## Archive for the ‘Science’ Category

### My new geek clock

I’m loving this new addition to my flat: a geeky maths/science clock. It was designed by myself and Albert and then built by Kate Wharmby, who is also very talented at making stained glass and has made me a lovely trefoil knot too.

I thought I would go through the numbers and say what they mean and why we chose them. All physical constants are in standard SI units.

1. ℏ × 1034 = 1.05 is the reduced Planck constant; that is, the Planck constant divided by 2π. This number relates the energy of a photon to its angular velocity and is one of the basic units in quantum mechanics. Its existence means that energy only comes in discrete packets, or quanta, which was a massive discovery in 20th century physics.
2. $\sum_{i=0}^{\infty} 2^{-n}$ is the sum $1 + \frac{1}{2} + \frac{1}{4} + \frac{1}{8} + \dots$ which turns out to be exactly equal to 2. It’s an example of a geometric series and was first discussed in ancient Greece when Zeno came up with his paradoxes. He claimed that motion was impossible, because before you could get somewhere you’d have to get halfway there, but then you’d have to get halfway to the halfway point and so on. However, despite the infinite number of steps in the sequence it actually has a finite value.
3. c × 10-8 =2.9979 is the speed of light in a vacuum, measured in metres per second. The theory of relativity says that this is constant, regardless of the observer, and that nothing in the universe can go faster than this. The fact that c is constant leads to lots of crazy consequences, such as time passing slower for moving objects and moving objects shortening in length.
4. $\int_1^5 \ln x \, dx = 4.047$ is the integral (area under the curve) of the natural logarithm function between $x=1$ and $x=5$. Logarithms were invented by the Scottish mathematician John Napier and are important in many branches of maths and science. The natural logarithm is related to the mathematical constant e, which arises whenever a quantity is growing at a rate proportional to its current value; for example, compound interest.
5. det(12n488) is the determinant of the 488th non-alternating 12-crossing knot. This was a knot which featured in my thesis, as I used new techniques to show that it had infinite order in the knot concordance group. Finding the determinant was the first step in this method. You can find tables of knotty things on the website KnotInfo, including any values which are still unknown.
6. 29ii = 6.03 shows off the surprising fact that an imaginary number (the square root of -1) to the power of an imaginary number is actually a real number. Actually, i is equal to $e^{-\frac{\pi}{2}}$.
7. $\phi^{2^2} = 6.84$ is the golden ratio squared and then squared again. The golden ratio arises if you want to divide a line into two parts so that the ratio of the larger to the smaller part is the same as the ratio of the larger part to the whole line. It is often described as the most aesthetically pleasing ratio, and is also the ‘most irrational’ number in the sense of being most badly approximated by rational numbers.
8. NA.kB = 8.314 is the ideal gas constant which relates the energy of a mole of particles to its temperature. It is the product of NA, which is Avogadro’s constant (the number of particles in one mole of a substance – see 12), and kB, which is the Boltzmann constant (which relates energy of individual particles to temperature).
9. me × 1031 = 9.109 is the rest mass of an electron which is one of the fundamental constants of physics and chemistry. It is actually impossible to weigh a stationary electron, but we can use special relativity to correct our measurements of the mass of a moving electron.
10. g = 9.81 is the acceleration of objects in a vacuum at sea level due to Earth’s gravity. This is actually an average value, as the force of gravity varies at different points on the Earth’s surface. Things affecting the apparent or actual strength of Earth’s gravity include latitude (since the Earth is not a perfect sphere) and the local geology (since the Earth does not have uniform density). The force is weakest in Mexico City and strongest in Oslo.
11. $\frac{ \pi^e}{2}$ = 11.23 is a combination of everyone’s favourite mathematical constants, pi and e. These numbers are not only irrational but are transcendental, meaning that they are not the roots of any integer polynomial equation. It is still unknown if $\pi^e$ is transcendental, although we know that $e^{\pi}$ is.
12. 12C = 12 is the isotope of carbon having six protons and six neutrons in its nucleus, giving it a mass of 12 atomic mass units. More importantly for chemists, IUPAC defines the mole  as being the amount of a substance containing the same number of  atoms (or molecules, electron, ions etc) as there are the number of atoms in 12g of carbon-12 (which is Avogadro’s number – see 8).

