My former student, and now high flying postdoctoral researcher at Leiden University, Dr Camila Correa answered one of the basic questions in galaxy formation in this paper - how does gas get to the galaxy from the larger Universe? The simple answer is, it depends. Essentially the bigger you are the more gas you can pull in, until you get to something the size of our Milky Way, when the `accretion' rate of material infalling then flattens out. This picture is complicated as the hot gas halo surrounding a galaxy is responsible for preventing new material from infalling as it shocks against the hot halo. The amount of the hot halo depends on the type of energetic events within a galaxy, be it exploding stars (supernovae) or accreting black holes (AGN). A beautiful bit of work that will inform theorists and observers for years to come!
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I've kept the previous post up but sadly it's with regret that I have to pass on the message from Lateral Events that despite all our best efforts, What’s NEXT? has been cancelled in Sydney, Melbourne and Brisbane. All ticket buyers will be provide with a full refund within the next seven days (i.e. mid-August latest) by Ticketmaster or Ticketek. Sorry all.
I cannot believe I get to write this but Nobel Prize-winning and Interstellar science consultant Prof Kip Thorne is touring Australia and I AM ON STAGE WITH HIM! Prof Kip Thorne is quite literally one of the smartest humans in the world, co-sharing the Nobel-prize for finding gravitational waves.
Tickets are out NOW. Get them at the LateralEvents link and I'll see you soon Australia... but more importantly you'll see the future with Prof Kip Thorne. And that is an unforgettable experience.
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Over half a century ago this nation became only the third in the world to build and launch a satellite from its own territory. Since that time aerospace ambitions in Australia have waxed and waned but with the announcement by the Turnbull Government of a National Space Agency, led by former CSIRO-head Dr Megan Clarke, it is clear that we are ready once again as a Nation to take our place in space.
The Victorian Minister for Industry and Employment Ben Carroll as well as Victoria's Lead Scientist Dr Amanda Caples believe that the natural home for this Agency is right here in Melbourne and were good enough to let me launch the bid alongside them, at Swinburne's Eric Ormond Baker Charitable Fund Remote Observing Facility in front of media from every TV, print and radio station. It was an unbelievable experience..!
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One of the challenges in exploring the early universe is that it is so far from us, as we peer billions of light years away to see it as it was all those billion of years ago. That means small faint objects, like dwarf galaxies, that we suspect do the main job of reionising the universe are nearly impossible to measure. It's therefore a challenge to constrain the DRAGONS universe; one way is to wait until little things build into bigger things that you then can see and test those. The other is to constrain the Semi-Analytic Models against the hydro simulations of Smaug. In this astounding exhaustive and thorough review of the two techniques my student Yuxiang Qin explores the connections and learns what to modify in one to mimic the other. Just being on top of one of these techniques would considered impressive in a PhD, to do both is truly exceptional.
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The latest series of the ABC Radio National podcast #CosmicVertigo is out and we're taking things to the EXTREME. I have to say I have the most fun with Dr Amanda Bauer recording these, they're made for your listening pleasure so I hope you enjoy it as much as I do... subscribe where you get your podcasts. Rate and review etc.
However this time you can also ask us questions online or by email (especially if you record them!) and we'll feature the best (or at least the ones I can answer) on the show. Enjoy!
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It's hard to put into words how significant Prof Stephen Hawking was for me on a personal level. His book "A Brief History of Time" was a defining moment as a young teenager to realise that you could have a career to explore the Universe; to spend a life studying the nature of expanding universes, blackholes and dark matter. More important than even his science he also showed the value of communicating that science.
His death hit me hard and it was a crazy day speaking on radio, TV and print to explain just why he was such an incredible and unique figure. I've shared a few of these TV interviews below. The first TV interview I ever gave was about him, and I was honoured that I could also speak at the end.
