The Sun's Bubble

This guest post is by Roger Duthie, Doctoral Candidate in Space Plasma Physics at the Mullard Space Science Laboratory.

In the late 1970s, Nasa’s Voyager probes began an epic journey through the solar system to explore the outer planets (Jupiter, Saturn, Neptune & Uranus). The “in-situ” measurements sent back from Neptune and Uranus by Voyager 2 are still the only local observations of the magnetospheres of these ice giants. But what is so very special and unique about the Voyager missions is that they are still operational over 35 years on and they are heading out of the solar system into new territory within our galaxy (the Milky Way) at large.

NASA's Voyager probes are the furthest man-made items from the Earth.
Image Courtesy NASA/JPL-Caltech.

The Earth's magnetosphere is also important for keeping
ahold of the planet's atmosphere. Image credit: ESA

The solar system of eight planets, plus many minor planets, asteroids and comets, is bathed in plasma ("solar wind") streaming outwards from our single, central star (the Sun). The Sun also provides a magnetic bubble in the form of the heliosphere, much like the magnetosphere which Earth possesses. The Earth's magnetosphere is the region around the planet where its' magnetic field dominates, and to some extent it protects the Earth from the impinging solar wind; the heliosphere plays the same role for the entire solar system, diverting the plasma of our galaxy's interstellar medium (the ISM). Where we are able to extensively probe and measure the structure of the Earth's magnetosphere and interaction with the solar wind with satellites and even observations made from the ground, the outer reaches of the heliosphere are the sole domain of the Voyager spacecraft. It happens that they are both heading out towards the 'nose' of the heliosphere, one into the northern part and one to the southern. The nose is the direction facing upstream within the flow of the ISM; in the downstream direction is the heliosphere's tail.

Apocalypse When?

Today marks the end of the Mayan long count calendar. So will the world come to an end today? Probably not. But the world will come to an end eventually, and there are a number of scientists looking into various possible ways it might happen.

All life on Earth depends on the Sun. Without its energy plants couldn't grow, and everything would freeze before you could say "it's a bit chilly today". So it is perhaps fitting that the Sun may also be the doom of the planet, in about 5 billion years. Or maybe 6 billion. Our Sun isn't big enough to explode as a supernova, that most spectacular firework of nature, but it will start to get bigger. Much as we fear running out of oil on Earth today, sooner or later the Sun will run low on hydrogen, and will start to change.

Our Sun is performing a balancing act. Its gravity is trying to make it collapse to a tiny point, but the energy from nuclear fusion counteracts it. You can think of it a bit like a balloon, the elastic skin is trying to squeeze it all together, but the pressure of the air inside is keeping it at a steady size. Take away the gravity (elastic) and it would fly apart - but take away the air pressure, and it contracts. When the Sun runs out of hydrogen, this energy will reduce, and gravity starts winning, making the star smaller (our Sun is a star). But it won't make it to a tiny point, because as it gets smaller the pressure gets higher (try compacting a tin can into the size of a pea) and nuclear fusion starts up again - this time, burning helium.

What would our Sun look like as a Red Giant?
Image credit: Hiro Sheridan (Creative Commons)

But as the core of the Sun collapses in this way it also gets hotter, so the outer layers of the Sun will expand and turn the Sun into a red giant - about 250 times bigger than it is now. There has been quite some debate about exactly how large the Sun will get, and what will happen to the Earth. Mercury and Venus will be swallowed, but the Earth may be left intact. As well as being scorched to a crisp, the Earth's gravity may create a 'tidal bulge' on the surface of the Sun, which could eventually drag the Earth down to fiery doom. Either way, you wouldn't want to be around.

Whether or not humanity will survive to see this happen is another question entirely. Or rather, several questions. There are so many possible ways for humanity to meet its grisly end, that it might feel we should be asking "which one will get us first?"

Biofuels – Why bother?

A while ago someone figured out that the Earth's ever fluctuating climate was now changing too quickly and blamed it on excessive emissions of carbon dioxide from human activities. The scientific community, policy makers and the general public more or less agreed that something ought to be done to prevent a global catastrophe. One of the main sources of such climate-harming gases is burning fossil fuels for our transport and industries. Conveniently, such fuels are also a cause of great economical and geopolitical distress in the whole world, since every country needs them but only a handful are able to supply them.

One possible solution for these issues is the use of "biofuels". Biofuels are burned to release energy, much like conventional fuels, but whose energy was stored by consuming (sequestering) carbon dioxide in the first place.  In other words, using biofuels only releases the carbon dioxide that was removed from the atmosphere by making it, resulting in no overall increase. The most obvious example of biofuel is wood.

This grass is grown as an annual crop for biofuel, burned at Drax power station in Northern England.
Photo credit: Allan Harris (Creative Commons)

Would you like to write for us?

Do you work in science and could share some of the things we don’t know about your area of expertise or research?

We’d love for you to write a guest blog post for us to publish on this site.

The process is pretty simple, all we need is a:

• Few hundred words on a topic of your choice
• Relevant image or two if possible
• Couple of sentences about you to help readers learn more about our guest bloggers.

We’ll run the post past our editorial team here before it’s published just to check it’s clear and easy for our non-scientist readers to understand.