### Guest Post: Topological Crystallography in Stockholm

Here I am at one of the beamlines at Petra synchrotron, at DESY, Hamburg. The tube behind me is where the beam comes from… scary!

Albert here! Some of you may recognise me from Haggis’ Twitter feed and from Haggis’ 2011 New Year’s post (along with the rest of our family!). Last week I was in Hamburg at PETRA III, a synchrotron at DESY. After some successful measurements there, I made the short hop across the Baltic Sea to the lovely city of Stockholm, for the 4th International School on Crystal Topology.

First I should say a little about what I do. I’m interested in chemistry, especially materials called Metal-Organic Frameworks (MOFs).

An example of one of the first MOFs, MOF-5. Chemists use rigid organic struts (top left) to link clusters of metal atoms (in this case four zinc atoms, bottom left) to build open framework-like materials (right).

These are a new type of material made from clusters of metal and oxygen atoms which are linked together by long rigid linkers – think of it kind of like a climbing frame. These materials are interesting as they might help to combat climate change by sieving out CO2 in a process called Carbon Capture and Storage (CCS made it into the Oxford English Dictionary recently!).

But what does this have to do with topology? Chemists simplify the structures of MOFs down to a series of rods (edges) and nodes where these rods meet (vertices) – the simplified structures are mathematical graphs. We can then see how the structure is connected together as a network, without unnecessary molecular clutter. As chemists we want a way to classify the networks of our materials for two reasons. Firstly, so we can see if similar networks have been made before by other researchers, and secondly to help us design new materials. We might, for example, find that a certain network is really good at storing CO2; using a linker molecule which holds onto CO2 really well and the right topology to form our target network, we could make a new material which is even better at capturing CO2. To classify our networks we need to use graph theory.

Charlotte Bonneau (left), Michael O’Keeffe (middle left), the person I hitched a lift to Stockholm with (middle right), Xiaodong Zou (right)

However chemists are not normally trained in graph theory, so this was the aim of the Stockholm school. The school was taught by Prof. Michael O’Keeffe (emeritus Regents’ Professor at Arizona State University), who taught us about the mathematical ideas necessary to deconstruct a crystalline network, and Dr Charlotte Bonneau (currently a full time mother to the adorable Leonie), who focussed more on the use of software to analyse crystal structures, such as systre and Topos.

During Mike’s lectures we were told about the graph isomorphism problem of determining whether two finite graphs have the same connectivity. This is of importance to chemists, as we want to be able to compare our networks to see if they have been reported before! Graph isomorphism is also a specific example of one of the million dollar maths problems, P versus NP, which asks whether every problem for which a solution can be quickly checked, may also be quickly solved by a computer. One of Mike’s collaborators, Dr Olaf Delgado-Friedrichs, has attempted to address the graph isomorphism problem in the program systre. systre uses a barycentric method to raise the symmetry of a collection of atoms in a graph to the highest symmetry representation. The barycentric representation is effectively like replacing all the edges in the graph with springs and these pulling the vertices to their weighted average positions. Although systre is able to classify most graphs, it is unable to deal with graphs where applying the barycentric approach causes two nodes to collapse into one another (a so-called collision – see picture). So unfortunately, it’s not a complete solution to P versus NP.

A graph showing a collision. When you put this into a baricentric representation, the two red nodes collapse into one another. Back to the drawing board for a solution to the graph isomorphism problem then…

The rest of the course was full of lots of useful information which will help in making new materials and further classifying old ones. The course as a whole was a lot of fun and it was great to meet such a friendly bunch of people! That’s it from me for the minute, but look out for more photos of me on Twitter at exciting scientific/mathematical locations – Albert out.

### Bright Club

When I told friends I was planning to spend the evening watching university academics doing stand-up comedy, the response was a look of confusion and a placatory “That should be…interesting.”

