Summer Physics Internships 2013

Happy Easter from the TWDK team! If you've been following us for a while now then you will probably remember Jon Cheyne, who wrote a number of articles for us last summer while he did an internship with us through the South East Physics Network (SEPnet).

So it is with great pleasure that we can announce we will be hosting another two physics interns through our partnership with SEPnet this summer, and we've already received a lot of really great applications. We'll be holding interviews and making our decision over the next few weeks, so you can look forward to some more great posts from June onward by our new interns!

The beast with a billion backs: Part 1

We like to think of ourselves in the singular, but the reality is we are a swirling composite of thousands of species, more accurately thought of as an ecosystem than as an individual.

There is the core ‘us’, the cells that contain our DNA. But we are also like the land on which a rich forest might grow, with every niche – every nook, cranny, and crevice – a unique home for some of the trillions of bacteria that call us home. Together they are our ‘microbiome’.

Our relationship with bacteria is a complex puzzle.
Image Credit: Gavin Hubbard

But before you run off screaming to the shower, with bleach in hand, you should know that this is no bad thing. For example, in return for shelter and a share of the spoils from our meals, some make vitamins, liberate nutrients and energy from food, and protect us from their pathogenic cousins. Millions of years of co-evolution with our microbial horde have forged this relationship, shaping us both in ways whose significance we’re still trying to understand.

This is the first of a couple of posts that hopes to briefly explore some of the unknowns and open questions surrounding the microbiome and its relationship to our health and well being.

It was about 15 or so years ago that interest in the microbiome really started to pick up. Since then, we’ve caught tantalising glimpses of the bigger picture, and managed to fit some of the pieces of this puzzle together; we’ve even managed make use of the microbiome to cure disease, but much remains a mystery, with only hints about where and what to look at.

Detection and Discovery of Exoplanets

The first planet discovered orbiting another star was detected by astronomers at an observatory in France in 1995. The planet is an enormous gas giant, half the mass of Jupiter, orbiting very close to the Sun-like star 51 Pegasi in the constellation Pegasus, 50 light-years from Earth. The existence of other planetary systems had been predicted by astronomers for centuries and the discovery marked a monumental breakthrough in astronomical research. Since then, rapid improvements in technology and observational techniques have resulted in the discovery of 863 confirmed ‘exoplanets’ to date.

How many planets are there? As astronomers hunt for planets orbiting other stars, we are starting to form a picture of  how many planets there are in the galaxy. Image credit: Luke Surl, for TWDK

Unlike the direct observation of stars, the detection of planetary bodies requires astronomers to use a number of indirect methods to infer their existence. Due to the immense distances involved, the distance between any planet and their host star when viewed from Earth is tiny, and the brightness of the star itself effectively blinds instruments and obscures any planets in their orbit, which are much less bright by comparison. Therefore, astronomers have devised a number of ingenious methods to tease out planet data from their observations, but they require a great deal of skill, a generous helping of statistical analysis and a pinch of luck.

The most successful means of planet detection to date, yielding roughly 58% of all discoveries, is called the radial velocity method. This technique exploits the fact that the host star and its planets orbit a common centre of mass, and the planets exert a tiny ‘tug’ on the star that results in a very slight wobble – a signature that can be detected and used to infer the existence of one or more planets. Another successful indirect method of detection, responsible for a third of exoplanet discoveries, is called the transit method. When viewed from the Earth, a planet orbiting a star periodically passes in front of the star (‘transits’) and obscures a very small amount of its light, resulting in a tiny but consistent reduction in the amount of light received by Earth-based instruments. The amount of light that is blocked out provides some information about the size of planet, as larger planets will obscure relatively more light, and the frequency and duration of the transit can be used to infer the distance from the star that the planet orbits. NASA’s Kepler space telescope, launched in 2009, uses this method and it has proved extremely fruitful, resulting in the discovery of 105 confirmed exoplanets to date. Additionally, there are a further 2,740 potential planets (called ‘planet candidates’) detected by Kepler awaiting confirmation.

Growing the TWDK Team

We were overwhelmed with interest in our Chemistry internship role late last year, and after reading many applications, and interviewing some really strong candidates we chose two students currently studying Chemistry to join us for the next few months. We would like to thank everyone who expressed an interest in working with us, it's great to see the amount of passion out there for what we're doing!

And now to extend a very warm welcome to Freya and Lucy, our two latest content writers who will be writing about the open questions of Chemistry. Freya is at the University of Bradford, while Lucy is studying at Imperial College, London. Look out for blog posts from both of them soon.

We are also very happy to report a new staff writer joining our team from today. Ginny Smith, better known for her role as a "Naked Scientist", promoting science through radio, live lectures and internet journalism. Their award-winning weekly BBC radio programme has a potential audience of 6 million listeners across the east of England, and can be listened to from anywhere in the world via internet. Ginny studied natural sciences at Cambridge University, specialising in psychology. In addition to preparing content for our main site, watch out for the occasional post from Ginny on our blog, too.