The Best Australian Science Writing 2012 Page 4
If a particle is able to travel faster than c, a few odd things happen. Critically, it breaks special relativity, which states that there’s an absolute speed limit – the speed at which massless particles travel – that doesn’t depend on relative motion. One practical aspect of special relativity is that the concept of ‘simultaneity’ – two things happening at the same time – is frame-dependent. If two events occur at the same time but at different locations, say flashing a torch, then depending on how you are travelling relative to each of those events, you may see them occurring at different times. For instance, if you are accelerating relative to one then you will see it occur later, as if time is slowed.
Now let’s have a machine that turns on two torches at the same time. If the first of those is a normal torch and the second emits faster-than-light luminous particles, then from a distance you might think that the second torch was turned on first because you saw it first, even if you aren’t moving relatively – it’s as if it was turned on in the past. So the particles can appear to travel back in time (hence the backwards ordering of the joke about the neutrino entering a bar) … but there’s still no method of accelerating a cyborg killing machine to super-luminal speeds.
Is the latest potential finding an isolated incident? Apparently not. In 2007 the MINOS experiment, located in the US and with a similar source-detector distance to the CERN-OPERA path, observed the same thing, albeit with a smaller significance (1.8 standard deviations – not enough to get excited about) and a larger error (allowing for neutrinos travelling exactly at c). Measurements of arrival times of photons and neutrinos from supernova SN1987a in 1987 provided a much better agreement with the speed of light, but those neutrinos were of a much lower energy. The possibility remains that the velocity of a neutrino depends on its energy. Somewhat less rigid explanations include neutrinos taking ‘shortcuts’ through extra dimensions. Undoubtedly many more possible explanations will arise if all conventional sources of error are excluded.
The much more likely scenario is that the analysis has overlooked some seemingly insignificant but critical aspect, and that re-analysis will lead to a very good agreement with the speed of light.
Should that be the case, the follow-up press release will no doubt refer to the ‘Phantom of the OPERA’.
Postscript: 1 May 2012
For every complex phenomenon there is an explanation which is simple, concise, and wrong. The OPERA faster-than-light neutrino article generated a flurry of explanations, both online and within the scientific community, claiming to resolve the problem via strange new mechanisms. In the end, a loose coupling in the GPS wires mentioned in the above article was found to be responsible for the apparent velocity increase.
Even though the OPERA team was agnostic to sources of error, and announced their findings expecting that they would be proven wrong, the fallout has been dramatic. The two OPERA scientists in charge of the collaborative experiment, spokesperson Antonio Ereditato and physics coordinator Dario Autiero, resigned from their posts following a vote of ‘no confidence’. The timing of the signal travelling between the surface GPS and the underground detector was measured originally by Autiero in 2008, but was not rechecked recently. Doing so would likely have implicated the loose connection and forced a re-evaluation of the spurious data before making it public.
Since then, the ICARUS experiment (also based at Gran Sasso) has confirmed the neutrino speed as matching the speed of light to very high precision, a confirmation that would have also prevented the premature publication of the OPERA results.
The widely varying mechanisms invoked to explain how neutrinos could travel faster than light will no doubt be shelved until the next anomaly. In an ideal world the vanishing of such a discrepancy would serve as a constraint on wacky theories, but in reality the goal posts are too often moved to suit specific purposes. Experimental errors are an ever-present ‘unknown’ in any facility, and events like this should leave us even more impressed with the enormous precision and sensitivity of experimental efforts like the LHC.
More importantly, we should continue to suspect horses, not zebras, when we hear hooves.
Strange physics
Travel
Blank canvas
Corey Butler
Walking up to the flowering mallee growing in the red dirt of South Australia’s Bon Bon Station Reserve, I was so amazed by the amassed hum of thousands of native bees that I didn’t notice the brightly coloured beetle perched on one of the flowers.
When the insect did finally catch my eye, I took a quick snap of its shiny shell before returning my focus to the bees flocking around on the small tree (Eucalyptus socialis).
