Keep Looking Up

I chalked up a personal first yesterday; I saw an aurora with my own eyes and it was every bit as remarkable as I could have hoped for. I was not alone in sharing this special moment – anyone outside before midnight without clouds overhead in New Zealand (and, in fact, much of the world outside of the tropics) could have done the same, as these displays are driven by a once-in-decades solar storm.

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One Small Step

One of my earliest memories is standing with my father on the balcony of my grandmother’s house in Auckland. “Ma’s House” had a spectacular view northwards, across Auckland’s Hauraki Gulf, and the Moon was visible in the early evening sky. Following my eye, my father pointed and said, “I think there are people there at the moment.”

I would love to describe this as the father-son moment that lit my lifelong passion for astronomy, but doing so would take me far from the truth. My love of astronomy must have already been well aflame, because my actual recollection is that this was the first time I saw my father – a man frequently summoned to the hospital to tend the sick, who could fix any broken toy and who was able to split logs with an axe – as imperfect, fallible and human. How could any adult, I wondered, not know exactly how many people were standing on that pale little ball at any moment? 

My memory is that this moment took place during a pre-Christmas visit. Looking at the list of Apollo missions I can work out the date: the only landing in any December was Apollo 17, the last mission, just after my sixth birthday in 1972. While it was clear that there would be hiatus in lunar travel after Apollo 17, it is still a shock to realise that I am now in my 50s and that no one significantly younger than me can have a clear memory of a moment when human beings were standing on another world. Ever since that day there have always been precisely zero people standing on the surface of the Moon. 

The Apollo landings took place against alongside the Vietnam War and the Civil Rights struggle and constituted the winning entry in a race with the Soviet Union, a competition animated by superpower rivalry. But they are also a story of commitment, courage, teamwork and vision, a literal moonshot that shines as a moment of optimism and purpose. Perhaps even more so when you set it against the wider turmoil of the 1960s. I am not the first person to say this, but before Apollo “flying to the Moon” was a byword for an impossible, ridiculous dream – afterwards it was a metaphor for what can be done when we set ourselves to achieve lofty goals.

Sooner or later we will go back. Several countries and even SpaceX, a private company, are developing concrete plans to return human beings to the Moon. However, even with the most optimistic schedules those new voyages are still a few years off. 

If it seems that we have had an unduly long wait, it is worth recalling that after the first trips to the South Pole — with sleds pulled by men and dogs — it was close to 50 years before human beings again stood at 90 degrees South but those subsequent visits were made with tractors and planes, and marked the beginning of a permanent human presence at the Pole. 

Similarly, the Apollo missions pushed their 1960s technology to the absolute limit, and Apollo 13 escaped tragedy by the narrowest of margins. While the final missions spent several days on the lunar surface, the Apollo programme would have been hard-pressed to provide the foundation for a permanent lunar base. When humans do go back to the Moon, they will do so using spacecraft and rockets that have been developed to the point where lunar travel can conceivably become routine. 

And then – perhaps in a decade or two — a permanent human presence on the Moon will develop to the point where even the best-informed parents might be forgiven for not knowing exactly how many people are standing on the Moon.


IMAGE: The header image is from the Apollo 16 mission. The launch photo above is Apollo 11, on its way to the moon atop a Saturn V rocket. Both images via NASA.

The analogy between lunar and polar exploration has been made by a number of people — I believe I first heard it from the (now sadly deceased) polymathic Columbia astronomer Arlin Crotts, when we were colleagues in the early 2000s, and it appears in his book The New Moon.

Its Dark Materials

Each galaxy lives within its own three-dimensional halo of dark matter whose gravitational field corrals the stars within it. Without the stars, the halo would still be there, albeit invisible to our eyes; but if the halo vanished, the stars would scatter into the depths of the universe – just as a Christmas tree remains a tree with or without the pretty lights. Whereas without the tree, the lights would merely be a puddle of colour on the snowy ground.

Growing up in the Southern Hemisphere, the traditional trappings of Christmas were always out of step with the onset of summer around us: Santa in his cozy suit, imagery of roaring fireplaces, snowy scenes on Christmas cards, a heavy meal we consumed on a hot day before a swim.

But after I’d experienced my first Northern Hemisphere Christmas in Ithaca, New York — which, with several feet of snow on the ground, was something close to Narnia — the childhood strangeness of that transplanted holiday melted away and the seasonal symbolism at last made sense. A festival of light in the darkness of midwinter; gathering around a warm hearth while it snowed outside.

