Little Green Man’s Guide to the Galaxy


This weekend, Oxford Astrophysics is taking a field trip. No, not to a telescope or a conference for once: we’re going to a music festival! A few months ago, our DPhil. student and dotAstronomer Ruth Angus had the great idea of pitching an idea to the excellent Green Man Festival in Wales to bring an astronomy stand. Green Man have an area on the festival site called Einstein’s Garden (also on twitter) for science-related activities, and we came up with some good ideas for astro-related fun for kids and grown-ups during the festival. Luckily the Green Man organisers agreed, and to help us out with the organisation we got a really generous grant from the Institute of Physics.

So a group of students and postdocs are off to the Brecon Beacons bright and early tomorrow. I helped out with the proposal writing and preparing some of the activities, but for all kinds of diary-related reasons I’m not joining the festival fun myself – boo to that.

Our main activity for the weekend will be observing the Sun through our department’s solar telescope, and making your own pinhole camera – fingers crossed for the big yellow orb making an appearance at some point! We prepared star charts showing the festival goers what’s up in the night sky this weekend, and of course there may be some lovely Perseid meteors to see overhead as well.

Green Man looks like a fun festival, and apart from a nice musical line-up they will have a huge range of other activities to keep people occupied. If you’re going to the festival, go say hi to the Oxford astro group and follow @GreenManGalaxy on twitter.



Conferencing and Hack Days in Canada

Woman with poodle

Woman with poodle

Every two years the instrumentation building community in astronomy get together for conference organised by SPIE, the international optical engineering society. It’s big and tiring and crowded, and the best place to get the updates on how all the major telescope and instrument projects around the world are getting on – not to mention a whole lot of community gossip. It’s also a nice opportunity to catch up with friends and former colleagues from around the world. The conference location alternates between Europe and North America, and this year we’re in lovely Montreal.

I’ve already written about the Hack Day I was asked to organise this year, and I’m excited that that will be happening tomorrow. I’ve had some great conversations already with people about their hack ideas, and I’m looking forward to seeing how things come together.

The first talk I attended all week (Sunday morning! not cool, organisers) was by Phil Crosby of CSIRO in Australia, who spoke about success drivers for large high-technology projects, such as the E-ELT and the SKA. Having had a taste of a management role in my job at MPIA in Heidelberg, this is a subject I’m actually really intrigued by. As a manager, PI, or systems engineer how do you ensure that your project really is under control, and importantly, that you recognise red flags when they arise?

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Astro Hack Day, Take Your Pick: SPIE or UK National Astronomy Meeting!

The Astronomy Hack Days we’ve been hosting at the .Astronomy conference since 2009 have been a great success; they are a huge reason why people come to the conference every year. Some of the hacks the .Astronomers have produced over the years have been amazing, and every year they get more impressive too. That’s why it’s fantastic to see the concept spreading: hack days are being organised at other major astronomy conferences, or as standalone events. Most recently, the January AAS conference had an amazingly successful event – I’ve included a few links to reports about it below.

Two more events are coming up in the next few months. First, the UK National Astronomy Meeting in Portsmouth (23-26 June) will host a Hack Day. As it’s my first year back as a UK astronomer I would have loved to attend, but that same week I’ll be at the bi-annual SPIE conference on Astronomical Telescopes & Instrumentation, which will be held in Montreal. It’s the big meeting for everyone involved in instrumentation and software in astronomy, and excitingly I’ll be hosting the first ever SPIE Hack Day on Thursday 26 June, together with fellow postdoc Casey Deen at MPIA, Heidelberg.

The SPIE Hack Day is nominally tied to the conference session on software and cyber-infrastructure, but in good Hack Day spirit everyone is welcome to work, learn, talk, and share their ideas. As it’s an instrumentation conference and we’re all Tinkerers, we’re not even necessarily limited to software – yes, hardware hacking is a thing too!

We’ve created a sign-up form on a dedicated webpage, where you can leave your details to receive more practical information closer to the time. This isn’t a formal commitment (though of course I hope you’ll come!), so don’t worry if you have schedule clashes. We’ve also created a space on GitHub where we can share code and you can find much more information and links on those pages.

Some useful reading and links for inspiration:

Or email spiehack2014 AT for more information, comments and suggestions!

Spotted! The signature of our inflationary Universe?


Image: BICEP2 collaboration

It’s a good thing we got that Higgs Nobel prize out of the way last year, as we’ve got a big new contender lined up. After a few days of rumours, the team behind South Pole telescope BICEP2 today announced their detection of the signature of inflation in the polarization of the cosmic microwave background (CMB). In case the big words coming to you from the BBC, the Guardian, Nature, the New York Times, Peter Coles, Sean Carroll, roughly 500 twittering astronomers and Andrei Linde himself have not yet convinced you, let me add to those: if (if!) it stands, this is a Very Big Deal.