Academics and comedians normally form completely non-intersecting parts of a Venn diagram. After all, what is funny about a gamma ray burst, tree conservation or crayfish? When was the last time a seminar on genetics cracked you up with laughter? To be fair, I do often hear mathematicians making jokes, but normally they are so obscure that only the 3 other people in the room would have a clue why they were funny.

So I really didn’t know what to expect when I went along to Edinburgh’s first Bright Club at the City Cafe on Blair Street. I certainly didn’t expect there to be a long queue at the door because all the tickets were sold out! After a tense wait I was relieved to find myself inside, albeit with standing room only. In a stroke of luck, I spotted my colleague and fellow tweeter Karon McBride who squeezed me in on the seat beside her. She explained that she was quite interested at having a go at the comedy herself and was excited to see how the first session went.

Well, I don’t think that any of you readers are going to be surprised when I say that it was a fantastic evening.  Steve Cross, the founder of Bright Club, came all the way from London to start the proceedings, and we had the enthusiastically foul-mouthed Susan Morrison as our compère for the night. The first academic was none other than fellow mathematics PhD student Hari Srithkantha, which I’m very proud of because it was me who encouraged him to sign up for Bright Club! Hari is already making a name for himself in stand-up, taking part in the Chortle Student Comedy Awards and playing gigs around Edinburgh. However, it was great to listen to him making his research (into gamma ray bursts) the butt of his gags, which I think is something he hadn’t tried before. Even more than that, it was great to find out what he was actually researching! He is probably only the second person (after Matt Parker) to use a graph to make the audience laugh.

Of the other 7 academics, I don’t think any of them had tried stand-up before, so I was really really impressed with their efforts. Highlights for me were Dan Ridley-Ellis, who talked about the stiffness of wood but managed to avoid all the obvious jokes, Zara Gladman, a zoologist studying crayfish who wrote a song about how they are damaging our ecosystems, and Dan Arnold, who talked about uncertainty and ‘unknown unknowns’. As well as laughing for the whole two hours, I also felt like I learnt a lot about all the science topics on offer, and thought it was an unexpectedly brilliant way of doing public engagement with science.

It is also great to see the nationwide news coverage that Bright Club is getting. The BBC covered the story back in February and the Edinburgh Evening News wrote an article earlier this week. BBC Radio Scotland are running a piece on Friday at 13:15 as part of their Comedy Cafe and there is going to be a BBC Fringe show in Edinburgh on 24th August with all the academics doing the show again. So if you missed it then don’t worry, there will be a chance to catch up – but only if you’re quick! Tickets for the BBC show are only available until 8th August (despite what it says on the website) so make sure you sign up pronto!

Bright Club is going to be a monthly event in Edinburgh, so I look forward to seeing Karon and other academics getting on stage and making people laugh with their research. It’s going to take a lot more persuading to get me to think about having a go though!

### A week in the life: Friday

Gosh, I’ve not done very well in keeping up with this series of blog posts, have I? For the past week I’ve been caught up in the Edinburgh International Science Festival, helping to chair some talks and run an exhibition at the National Museum of Scotland about game theory. More on those in another post perhaps.

So, Friday. Although it’s been over two weeks since this particular Friday, I remember it very well. It was on this day that we were lucky enough to have a visit by the distinguished professor Eric Mazur.

Mazur & Me

Although Mazur is distinguished in his field of physics (lasers, semi-conductors, optical fibres), it wasn’t a physics lecture that everyone turned out to hear. Surprisingly (even to himself) he has become most well known for his radical teaching method, known as peer instruction. The talk that he gives about this is really fantastic, and I recommend that everyone watches it on YouTube.

It is ironic that Mazur should be touring universities around the world, giving lectures about peer instruction, when a fundamental tenet of the theory is that we shouldn’t be lecturing to students! The idea is that people don’t take in information when they are forced to sit and listen to something; they have to be doing and discussing the subject matter in order to really engage with it. This became especially clear when Harvard University physics students were given a simple exam which tested their basic understanding of Newtonian physics.

Big truck vs little car

For example, suppose that a heavy truck and a small car crash into each other. At the moment of impact, is the force of the truck on the car (a) larger than, (b) smaller than or (c) equal to the force exerted by the car on the truck? Think about this for a moment…….. Your intuition is probably telling you that the truck exerts a larger force on the car than the car on the truck. Yet anyone who can remember their high-school mechanics should know Newton’s 3rd law: that forces are always equal and opposite.

