climate requirements.

I spoke to lead researcher Dr Cor Vink about this work and how they are developing new approaches and tools to ensure harmful organisms are kept out of New Zealand.

Click play below or listen to this show here.

Cor J. Vink, José G. B. Derraik, Craig B. Phillips, & Phil J. Sirvid (2010). The invasive Australian redback spider, Latrodectus hasseltii Thorell 1870 (Araneae: Theridiidae): current and potential distributions, and likely impacts. Biological Invasions


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And introducing....

2011-01-15 :: mrscienceshow@gmail.com (Marc West)

Hope you've all had a wonderful Christmas and New Year. We'd like to introduce you to our little bloke, Luka, born on the 29th December 2010. Everyone here is happy and healthy, if a little tired. I'll get back to the blogging and podcasting soon... …


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Ep 139: Christmas special - Santa, sport and out-takes

2010-12-24 :: mrscienceshow@gmail.com (Marc West)

It's scarcely believable that another Christmas has rolled around! I hope that 2010 has been a wonderful year for you.

In this year's Christmas podcast, I've compiled some of my favourite segments from the last few years. First up, I chat to Bianca Nogrady, who assembled a crack team of health experts to look into the health of Santa Claus. Not only does he eat copious amounts of sugar and drink gallons of beer, he is also at risk of altitude sickness, deep-vein thrombosis, jet-lag, zoonotic diseases from exposure to wild reindeer and countless other problems associated with lack of sleep and poor diet. Not to mention all the concerns associated with smoking. However, he does compile the naughty/nice list each year, keeping his mind active, and unlike many other elderly folk, he gets out of the house and travels. You can read more about the findings of the Santa-team in Bianca's original article Health alert for Christmas visitor, and also at Ep 98: Santa Claus - a fat, diabetic substance abuser?

Next up is a classic out-take from Diffusion Science Radio from the velvet-voiced Matt Clarke discussing the fact that some women are allergic to their partner's semen. You will also hear the laughing of myself, Darren Osborne, Lachlan Whatmore and Tilly Boleyn (and possibly Ian Woolf). These same folk then join me in an interesting, and irreverent, take on some of the mental aspects of cricket. These recordings were originally released in the episode North Koreans, Mammoths, Invisibility and what did not make it to air on the Diffusion Radio Science Show.

Take care this break, and see you in the new year, when my family will have expanded by one!

Click play below or listen to this show here, and have yourself a merry Christmas!


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Ep 138: The health benefits of breakfast

2010-12-23 :: mrscienceshow@gmail.com (Marc West)

A world first study conducted by Menzies Research Institute Tasmania has shown that skipping breakfast over a long period of time may increase your risk of heart disease and diabetes.

The study, Skipping breakfast: longitudinal associations with cardiometabolic risk factors in the Childhood Determinants of Adult Health Study, published in the American Journal of Clinical Nutrition, followed up a 1985 national sample of 9–15 year old Australian children. The original work looked at whether these children ate breakfast before school. In 2004–2006, the authors of the new research tracked down 2184 participants of the original study (26–36 years of age) and enquired into their breakfast eating habits. This style of study is called a Longitudinal Study.

After adjustment for age, sex, and sociodemographic and lifestyle factors, participants who skipped breakfast in both childhood and adulthood had a larger waist circumference, higher fasting insulin, and higher total cholesterol concentration than did those who ate breakfast at both time points. The researchers conclude that skipping breakfast over a long period may have detrimental effects on cardiometabolic health.

I had a great chat to lead researcher Kylie Smith about her study. Listen in to this show here (or press play below):

Songs in the podcast:
Harry Allen
"Breakfast At Tiffany's"

from "I Love Mancini" Amy Stephens Group
"Breakfast In Atlanta"

from "My Many Moods"
Smith KJ, Gall SL, McNaughton SA, Blizzard L, Dwyer T, & Venn AJ (2010). Skipping breakfast: longitudinal associations with cardiometabolic risk factors in the Childhood Determinants of Adult Health Study. The American journal of clinical nutrition, 92 (6), 1316-25 PMID: 20926520


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2D / 3D / 4D Baby Ultrasounds

2010-12-13 :: mrscienceshow@gmail.com (Marc West)

Being able to see your unborn child is truly an amazing experience. Ultrasound (diagnostic sonography) is a common diagnostic tool for, among other things, imaging the foetus to determine its age, look for abnormalities and observe blood flow in the umbilical cord. But possibly its most memorable effect is seeing your baby's heart beat - and in 3D/4D ultrasounds, seeing your baby's face.