It wasn’t until I returned that night to the shed where the team of scientists and naturalists were based, and showed entomologist Andy Young the picture of my ‘cute beetle’, that realisation hit us: I’d come face to face with a new species of beetle. And let it go. He looked at me as if I’d won the lottery, but lost the ticket.
In my defence, I had tagged along as an observer, to document the week-long biodiversity field trip arranged by Bush Heritage Australia, a non-profit organisation seeking to protect flora, fauna and habitats.
* * * * *
Dubbed a ‘biodiversity blitz’, it was a large-scale effort to collect and classify as many species as possible. No one had asked me to keep an eye out for new beetle species.
It’s hard to get your head around the size and scale of Bon Bon Station Reserve, an old sheep station south of Coober Pedy. At around 70km long and 30km across, it’s double the size of Auckland, New Zealand, spanning 216,700 hectares of arid South Australian outback.
It had been a working sheep station for 130 years, mostly untouched and unexplored by science – a blank canvas of biodiversity. Bought by Bush Heritage in 2008 with funding from the Federal and South Australian governments, it has 14 different types of habitats, ranging from freshwater wetlands to salt lakes.
But nobody knew what species it held. So in September 2010, Bush Heritage assembled a team of 20 scientists and volunteer naturalists – experts on mammals, invertebrates, reptiles and plants – to conduct a large-scale biodiversity survey. And I tagged along.
* * * * *
Touching down in Kingoonya on what the locals call an ‘airstrip’, 600km north of Adelaide, I realised just how isolated the site was, and why it took Bush Heritage two years to put the week-long survey together.
Not only did all the scientists have to be shipped in by fourwheel drive, but so did the mountain of trapping and sampling equipment, scientific instruments and the food and water required to support the team.
The base was the old farm homestead – as well as a scattering of small tents, a portable cool-room and a transportable toilet block the size of a semitrailer. A noticeboard on a verandah outlined the names, whereabouts and satellite phone numbers of the seven research teams currently scattered across the reserve.
A biodiversity survey involves observing and documenting all the species (both plant and animal) in a specific location. It sounds simple, but in reality involves trapping and releasing hundreds of mammals, reptiles and insects and finding and identifying thousands of seemingly similar-looking plants.
The project had begun two weeks before my arrival, when Jim Radford, Bush Heritage’s science and monitoring manager, arrived to select the sites the scientists would be searching.
He had also begun digging the pitfall traps used to collect small terrestrial animals, so there would be enough time for the soil disturbance to settle, and for the animals to feel comfortable enough to venture back into the area.
* * * * *
Of the many different types of traps used throughout the survey, the pitfall traps were perhaps the most labour-intensive.
They involved the construction of a miniature fly screen fence, dug down into the soil, which formed a barrier that mammals, reptiles, amphibians and insects would hopefully encounter.
Every few metres, buckets or
large tubs were dug into the ground so that the top was level with the soil surface, in the hope that the animals scurrying along the fly screen would fall in, ready for the researchers to observe and identify them.
Inside the buckets was soil or an empty section of an egg carton, to give the trapped creatures a place to shelter until one of the teams arrived and either recorded and freed the sample, or packaged it for delivery to the station headquarters for the evening cataloguing session.
Because of the size of the reserve, it was important to visit the traps on a regular basis: a trapped skink might be stuck in a bucket next to a hungry colony of bull ants.
And how do you know that the lump halfway down a captured 1.8m brown snake wasn’t a native dunnart – a rare marsupial – that the snake slid down to devour? The trapping game is one of timing, constant observation and, yes, a bit of luck.
* * * * *
After a few hours following the scientists as they discovered creatures at every pitfall trap – and of sometimes plaintive pleading to be allowed to uncover some treasure for myself – I had a thrilling first find.
Approaching a trap, I was delighted to see that the egg carton base concealed a prize. It wasn’t until I was lying face down, with my entire arm down the trap, that I discovered there was not only a banded snake underneath the carton, but three native scorpions hanging upside down beneath it, dangling just centimetres below my fingers!
