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Thursday, 22 September 2016

Posted at 03:46PM under 2016S1 SCIENCE Podcast .

Lightspeed Delay

So while we're all just sitting around here waiting for me to come up with something original, here's another interesting relic from my uni work:

If your browser doesn't support HTML5 audio, here's a link to the audio instead.

It's a podcast. I have a bit of a confession to make: it was distressingly fun and easy to make. And, despite being a little overproduced, I think it came out pretty well.

The parameters of the assignment were to produce something that lasted pretty much exactly three minutes, and if you give it a listen, you'll see how I turned that into a classic example of limitations acting as inspirations. What the podcast wasn't quite long enough to feature, though, was that Mars and Earth have never actually been that close. "Almost exactly three" light minutes (3:02, to be precise) is just the theoretical minimum. The smallest observed signal delay between the planets was 3:06, in 2003. Most of the time though, they sit around 12-ish light-minutes apart.

I'm curious about how far you could take this concept, though. What other processes or phenomena take a very specific, roughly minutes-scale amount of time to happen? Would there be enough of them for a regular series?


Thursday, 21 July 2016

Posted at 10:26PM under SCIENCE .

Continuous Consumption

So I was walking home from the train station the other day, just drinking my choc milk and minding my own business when I had an idea. Always a dangerous phrase to hear, I know.

Inspired in part by the alt-text on this xkcd, I started to wonder if I could get trapped in some kind of continuous energy loop. At what rate would I have to consume my nutrient rich slurry to precisely cancel out the energy I was burning on my walk home?

delicious milk

My purple drink of choice contains 364kJ per 100mL, and apparently one carton contains approximately 25% of my daily energy needs. Given that I do more in one day than just walk to and from the train station four times, I think we can safely say say that my walk home comes out at a net energy surplus.

(I think we can also fairly safely say that this stuff is pretty bad for you, but I'm going to keep drinking it. Possibly, if the maths comes out right, forever.)

Now I need to figure out what my burn rate is. For that, rather than trusting the eighty bazillion diet websites that Google turns up, I think I'm going to trust Wolfram Alpha.

Wolfram wants to know my speed. Which would be a tricky to figure out, except that Google is a massive creep, and is kind of tracking where I walk. A little bit of a dig through Maps gives me a moderately clean bit of data for my walk home. Apparently I walked 1.3km in 17 minutes, making my speed 4.59km/h, which according to Wikipedia, is slightly lower than the human average.

With that speed, and a little personal information sprinkled on top for good measure, Wolfram reckons I burn 34kJ per minute.

In an very satisfying alignment of numbers, that's almost exactly 10mL of milk per minute of walking. The full 600mL carton, then, would power about an hour of walking at my regular pace. And that, in turn, comes out to be pretty close to five kilometres.

And that, my friends, means that one carton of mocha-flavoured milk is almost exactly one egg.

pokemon go is topical, okay?


Tuesday, 21 June 2016

Posted at 04:33PM under 2016S1 .

Buying Innovation

I know infographics are a little bit old hat these days, but I did have fun with this one.

Buying Innovation: A look atAustralian Government research funding

This graphic is based on the SRI tables, a dataset produced by the Australian Government's Department of Industry, Innovation and Science, and available from under a Creative Commons Attribution 3.0 Australia License.

Creative Commons License
Buying Innovation by Rockwell McGellin is licensed under a Creative Commons Attribution 4.0 International License.
Based on a work at

.pdf / .svg


Sunday, 19 June 2016

Posted at 03:10PM under 2016S1 Writing .

Farming the Final Frontier

In a glowing pink cabinet 400 kilometres above the surface of the Earth lives the loneliest lettuce alive.

Don Pettit's space zucchini, grown in nothing but a ziplock bag and a few drops of water. If only it were so easy. Image credit: Don Pettit / NASA

Plants in the International Space Station’s VEGGIE experiment grow in fibrous nutrient-rich pillows with water delivered from below. Light shines from racks of LEDs above, bathing the plants in a distinctive pink hue. By dropping the green light, which plants can’t use, VEGGIE saves valuable power but makes the plants inside look pitch black. The entire system is regulated by computer and monitored constantly from mission control.

It’s a long way from Earth, but this could be the future of farming.

Sowing the seeds

As with most space science, the craft of growing plants in orbit was pioneered by the Soviet Union. Cosmonauts tended wheat, peas and maize aboard the Salyut and Mir space stations in the 1970s and 80s. They were the first to grow an entire generation of plants in space, growing some cress-like weeds from seeds until they produced seeds of their own. NASA eventually caught up, but after the fall of Skylab in 1979 they were limited to short tests aboard the Space Shuttle.

Even today the Russians are ahead. While NASA astronauts ate their first lettuce with much fanfare earlier this year, Russian cosmonauts have been eating half their crop from their own greenhouse for years, with the other half sent home for more rigorous testing.

