Oh When the Science!

A science version of Oh When the Saints! I’m singing the hopes and dreams of every scientist. They dream of getting published, winning grants, tenure and a Nobel Prize! In my experience, to have success in science you need to clone yourself – twice. And then a bit of prayer could be handy…

More of Phil and co is at the Dramatis Scientificae website. I created the Oh When the Science video for AIP Physics in the Cloud, October 2021. Want more songs? Try a Chemistry love song about sodium chloride, or Pluto!

Apologies to Brian Schmidt, who was the original VC cited in this song (and whose name scanned better) but as this was a NSW-based show I had to switch to a selection of Sydney-based vice-chancellors. I apologiese also to Attila Brungs – whose name I eliminated due to bad scansion.

I thank the generation of musicians who brought the song into being around 100 years ago – there seems to be no single original composer, although a few have tried to claim it.

This is part of the 2021 Physics in the Pub (-Cloud, thanks to lockdown 2021) which Phil brings you in partnership with the Australian Institute of Physics NSW Branch.

Oh When the Science! sings Phil
Oh When the Science!

It was a laugh creating this video. But I drove my partner crazy – listening to me lip sync the song a thousand times… badly as you can see. I need a camera operator!!

Continue Reading Oh When the Science!

The Physics of Beer

It’s a common pub prank to tap the top of a friend’s beer, to make it suddenly erupt in froth. Funny to some people, annoying to others; but to Spanish physicist Javier Rodríguez-Rodríguez, intriguing.

Rodríguez-Rodríguez, from the University Carlos III of Madrid, decided to investigate the strange phenomenon, and in the process has discovered a host of complex physics in a glass of beer, which could help scientists understand all kinds of processes, from volcanic eruptions to the formation of asteroids.

“There are many different physical phenomena going on in a beer glass, and every time you drink a beer, all this physics is right before your eyes,” Rodríguez-Rodríguez says.

His thirst for knowledge has even led him to convince his PhD students to drop beer off a 100-metre high tower to study bubble formation in the micro-gravity environment of free-fall.

“Carbonated beverages are portable laboratories that can be used to demonstrate in an amusing way the working of many flows also found in nature and industry,” he and co-author Robert Zenit write in a review of the beer facts they have discovered, published in the magazine Physics Today.

The key to many of the processes in beer is that it is carbonated – a colloquial term for it being a super-saturated carbon dioxide solution. As the beer brews, fermentation by yeast emits micro-farts of carbon dioxide, building up pressure in the bottle.

Some of the carbon dioxide gas dissolves into the beer: the fraction is determined by Henry’s law, which holds that the higher the pressure, the more gas is dissolved.

When the bottle is opened, the pressure is released, meaning that amount of gas the liquid can hold is lower: suddenly the solution is super-saturated. But it takes a while for the solution to catch up. Over a few hours the carbon dioxide seeps out until it reaches its new equilibrium point, termed by beer lovers as “flat”.

The rate at which the gas departs, and the dynamics it sets off, forms the basis for much of beer’s intriguing behaviour – such as in the beer-tapping prank.

Rodríguez-Rodríguez’s study of it was first published in the journal Physical Review Letters and revealed that the trigger for the beer volcano is a pressure wave sweeping upward through the liquid.

The sudden jolt leaves the beer behind momentarily. At the sides of the bottle, the effect is minimal as the glass slides past the beer.

However, the downward shift of the base of the bottle has much greater ramifications, and creates a sudden drop in pressure in the liquid at the bottom. This low-pressure region propagates upward, triggering the dissolved carbon dioxide in the beer to suddenly form bubbles.

The beer then catches up with the bottle and the pressure rebounds. This sudden high pressure fragments the bubbles that have only just formed. Rodríguez-Rodríguez found each one breaks into as many as a million smaller bubbles.

These, now in a cloud formation, begin to rise, growing as they suck in more carbon dioxide. It takes a second or two before they reach the top and froth up.

The rise of the cloud is due to the buoyancy of the bubbles, which set Rodríguez-Rodríguez and his team thinking about what would happen in zero gravity.

Rather than sending beer into space, they decided to drop some off the 100-metre high drop tower of the Centre of Applied Space Technology and Microgravity (ZARM) in Bremen, Germany.

For the actual experiment they had to find a substitute liquid. “We cannot use beer,” says Rodríguez-Rodríguez. “It’s too dirty.”

Using carbonated water, the team could observe the evolution of the bubble cloud as it hovered within the liquid, capturing high-speed video of the process.