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The Australian Space Agency review is to be released in a matter of days but do you know what it means for you, your children's future careers or even how much you already use space in your everyday life? Well with the team at The Royal Institution of Australia we put together a package answering all of these issues on Australia's Space Future. I'm really proud of the team's exhaustive efforts and also amazed by the careers of talented female scientists and engineers like Andrea Boyd, Flavia Nardini and Lisa Stojanovski who we were able to feature. In space our future really is unlimited.
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It was truly a remarkable privilege to be one of the #CHOOSEMATHS Ambassadors and speak to 400 young girls about the value of maths in their careers. My thanks to AMSI for the opportunity as well as allowing me to hear the fantastic female ambassadors onstage - their stories and range of careers will inspire that audience to know a background in maths is a valuable (and valued!) one for any future job they may strive towards. Also my thanks to IMAX Melbourne for hosting us all, it was a fantastic place to enjoy the #CHOOSEMATHS ambassador's career videos - for more on why I think maths is key to all our futures (and in particular for women) head to the women in education special in The Australian #IWD2018
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Incredibly excited to announce that Inspiring Australia has once again decided to support the Science in VR live experience with a National Science Week grant! We will give two live Virtual Reality (VR) talks using the SciVR app with bespoke Google cardboard VR headsets, as well as coordinated regional viewing parties, all with tailored educational material for the hidden universe! This year I will joined by my amazingly talented colleague Dr Rebecca Allen, can't wait to reveal more info soon on this! But you don't have to wait for the show to enjoy the app, just head to the Apple AppStore or Google Play and download SciVR for free, and can buy headsets from the Swinburne Bookshop for an even more immersive experience.
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It's truly a remarkable thing to get to present your research to the Assistant Minister for Science, Jobs and Innovation Zed Seselja alongside fellow scientists in ecology, quantum computing and mining... this is what makes Science Meets Parliament such a unique experience and one I'm proud to have assisted as an executive of Science & Technology Australia.
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One of the coolest parts of my job is that I can take film-crews around the world and showcase the incredible science and technology that is out there, but seeing the SpaceX Falcon 9 rocket launch at NASA's Kennedy Space Centre just tops everything. My huge thanks to ABC Catalyst for letting me reveal the change space race that means the return to the moon is a competition between startups not superpowers. This is a topic I raved about in the Sydney Morning Herald, and there was also a really nice review of the TV episode in The Australian. You can watch the episode online on ABC iView.
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At the truly epic World Government Summit I was privileged to lead the discussion of Mars settlement by the best and brightest from the UAE Space Agency and make the broader case for space with an international panel. Apart from that I got to hear from Forest Whitaker, Neil DeGrasse Tyson and Michio Kaku all in one day..! The #worldgovsummit is truly an extraordinary meeting of the world’s best minds. Just as exciting will be to see the new businesses and activities that come from this meeting, I certainly aim to work more closely with an international range of impressive people, all with varied backgrounds I could never hope to have met at any other meeting. It was a genuine pleasure to meet and discuss space technologies with the extraordinary young engineers of the Mohammed bin Rashid Space Centre. I have to say the task facing the program director for Mars 2117, Saeed Al GerGawi, are humbling - but he and his team are more than up to the task if this gorgeous VR tour of their Mars City is anything to go by!
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The grassroots effort to map out the best place to view MelbHenge as the Sun sets between a mile long corridor of Melbourne's skyscrapers continues to grow. This headline photo courtesy of LookAboutPhotography is just one incredible example of that.I'm always amazed at how many people get out and share their photos of this epic event... but we still don't know where best to view it! So we asked Melbournians to take a photo, share the location and use #MelbHenge so Swinburne University of Technology astronomers could update our map of the city to make this event bigger and better each year. Last time was featured on the BBC world news, let's see what we can do in the years ahead.
