Five minutes with… Brynley Pearlstone

Brynley Pearlstone is a PhD student in the University of Glasgow’s Institute for Gravitational Research. Last year, he shared his experiences of chasing gravitational waves with the ‘Chasing the Waves’ team, and also took part in Q&A sessions with hundreds of school children. Today he stopped for a chat with the GSF blog!


I am Brynley Pearlstone, and I am a Ph.D student, researching ways to analyse data from the LIGO experiment, in order to find very weak but longer lasting gravitational waves from rapidly rotating neutron stars.

2. How long have you been researching gravitational waves?

About 2 and a half years now

3. What’s the best bit about being a scientist?  And the worst bit?

The best bit about being a scientist? Well, there are a few. The people you meet, the hands you shake, and the scientists you work with are great people, often with closely shared interests, quick thinkers, and good chat. And you get to meet these people from all over the world as well!

The worst part is probably when you’re telling somebody else that you’re a research student, some of the responses are “Oh, so you’re still at school?” with a little laugh. That isn’t great.

4. How were you involved with ‘Chasing the Waves?’

When the team behind Chasing the Waves was getting going, I was asked to have a chat with them about some time that I had spent at one of the LIGO sites. I sat in front of an iPad as it recorded me, and chatted with some of the people involved.

5. What did you think of the show?

I really enjoyed the show! Some of the in-jokes were great, particularly the “Stock Response” skit. My experience of being at the site rang true in parts of how the show portrayed it.

6. Tell us your favourite science joke or fact.



Five minutes with… Prof Jim Hough

Our new show, ‘Chasing the Waves‘, funded by the STFC, uses music and comedy to explore how Glasgow scientists contributed to one of the biggest discoveries of the century: the detection of gravitational waves.


Prof Jim Hough

Professor Jim Hough has been at the heart of gravitational wave research for decades. He has also been at the heart of ‘Chasing the Waves‘, sharing his stories and expertise with the creative team to help develop the show. We grabbed five minutes for a chat  about his involvement.

1. Who are you and what do you do?

I’m Jim Hough, experimental physicist. I work on suspensions, mirror coatings etc. for next generation gravitational wave detectors

2. How long have you been researching gravitational waves?

Since 1971

3. What’s the best bit about being a scientist?  And the worst bit?

Best bit – the thrill of solving problems

Worst bit – doing the admin

4. How were you involved with ‘Chasing the Waves?’

Wearing a wig and behaving like an idiot. You can watch Jim in our music video here.

5. What did you think of the show?


6. Tell us your favourite science joke or fact.

The lion and the rabbit

The Gravitational Wave Detectors

Communicating complex concepts and specialised research is a big challenge for scientists. This group of postgraduates have developed a fun, interactive activity to explain gravitational waves to a public audience at the Science Sunday Big Birthday Bash.



1. Who are you and what do you do?

Holly: I’m a PhD student in the chemistry department and I make materials that can levitate trains using powerful magnetic fields!

Euan: I’m a PhD student in the particle theory group of Glasgow university. I study ways of simulating small patches of spacetime on a supercomputer.

Finlay: I’m Finlay, and I’m a PhD student who fires lasers at strange liquids to make crystals grow in them.

Fraser: I’m Fraser, a PhD student in Biomedical Engineering at the University of Glasgow. I use nanotechnology to make millions of tiny pillars that fit on a slide no larger than your thumbnail, and we want to use these to get stem cells to do what they’re told.

2. What brings you to Glasgow Science Festival this year?

Holly: I’ve never carried out public engagement before, but am really excited about the prospect of making science cool for non-scientists!

Euan: Besides GSF I am a volunteer organiser for the Pint of Science festival, in which researchers give talks about their work to general audiences in pubs. I am attracted to public engagement by the prospect of inspiring the next generation of scientists.

Finlay: I love teaching, and helping others see that ‘complicated science’ is actually easier than it seems. This is my first time being involved with Glasgow Science Festival, but won’t be the last!

Fraser: I’ve never been properly involved with public engagement, but I’ve taught in a high school before as part of my undergraduate course in Physics. I really loved seeing young people, and even the teachers, getting involved in some “complicated” concepts like Gravitational Waves and Spacetime, and seeing the questions they asked and the ideas that they had towards it. Public engagement is also really good for teaching yourself things, because if you want to explain something in a really easy way to understand you need to really understand it yourself first.