The term "ultrasound" applies to acoustic energy (sound) with a frequency above the audible range of human hearing (20 Hz -20 kHz). When used in medical imaging, an ultrasonic sensor (or transducer) is placed on the mother's belly and produces pulses of sound. The frequencies used for medical imaging are generally in the range of 1 to 18 MHz. High frequencies (7-18 MHz) can be used to look for fine details but have low penetration, so to image deep tissue, lower frequencies (1-6 MHz) are used.

The sound waves are partially reflected from layers between different tissues inside the mother's body. Sound is reflected anywhere there are density changes - for example, at the baby's skin where it meets the amniotic fluid. The baby's internal organs can also be imaged depending on what frequencies you use. The reflected sound is then "heard" by the transducer, and the data analysed to produce the image. The amount of time it takes for the echo to rebound relates to how deep the sound penetrated, and the strength of the return signal relates to both the material it is reflecting off and its depth. The deeper the tissue from which the signal is being echoed, the quieter the return, simply because there is more sound loss (attenuation) the further the sound travels (it gets absorbed, scattered and reflected along the way). This information allows an image to be built up, whereby pixels at the appropriate depth are coloured by the strength of the return at that point. Generally, the sound waves are not 100% reflected at any stage - you can see "behind" objects because some sound penetrates through. However, as less sound is penetrating the deeper you go, the signals become fainter.

2D Ultrasounds

The typical ultrasound image is a "2D" image like the one above. In this image, the transducer is at the top and is sending sound waves down. The image is essentially a slice through the mother. It's called a 2D image as we can only see two dimensions - left/right and up/down. The 2D image is built by firing a sound beam down, waiting for the return echoes, and then firing a new pulse at a slightly different angle. This continues until an arc is swept. Combining the data from each line after the arc is swept gives the 2D image. The following images come from the excellent resource Basic ultrasound, echocardiography and Doppler for clinicians, by Asbjorn Støylen. The left image shows the transducer scanning whilst the right image shows how the pulses are sent down in lines.

Continual rescanning means that a 2D video can be produced with roughly 50 frames per second. The human eye can see about 25 frames per second and so the video looks smooth. This frame rate is also more than enough for 2D temporal visualisation of the baby's heartbeat (~70-150 beats per minute depending on age) and to watch blood flow through Doppler ultrasound. Due to the Doppler effect, the sound pulse will rebound with a higher frequency if it hits something moving towards it, and a lower frequency if it echoes from something moving away from it - this is the same reason the noise of a car has a high pitch when moving towards you, and a low pitch as it moves away. As blood is moving in the umbilical cord, the ultrasound can be coloured by the Doppler information to show the blood flow.

3D Ultrasounds

3D images are a fairly recent advance in diagnostic sonography. Instead of just seeing a slice through the mother, the images can show a surface - essentially adding depth (the third dimension) to the 2D image. Imagine you are looking at a car from front on - you have no idea how long the car is and you have no information on how many doors it has or if the boot is open. However, if you look at the car from another angle, you can figure this out, and the more angles you look down, the more depth information you can gain. This is essentially what a 3D ultrasound does - it stitches together multiple 2D shots from different angles to produce the image. Modern transducers have the ability to scan multiple cross-sections. If the baby is moving, there may be some blur, but as image processing is becoming quicker, the 3D images are becoming clearer. The colour of the image is not real as there is no way to see colour inside the mother. 3D scans provide information for the diagnosis of facial anomalies, evaluation of neural tube defects, and skeletal malformations, and also helps the parents bond with their unborn child (it's very cool). However, when compared to 2D scans, they aren't as useful for the diagnosis of congenital heart disease and central nervous system anomalies. One of the reasons why this is the case is because they are static, which leads us to...