What was interesting was that Harvard physics students got this question wrong almost as often as the general public did. It’s an extremely strong indication that students are only superficially learning information, memorising things in order to pass an exam but not really internalising the concepts. We see this all the time with our maths undergraduates too. They can compute all manner of difficult integrals and solve complex matrix equations, but in the end very few know what the answers mean or why they are important. What actually is the determinant of a matrix, or what does it mean to have an infinite decimal expansion?

But if lecturing doesn’t work as a means of education, then what else can we do? Eric Mazur’s answer is peer instruction, which works something like this. The students read the material in a textbook before the lecture, submit a list of things they don’t understand to the lecturer, then during class the students work through questions designed to address and correct their misconceptions. Questions are often presented in multiple-choice format and students have the chance to vote on an initial answer before discussing with their peers and then voting again on a new answer. From research into this method, it seems that students teach each other a lot more effectively than a lecturer can. They understand each other’s problems and can more easily get to the heart of the explanation. And nobody can just sit and sleep through the lecture, because there is constant discussion of the material in the class.

At Edinburgh, we would love to try and implement this method with our first year undergraduates in September. The main difficulty in starting out is getting those multiple choice questions which can really change people’s opinions about a subject. What are the common misconceptions in maths? When does our natural intuition override the definitions we are given in lectures, like in the physics example before?

The only university which has really implemented teaching like this in mathematics is Cornell University, and you can take a look online at their list of ‘Good Questions‘. Here’s one to get you talking:

Was there a time in your life when you were exactly pi feet tall?

A good question, to me, is one where you have an instinctive immediate answer, but then when you think more carefully you really get to very deep questions about the subject.

Can a person ever be exactly pi feet tall?

For example, someone might immediately think that the answer to the above question is “no”, because pi is an infinite non-repeating decimal and nothing can be ‘exactly’ pi feet long. But then they might think, is it really because pi is irrational that the answer is “no”? Was there ever a time when they were exactly 3 feet tall? Or they might think, there was a time when they were less than pi feet tall and now they are bigger, so surely there must have been a moment (however brief) when they were exactly pi feet tall. Discussions of this will get to the heart of the real number system and questions of approximation, which are essential for anyone studying analysis to master .

I would be really interested to hear from anyone with opinions about this. Do you remember which concepts in maths you struggled with the most? When do you think you learnt your specialist subject: through listening to lectures, or at home with a textbook, or chatting to friends? Do you believe that peer instruction can work or do you think the system is fine as it is?

### How to make a vortex cannon (and why!)

October has been a busy month of thesis-writing and conference planning (for a postgraduate conference “Engaging with Engagement” or “EwE” for short) but November is when life will really get exciting.  Julia has two masterclasses to give to S2 (13 year old) pupils, and we decided it was time to show that we meant business.  No more scrounging around the chemistry labs for bits of dry ice to put in the puny Airzooka.  It was time for a heavy duty smoke machine and a GIANT VORTEX CANNON.

I should probably say why this is necessary for a masterclass about knots, or you might think I’m slightly insane.  Well, once upon a time there were three great physicists in Scotland: Kelvin, Maxwell and Tait.  They wanted to understand the different elements in the periodic table.  What made an oxygen atom different from a calcium atom? One day Kelvin saw Tait experimenting with a vortex cannon; using a pungent mixture of ammonia and sulphuric acid he made smoke rings that could travel many metres across the room.

The scientists at that time believed in the existence of the luminiferous æther.  They thought that light was a wave, and that waves had to travel through something (you can’t have water waves without the water!), so this invisible substance was called the æther.  When Kelvin saw the smoke rings, he immediately had a great idea: that different chemical elements were different knots and links of the æther!  Not only was the idea beautiful and simple, but there was some evidence for it too.  Sodium, for example, has two distinct lines on its emission spectrum, indicating that it was made up of two linked knots.  Genius!