Putting down roots

Astronauts mostly still eat canned or dried food. Their atmosphere is still maintained not by photosynthesis, but by electrolysing oxygen from water, then scrubbing carbon dioxide away with canisters of lithium. Both the water and the canisters are supplied, like their food, from Earth.

As we explore further into the solar system, those supply runs are going to get harder, and the costs of failure higher. Right now losing a spacecraft, as both SpaceX and Orbital Sciences did last year, means a return to dehydrated food. During a Mars mission it might mean famine.

Taking plants up with us seems like the obvious solution, but it’s trickier than it looks.

Lettuce leave

Plants evolved to live on Earth under the steady pull of gravity. Without it soil simply doesn’t drain. Instead, water clings to plants’ roots and stays there, cutting them off from vital nutrients. The same happens to air around leaves: without ventilation plants quickly use up all the carbon dioxide nearby and starve in a stagnant pool of photosynthesised oxygen.

VEGGIE is the latest attempt at solving these problems, but introduces some of its own. The pillows keep roots nourished and well-drained but are quickly depleted and need replacing from Earth. Plants are exposed to the space station’s atmosphere for ventilation but then have to be sanitised to ensure that lettuce, and not microbes from the air, is all the astronauts are eating. And sometimes, for an exciting new reason every time, the plants just refuse to grow.

These problems will be solved too, but at the cost of complexity. Just how much of Earth’s environment are we able, and willing, to re-engineer in orbit?

Further afield

Farming might never be worthwhile in low Earth orbit. For the rest of the solar system, especially Mars, it makes a little more sense. Thanks to a series of robotic explorers, we know quite a bit about Mars’ soils. Enough, in fact, that we know we can find very similar ones near volcanoes here on Earth. Just like their Martian cousins, they’re rich in trace elements, poor in nitrogen and very slightly alkaline.

A team of Dutch scientists, not NASA or Russia, are leading this particular field. They are well into their second attempt at testing these soils, growing carrots, tomatoes, cress and rye in painstakingly prepared pots of Mars-like dirt. And the almost-Martian soil, statistical glitches aside, seemed to work just as well as earth from Earth.

“That was a real surprise to us”, said Dr Wieger Wamelink, lead researcher on the project at the University of Wageningen in the Netherlands. “It shows that the Mars soil simulant has great potential when properly prepared and watered.”

The team plan to crowdfund a third experiment to start in April 2016.

“If the crops prove to be safe enough to eat, the funders will be invited for dinner where a ‘Martian meal’ will be served that includes the harvested crops; at least for those who dare!” Wamelink said.

And yes, potatoes will be on the menu.

Down to earth

Mark Watney wannabes aside, the real result of this research might end up closer to home. The Space Station is testing plants in the most hostile artificial environment imaginable. Simulated Martian soils are showing how to farm the most barren parts of our own planet. With increasing populations, growing urban sprawls and an erratic climate, it’s easy to see why this might be useful stuff to know.

Perhaps, rather than pink glowing cushions or bitter Martian grit, the future of astro-agriculture lies right here on Earth.

This article was originally written for SCOM2208 Science Writing at UWA in Semester 1 of 2016. As far as I can tell, the marker's favourite thing about it was the headline...


Friday, 17 June 2016

Posted at 05:57PM under IRL .

Return To Flight

Oh boy has this been a busy semester.

I don't know if it's been busier, or if the other parts of my life are busier, or if what I'm feeling is just that encroaching mental rustiness that you always heard mature-age students prattle on about, but... oh boy.

That's partly the reason I haven't really blogged in a while. The other part of the reason is that I've actually been writing exactly the kind of stuff I enjoy writing anyway as assignments. And, in one memorable and hopefully not isolated instance, for real dollars.

Yeah, that's right - I'm a published journo. Yes, it was basically a puff-piece, and yes, it was probably not exactly newsworthy, and yes, it's run out of the same place that I already work - but hey, I did it. I pitched to an editor. I did an interview. I wrote a story, accepted revisions, rewrote, sourced pictures, and then spruiked the heck out of the thing on Twitter. Journalism is one of those things they always tell you not to get your hopes up about, but I did it. And what's more, I reckon I could probably do it again.

In fact, probably the only reason I didn't turn around and do it again straight away is because of that aforementioned semester. In which I wrote a feature article, a news article, a press release, a 40-page-long consultancy report, and a paper in which I did my first real bit of statistics. All of which I'm actually thinking about hosting here over this break, so stay tuned for that.

What this semester, and this return-to-service post in turn, essentially boil down to is that I've been too busy writing for uni to do any paid writing, and I've been too busy doing paid writing to do any blog writing. Which, all in all, is not a bad place to be.


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