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My old student Camila Correa continues to revolutionise the basic fundamentals and assumed wisdom of galaxy formation. In particular she thoroughly explored the simple idea that infalling gas will shock against the other gas floating around the galaxy. In this paper, Camila used the EAGLE simulation series to explore the way in which exploding stars (supernovae) or feeding blackholes (AGN) impact that development of the hot halo. Essentially the supernovae ejects gas from the galaxy into nearby space, presenting a bigger target to infalling material, and hence makes the hot halo easier to form. The blackholes on the other are more energetic and eject material from the halo entirely, making it harder to form the hot halo in the first place. Overall, Camila showed that there was a critical halo mass above which the hot halo will form, around a half the size of the Milky Way at the present day.
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Australia's Chief Scientist recognises the critical importance of reading, and developing an early love of that reading! So he started the #StorytimePledge to call on scientists to share their books that they aim to read to loved ones over the holidays. My pledge? There's no better childhood story than Roald Dahl's "Charlie and the Chocolate Factory", and not just because I have a serious chocolate addiction.
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One of my favourite human beings, colleagues and collaborators - Dr Paul Geil - also came up with one of my favourite paper titles of all time. The work using DRAGONS focusses on the structure of the Epoch of Reionisation. In the first billion years after the Big Bang growing galaxies shone with ionising UV light, lighting up the Universe itself. This light ionised the hydrogen gas lying around the galaxies, creating cavities or bubbles in the intergalactic medium. the exact structure of the bubbles, how many of a given size and their rate of growth, is intimately tied to the nature of dark matter and the physics of galaxy formation. Paul predicted how new telescopes like the Square Kilometre Array can explore these bubbles, and exactly how awesome they will be at constraining all sorts of physics. A huge piece of work that will be years in the testing, so forward looking is its predictions.
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OK yes I know citation metrics are not the best way to measure performance. And yes by making the measure of success the target of success we then ruin the value of the measuring metric in, well, measuring (sorry for butchering your Law Goodhardt). But it was still a thrill to see one of my works be cited and used by international colleagues 500 times now. Amazing to think something I have done has been useful to so many great scientists!
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In Swinburne's version of the Oscars (yes, just as glamorous, albeit with less acceptance speech tears) we had our best and brightest recognised, and I was truly humbled to see my Science in VR team's efforts counted amongst such top Swinburne staff. SciVR won the VC Award for Community Engagement, which caps off an incredible year for this app. It was also fantastic to be highly commended with my colleagues in the Deans and VC Scholarship Network in the VC's Award for (Higher Education) Teaching Excellence. A great outcome for all and one I was proud to be part of in SciVR and the Scholarship Network. The partying continued well after the event too (sadly I was in bed as I'm now too old for these Oscar shindigs).
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One of the oldest questions in the study of Reionisation, the few hundred million years in which almost all of the hydrogen in the Universe was ionised effectively at once, is simple - where does the UV light to ionise the gas come from? One very popular idea is blackholes, or rather the accretion disks around them, where material swirls around the gravitational plughole become incredibly hot and bright in UV / X-ray emission. This fantastic work by Yuxiang Qin used DRAGONS universes to show that there simply isn't enough of these sources, known as AGN or Quasars, to do the job - or at least not if you want to match the number of blackholes that exist today. That's because to be bright, and reionise the universe, they have to feed a lot and in the process grow too large relative to what we see today. This work undoubtedly disappointed some Quasar fans out there, but that's the beauty of science, the facts don't care what you might hope and you have to follow the results to their conclusion.
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Where do galaxies form? how big can they be? Do galaxies 'prefer' to lie closer to one another or further apart? And how does all of this change across Cosmic Time? These are just some of the questions Jaehong Park asked within the DRAGONS team in this paper. To explore how galaxies grow near one another, known as clustering, and how they grow within the larger dark matter halos, aka bias, Jaehong analysed countless thousands of simulated galaxies. Compared against one another, at different outputs from the simulated universe of DRAGONS, the overall distributions were robustly analysed with statistical tools that then permitted comparison with images from Hubble. The work is a staggering scale and one I'm sure Jaehong will be proud of for many years to come.
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