As well as being of relevance to the formation of bodies such as asteroids and meteorites in low gravity environments, Rodríguez-Rodríguez’s research addresses the potentially important issue of astronauts drinking beer.

The buoyancy of the bubbles is what enables the gas from the carbonated drink to rise from the stomach and be expelled, but Rodríguez-Rodríguez points out that in zero gravity, they would not be buoyant.

“The bubbles would not be able to escape the liquid within the digestive system, leading to painful bloating in the stomach and intestines. So, sorry, no bubbly drinks for space people!” he and Zenit write in their review article.

Rodríguez-Rodríguez admits to enjoying drinking his experimental apparatus sometimes, but is careful to point out he is not doing so with government research funds. He says the guidelines for research preclude expenditure on alcohol, so he buys all beer for experiments from his own money.

“I consider it the Rodríguez-Rodríguez Foundation for the Advancement of Science,” he adds.

Results from the microgravity experiments are in preparation, and will be submitted to a journal soon.

Original published 29/5/19 https://cosmosmagazine.com/physics/in-lager-veritas-the-physics-of-beer

Continue Reading The Physics of Beer

Smells like Tauon Spirit

Tom Lehrer’s Elements Song is 150 years out of date – the science and the music (The Major General’s Song from Gilbert and Sullivan’s Pirates of Penzance) are both from late 1800s.

So it’s time for an update, to the tune of Nirvana’s Smells Like Teen Spirit. Video coming soon… email me if you want to hear it live!

SMELLS LIKE STANDARD MODEL

A memory for elements, I’ll leave that for the elephants
A 4×4 explains it all, matter, forces, light as well.

hydrogen , helium, lithium, they’re all done
Atom, proton, neutron they’re all gone.
Hello boson, hello lepton, Hello quarks in 3 rows-

CHORUS

Drop the table, Mr Lehrer, Standard model it’s much clearer
The colliders smash up atoms, matter’s only quarks and leptons,
like neutrinoes yeah neutrinoes ….

Quarks in threes are nucleons, But you can’t get a quark alone
The quarks in me are downs and ups, electrons, small, can’t break em up,

Quark charge, one third and sometimes two
Baryon three quarks, meson only two
Electrons’re leptons, neutrinos too, and there are two more rows-

CHORUS

There’s an up quark and a down one,
strange and charm quarks, Top and butt quarks.
Tau & muons are fat electrons, and neutrinos come in three rows

Yeah neutrinos, mu neutrinos, tau neutrinos,

Antimatter, it’s no sin,  just flip the charge and quantum spin
A photon’s light, waves of course, & carries electromagnetic force
Magnetic fields’re no magic trick, it’s just a boson swapping quick.
They’re virtual, too short to see. They bind the quarks in me-

CHORUS

Interactions, they’re all bosons, ‘lectromagnets are just photons,
there’s a strong one, it’s a gluon, weak force W and Z bosons.

In Geneva, found a big one, It’s not special, God’s no boson

Higgs boson, a higgs boson, a higgs boson …

Continue Reading Smells like Tauon Spirit

Quantum pancake reveals clues to better electronics

First published on Cosmos Magazine site, 25/9/18

An experiment with a cloud of ultracold atoms squashed into a quantum pancake has revealed never-before seen quantum effects that could lead to more efficient electronics, including high temperature superconductors.

A team at Swinburne University in Australia observed a quantum anomaly in lithium-6 gas cooled to a few billionths of a degree above absolute zero and squashed between two laser beams.

“We’re seeing quantum mechanics that’s visible on a macroscopic scale – a large collection of tens of thousands of atoms all behaving quantum mechanically,” says project leader Chris Vale, a researcher at Swinburne’s Centre of Excellence in Future Low-Energy Electronics Technologies.

The team’s work is published in the journal Physical Review Letters, concurrently with that of a team from Heidelberg in Germany which reported similar results.

The Australian team used laser beams focused into a flat plane to create a pancake of lithium-6 gas with a radius of 200 microns and the thickness of a single atom – around 500 nanometers. Then the researchers compressed the gas slightly with a magnetic field, to set it vibrating. Shining another laser from below, they measured the vibration frequency of the gas cloud by watching the shadow of the cloud on a camera.

The frequency of this radial vibration, known as a breathing mode, gave the telltale sign of a quantum anomaly: it vibrated 2.5% faster than the classical model predicted.