4D Ultrasounds

The term 4D refers to the addition of time to 3D scans. This is a very recent advance as it is only in the last few years that we have had the computing power to not only stitch together the 2D images to make the 3D images, but to create the 3D images quickly enough to play them consecutively as a video. Modern 4D scans play at roughly 12 frames per second, so they are a little jumpy.

Here is a little video I put together of our 4D scan.

I don't know if there is an upper bound on what ultrasound technology can do - as the speed of sound is ~1540 m/s in human soft tissue, and you have no choice but to wait for the return signal before you can process the image, it may be that a high video frame rate with decent resolution is unobtainable. Resolution depends on how many different lines you fire down to make the first 2D image - more lines mean better resolution, but currently you have to wait for the echo from one line before sending down the next, which means it takes longer to produce an image. I imagine one way of improving this would be to send down all the lines at once with slightly different frequencies or waveforms, and as such when the echo is received you would know where it came from. Perhaps this is already being done - let me know if you know more!

Check out the video of Massive Attack's Teardrop in which there is a singing foetus, and I also have more images over at my ultrasound set on flickr.

Kurjak, A., Miskovic, B., Andonotopo, W., Stanojevic, M., Azumendi, G., & Vrcic, H. (2007). How useful is 3D and 4D ultrasound in perinatal medicine? Journal of Perinatal Medicine, 35 (1), 10-27 DOI: 10.1515/JPM.2007.002  Carrera, J.M. (2006). Donald School Atlas of Clin. Application of Ultrasound in Obs/ Gyn www.jaypeebrothers.com DOI: 10.5005/jp/books/10226 Khanem, N. (2007). Donald School Textbook of Ultrasound in Obstetrics & Gynecology The Obstetrician & Gynaecologist, 9 (2), 140-140 DOI: 10.1576/toag. 


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Ep 137: Can your environment change your DNA?

2010-11-23 :: mrscienceshow@gmail.com (Marc West)

Did you know that worker bees and queen bees have exactly the same DNA?

Although they look and behave differently, at birth they have the same genome. Young queen larvae are fed a diet of Royal Jelly, a substance secreted by the worker bees which includes B-complex vitamins, proteins, sugars and fatty acids. It also contains trace minerals, enzymes, antibacterial and antibiotic components, and vitamin C. This concoction not only feeds the queen bees, it turns on and off various genes with what are known as epigenetic effects. Epigenetic effects - meaning "above the genome" - alter gene expression without affecting the baseline genetic code. They are the reason why cells in different parts of the body do different things. For example, liver genes are turned on in your liver but not elsewhere, even though every cell in your body contains all your DNA information. For humans, much of this happens when we are embryos before we are born, with various chemical signals switching on and off genes in various parts of the body.

The recent report The Honey Bee Epigenomes: Differential Methylation of Brain DNA in Queens and Workers, by Professor Ryszard Maleszka from The Australian National University’s College of Medicine, Biology and Environment and colleagues, details the extensive molecular differences in over 550 genes in the brains of worker and queen bees as a result of queen bee feeding with royal jelly.

The work is quite profound as it is a step towards understanding how our environment can change our DNA. There is a growing body of evidence that suggests some epigenetic traits may be passed on to following generations rather than just affecting the individual, and this could drastically change our understanding of the process of evolution. The work also has implications for the nature vs. nurture debate, if indeed our nurture can actually change our DNA - that is, our nature.

I had a fascinating chat to Ryszard about this study, the future of this work and his opinions on how this may change our understanding of evolution. Listen in to this show here (or press play below):

Please excuse the noise in the recording of the phone call.

Lyko F, Foret S, Kucharski R, Wolf S, Falckenhayn C, & Maleszka R (2010). The honey bee epigenomes: differential methylation of brain DNA in queens and workers. PLoS biology, 8 (11) PMID: 21072239


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Ep 136: Sexual Selection

2010-10-21 :: mrscienceshow@gmail.com (Marc West)

It's about time we put out a new podcast!

In this edition, I chat to Associate Professor Robert Brooks, Director at the Evolution and Ecology Research Centre, UNSW about sexual selection.