I was even more thrilled when I gently wiped my finger around the fine orange soil covering the bottom of the bucket and saw movement, and what I thought, at first glance, was a worm. After gently lifting the ‘worm’ into the daylight, Radford identified it as a blind snake – and I enjoyed all the euphoria of discovery that a child feels on a Christmas morning.
I could easily imagine what the survey scientists were feeling. Each team was made up of specialists, and for them, the blitz was like all their Christmases coming at once.
* * * * *
There were the ‘plant people’, a roving group who set up a mobile camp with a specialised 4WD and wandered off, heads down, scanning the terrain like hungry ants.
They could afford to be the slowest-moving group: after all, their specimens weren’t going anywhere, so they didn’t have the urgency of those hunting insects or reptiles.
They stopped occasionally to dig out a small seedling, or trim off a flowering branch, then scampered back to a fellow ‘plant’ person, or back to base to show off and discuss their finds.
If a sample is chosen for collection, a GPS reference is taken and painstakingly matched to a pre-printed label, which is then wrapped around the sample. The precious find is then carefully laid out on newspaper, and pressed on the spot into the bundle of samples to be taken back to the station and processed that night.
Processing occasionally included emailing the country’s archive of plants, such as the National Herbarium in Canberra, to help identify a specimen. The pressed samples might also be rearranged, seedpods opened and fanned for better viewing and all re-sandwiched into a preserving press.
It’s expeditions like this that many of the scientists look forward to. ‘You spend so much of your time indoors, so being able to collect samples is what we live for,’ said Helen Vonow, a botanist from South Australia’s Department of Environment and Natural Resources and the collections manager for the State Herbarium, as she showed me a flowering bluebush daisy.
* * * * *
We jumped back into a 4WD and used the satellite phone to establish which group was nearby. The reply came back: ‘the insect people’. On approach, all I could see was the swift swiping around of green and white nets, with some thrown over small bushes.
The scientists’ wrists snap back and forth with the precision of expert cake decorators, and the nets sweep so quickly that the unsuspecting insects don’t stand a chance.
After a suitable number of sweeps, the bottom of the net is held up to the light to inspect the captured prize. If the sweep is successful, scientists carefully extract the captured insects by gently sucking them into a plastic tube for easier identification.
The entomologists’ capture techniques don’t stop at sweeping nets. Soon after I met up with them, we got back into our 4WDs and travelled to an old decommissioned well shaft, its rusting windmill collapsed and lying ruined beside it.
After removing two of the railway sleepers sealing the top, entomologist Remko Leijs, from the South Australian Museum, lowered a weighted netting cone with a sample pot into the shaft and its still, stagnant water.
Then slowly, hand over hand, he retrieved the cone from the well floor with the water sample, some dirt and – hopefully – some subterranean insect life inside.
Whether in the air, perching on plants or swimming in water metres below, it seems there was no hiding from these determined scientists.
* * * * *
Just when I thought I’d seen the full extent of insect hunting, I arrived back at sunset to the homestead to encounter a set-up that resembled a strange ritualistic altar.
In a disused shed, a white sheet hung from a beam, weighted down with stones. Three tree branches were crudely knotted together in a teepee fashion, and hanging from these crossed limbs was a huge light bulb.
That’s when I was introduced to ‘the bug man’, Andy Young. Young, an entomologist from Kangaroo Island contracted by the South Australian Museum, offered to take me out to ‘the sheet’ later that night to show me how it’s used.
‘Come as you are, no cologne or Aerogard,’ he insisted. In this area, not wearing insect repellent is like walking naked and defenceless.
For the next hour, as we prepared, I heard murmurs about just how amazing – and gross – this experience could be. Still, even I, who rate The Silence of the Lambs as a favourite film, was psychologically unequipped.
As we approached the sheet, I saw Young lying on the ground, closely scanning the thousands of insects now on the sheet: they’d been attracted by the warmth and UV rays emitted by the only light in the dark night sky. I saw his eyes dart across the area my feet were about to land on and I stopped dead in my tracks, realising I might be about crush some of his prized specimens.