Maxwell went on to develop the physics of this theory while Tait started tabulating all the possible knots he could think of.  Thus was knot theory born!  Sadly the physical theory was proven to be wrong, because it was shown at the end of the 19th century that the æther could not exist, but the mathematics lived on and grew to great new heights.

For anyone who wants to read a detailed account of this story, there is a very good article by Dan Silver, in which he actually recreated the original vortex ring experiment!

Now, I like to tell this story to the kiddiewinkles, and I want to make it big and dramatic.  So I Googled “how to make a giant vortex cannon”, and this is what happened next.

1) I bought large garden bin.

2) I assembled some scary looking tools.

3) I needed to cut out a hole, about 6 inches in diameter, in the bottom of the bin.  This was not going to be easy!  A very sharp Stanley knife might have been my best bet, but I didn’t have one of those.  The way I did it was first to cut out a little hole using my biggest baddest meat cleaver:

Then I removed the saw from the hacksaw, put it into the hole and started sawing my circle:

This was almost certainly not the best way of doing things, but I got there eventually!I then filed down the rough edges and used a little scalpel thing to make the hole a bit more circular.  Don’t want the kiddies cutting themselves on sharp plastic!

[At this point, I thought I could get some artistic photos since the dustbin was open at both ends.  In the end I went for a James Bond style shot:The name is Bond.  Haggis Bond.  Double - 0 - sheep.]

4) I bought a cheap shower curtain:

5)  I covered the other end of the bin (i.e. the top end) with the shower curtain and secured with gaffer tape, cutting off the excess curtain.

6) I bought a smoke machine (Maplin, about £35) and got psyched up for hours of smoke-ring-generating fun!  (You put the smoke in, then bang the shower curtain end to push the smoke out through the hole, creating vortex rings.)

Unfortunately (and I’m really really sorry!) I got so excited about testing the cannon at this point that I forgot to remind Julia to keep taking photos/video.  So I haven’t got photos of the cannon in action, but when it finally gets used in a masterclass I will be sure to get some footage!

[Many thanks go to Peter Reid of SCI-FUN for supplying me with the hacksaws, scalpel, file and gaffer tape, and to Kizzy The Dog for accompanying me on the expedition to get the smoke machine.]

### Festival science

It’s August and it’s Edinburgh.  What else could there be to write about but the festivals?!  In particular the Fringe festival, which has had an amazing number of maths and science shows on this year.  I’m not sure if they’ve always been there and I’ve not noticed them, or whether something special has happened this year.  Putting on a science show at the Fringe seems like a brave thing to do: you need both a very talented (and preferably funny) performer/scientist, and also an audience who are enthusiastic about the material.  This year both of these requirements have very definitely been met!

And actually, it’s the second of these two things that I have been most surprised by.  I’ve met many talented science communicators over the years, so that’s certainly not a problem, but I’ve been pleasantly shocked about the enthusiasm of the Edinburgh audiences for all things scientific.  Again, I don’t know if it’s something special about Edinburgh (which is definitely a city full of well-educated and intelligent people) or whether science communication efforts are starting to pay off in a big way across the country.

Alex Horne

My favourite example of experiencing this enthusiasm was when I went to see a show by Alex Horne called Odds.  The blurb for the show does mention ‘numbers’ and ‘the universe’, but Alex himself has no scientific training and his comedy is not being branded as anything educational.  In his opening pitch, he told us that he would talk about golf (which got a small, slightly confused, “yay”), gambling (slightly louder “yay”) and quantum mechanics (giant cheer!).  I think that even he was taken aback by how excited the audience was about some physics being in the show!  And he did indeed get an awful lot of science, and especially maths, into his 1 hour.  I was at my most impressed when, in the space of 3 minutes, he managed to fit in a description of Hilbert’s hotel and its infinitely many guests.  Definitely a brave thing to try!

