Stefan Lines

King of the Jungle! Thank you everyone :D



Attended Plymstock School (Plymouth) until 2008. Graduated from the University of Exeter in 2012 (Masters). Now studying at the University of Bristol (PhD).


MPhys (Master of Physics), Working on the PhD!

Work History:

During my Masters at Exeter I worked on understanding more about massive planets like Jupiter in other solar systems. I also received a studentship for a summer project in which I computerised a Radio Telescope using a basic laptop and a simple electronic board called an Arduino.

Current Job:

Research Scientist / Studying for PhD in Astrophysics.


University of Bristol.

Me and my work

I Build Planets! (With Computers)

I am a computational astrophysicist working in the field of Exoplanets – and I can link my research to Star Wars and Doctor Who (read on to find out)! That is, I use computers and my knowledge of physics to try and understand more about planets that orbit around other stars. Working with exoplanets is unbelievably cool because it touches on many questions, one of the most important being; is there life out there in the rest of the universe? I bet you already know that we’ve discovered hundreds of exoplanets in recent years. Many of these have been found using a telescope you might have heard of named Kepler. We know these planets exist, but we don’t know a lot about how they formed. So my work essentially boils down to…

How do you build a planet?

We can’t really see planets forming with telescopes so we have to use computer simulations to try and create them based on our understanding of the science. We think that planets form from gas and dust that are mixed together in a big disk which surround a young star. Dust starts sticking together into small grains, and these grains stick together into larger rocks. These rocks collide with each other and sometimes merge into bigger and bigger rocks… until they get big enough to become a planet like Earth or Mars. If they get really big, then they start pulling the gas onto themselves and turn into a gas planet like Jupiter!

I use computer codes to generate big disks full of rocks… sometimes as many as over a million. You then evolve the disk under the forces you think they will experience such as gravity and friction. The problem here is that each rock (which we call a planetesimal) feels not only the star it orbits, but also every other planetesimal. So if you have a million rocks, you have to do around a million calculations to work out the force acting on just one rock. Then you need to do that for each of your other million rocks… Eugh! That’s one trillion calculations to do – and that’s just gravity – and just one moment in time!

Luckily, I get to use some of the most powerful computers on the planet to do these calculations for me…quickly. The job requires knowledge of programming to make sure the code does what you want, followed by analysing the data from millions of planetesimals. After thousands of years you can ask; did I form a planet?

To finish, more precisely I work on the formation of a type of planet called a circumbinary planet. We only know of less than 10 of these so far in the whole galaxy – and they are special because they are planets that orbit around binary stars (two stars). The planet Tatooine in Star Wars and Gallifrey (home of the time lords) in Doctor Who are both circumbinary planets – and you can see they have two sunsets. It’s much harder to make planets around binary stars because they introduce some crazy gravitational forces that make planetesimals explode on impact… rather than merge together and grow like we need.

My Typical Day

Program. Simulate. Analyse.

Generally speaking, as a computational astrophysicist, I spend most of my day working closely with computers. Aside from numerous coffee breaks and science-based chats with my colleagues, I’ll spend the day writing computer code and scripts, analysing data and producing fancy graphs to communicate my results to other people.

What I'd do with the money

Provide a selection of schools with their own Raspberry-Pi powered weather station where students could learn to analyze their own data!

This is a really flexible project where students and teachers could do as little (collecting data) or as much (manipulating data, programming etc) as they like. This makes it easy for all ages to get involved in what it is like to work with real scientific data.

Raspberry-Pi’s (R-Pi) are standalone computers which run Linux and are very cheap. They are fantastic for connecting up external sensors which feed back data that can be stored and analyzed.

Due to the cost of these devices, with the money I would be able to provide a few schools with a modified R-Pi for Metereological purposes, allowing students and teachers the opportunity to collect temperature, pressure and humidity data from their own grounds.

The opportunities from here are almost endless – students could learn to do simple programming to manipulate or display the data, use the data for statistical analysis in science classes, or even just publish the data to the web allowing the whole school to see the weather in real-time.

My Interview

How would you describe yourself in 3 words?

Geeky. Passionate. Indecisive?

Who is your favourite singer or band?

Ed Sheeran.

What's your favourite food?

Maple Syrup Pancakes.

What is the most fun thing you've done?

Snowboarding in the Alps.

What did you want to be after you left school?

Until I started my A-Levels I wanted to become a Meteorologist.

Were you ever in trouble at school?

Well, this one time… Let’s just say, never use a bunsen burner in Chemistry class to burn a whole roll of Magnesium ribbon…

What was your favourite subject at school?


What's the best thing you've done as a scientist?

Two answers to this: 1) Writing and publishing my first scientific paper. 2) Using one of the world’s fastest and most powerful super-computers that can do about 30 TRILLION calculations per second.

What or who inspired you to become a scientist?

All the questions I and other people have ever asked. Some of them still need answers.

If you weren't a scientist, what would you be?

A Pilot.

If you had 3 wishes for yourself what would they be? - be honest!

Have my own TARDIS. Go into Space. Not to have to tell another joke ever again…

Tell us a joke.

How does the man in the moon cut his hair? Eclipse it.

Other stuff

Work photos:



This is the School of Physics building (called the HH Wills Physics Laboratory) at the University of Bristol in South West England. I work on the 4th floor in the Astrophysics Department. I can see the whole of Bristol from the top! We have three telescopes on the roof too; a regular visible light one to look at the stars, nebulas and galaxies at night, a solar one to look at the sun in the day, and also a massive radio telescope that has its own control room.




This is where I work; desk in a small office! Not so glamorous, but it has everything I need to do the Science. If you’re interested, my Desktop machines are a custom i7 Mac Mini and a home-built Linux powered 8-Core AMD FX. Both run 16GB of RAM. I need semi-powerful machines to test code and run simple simulations before I submit them to the supercomputer (which is over 1,000 times more powerful than a single PS4). I also use my machines for writing C code, plotting images, generating movies for visualisation purposes, writing scientific papers and of course… surfing the web.




If you’re still reading, you must be keen. Good! Ok, so the image above is one I generated from a simulation I did. It shows a disk of solid material (one million rocky planetesimals in this case) surrounding a binary star system. You can see a wave-like pattern in the disk, which is caused by the gravity from the binary stars.




This is a silly image I took in the office of a rainbow which just *happens* to align perfectly with the solar telescope in the office 🙂