The smell of rain: how our scientists invented a new word

Rain: you can tell when rain is coming just by the smell. Flickr/Ulf Bodin, CC BY-NC-SA

Rain: you can tell when it’s coming just by the smell. Flickr/Ulf Bodin, CC BY-NC-SA

By Howard Poynton, CSIRO

Australia’s CSIRO has come up with some pretty amazing inventions over the past 86 years of research, from polymer banknotes to insect repellent and the world-changing Wi-Fi. But we can also lay claim to something a little more esoteric – we actually invented a whole new word.

And no, we’re not talking about one of these new-fangled internet words like “YOLO”, “selfie” or “totes”.

The word is “petrichor”, and it’s used to describe the distinct scent of rain in the air. Or, to be more precise, it’s the name of an oil that’s released from the earth into the air before rain begins to fall.

This heady smell of oncoming wet weather is something most Australians would be familiar with – in fact, some scientists now suggest that humans inherited an affection for the smell from ancestors who relied on rainy weather for their survival.

Origins

Even the word itself has ancient origins. It’s derived from the Greek “petra” (stone) and “ichor” which, in Greek mythology, is the ethereal blood of the gods.

But the story behind its scientific discovery is a lesser known tale. So, how is it that we came to find this heavenly blood in the stone?

Nature of Argillaceous Odour might be a mouthful, but this was the name of the paper published in the Nature journal of March 7, 1964, by CSIRO scientists Isabel (Joy) Bear and Richard Thomas, that first described petrichor.

Thomas had for years been trying to identify the cause for what was a long-known and widespread phenomena. As the paper opened:

That many natural dry clays and soils evolve a peculiar and characteristic odour when breathed on, or moistened with water, is recognised by all the earlier text books of mineralogy.

rain 2

Was it something in the soil that gave rise to the smell? Flickr/Georgie Sharp, CC BY-NC

The odour was particularly prevalent in arid regions and was widely recognised and associated with the first rains after a period of drought. The paper went on to say:

There is some evidence that drought-stricken cattle respond in a restless matter to this “smell of rain”.

The smell had actually been described already by a small perfumery industry operating out of India, which had successfully captured and absorbed the scent in sandalwood oil. They called it “matti ka attar” or “earth perfume”. But its source was still unknown to science.

Joy and Richard, working at what was then our Division of Mineral Chemistry in Melbourne, were determined to identify and describe its origin.

By steam distilling rocks that had been exposed to warm, dry conditions in the open, they discovered a yellowish oil – trapped in rocks and soil but released by moisture – that was responsible for the smell.

The diverse nature of the host materials has led us to propose the name “petrichor” for this apparently unique odour which can be regarded as an “ichor” or “tenuous essence” derived from rock or stone.

The oil itself was thus named petrichor — the blood of the stone.

Bring on the humidity

The smell itself comes about when increased humidity – a pre-cursor to rain – fills the pores of stones (rocks, soil, etc) with tiny amounts of water.

While it’s only a minuscule amount, it is enough to flush the oil from the stone and release petrichor into the air. This is further accelerated when actual rain arrives and makes contact with the earth, spreading the scent into the wind.

According to the Nature Paper:

In general, materials in which silica or various metallic silicates predominated were outstanding in their capacity to yield the odour. It was also noted that the odour could be obtained from freshly ignited materials rich in iron oxide, with or without silica.

It’s a beautiful sequence of events, but one that may be hard to visualise.

Thankfully, in a testament to the ongoing scientific fascination with this finding, a team of scientists at the Massachusetts Institute of Technology have just this year released a super slow motion video of the petrichor process in motion.

Using high-speed cameras, the researchers observed that when a raindrop hits a porous surface, it traps tiny air bubbles at the point of contact. As in a glass of champagne, the bubbles then shoot upward, ultimately bursting from the drop in a fizz of aerosols.

The team was also able to predict the amount of aerosols released, based on the velocity of the raindrop and the permeability of the contact surface which may explain how certain soil-based diseases spread.

Lasting legacy

There’s a small body of research and literature on petrichor that’s fascinating in its own right, including Thomas and Bear’s subsequent paper Petrichor and Plant Growth a year after they first named the smell.

So what happened to Joy Bear and Richard Thomas?

Richard Thomas with Joy Bear, studying petrichor (date unknown).

Richard Thomas with Joy Bear, studying petrichor (date unknown).