Charles Darwin described sexual selection as "struggle between the individuals of one sex, generally the males, for the possession of the other sex" and nature abounds with strange examples of where animal features have evolved way past their survival needs - for example, reindeer antlers, peacock plumes and quite possible human vocabulary - humans and other primates survived quite nicely without a wide vocabulary, why do we now possess one?

Rob is a leading world expert in the area, listen in to find out what he had to say.
Listen in to this show here (or press play below):

If you would like to hear more about the science of sex, check out The Beer Drinking Scientists episode Let's talk about sex.

Brooks, R. (1999). The dark side of sexual selection Trends in Ecology & Evolution, 14 (9), 336-337 DOI: 10.1016/S0169-5347(99)01689-4

Brooks, R., Hunt, J., Blows, M., Smith, M., Bussiére, L., & Jennions, M. (2005). EXPERIMENTAL EVIDENCE FOR MULTIVARIATE STABILIZING SEXUAL SELECTION Evolution, 59 (4), 871-880 DOI: 10.1111/j.0014-3820.2005.tb01760.x


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Ep 135: Why do I sneeze at the Sun?

2010-09-27 :: mrscienceshow@gmail.com (Marc West)

Do you sneeze at the Sun?

I do. My brother does. Both my parents do. In fact, we are a family of Photic Sneeze sufferers.

The Photic Sneeze Reflex (PSR), also known rather ridiculously as Autosomal Dominant Compelling Helioophthalmic Outburst (ACHOO) Syndrome (how long do you think it took researchers to figure out that acronym....) is a dominant genetic condition affecting around 10% of the population. When a sufferer moves from a region of darkness to a region of bright light - for instance, walking outside and looking at the Sun - multiple sneezes occur. Research into the disorder has yet to explain either its mechanism or an evolutionary reason for why it occurs. One theory is that there is a "short circuit" in the brain, with the stimulated optic nerve somehow triggering the sneeze reflex.

Professor Louis Ptáček runs the Laboratories of Neurogenetics at the University of California, San Francisco. The aim of the lab is to study familial disorders with strong genetic contributions, and thus localise and identify genes that cause human disease. Other conditions in which he is interested include migraine and epilepsy, and an intriguing condition whereby certain sounds cause seizures. He considers PSR to generally be a midly annoying condition, unless you are a combat pilot, where sneezing at the Sun could indeed be life threatening.

I had a really interesting chat to Louis about PSR, and I've left the recording a little longer than usual, as we were really able to explore some fascinating ideas involved with PSR - it was a great chat. Listen in to this show here (or press play below):

Other interesting write-ups of PSR include neurotopia and Scientific American.

This topic came in as part of my call for questions for Science Week, so thanks @lisushi for the question! I'll be putting up more blogs and podcasts to answer the other questions that came in over the next few weeks.

Breitenbach RA, Swisher PK, Kim MK, & Patel BS (1993). The photic sneeze reflex as a risk factor to combat pilots. Military medicine, 158 (12), 806-9 PMID: 8108024 

Langer N, Beeli G, & Jäncke L (2010). When the sun prickles your nose: an EEG study identifying neural bases of photic sneezing. PloS one, 5 (2) PMID: 20169159 

MADIGAN, J., KORTZ, G., MURPHY, C., & RODGER, L. (1995). Photic headshaking in the horse: 7 cases Equine Veterinary Journal, 27 (4), 306-311 DOI: 10.1111/j.2042-3306.1995.tb03082.x

Songs samples in the podcast:
The Steve Wilson Band 
"Stare At The Sun"
from "Sideshows And Fairytales"
Buy at iTunes DJ Smiths vs Markanera
 "Watching the Sun Goes Down"
from "Watching the Sun Goes Down"
Buy at iTunes Alexis Cuadrado 
"Bright Light"
from "Puzzles"
Buy at iTunes


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The Beer Drinking Scientists talk Sex

2010-09-05 :: mrscienceshow@gmail.com (Marc West)

Over at my other podcast, The Beer Drinking Scientists, we like to tackle the big science topics down at the pub. And what better topic to talk about over a beer than sex?