Your Days are Numbered: The Maths of Death

The only specially dedicated maths show of the Fringe is Your Days Are Numbered: The Maths of Death by Matt Parkerand Timandra Harkness.  It’s a breathtaking whirl through the subject of death statistics and the humour and fallacies that accompany them.  Did you know that you have a 0.01821% chance of dying by falling out of bed?  A 0.06584% chance of dying by “foreign body entering through natural orifice”?  Or simply a 0.000043% chance of dying during the show itself?  (You can actually get various clothing items with these fun facts on! I’m very tempted…)  In their hour on stage, Matt and Timandra teach us how to interpret statistics in the media, how to decide how dangerous something is (using death measure the ‘micromort’) and what things we can do to live longer (drink more alcohol!), as well as killing off the audience bit by bit.  And of course there is a very funny finale, which I won’t spoil in case anyone is still planned to see the show!

A staple of my festival diet this year has been Skeptics on the Fringe, which is an offshoot of the ‘Skeptics in the Pub’ movement and which I’m surprised not to have known about before.  During the Fringe they have been hosting a series of intelligent and often funny talks about all things skeptical, such as debunking psychics and ghost stories, explaining why so many people believe in the paranormal and exploring human psychology more generally.  Simon Singh talked about libel reform, Richard Wiseman discussed his research on luck (on Friday 13th!) and Matt Parker showed that coincidences are less rare than we expect.  Not only have I enjoyed the talks, but I’ve also been glad to get to know the organisers and other skeptics in the pub afterwards.  I guess I’m a bit reluctant to label myself as anything, even a skeptic, but I definitely feel it’s important to educate the public about pseudo-science and to give people an appreciation for how much more amazing real science is!  It might be fun to believe in the paranormal sometimes, but I think it’s much more exciting to learn about the human brain and how/why it tricks us into believing such things.

Some more science-y shows on during the Fringe are:

A lot of these shows are free and the rest are pretty cheap, so if you’re in Edinburgh and you haven’t been to any of these shows, then there’s really no excuse!  The annoying thing is that there is no dedicated ‘science’ section at the Fringe, so it’s hard to search for these kinds of shows if you don’t know about them already.  But the skeptics group, together with the organiser of the PBH Free Fringe, are going to try organising a special science fringe for next year, which would be great.  We just need to convince some pubs that science shows are very popular and would pull in large crowds!  From what I’ve seen of this year’s festival, I’m glad to say that that is entirely true.

### EUSci seminar

Tonight was the last EUSci seminar of the year, and we certainly had an interesting enough set of talks to see us through the empty summer months.  The speakers and audience seem to consist mainly of biologists, which should be an incentive for me to persuade some mathematicians to take the floor and give a talk in future!

Why don't we all look like this?

The first talk was about the Human Epigenome Project, by Sam Corless. He started off by asking the question “if every cell in our body contains the same DNA, they why don’t we look like amorphous blobs?”.  The answer is epigenetics.  Sam describes this as being like a set of post-it notes on every cell of your body, describing which genes from the DNA it wants to use or inhibit.  So there are epigenetic markers in your eyeballs to tell the cells to activate the eyeball genes and inhibit the bone-making genes, for example.

There are some diseases which are genetic (e.g. baldness); these result from mutations in your genes, and are not curable using drugs.  You’d have to replace your whole DNA with a non-mutant, normal version of the gene to fix the problem.  However, some diseases (e.g. diabetes and some types of cancer) have been shown to be epigenetic: it’s the markers on the cells which are the problem, not the DNA itself.  These diseases can very often be cured with drugs, which is why scientists are so interested in trying to understand these markers better.  The Human Epigenome Project has the goal of mapping out 1000 genomes in the next 7-10 years, which is going to be a very tough job but we are already seeing the benefits in new medicines that are coming out of it.

The second talk was called ‘An Evening of Excitation’ by Catie Lichten, and is a talk that Catie will be giving at the National Museum of Scotland in a few weeks’ time.  I’m sure it’ll go down great – it was certainly a hit with the postgrads!  Catie explained to us the principle behind fluorescence: some objects can absorb energy from a light source (e.g. the sun, or a lamp) and then emit it again later.  The colour of light tells you how much energy it has, with blue light being the most energetic and red light the least.  Under a UV lamp (which is very energetic!) some examples of objects which fluoresce are bananas (especially if they are a bit bruised!), tonic water (it goes a nice blue colour) and, of course, fluorite rock (where the word fluorescence comes from!).