Richard had actually retired from CSIRO in 1961 when he was First Chief of the Division of Minerals Chemistry. He died in 1974, aged 73.

Joy, aged 88, a true innovator and pioneer in her field, retired from CSIRO only in January this year, after a career spanning more than 70 years.

The joint discovery of petrichor was just part of a truly remarkable and inspiring career which culminated in 1986, with Joy’s appointment as a Member of the Order of Australia for services to science.

We are thankful to both for the lasting legacy on giving a name to the smell of rain and to Joy for the role model she has been to so many women in science.


This is part of a series on CSIRO Inventions.

This article was originally published on The Conversation.

Read the original article.


Happy Valentine’s Day! Our hearts beat for you… with about 1.6 Watts.

hearts

Solar research makes our hearts beat faster. [Image by Wendy Brian of iHeartGuts.com]

By Tania Ritchie, Valentine’s Day 2013 

Aww. It’s Valentine’s Day today in many countries around the world, meaning the annual bombardment of hearts is upon us again: sugary-sweet hearts, super-sweet hearts, super-sized hearts and even some super-strange hearts. But the iconic curvy ‘love heart’ might have originated from a simplistic drawing of the human heart, which long ago was seen as the place in the body where the soul (and, presumably, romance) lived.

Nowadays, thanks to science, we have much less poetic notions about what the heart actually does (although, to compensate, what we know now is much, much more likely to save your life). We all know, for example, that the heart is the powerhouse that keeps your blood circulating.

So, just for fun, we thought that this Valentine’s Day it’d be fun to compare the power of the human heart to the power we can get from some of the different technologies we’re working at CSIRO.

The power of the heart

We can work out the average power of the heart by multiplying the peak pressure inside the heart (120 mmHg, or 16 kPa) by the rate of blood flow (say about 6 litres per minute, or 0.0001 m3/s). This gives us the magic number we’re going to use for the heart’s power: 1.6 Watts. Over the course of a day, this adds up to an energy output of 140 kJ (or 33 Cal) each day.

So we created a thing called the Heart-o-meter. It shows the power output of some of our energy technologies from our National Energy Centre in Newcastle, in a unit we’re pretty sure we’ve just pioneered here at CSIRO – equivalent human hearts. Aww. Who said science can’t be romantic?

2013-02-14_valentinegraph

You can see that yesterday the photovoltaic cells in our Virtual Power Station had a power output that equalled, at one point, the total number of people’s hearts in Newcastle. That’s a lot of love.

Happy Valentine’s Day.

This article was originally published in February 2013. 


Viva Parkes-Vegas!

Viva Parkes-Vegas!

When stars collide: Elvis meets The Dish

By Glen Nagle

The town of Parkes, NSW – home of our famous Parkes Radio Telescope – has slipped on its Blue Suede Shoes.

In the second week of January each year, Parkes marks the birthday of Elvis Presley with a massive festival celebrating everything Elvis. It started over 20 years ago as a one-day get together of just a few hundred fans. In 2015, the festival has grown to cover a week of events, shows, parades and exhibits and over 15,000 visitors more than doubling the town’s population.

Along with one of the largest collections of Elvis memorabilia on permanent display at the Henry Parkes Visitor Centre (donated by Wiggles performer, Greg Page), the Parkes Elvis Festival is one of the town’s major icons.

The other great icon of course is the Dish – our very own Parkes radio telescope – so combining these two great icons into one stellar event was always going to be, quite literally, a match made in Heaven.

'Return to sender' took on a new meaning for the Dish last night.

‘Return to sender’ took on a new meaning for the Dish last night.

On Wednesday, 7th January an inaugural concert was held at the Dish to help mark the opening night of the Festival – and to celebrate what would have been the King’s 80th birthday the following day.

Starring popular Elvis tribute artist, Shakin’ Rick Mackaway, and backed by the fabulous rock band, The Wilsonics, the dinner and show night attracted hundreds of people from across the region and as far and wide as Canberra, Wollongong, Sydney, Adelaide and Melbourne.

Storm clouds threatened earlier in the day, but nothing was going to rain on this parade of love for the King and the Dish. The clouds almost magically bypassed the telescope and the brightest stars in heaven came out for an incredible night of songs, dancing and laughter against the impressive backdrop of Australia’s iconic radio telescope.

Shakin' Rick, rockin' in to the night.

Shakin’ Rick, rockin’ in to the night.

