Archive for How Things Work

Chasing the aurora

// April 6th, 2012 // Comments Off on Chasing the aurora // How Things Work

Own picture, free to use or share

A brisk wind flowed through the trees as I retreat for the car. Ignition on, -17°C outside, warm air flows through the vents. Another cold clear night – perfect for viewing the elusive aurora borealis. We’d been sitting out for almost two hours, but it was 1:20 am and we were throwing in the snap frozen towel for the night. Nada.

The next day we went on a wildlife tour, and the British travellers in front of us were showing off their pictures on a camera. “When did you see the Northern Lights,” I asked. “They look amazing!”

“Last night,” one of them replies, “about 1:30am”.

Bummer.

That night we stayed inside and watched TV until 1 am, then took a mug of hot chocolate and plenty of warm clothes to go aurora hunting. It’s 4:30 am before we give up, with cold noses and toeses, having missed them again. The next morning (well, afternoon by the time we wake up) we find out the lights had started early, about 10 pm.

Bummer bummer.

Three more days we stay in Whitehorse, Yukon Territory, Canada, hoping for a glimpse of the lights. Once we saw a pale white streak across the sky, which showed up green on the camera under long exposure.

Disappointing, really, as we head back South – away from the elusive Northern lights.

First stop is Liard hot springs, and I recommend it a LOT. Wow, is it steamy! Anyway, we went for a dip, and as we were walking back to the accommodation, we saw them!

Green swirls, curtains and purple streaks!

The colours come from electrons around atoms jumping back and forth between orbits. Electrons absorb light to move up an orbit, then emit light of a particular wavelength to fall back down. Some excited states are more stable than others, and certain transitions happen more readily.

Own picture, free to use or share

Green light is emitted by oxygen atoms at lower altitudes, while a red glow can be seen from another oxygen transition at high altitudes. Purple is from transitions in nitrogen molecules that emit blue and red. A mix of the colours can appear white. A great chemistry-heavy explanation of the colours can be found here.

Did you know the northern magnetic pole is moving towards Siberia at a rate of around 40 kilometres per year? Aurora hunters in the US in 2060 might be more unlucky than we were!

Here’s a screenshot of the aurora predictor on the night we snapped these pictures, to give you some idea of what the conditions were like that allowed the aurora to occur.

Want more aurora? Check out this video which describes how they occur, and shows footage from above filmed on the International Space Station.

SKA, supercomputers and information technology

// May 18th, 2011 // 1 Comment » // How Things Work

Image by SPDO/Swinburne Astronomy Productions

Since seeing the RiAus event on the Square Kilometre Array (SKA) with Professor Peter Quinn speaking, I’ve been posting bits and pieces from the night.

I wanted to touch on the huge computing requirements needed to support just the insane amount of data collected by this radio telescope.

To recap: the SKA will be 10,000 times more powerful than any existing radio telescope. Either South Africa or Australia will host the spiral of dish antenna extending over 3,000 kilometres across, the decision will be made next year.

Every day the SKA will collect one exabyte of data. That’s a ten with 17 zeros behind it, a binary bucketload of information.

To process it all, we’ll need the world’s largest supercomputer on site at the SKA core, so the data is processed real-time as it’s collected.

According to the SKA website, they need something about 50 times more powerful than the world’s most powerful supercomputer in 2010, the processing power of a billion PCs.

Optical fibres will be critical for the physical network, as they can transmit large amounts of data at high rates. These fibres are as fine as human hair, and made of silica glass.

Okay, so this is fibre optics rather than optical fibre. Same difference, right? Image by Twistiti

Because the SKA antennas extend for such long distances, up to 5,500 kilometres, or from Western Australia to New Zealand, the length of cable they need would be enough to wrap around the globe – twice!

The national broadband network proposed for Australia would hugely benefit the SKA, providing some of the infrastructure needed for data transmission. We need the NBN! It would make everything so awesome!

Once collected and processed, the data will be available to an international community of astronomers – yet another challenge.

Can it be done? Professor Quinn says yes, though it will require new technologies and creative problem solving. This is no small step for mankind, but we’ll be going much further than the moon.

More information on the SKA technology can be found here.

SKA – Something Kinda Awesome and a tremendous telescope

// May 12th, 2011 // Comments Off on SKA – Something Kinda Awesome and a tremendous telescope // How Things Work, Recent Research

The Australian Government just announced it will spend 40 million dollars over the next four years to support Australia’s bid to host the Square Kilometre Array (SKA.) If, like me last week, you’re not really sure what the SKA is and Google seems to think it’s some kind of music – here’s the lowdown based on the RiAus event I went to on Thursday hosted by Professor Peter Quinn.

The SKA is a radio telescope 10,000 times more powerful than any other, a single scientific instrument comprised of individual dish antennas 15 metres wide working together.