Darren and Marc review the history of research into sexuality, including the seminal Kinsey Reports, the Masters and Johnson research into the diagnosis and treatment of sexual disorders and dysfunctions, and the more recent, and intriguing, study that Partner wealth predicts self-reported orgasm frequency in a sample of Chinese women.

We also take a look at how sex might have evolved. Why is it that it takes two people to have sex? Wouldn’t evolution be quicker if we could simply reproduce on our own? This is known as the twofold cost of sex - what are the benefits of having two people mix their genes to reproduce? Sexual Selection is another topic up for discussion. Charles Darwin described sexual selection as “struggle between the individuals of one sex, generally the males, for the possession of the other sex” and nature abounds with strange examples of where animal features have evolved way past their survival needs - for example, reindeer antlers, peacock plumes and quite possible human vocabulary - humans and other primates survived quite nicely without a wide vocabulary, why do we now possess one?

We could not possibly tackle this topic without discussing the Sexy Son Hypothesis, or without having a chat to the punters in the pub. Tune in to hear the public’s thoughts on sex, the science involved, length, width, money, style, cuteness, attraction and also hear Darren provide solace to a broken hearted drinker.

Of course, over a beer, much is talked about and you’ll have to tune in to catch the rest! Get over to The Beer Drinking Scientists website to subscribe, listen in to this show here, or press play below:


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Ep 134: Climate Change Vox Pops in Paddington

2010-08-10 :: mrscienceshow@gmail.com (Marc West)

With climate change seemingly falling off the agenda of Australia's major political parties in the lead-up to the 2010 federal election, I wanted to see whether this inaction reflected the views of the community. I headed down to Paddington Markets, on Ox…


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Ep 133: Senator Bob Brown on Science Policy for the 2010 Australian Election

2010-08-10 :: mrscienceshow@gmail.com (Marc West)

In the tradition of UK newspapers, this blog/podcast has decided to throw its (rather small) weight behind a political party at each Australian federal election. And this time around, the decision is easy. The 2010 Australian federal election is the most…


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Ep 132: Science of Superheroes - The Hulk

2010-07-21 :: mrscienceshow@gmail.com (Marc West)

The science of superheroes is taking a green and nasty turn this week as we discuss the largest superhero of them all, The Hulk. Join myself and our regular superhero expert Dr Boob as we delve into the science of how we might realise The Hulk in the lab.…


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Ep 131: The Science of Sport at Altitude

2010-07-11 :: mrscienceshow@gmail.com (Marc West)

Professor Chris Gore, head of Physiology at the Australian Institute of Sport, has had over 20 years experience in the science of sport at altitude, including the study of the physiological effects of altitude on the body and designing altitude training r…


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Ep 130: Using Twitter to predict Movie Box Office Revenue (and the future...)

2010-06-23 :: mrscienceshow@gmail.com (Marc West)

Ever wondered what good Twitter actually does? Personally, I love it, but really, is it anything but noise? One of the pipe dreams for online social media is the ability to track opinions and interests in real time. In their paper Predicting the Future Wi…


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Ep 129: The domestication of the dog and the Australian dingo

2010-06-23 :: mrscienceshow@gmail.com (Marc West)

The Australian dingo and the New Guinea Singing Dog may be the world's oldest dog breeds. The study, Genome-wide SNP and haplotype analyses reveal a rich history underlying dog domestication, which was published in Nature and is a major genetic study into…


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Ep 128: Another demotion for Pluto? Or is it about to become King of the Dwarfs?

2010-05-05 :: mrscienceshow@gmail.com (Marc West)

Is Pluto is set to become an also-ran in the astronomical world? Already demoted from the exalted planet club, Pluto could be joined by up to 50 other objects in the ever-expanding "dwarf planet" club if the new definitions of dwarf planet, recently propo…


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Ep 127: Conditioning quolls against cane toads

2010-04-27 :: mrscienceshow@gmail.com (Marc West)

The cane toad in Australia is a text book example of a feral species. As an introduced species, it has no natural predators and out-competes native animals for food and habitat. Things are made worse by the fact that cane toads are highly poisonous - so p…


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