Continuing to observe the heavens throughout the show, the Dish even performed during the intermission with several large moves enthralling the audience and provoking  questions about both the science behind, and the history of, the Dish.

As the evening came to a close with a final encore performance and the audience departed, the number one question was, “Are you going to do it again next year?!”

Hmmm? Elvis and the Dish 2! Two icons, exciting audiences everywhere with music and astronomy.

The possibilities are endless. Watch this space.


Sports science is getting gnarly, dude

The future of surfing? Credit: Seth de Roulet / Red Bull Content Pool

A laptop backpack: the future of surfing, or a sure-fire way to get dropped in on? Credit: Seth de Roulet / Red Bull Content Pool

A company more traditionally associated with energy drinks has been busy making waves in the world of sports science. Red Bull recently took two top professional surfers and a team of scientists to Mexico to test a range of new performance-enhancing technologies in one of the harshest arenas possible: an overhead, barreling wave breaking only a few feet over a bed of sand and rock.

We’re all for trying out new technologies in novel conditions, but this was a particularly impressive feat – the surfers were hooked up with all sorts of electronic equipment before paddling out into the lineup and doing their thing. At one point, surfer Jake Marshall even managed to ride some amazing waves with a laptop strapped to his back.

Surfing is a sport that is usually described in terms of instinct, intuition and unpredictability – so studies like this are providing scientists with amazing insights into areas of surfing that have previously held an almost mystical status. As well as hooking up the surfers with wi-fi headsets for instant feedback from coaches on land, and pressure-sensing feet ‘booties’ to analyse and optimise how they controlled their boards, the scientists were even able to measure surfer ‘stoke’ levels using a waterproof EEG.

You can watch the video here:

We’ve done a fair bit of sports science ourselves, too. Most recently, we partnered with Melbourne company Catapult Sports to deliver a new wireless athlete tracking device using our Wireless Ad-hoc System for Positioning (WASP) technology. The device, called ClearSky, gives coaches the ability to monitor their athletes more accurately in indoor and GPS-poor environments.

It works much like a GPS, but instead of using satellites in space, ClearSky uses fixed reference nodes that are located either within or just outside of a building. You can read more about the benefits of it here.

ClearSky can triangulate an athlete’s position to 20cm accuracy. Credit: Catapult Sports

ClearSky can triangulate an athlete’s position to 20cm accuracy. Credit: Catapult Sports

Of course, it doesn’t take a scientist to figure out how useful this technology could be on a cloudy day at a Melbourne AFL match when traditional GPS coverage is low. But it also has great applications for other (editor’s note: wussier) sports that are played undercover, like American football, basketball and soccer.

Indeed, the Catapult client list is a veritable who’s who of the international sporting world: the New York Giants (NFL), Orlando Magic (NBA), AC Milan (soccer), the Socceroos (soccer), Brisbane Broncos (rugby league), New Zealand Silver Ferns (basketball) and dozens of others. Many of these organisations are either already using ClearSky, or are preparing to do so.

Obviously, this is a winning technology that can be applied across a diverse range of sports. Who knows, maybe one day ClearSky will even be used to track the performance of professional surfers in a wave pool in the middle of Melbourne?

But in the meantime, some mysteries of surfing – like why the waves were always better yesterday, who stole my wax, and where surfing commentators get their t-shirts from – will forever remain unanswered.

Find out more about WASP here. 


Energy in a flash – what can we do with lightning?

Lightning is one of the scariest forms of energy in nature. What Halloween movie isn’t complete without a sudden thunderous bolt from the heavens right when the bad guy emerges from the shadows?

But lightning isn’t all just theatrics. It also contains a lot of power which, if it could be harnessed, could be of great use. This week’s dramatic electrical storms in Melbourne and Adelaide (storm photo gallery, ABC News) got us thinking… if we could capture lightning, what would we do with it?

*cue maniacal laugh*

In the 1931 film Frankenstein, the eponymous scientist used lightning-like bolts of electricity to create a monster.  In the 1990’s film Back to the Future, Doc used lightning to power his DeLorean to travel in time.

While it is fair to say we’re not quite ready to raise the dead or travel in time, using lightning to power our homes – or even a simple appliance like a toaster – could one day be a possibility.

Tall buildings like The Sydney Tower are regularly hit by lightning. According to recent reports, a million volts can charge through the Sydney Tower’s metal frame countless times per storm. Depending on which reports you read, there are about 500 megajoules in the average bolt.  This could easily power a 1000 watt two-slice toaster for over a year.

storm

Capturing the energy in a lightning bolt has been tried but with limited success. Other ideas have included conducting electricity using rods, or using the energy to heat water which could then be used to generate electricity. This is similar to solar thermal technologies which use the sun to heat water and then generate electricity.