Artist impression of SKA

Artist's impression of dishes that will make up the SKA radio telescope. Credit: Swinburne Astronomy Productions/ SKA Program Development Office.

From a central, densely packed core, receiving dishes will spread outward an area of over 3,000 kilometres. Combining their signals creates a telescope with the collecting area equivalent to a single dish one square kilometre in area.

Where will this massive instrument live?

The shortlist has been whittled down to two: South Africa and Australia. If in South Africa, the dishes will reach onto islands in the Indian Ocean. If in Australia, they will extend into New Zealand.

The final decision will be announced next year. Being Australian, naturally I’m hoping we’ll get the honour.

Murchison SKA candidate location

The candidate core site in Murchison Shire, WA. Credit: Ant Schinckel, CSIRO.

Our bid puts the SKA core in the Western Australia desert, Murchison Shire.

From here, the dishes would spiral out in five long arms across Australia and New Zealand.

The proposed core site is a space the size of the Netherlands, it contains 110 permanent residents.

With low population comes low radio interference. CSIRO scientists are working on innovative solutions to keep the site radio-quiet.

For example, trains in the region currently communicate by radio, and there’s dialogue to come up with an alternative that will work for trains without interfering with the SKA.

What will we find out there with our powerful telescope? Well, if ET phones home within our galaxy, with the SKA, we’ll hear it. In the next post, I’ll talk more about finding first light, when the galaxies began to glow.

Here’s more about the SKA: Australian site and International site.

Ferrofluid patterns and dancing art, fun with magnets

// April 29th, 2011 // 1 Comment » // How Things Work, Just for Fun, Science Art

Behold ferrofluid, nanoparticles of iron coated in a surfactant and suspended in a solution of oil or water.

The surfactant can be citric acid or soy lecithin, among other things, and is used to stop them sticking together

It’s like magnetic dust.

Put a magnet under some ferrofluid and the particles align themselves in patterns to show the field.

The magnetic attraction is so strong, the ferrofluid will stick to a magnet and then you’ll never get all the iron particles off it. They’re stuck for good.

To prevent that happening, people usually play with ferrofluid inside a sealed container.

And play it is, this stuff is fun.

Usually.

A friend of mine put a magnet above some ferrofluid with the lid off, and was abruptly COVERED in black gunk which stuck to him despite three showers. He wasn’t too happy, I think it smelled pretty bad. Hardcore.

Like most hardcore stuff, it’s been turned into kickass art. This video pretty well blew my mind.

Sachiko Kodama and Yasushi Miyajima created the piece, two ferrofluid sculptures which move synthetically to music. The two towers are iron cores of electromagnets sitting in a pool of ferrofluid. Etched with a helix pattern, the ferrofluid can move up the tower if the magnetic field is strong enough, stretching out in spikes as it goes.

The strength of the electromagnet is linked to metadata in the music controlling the voltage and AC pattern. To correct for the time delay, the electromagnet controls starts early so the maximum size of spikes coincides with beats of the music.

The result is a choreographed pattern that dances and winds like a living thing.

You can buy ferrofluid from Emovendo.

Hat tip to @DrSkySkull, who bought some ferrofluid as a classroom demo and supplied the picture at the top of the article.

So many baby octopuses

// March 8th, 2011 // Comments Off on So many baby octopuses // How Things Work, Just for Fun

One of my guilty pleasures is my RSS subscription to Zooborns, a blog all about baby animals. When I check Google Reader, I read sensible, serious blog posts about science until I finally cave and look at the cuteness.

Amongst the treasure trove of nursing giraffes and clinging baby apes was a clutch of baby octopuses! Perhaps clutch isn’t the right word… a handful? An armful! An armful of baby octopuses. Check it out.

Baby octopus at California Academy of Sciences

Baby octopus at California Academy of Sciences

Conception occurs when a male octopus inserts a modified sperm-containing arm into the female’s oviduct, though sometimes he removes his arm and she stores it in her mantel for later. Each egg, as it is laid, contains a long thread which the octopus uses to hold them all together like a bunch of grapes. A thoughtful mother, she protects them from predators and blows water currents across them for cleaning.

Biologist Richard Ross caught the hatching of the eggs on video, and described it as a waterfall flowing upwards towards the surface.

It’s an exciting event, but unfortunately a mother octopus stops eating to care for the eggs and dies which is a total bummer. With millions of tiny planktonic octopus young born, some should survive, though they are hard to feed and raise.

On a lighter note, Zooborns recently posted pictures of a Snow Leopard cub born in Chattanooga Zoo. Snow Leopards happen to be my favourite animal and the cub is so exceedingly cute I might die. A less attractive addition in Australia is the first palm cockatoo zoo bred in 40 years which has passed through the awkward teenage stage and is starting to fly.

Damn I want to work at a zoo.






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