There are other ways that objects can emit light other than fluorescence.

Glowing shrimp vomit

• Chemoluminescence: object emits light as a result of a chemical reaction. E.g. when you crack a glow stick.
• Bioluminescence: same as the chemi-one but happening inside a living organism. E.g. there is a shrimp whose vomit is bioluminscent in order to scare away predators.
• Triboluminescence: glowing that comes from breaking a material apart. E.g. Catie recommends breaking a polo mint apart with a pair of pliers in a dark room.

So, where is the research in all of this?  Well, there are jellyfish which are fluorescent, and it was discovered that their cells contain something called green fluorescent protein or GFP for short.  The discovery and isolation of this protein turned out to be so incredibly useful in biology that the guys who found it won a Nobel Prize in 2008!  Scientists inject this protein into living cells so that they glow and can be tracked and analysed in real-time.

The humble zebrafish

One animal they’ve been injecting it into is the zebrafish, which brings me nicely onto the third talk of the evening, by Carl Tucker.  His job was to explain to us why it is that zebrafish are being so useful in medical research.  Believe it or not, these little 4cm-long fish are being used to investigate diseases such as congenital heart defects, deafness, multiple sclerosis and muscular dystrophy.

Casper

The main reason that zebrafish are so useful is that the embryos are completely transparent, allowing scientists to see the development of all the internal organs.  At the harder-to-reach places they can inject GFP to be able to watch things like blood vessels forming.  A day-old fish heart is remarkably similar to a 23-day old human heart in terms of the way the tissues are forming (apparently).  Of course, adult zebrafish are fun to study too, but the majority of them aren’t see-through. (However, a transparent zebrafish has now been bred – it is called Casper for obvious reasons!)   We can use ultrasound to ‘see’ inside the fish, and they don’t even need anaesthetic because they fall immediately asleep when turned upside down!

Probably the most amazing thing about zebrafish is their ability to regenerate bits of themselves.  Being a bit evil, some scientists decided to shoot a hole in the heart of a fish using a laser; within 24 hours the fish was completely back to normal.  The spine regenerates fully within a month.  With a good microscope, you can simply watch the white blood cells ‘bimbling around’ (in the words of Carl) and heading off to heal wounds.  If we can figure out what exactly is going on inside these fish then there’s a clear hope of being able to heal similar wounds or defects in human hearts and spines.

So, another set of inspiring biological/medical talks that give us lots of hope for curing a range of diseases in the future.  Keep up the good work guys (but go easy on the poor fishies…)!

### Tam Dalyell Christmas Lecture

Professor Chris Bishop

Last Wednesday I was fortunate enough to be in the audience when Chris Bishop gave the Tam Dalyell Christmas lecture and accepted this year’s prize for science communication. Chris works in the Informatics department at Edinburgh and is also employed by Microsoft to do research on Machine Learning.  I loved the lecture not so much because I learnt new things about computers (although I was intrigued by the idea of using DNA as a computer) but mostly because I came away with so many ideas about maths outreach.

I’ve often complained that mathematics is the hardest of the science subjects to design outreach activities for.  In Physics and Chemistry there are many cool experiments – you can blow things up, make things really hot/cold (liquid nitrogen is always fun!), play with strange materials or recreate the conditions on, say, Mars.  Biology is directly relevant to all humans, no explanation required, whilst Technology and Computing are automatically cool because the future will depend so heavily on them.  On the other hand it is very difficult to motivate mathematics for its own sake; to explain the beauty without having to resort to explaining how it is useful in other subjects.  It is difficult to design physical experiments to illustrate things that we’ve only seen inside our heads, only manipulated using abstract symbols instead of hands.

Well, Chris Bishop has taught me that it is possible!  I just need to have a little more imagination, a little more ambition, and possibly access to the equipment in a chemistry or physics lab…  Here’s a clip of Chris explaining exponential growth using a sequence of mousetraps with ping-pong balls in them.  One ball is dropped onto one mousetrap, causing both the old and the new balls to rebound.  Each of those hits one other mousetrap, releasing four balls, etc.  A very simple but effective visual experiment that explains more in 5 seconds than a graph might in half an hour.  In another experiment, Chris gave the audience an idea of very small numbers by blowing up a snowman (it looked like cotton wool but was made of some kind of explosive) in a very short amount of time.