Fast forward a few years and I was living in New York City, where the Rockefeller Christmas tree (and the ice skaters beneath it) stands as a marker of the turning seasons. Another few years further on, my family and I were living in Connecticut, where the town of New Haven marks the season by selecting an enormous local evergreen to make the ultimate sacrifice in exchange for the chance to stand, dramatically lit, in the New Haven Green through the Yuletide season. We lived close by, and it became an annual ritual to walk to see the tree with the kids, always in winter jackets, often with snow on the ground.

New Haven Green. Image: Richard Easther

New Haven Green. Image: Richard Easther

Once, as we approached the illuminated tree, my wife Jolisa – a literature person, never not searching for metaphors to help make sense of science – asked: “You know this dark matter stuff that you talk about, is it something like a Christmas tree at night — we can see the bright twinkling lights, but we can only make sense of why they’re hanging in the air in that shape if we know about the tree that holds them up?”

And she was exactly right.

Our sun is one of roughly 100 billion stars in the Milky Way Galaxy, and the Milky Way is itself one of roughly a trillion galaxies in the visible universe. For over 100 years, astronomers and physicists have been trying to understand how galaxies, the giant islands of stars that are the large-scale buildings blocks of the universe, hold themselves together. If galaxies are made entirely of stars – in other words, if what we see is all we’ve got – the stars would be moving too fast for their mutual gravitational attraction to hold a galaxy together.

A selection of galaxies; each image contains over a hundred billion stars.

To make sense of this, the vast majority of astrophysicists and astronomers have come to believe that the cosmos is now contains far more than our eyes can see. As we now see the universe, each galaxy lives within its own three-dimensional halo of dark matter, whose gravitational field corrals the stars within it. Without the stars, the halo would still be there, albeit invisible to our eyes; but if the halo vanished, the stars would scatter into the depths of the universe – just as a Christmas tree remains a tree with or without the pretty lights. Whereas without the tree, the lights would merely be a puddle of colour on the snowy ground.

So if you are seeking a secular interpretation of the iconography of Christmas, you could do worse than seeing a well-trimmed Christmas tree, illuminated with lights and bedecked with tinsel, as a metaphor for the cosmos.

Dark matter – by definition – neither emits nor absorbs light, and cannot thus be made of atoms, or indeed any of the fundamental particles known to physicists; it must be something entirely novel. So likewise, let the spectacle of a galaxy serve as a reminder that there is literally more to the physical world than meets the eye, and that there are deep mysteries for us to solve in the years and decades to come.

Happy holidays and compliments of the season.

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The Milky Way over Portobello, Dunedin. Image: Ian Griffin.

The Milky Way over Portobello, Dunedin. Image: Ian Griffin.

Footnote: Actually this sort of was my TED talk. And, full disclosure, we can’t (and shouldn’t) be sure about dark matter until we have a better idea of its properties and composition.

How to Talk to Kids With Dreams

A few weeks ago I listened to a bunch of super-enthusiastic high school students share their excitement about astronomy, astrophysics and the space industry. We were at the Royal Astronomical Society of New Zealand’s annual meeting; every year they fund a dozen or so keen students from around the country to attend the event. It’s competitive, with many more kids applying than there are places to take them. 

The students get to share what lit their passion for space, but as they recounted their stories maybe a third of them mentioned a teacher or career counsellor who had done their best to quench that fire. “There’s no jobs in that.” “It’s really hard,” “You can’t do that in New Zealand.” “It won’t help you get into university.” And I wondered who listens to a smart, ambitious youngster’s hopes and dreams and tells them to play it safe?

It isn’t all teachers – others told of enthusiastic and supportive mentors – but it was potentially way too many of them, even if the nay-sayers imagine they are protecting kids from disappointment or quietly steering them away from games that are out of their league. Ironically, this is happening at a time when there is a lot of talk about reinventing school – getting kids to code, preparing them for a future where machine learning, AI and 3D printing are big things, building baby entrepreneurs. But none of that will be much use if some teachers are telling students not to chase their dreams.

Ironically, when educators talk about preparing kids for the future, part of their message is usually that the age of linear careers is behind us and today’s kids will change jobs more far frequently than their parents did. Which makes it particularly strange for teachers to tell students to aim only at safe and dependable careers as they chart their educational trajectory.

So what should you say to a smart kid with dreams that would take them off the beaten track? Here’s my list: 

  1. Tell them “Wow that’s great. Go for it!”

  2. Say to them “That sounds like it’s going to be a lot of work.”

  3. Ask them if they know what they need to do to get to their goal. What skills will they need?

  4. Tell them “That sounds awesome” (whatever it is).

  5. Tell them “Go for it. Whatever happens, you will be OK”, but help them figure out what they are likely to hit if they miss their actual target. Don’t be negative, it just never hurts to look before you leap, to make sure they will be ok.