The distinctive wiggles found in the CMB polarization map are the imprints of the gravitational waves that accompanied inflation, the faster-than-light expansion the Universe underwent less than one-trillionth of a second after the Big Bang (13.8 billion years ago). This expansion explains why the Universe looks so smooth and uniform in all directions, despite its vastness.

If we leave aside the awesomeness of being able to detect any signals from anything that happened at this esoteric time, let alone offer a sensible interpretation, this is a major discovery for a number of reasons. It is very strong evidence that inflation actually happened as it was thought out by the early theoreticians who pioneered the theory. This in itself is a big missing piece of the puzzle of our Universe. In addition, the observed signal lends support to the notion that gravity was unified with the other fundamental forces in the hot early Universe. Finally, this is the first direct detection – or one the first, depending on how you define “direct” – of the highly elusive gravitational waves that astronomers have hunted for decades.

This stuff is too far from my own field for me to understand the details of the data or their interpretation, but the general consensus amongst social-media-connected astronomers is that the data look good and the analysis extremely rigorous. Teasing such a faint signal out of observational data is invariably a very tough task, with lots of systematics in the measurements to account for. Some scientists seem pretty skeptical, and that is a good thing. The data and accompanying papers will still need immense scrutiny and very thorough peer review before being officially accepted as Real and True. Whatever the outcome, this has clearly been a huge effort by the BICEP2 team, and they deserve a big congratulations for these results.

If you want to learn more about the physics of the very young Universe, I can highly recommend Alan Guth’s own book on his journey developing the theory of inflation, The Inflationary Universe, which is one of my all-time favourite popular science books. More generally on gravity and general relativity, fellow Oxfordian Pedro Ferreira just published a book entitled The Perfect Theory, which I’m enjoying at the moment.

A number of cosmologists have given their (more technical) opinions and interpretations online: Peter Coles at Sussex, Phil Bull in Oslo, and I’ll add a few more as I find them. 18/03: this from Renée Hlozek at Princeton,  more from Peter Coles,

The official papers and data are publicly available here.


Sunshine and Big Mirrors

Blue skies and citrus

Tucson in January: Blue skies and citrus

Last week I got back from a great work-pleasure jaunt to the United States. I started off in Tucson, Arizona, where I met with the MIRI test and calibration team to further our plans for space domination instrument testing, calibration and software development for our instrument, which will be launched on board the James Webb Space Telescope in 2018. I’ve been involved in testing MIRI for my entire postdoc career now and it’s always a pleasure to meet with the team, and see how far we’ve come in the project.

Many people ask me what there is left or us to do, now that MIRI is in the hands of NASA in the US. The answer to that is “LOTS”. Even though the immediate task of assembling and testing the actual instrument hardware is completed, we now have to work with our NASA colleagues to integrate MIRI further with the rest of the spacecraft and test over and over again that everything is still in working order. In addition, we have to define calibration procedures and the data and algorithms that are required for that, and develop software. There’s an awful lot of work still happening!

Aside from the productive meeting I was really pleased to get a tour of the Steward Mirror Lab, which I’d heard lots about. Several of the world’s largest astronomical mirrors were cast and polished in giant spinning ovens, deep in the bowels of the University of Arizona’s football stadium . In these ovens, heat melts the glass until it’s molten, and the rotation shapes it into a nice parabolic shape while it’s in that state. The temperature is then lowered very slowly in a controlled way to stop stresses and bubbles forming in the glass. The mirror is shaped around a honeycomb structure that is later removed, producing a nice lightweight mirror.

With this technology Steward produced the mirrors for the 3.5-m mirrors for the ARC at Apache Point, New Mexico, and the WIYN at Kitt Peak, AZ; the 6.5-m’s for Magellan in Chile and for MMT at Mt. Hopkins, AZ; and the twin 8.4-m mirrors for the Large Binocular Telescope at Mt. Graham, also in Arizona.

Excitingly, several large mirrors are currently in production there at the moment. The first two 8-m segments for the Giant Magellan Telescope have been produced, and a third is under way. The primary mirror for the Large Synoptic Survey Telescope (LSST) was being polished while I was there. This mirror is pretty amazing, as it contains both the blanks for the primary and the tertiary mirror, so two different profiles are being polished into it. I’ve included some pictures below [feel free to use them but please credit to me when you do!].


Steward Mirror Lab

Steward Mirror Lab

Arizona stadium

Arizona stadium

Arizona stadium, home of the Steward Mirror Lab.

Arizona stadium, home of the Steward Mirror Lab.

The LSST primary and tertiary mirrors, being polished.

The LSST primary and tertiary mirrors, being polished.

The polishing tool working its way around

The polishing tool working its way around

Preparing for another GMT mirror segment

Preparing for another GMT mirror segment