Another thing I learnt from the lecture is that if you have a really cool experiment, it is reasonably easy to find an excuse to fit it into your talk!  At one point Chris had a balloon filled with oxygen and hydrogen which he enjoyed exploding with a loud bang, just to make the point that chemical reactions usually only go in one direction.  Towards the end, he mixed liquid nitrogen with boiling water just to fill time whilst waiting for another experiment.  Both of these are visually and audibly stunning – they wake the audience up and get them listening to you, ready for what you *actually* want to say afterwards.

I’m already looking forward to my next maths communication challenge to see if I can come up with exciting visual and physical props to make maths sound just as cool as Chris made computing.  I’m sure it can be done!

### EUSci seminar

EUSci is the Edinburgh University Science magazine, and this evening they held the first lecture in a new seminar series. Before the talks there was pizza and drinks and plenty of opportunity to chat to other scientists: G and I got talking to a master’s student in ‘Ecological Economics’ (or ‘Economics for hippies’ as he put it) and a new PhD student in Chemistry (she gets to play with big machines that do lots of squeezing).

There were three talks over the course of the evening, all fairly biologically based.  I was very impressed by the quality of the speakers, who were only graduate students, and I’d like to tell you a bit about the topics they introduced us to.

First up was Katie Marwick talking about ‘Cognitive Enhancement’.  There are some drugs on the market that are designed to help people with mental disorders, for example, Ritalin for ADHD and Donepezil for Alzheimers, but the same drugs administered to ‘normal’ subjects resulted in an increase in some cognitive functions, such as alertness, memory and awakeness.  These drugs appear to have no short-term side effects but the long-term effects of regular use are unknown. Katie raised a lot of ethical questions associated with these kinds of drugs:

• Should they be legalised so that you can get them without a prescription?
• Is it fair for some people to take them, for example, before an exam?  Is this any more unfair than giving some children a private education or raising them with more books to read as they grow up ?
• Should some people be forced to take these drugs?  For example, doctors on night shifts to prevent them making as many mistakes?
• Would taking these drugs alter your personality?  If you considered yourself an absent-minded person then would removing that trait change who you see yourself as?

Sheep on St Kilda

Next was Adam Hayward talking about ageing in wild sheep populations.  A particular sheep population on St Kilda, to be precise.  He spends his time researching how much of an effect the environment has on the aging process of an animal.  To do this, he measures the amount of a certain parasite in the faeces of the sheep to see how good the sheep are at fighting off disease.  Firstly, it turns out that female sheep are much better at fighting the parasites than males, and they also have a life span that is about twice the male one (15 years compared with 7 or 8 years, although castrated males can live up to 17 years!). Adam also found that sheep who had lived a better life got better at fighting the parasites as they got older, whilst those who had had particularly hard lives (usually through weather conditions) tended to have more parasites in their bodies as they got older.  So, some lessons for humans: eat well and live happily (and get castrated!) if you want to have a better old age!

Finally we had Sarah Kabani who does her research on the parasite causing African Sleeping Sickness.  The parasite has a hard life, since it must survive both in the stomach of the tsetse fly (where it is attacked by gastric juices) and in the human bloodstream (where it is attacked by the immune system, but at least has plenty of sugar to feed on).  Sarah studies the transition in the genome of the parasite as it changes from ‘fly state’ to ‘human state’, using some fairly impressive-sounding technology.  Apparently they can print all 8,000 of the parasite genes onto a single microscope slide, and then they can make the genes glow at various intensities to show which ones are being used at which times.  The hope is that they can identify the genes which are most crucial to the parasite’s survival and then create drugs which can target these particular genes.

I very much enjoyed listening to all the talks, not just to learn more about the science but also to learn how scientists in other areas carried out their research.  There is quite a difference between a mathematician sitting with a pen and paper (and perhaps a computer) and biologists who are examining faeces, testing drugs on patients or scrutinising tiny glowing dots of genes.  I look forward to the next EUSci seminar!