As you can tell from our name, we are focussing on the Things We Don’t Know in science, so some background on the topic you're writing about is fine, but remember to tell us mainly about the things that are still open questions.

If you’re interested in writing a guest post for Things We Don’t Know drop us an email (contact@thingswedontknow.com) or leave a comment below.

Why do we yawn?

Babies: A common cause of yawning worldwide.
Image credit: Björn Rixman (Flickr/Creative Commons)

With a newborn baby at home, you probably won't be surprised to hear I yawn a lot these days. But why do I do it? Although the answer seems obvious: "I'm tired", the question "why do we yawn" is very much unsolved.

Boredom and tiredness are the two most stereotypical reasons for yawning, but what's the connection between these two conditions? Neither explains why we yawn because we saw somebody else doing so, and there's even a good chance that simply reading this article will make you yawn - and hopefully not because you're bored! Why do we yawn? Is there a physiological reason? Or a psychological one? How about evolutionary? Why can't we control whether or not we do it?

It has been suggested, and even taught, that yawning is a response to a need for more oxygen in the brain, but this has been shown to be wrong¹. But what about temperature? It could be that we yawn because the brain is getting too hot, and that yawning helps cool it down again. The cooling effect is thought to come from both the air flowing through the skull as a result of the deep breath, and by increasing the blood flow to the brain by stretching the jaw. This research so far seems promising, but this still wouldn't explain why it's contagious.

Things We Don't Know on stage in Berlin

The Sophiensæle, Berlin - former meeting place of the German Communist Party, and now a theatre, is probably not the sort of place you expect to find a group of entrepreneurs explaining their new business ideas. And yet earlier this week, that is exactly what happened.

Sophiensæle, Berlin

When I received an email from Thom Reinhard via the Hub, it immediately leapt out at me as something special. A business school graduate turned artist, Thom was looking to combine the worlds of business and art with his partner Monica Truong. Specifically, they wanted to put social enterprise on the stage.

You probably know Things We Don't Know is a social enterprise. What may not be obvious is that in order for us to focus on explaining science well, we have to pay a lot of attention to aesthetics, design, language, imagery... in other words, art. 

Their concept was quite straightforward - they wanted to conduct an experiment. "What happens if you take an entrepreneur looking for funding, have their pitch rewritten by a team of artists, get a professional actor to train them and put them on the stage?" The result is the theatre performance "Invest In Me!", part of the Freischwimmer international arts festival, now touring Germany, Austria and Switzerland.

The opportunity to connect with "non-traditional" science audiences was too good to miss. When I contacted Thom and Monica, they were immediately as excited about what we're doing as we were about them, and in August we announced that we would be joining their project.

A few short but very intensive months later, Tuesday evening was the show's première where we had a very warm reception from the audience. I can't say too much about the show itself without giving away surprises for our future performances, but it was great to connect with people from both the art and business worlds, and hear their feedback and perception of what we're doing. I will say that we have three very unique social entrepreneurs, with very different concepts and equally unique performance styles.  It was particularly interesting to hear one person describe our concept as creating the first "uncyclopedia", we hadn't really looked at it like that!

Setting up the "Invest In Me!" stage

For anybody who saw us on stage and is now reading the site, thank you for your support! Next stop: Vienna.

We’re recruiting!

Would you like to join Things We Don’t Know in explaining the questions to which science still seeks the answers?

We are creating an interactive repository where people can read about all the mysteries that science has not yet found the answer to - in other words, the rationale for current scientific research.

To help fill this repository with the "things" that we don't know, we are employing interns from universities around the world, and have a new vacancy.

We’re looking for a student currently studying Chemistry, or a related subject, to join the team on a part time basis. The role will require you to explain complex problems in simple language, and involve interviewing science researchers at your institution and writing up these pieces for the database. You will learn and develop a range of skills - improving writing skills, learn how to interview people, manage your own time etc.

The role is a paid internship, working part time (approximately 10h/wk) initially for a 3 month period, starting in January 2013.

Our main office is in London, but our team is intentionally distributed around the world and we rely heavily on digital communication and collaboration tools. As the role is intended to run concurrently with studies, we don't expect the successful candidate to be working from our London based office. Indeed, given the role requires talking to researchers at your university, it would make little sense! Therefore you will be "working from home". 

If this opportunity interests you and you think you fit the criteria please send your CV and covering letter to our recruitment team by emailing recruitment@thingswedontknow.com by 17:00 on Friday 30 November 2012.

Open Questions in Embryo Development

There are many things we still don't know about the very first hours of an embryo's development. In this time, does an embryo separate its back from front? Left from right? Or is this decided later?

We know about certain pathways that are involved in the early development of embryo.  But do we have the whole picture? And how can we even try to look at it?

This is what I am interested in my work. On my daily commute people often ask what it is that I work with. I tell them I use a technique to try to look at all the proteins at once within early embryos, mass spectrometry proteomics.

"What kind of embryos?  Human (with varying tones)? Mouse? Rat?"

"No."  I reply.  "Frogs."

A frog embryo, more commonly known as 'Frogspawn'.
Image credit: Andrew Michaels (Creative Commons)