  6. Ask them, “What can you do right now that will get you closer to your dream?” Get them doing things today that will engage their passion.

  7. Ask “How can I help?”

Item 1 is easy, and it works for anything. Item 2 is honest – no-one sleepwalks to being an astronaut or an All Black – and it is likely part of the fun.

Item 3 is a biggie, and for some goals the answer will be more obvious than others. What should someone who wants to be a professional athlete do, beyond just training for their sport? I’m not the best person to ask about that (really, I’m not) but whatever you want to do, my guess is that some of the things that will get you there won’t always be obvious: one of my key skills as a scientist is that I like to write and know how to tell a story. (Seriously: every grant application is a story about what I would do if you gave me money – and it helps if I tell it well.) If a kid at your school wants to get into astronomy (something I do know something about), it could be a long wait before they can actually do astronomy. But astronomers need to know maths, computing, statistics and physics – does the kid you are talking to know this? Set them to finding out what is on their list. 

Item 4 leads into Item 5. If a kid chases their dreams, are they really taking their whole future into the Casino of Life and putting it all on 22? Or are they laying down skills that also lead to all sorts of other opportunities? If I am brutally honest, I will only retire once, and while my field is growing it is certainly not expanding fast enough to accommodate everyone who trains to work within it. Numbers as miserable as a 2 or 3% success rate for making the transition from a PhD to a permanent job in the field are thrown around – the situation is not as dire as that, but in astronomy the success rate may be around 20% for people who actually get PhDs. At some point, it is possible students stand a better chance of success if they don’t spend too much time stressing about the odds. But all my former students are doing well. Some have tenure – and others have successful startups or jobs in Silicon Valley where they use knowledge they acquired while they were working with me.

Someone chasing their dreams may be walking a high wire, but they can build a safety net by laying down serious and transferable skills. (And many of the people I know who pulled the cord on their personal Plan B made a conscious decision to do something new; ambitions change.) Help them figure out what those will be for them. The real trick to Item 5 is to help kids take measured risks without hinting you don’t think they can do it. And this goes double if you are talking to people who might feel that they won’t fit naturally into their chosen field – my friend Chanda Prescod-Weinstein often says that African American students hear well-meaning talk about a personal Plan B as “I don’t think this is for you”; the same likely goes for Māori and Pasifika kids in New Zealand, or girls heading into fields where women are scarce. 

Item 6 and 7: whatever it is they want to do, there will always be something they can start on right away. There’s no time like the present. And be there for them. Check in. Ask how they are getting on. And wish them well.


And one last question: if you’re a teacher, what’s your ambition? It’s got to be better to watch your students chase their dreams than, when they come to tell the story of their success, be remembered as the person who said they couldn’t do it.

CODA: It is also true that if we are talking about academia, it is not just the student’s job to be sure they have a Plan B, it is up to their teachers to recognise that many of them will need one, make sure that they get the chance to maximise their transferable skills and know how to demonstrate them to potential employers. But that’s a story for another day.  

IMAGE CREDIT: The image is from NASA.  

Bike Bridges of Auckland


A city can simply happen, its location and form shaped by millions of people choosing where to live and what to build. This is a classic example of emergence or complex phenomena arising from simple ingredients, one of the key ideas science uses to make sense of the world.

Of course, cities don’t just happen; they reflect decisions made by a society or, more accurately, by those with power within a society. Where will the roads go? What are the planning rules and regulations? What activities and assets will be taxed? What do the laws say? Where are the schools and hospitals?

Ironically these decisions bring their own, additional layer of emergence. No-one decides that traffic jams make for a better city but the roads in many cities are clogged morning and evening, a consequence of policy choices which see private cars as the primary means of transportation. To my physicist’s eyes, efficient transport is a matter of density and energy: cars take up more space per passenger than bikes, buses and trains, so building infrastructure to properly support cars is expensive* and moving people inside cars costs more energy than the alternatives.  

Unpicking the unintended consequences of design decisions is hard; new resources must be threaded through a complex environment. To its credit, Auckland is solving this problem with trainsbuses and bicycles, although “mode share” for bikes is still a small slice of the transport pie. However, cycling is perhaps the most energy efficient transport option known to human beings, better even than walking** and usage of the Northwestern bike path and my regular commute is growing at an annual rate of20%. This may even pick up a notch in the coming year, as the Northwestern is connected to the new Waterview Shared Path which opened in the last few days. I went for a ride along the new tracks today and was stunned at how well this set of cycling arteries has been stitched into the suburbs of Waterview and Mount Albert.