3. 2016 is Scotland’s Year of Innovation, Architecture and Design. What innovation could you not live without?

We’ve built ourselves a pretty cool make-shift gravitational wave detector that you can come and try out to detect a gravitational wave, and have a chunk of spacetime that we’ve cleverly captured in a tupperware box, along with a star on a stick, to show you how spacetime really makes gravity happen.

4. It’s Glasgow Science Festival’s 10th birthday! We’ll be celebrating with some science-themed cake and balloons. What’s your birthday treat of choice?

Holly: Definitely mascara.

Euan: google maps

Finlay: My GPS watch.

Fraser: Hot showers. Have you tried going a day or two with only cold showers? Brrrr.

5. And finally: impress us with your favourite science fact or joke.

There are places in the universe which are physically impossible for humans to reach, since they are moving away from us faster than the speed of light.

Holly, Euan, Finlay and Fraser will be at the Science Sunday Big Birthday Bash on 19th June from 10:00-16:00 in the Hunter Hall, University of Glasgow. For more information, visit the website.


Making Waves

Prof Martin Hendry has been a major contributor to Glasgow Science Festival since its inception 10 years ago. As in previous years, he’ll be sharing his passion for physics and astronomy with the public through some fantastic free events.


1. Who are you and what do you do?

I am Professor of Gravitational Astrophysics and Cosmology at the University of Glasgow, where I am also Head of the School of Physics and Astronomy.  I’m a member of the LIGO Scientific Collaboration, a global network of more than 1000 scientists who in February 2016 reported the first ever direct detection of gravitational waves – a discovery that finally confirmed the predictions of Albert Einstein made 100 years ago and opened an entirely new “dark” window on the cosmos.  Here’s a photo of me at the USA Science and Engineering Festival in Washington DC, in April 2016 where a certain visitor to our LIGO exhibit said “good job”. (I’m the one on the right, by the way!)

 2. What brings you to Glasgow Science Festival this year?

Well, I’ve been a strong supporter of the Science Festival ever since it began, but this year I’ll be involved in various events to celebrate our first ever direct detection of gravitational waves – which was a huge global news story, and a particularly big story for Glasgow University given our key role in the discovery.  Moments like this don’t come along very often and it’s been amazing to be part of the enormous “wave” of publicity!  Just recently the entire collaboration was honoured with the award of the 2016 Special Breakthrough Prize in Fundamental Physics ( so it seems clear that the world has been really captivated by this story – and who wouldn’t be captivated by an everyday tale of two black holes colliding 1.3 billion light years away!

3. 2016 is Scotland’s Year of Innovation, Architecture and Design. What innovation could you not live without?

It took me a while to get one, but now I couldn’t live without my smart phone!  And it’s amazing to think that its built in GPS system relies on Albert Einstein’s theory too:  according to relativity time runs a tiny bit faster at the altitude of the GPS satellites because gravity is weaker up there.  Without correcting for this, my GPS would get me lost PDQ…Just another example of where fundamental physics underpins our everyday lives.

4.  It’s Glasgow Science Festival’s 10th birthday! We’ll be celebrating with some science-themed cake and balloons. What’s your birthday treat of choice?

Probably a nice brunch followed by a trip to the cinema.  In 2014 I got to see “Interstellar” on my birthday, which was a real treat!

5. And finally: impress us with your favourite science fact or joke.

I’ll leave the jokes to others and go with an amazing fact.

The gravitational wave event GW150914 that we detected last September (and announced in February 2016) was the merger of two massive black holes more than a billion light years away.  As they merged together they released about 50 times as much power, in the form of gravitational waves, as the light power released by all the stars in all the galaxies in the entire observable universe.

Listen to Martin and other LIGO scientists at ‘Making Waves: Listening to Einstein’s Universe’ on 10 June from 18:00-20:00. FREE. Book tickets online.  You can also meet black hole hunters at Science Sunday on 19 June, details here.



So, you discovered gravitational waves…

Last week there was a buzz around the Kelvin Building at the University of Glasgow as physicists excitedly prepared for the announcement they’d been waiting to hear for decades: “Ladies and gentlemen, we have detected gravitational waves. We did it!”