Stock-still a metre behind him, I was close enough to watch as moths, flying ants, wasps – and too many other bugs to classify – dropped from the sheet onto Young’s head, shoulders and everywhere else, and began their trek to any warm dark hiding place: the back of his neck, under his shirt, and around the folds of his ear.
I was so mesmerised watching Young being covered in insects that I hardly noticed something land on my eyebrow, then dart into the corner of my eye, trying to burrow into my head.
I flicked it away and instinctively proceeded to swat my forearms a few times to remove the critters that were now crawling all over me.
Standing there with no insect repellent and thousands of bugs flying in and around me, and on me, crawling towards the light, I felt waves of skin-crawling goosebumps dancing across my skin.
Something wriggled through my armpit, while something else slithered upwards along the back of my thigh. I watched as, nearby, an entomology student stood in shock, mouth open (and in my mind I screamed, ‘Quick, shut your mouth!’).
I knew I needed to let the bugs roam over my body in order to get good pictures. So I blocked out what was occurring on the surface of my skin for more than an hour, until Young finally, blessedly, decided he had enough samples.
He invited me to return to his classifying desk and watch him process the findings. The light flicked off, and the live specimens were taken back to a desk filled with containers of pins, killing jars and mounting boards.
Young worked quickly, explaining the need to get the specimen pinned and its legs and wings splayed out as soon as possible after it is euthanised and before rigor mortis sets in and the limbs snap off when he positions them.
I watched in awe as, without references, Young sorted and classified the species, leaving aside a jar full of new discov
eries. At around 2.15am, in the pitch black, we finally retired to our swags for some much-needed rest.
* * * * *
My legs were being shaken. I was groggy from slumber, tired, and it was still pitch black when I realised that the ‘bat man’ David Stemmer, the South Australian Museum’s collection manager of mammals, was trying to wake me up. Stemmer and I had made a pact that we would head out early in the morning to check the harp trap for bats.
The harp trap is a metal frame with a series of fishing line ‘strings’ arranged in vertical succession, and a collection trough at the bottom of the strings. When placed in a corridor of scrub, the bats don’t notice the strings with their sonar, so they hit them and drop into the soft collection trough, where they’re trapped.
After many nights without success, this night’s haul was an exciting six bats. Each the size of a mouse and with huge rubbery ears, they clumsily tried to grip the sides of the trap as they hobbled around, looking for a darker place to hide.
After following Stemmer for a while, I succumbed to fatigue and soon was, like the bats, clumsily crawling into the dark of my swag to finally get some rest.
It was a successful blitz, and it could take up to a year to sort through the extensive haul of specimens and determine how many species were new or new to the area.
By the end of the week, the group had collected 450 plant specimens, and had used various trapping techniques to acquire five native small mammal species, one bat species, over 40 reptile species and many thousands of insects. And – of course – they had a photograph of one very attractive beetle that your correspondent let escape.
Creepy crawlies
Biodiversity
Under the hood of the universe
Margaret Wertheim
What drives a man with no science training to think he can succeed where Einstein and Stephen Hawking have failed? In 1993, Jim Carter sent out to a select group of the nation’s scientists a letter announcing the publication of his book The Other Theory of Physics, in which he promised a complete alternative description of the universe. ‘Never before has any theory offered such a comprehensive explanation,’ his letter enthused. In addition to ‘shedding new light on phenomena that have long been considered to be well explained’, the book would contain solutions to ‘mysteries and paradoxes that have plagued physical science for centuries’. The ‘origin of the moon’, the nature of gravity, the structure of matter, the relationship between space and time – all these Carter proposed to clarify through a concept he called ‘Circlon Synchronicity’. This was not an extension of existing physics but a wholesale reconstruction. If his ideas were accepted it would be the greatest upheaval in science since the Copernican revolution; he would be not just the next Einstein, but the Isaac Newton of our time.