Te Whitinga Bridge across SH 20; south of the Waterview Tunnel.

Te Whitinga Bridge across SH 20; south of the Waterview Tunnel.

Unlike almost any other form of transport, regular cycling leaves you fitter and healthier than sitting in a car, a bus, or a train. Not only that, Auckland’s best cycle paths run through parks and incorporate a series of stunning bridges, so you are likely to arrive at work with a smile on your face.

Even though you are rolling through parkland and alongside a stream for much of your journey the regular city environment reappears here and there; train tracks, shops and streets, just to remind you what you are missing.

And the designers seem to have a sense of humour – an older ramp on the Northwestern near the junction with the newly-built path has received an upgrade of its own.


Ironically, the new Waterview paths were built alongside a massive highway project, which completed a central loop in Auckland’s motorway system. 

Last of the roadwork at the Waterview interchange?

Last of the roadwork at the Waterview interchange?

And, as a closing thought, Auckland’s cycleways and motorways have a more synergetic existence that you might expect. The central city boasts the now-iconic “Pink Path” (Light Path / Te Ara I Whiti to its designers) which was built on a disused motorway off-ramp and in the coming years “Skypath” will hopefully add walking and cycling options to the eight lanes of traffic on our Harbour Bridge. Personally, I can’t wait.

CODA: In fact, it is no coincidence that the Waterview path was built alongside the massive motorway project. Community and bike advocates campaigned for it, both to mitigate the impact of the motorway construction and to deliver more comprehensive transport connectivity, which was the overall goal of the project.

* Ironically, building better roads to beat traffic jams tends to increase the amount of driving people want to do, making the traffic jams come back – what planners called induced demand. 

** Including the embodied energy used to make the cars and bicycles as well as the energy costs of making both food and fuel complicates this simple picture. But for many short journeys cycling is a time and energy efficient way to get around. 

IMAGES: All by me except the Lightpath picture (BikeAuckland) and the Skypath mock-ups (Reset Urban Design)

Your Mileage May Vary

Auckland’s 2017 Bike Challenge winds up today; February may be the shortest month, but it is prime cycling season in Auckland, with decent weather and long evenings. I don’t usually log my saddle-time, but I tracked my activity while taking part in the challenge. In the course of the month I made 36 trips covering 345km on my bike. If I’d traveled the same distance by car, I would have emitted 69 kg of carbon dioxide.

I can add a few more stats to that: the same amount of travel by car would have cost me a couple of hundred dollars (that’s just for petrol, plus parking in central Auckland), or a bit over a hundred by bus.

On the other side of the ledger, while the running costs of a bike are close to zero, it occasionally needs a little love from a mechanic – and I find that the rider appreciates a bonus mango lassi with his lunch.

Over the last year, I’ve moved from a fair-weather cyclist to something close to a year-round rider. My trousers fit a little more loosely than they did 12 months ago, as I am around 5kg lighter. Not a huge change, but a result that goes against the run of play for a (let’s be honest) middle aged guy who spends a lot of time at a desk. I don’t puff so much going up the hills any more, and a long walk seems a lot shorter than it used to. An e-bike may lie over the horizon, but for now I’m fully pedal-powered. 

It’s not easy to acquire a new habit that’s stuck as well as this one has, so what made it possible? The first answer is infrastructure;  my commute is mainly along Auckland’s Northwestern Cycleway, which runs along the side of the highway to town – and it is just much (much!) nicer to be riding down a tree-lined car-free path than it is to be sitting in traffic on the adjacent motorway. 

My commute –  Auckland’s Northwestern Cycleway

Clearly, I am not the only person to think so, as traffic on the Northwestern cycle path has been growing at around 15% a year over the last five years, to the point where speeding road warriors need to learn to move more slowly around pedestrians and upright cyclists. It’s still not perfect, and I face a few hundred hairy metres along Symonds Street where I can dodge buses and connect with my inner cycle courier, but it’s clearly good enough. 

The second ingredient you need for a year-round cycle commute is the “end of ride” facilities – not just  a place to lock my bike (with a decent lock, since theft is an issue in town), but a shower at work, for reasons that surely need no explanation. In fact, with an increasing number of my colleagues starting to show up on bikes there is occasionally a queue for the shower in my building, which can make the workplace feel a little like an old-school student flat in a house with a lot more bedrooms than bathrooms. 

And that is the third part of the recipe – I am not doing this on my own. Which is, of course, exactly the idea behind the Bike Challenge, since nudges from our friends and colleagues are potent tools for changing our habits.