Martin Hendry is Professor of Gravitational Astrophysics and Cosmology at the University of Glasgow and part of the global team who made the discovery.  He has also been a part of Glasgow Science Festival since its inception ten years ago, sharing his passion for physics and astronomy with thousands of people. Martin answered our questions on what this discovery means and its link to Glasgow research.

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In addition to being a world-leading astronomer, Martin is a self-professed Star Wars geek. In reference to gravitational waves, he said “In Star Wars, Darth Vader tells us not to ‘underestimate the power of the dark side.’ This amazing discovery shows how right he was.” – Read More in Time Magazine.

What are gravitational waves?

Gravitational waves are ‘ripples’ in the fabric of space-time caused by some of the most powerful processes in the universe – colliding black holes, exploding stars, and even the birth of the universe itself. Albert Einstein predicted the existence of gravitational waves in 1916, derived from his general theory of relativity. Einstein’s mathematics showed that massive accelerating objects (such as neutron stars or black holes orbiting each other) would disrupt space-time in such a way that waves of distorted space would radiate from the source. These ripples travel at the speed of light through the universe, carrying information about their origins, as well as clues to the nature of gravity itself. – See more at:

How do we detect them?

We can detect using what we call a laser interferometer.  LIGO (Laser Interferometer Gravitational Wave Observatory) is the world’s largest gravitational wave observatory and one of the world’s most sophisticated physics experiments.  LIGO consists of two laser interferometers located thousands of kilometres apart, one in Livingston Louisiana and the other in Hanford Washington State.  LIGO uses the physical properties of light and of space itself to detect gravitational waves. An interferometer like LIGO consists of two perpendicular “arms” (in LIGO’s case each one is 4km long!) along which a laser beam is shone and reflected by mirrors at each end.

When a gravitational wave passes by, the stretching and squashing of space causes the arms of the interferometer alternately to lengthen and shorten, one getting longer while the other gets shorter and then vice-versa.  As the interferometers’ arms change lengths, the laser beams traveling through the arms travel different distances – which means that the two beams are no longer “in step” and what we call an interference pattern is produced. (This is why we call the LIGO instruments “interferometers”.)

Now the effect of this change in arm length is very small — for a typical passing gravitational wave we expect it to be about 1/10,000th the width of a proton! But LIGO’s interferometers are so sensitive that they can measure even such tiny amounts.

What is Glasgow’s involvement with this research?

The Institute of Gravitational Research at the University of Glasgow has been at the heart of the search for gravitational waves for decades, and pioneered some of the key technologies that have made this remarkable scientific discovery possible.  For example Glasgow led a consortium of UK institutions that played a key role – developing, constructing and installing the sensitive mirror suspensions at the heart of the LIGO detectors that were crucial to this first detection. The technology was based on our work on the earlier UK/German GEO600 detector. This turned LIGO into Advanced LIGO, arguably the most sensitive scientific instrument ever, to give us our first direct glimpse of the dark universe.

Why is the discovery of gravitational waves significant?

Overall, I believe our discovery is an astounding scientific achievement:  it provides the first direct evidence that black holes exist, that they can exist in pairs, and that those pairs can collide and merge – releasing enormous amounts of energy in the form of gravitational waves in the process, in fantastic agreement with the predictions of general relativity.

Our discovery isn’t just about checking if Einstein was right, however.  Detecting gravitational waves will help us to probe the most extreme corners of the cosmos – the event horizon of a black hole, the innermost heart of a supernova, the internal structure of a neutron star: regions that are completely inaccessible to conventional telescopes.   So the first direct detection of gravitational waves and the first observation of a binary black hole merger are remarkable achievements, but they represent only the first page of an exciting new chapter in astronomy.

The next decade will see further improvements to the Advanced LIGO detectors and extension of the global detector network to include Advanced Virgo in Italy, KAGRA in Japan, and a possible third LIGO detector in India.  This enhanced global network will significantly improve our ability to locate the positions of gravitational-wave sources on the sky and estimate more accurately their physical properties.  The new field of gravitational-wave astronomy has a very bright future!


The first direct detection of gravitational waves. Graphic by Daniel Williams

For more information visit the LIGO FAQ page, authored by Martin.