For now, we’d say you’d be mad to try and power your toaster with lightning (unless you like it really burnt); but if we can find an efficient way to capture, store and distribute this energy, then one day it may form a small part of our energy mix.

Learn more about how we’re already harnessing nature’s power to produce energy with supercritical steam.


Four ways to lose weight and feel ‘electric’ this summer

As the mercury rises and our focus turns to hitting the gym and shedding those cuddly winter kilos, we thought we’d take a look at a few ways we could be making our workouts really count.

While the idea of working up a sweat and electricity might sound like a recipe for disaster, you’d be surprised how people and businesses are using sport and exercise to create electricity – with a conscience.

Giving light to rural communities


A company in the US has created a soccer balled called Soccket which can generate three hours of light with just thirty minutes of play. The ball is being used in rural off-grid areas of Mexico. Soccket stores the kinetic energy built up while you play using a pendulum-like mechanism.

Creating greener stadiums
At the Homes Stadium in Kobe City, Japan, the floorplan has been designed to harness vibrations made by cheering fans to create electricity. The electricity generates is fed back into the stadium’s power supply. The more fans cheer the less power the stadium needs to take from the ‘grid’.

Building safe places for kids to play


Soccer superhero Pele recently teamed up with global energy company Shell to launch a new type of pitch in a Rio. It is made from tiles which capture kinetic energy created by the movement of the players. The light is being used to power the pitch at night, resulting in a safe and secure community space.

Keeping your gym green
A gym in the UK made history by becoming the first self-powered gym using the energy of bikes, cross trainers and ‘vario’ machines to power its lights. Each machine feeds around 100w per hour back into the gym’s power supply. Treadmills also generate enough energy to power their own information screens.

And for those of us who may not be able to book a round the world trip purely for exercise purposes, why not try signing up for our new Total Wellbeing Diet online trial? Visit the website for more information and to sign up.

 


Want to see what we collect?

Mould spores. We collect them

Mould spores. We collect them

We collect things. Lots of things.

You might have heard about our major collections – the National Wildlife Collection, National Fish Collection, National Insect Collection, National Herbarium. You might even have heard of the Cape Grim Air Archive. But what about the National Soil Archive? Let alone the Fungus Collection or the Algae Collection.

The National Soil Archive contains more than 70 000 soil samples from nearly ten thousand sites across Australia. They’re not just bits of dirt picked up from anywhere. Not only are the samples representative of soil types throughout Australia, they’re a time capsule of sorts as well. Quite a lot of the samples date from the early 1920s, before widespread pesticide use.

Having these old samples gives us an historical record of soil carbon, so they’re an important resource for our work on climate change. They also provide an interactive key to Australian soil classification, which is a handy tool for landcare advisors, agronomists, environmental consultants, ecologists, foresters, geomorphologists, land use planners and catchment managers, and they form the backbone of our SoilMapp tool. Who’d have thought?

And there are actually three different fungi collections. There’s the Wood-Inhabiting Fungi Collection, which is self-explanatory. Then there’s the WA-based Mycology Herbarium, which deals with fungi as parts of ecosystem biodiversity. Blue-fungi-on-wood

The third is a little more off-putting. It’s the FRR Culture Collection. It’s a comprehensive archive of filamentous fungi and yeasts of the kinds associated with processed food spoilage. To put it simply, the national mould collection is a real thing. It’s not in a student share house fridge, but carefully stored and catalogued at CSIRO.

We mustn’t forget the algae. We have a comprehensive collection – the Australian National Algae Culture Collection – stored in Hobart: more than 1000 strains of over 300 species. It’s an important resource for two reasons. The first is that the nutrient value of algae is of growing scientific interest. The second is – and this volvox-aureus-green-alga_32106_1might come as a surprise – it’s aligned with CSIRO’s Microalgae Supply Service. This provides microalgal strains for ‘starter cultures’. They go to industry, research organisations and universities in more than 50 countries. We also supply starter cultures to the Australian aquaculture industry: microalgae are the essential first foods for larval and juvenile animals. They’re also the basis of our Novacq™ prawn food additive.

We think the contents of our cupboards are pretty interesting. They’re certainly unusual.


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