Symmetry in the classical model dictates that gas properties such as pressure and density should scale in a straightforward way as the size of the gas cloud oscillates. But the full quantum analysis predicts a higher frequency: the classical theory breaks down because of strong interactions between the gas particles.

To further test the model, the scientists jammed more atoms between the laser beams, and turned the pancake from a two-dimensional crepe into a fatter flapjack. Its three-dimensional nature conformed to the classical model.

Vale says the interactions between the gas particles in the quantum crepe was mid-way between two well-known states of matter: Bose-Einstein condensates, in which atoms in a gas interact strongly and exhibit uniform quantum behaviour, and low temperature superconductivity, in which electrons in a material form weakly-bound pairs known as Cooper pairs that can carry electricity through a material with no energy loss.

“There’s a continuous crossover between these two limits, what happens in the middle is not well understood,” he says

“There’s a lot of interesting physics there. For example, this is where we find the highest superfluid transition temperatures, in the intermediate zone where the binding energy of the fermion pairs is similar to the natural energy scale for the system, the Fermi energy.”

By studying a two-dimensional system, Vale hopes to spark developments of new materials for the electronics industry, for example topological insulators or high-temperature superconductors.

In the current highest-temperature superconductors, ceramics based on copper oxide, the superconducting current is carried in two-dimensional layers within the material – although exactly how the electrons pair up is not fully understood.

The power of the experiments at Swinburne is their simplicity, says Vale – the microscopic properties of the lithium atoms and their interactions are precisely known, which is not always possible in more complex materials such as solids.

“In a sense, our cold atoms are acting as a quantum simulator, where we can test models of many-body physics with precisely known inputs that can be difficult to pin down in other materials,” he says.

Continue Reading Quantum pancake reveals clues to better electronics

Would you let me put drugs in your brain?

The amazing Dr Kiara Bruggeman gets all Dr Seuss with her rhyme about her PhD research to develop a bandaid for the brain. Previously she won FameLab people’s choice award with this piece.

 

Filmed at Health and Medical in the Pub at Smiths Alternative in Canberra. Supported by National Science Week ACT, ANU Medical School, Australian Society for Medical Research.

Continue Reading Would you let me put drugs in your brain?

Wave of the Century

Originally published in ANU Reporter:

The discovery of gravitational waves is the culmination of a search by a generation of ANU physicists, reports DR PHIL DOOLEY, BSc (Hons) ’90, PhD ’99.

An excited hush fell over the briefing room at Parliament House as Professor David McClelland stepped up to the microphone.

“I’m pretty sure you all know by now but I want to say it. We’ve done it,” he said as his voice quavered.

Spontaneous applause broke out, as McClelland allowed himself a smile. Camera flashes popped and TV cameras zoomed in.

“We detected a wave that was generated 1.3 billion years ago when two black holes crashed into each another… the most violent event ever witnessed.”

The announcement was sweet reward for McClelland, an ANU laser physicist who has spent his career working towards this moment.

Albert Einstein predicted the existence of gravitational waves but thought they were too small for humans to ever detect.

To prove Einstein wrong and right in a single stroke is rare treat for a scientist.

“This is a moment that will be remembered for a thousand years,” McClelland said.

Gravitational waves are vibrations of space and time themselves, one of the most outlandish predictions of Einstein’s 1916 General Theory of Relativity. Yet, they appeared exactly as predicted and join the long list of successes of Einstein’s theory over the last century.

The first success of Relativity came three years after Einstein’s publication, when a solar eclipse allowed astronomers to pick out the tiny deflection of distant starlight by the sun’s gravity.

25 years of chasing Einstein’s theory

In 1990, at the ANU Physics Department, McClelland and Emeritus Professor Hans Bachor AM gathered people from across the world to assess the challenges of that dream.

The microscopic effect was exactly what Einstein’s revolutionary concept of space and time that was warped by huge masses predicted. The charismatic genius became a superstar overnight.

Einstein’s vision of stretchy space was not just static, it also predicted large masses moving or colliding would make waves through space, effectively a spacequake.

To make a gravitational wave of any significance needs a cataclysmic event happening to a huge mass, a star exploding or black holes colliding.

But such events are rare and unlikely to happen close to Earth, so scientists need to extend their search beyond our galaxy.

It would be 75 years before physicists would dare dream of looking for gravitational waves.

In 1990, at the ANU Physics Department, McClelland and Emeritus Professor Hans Bachor AM gathered people from across the world to assess the challenges of that dream.

One-by-one, a who’s who of gravitational wave specialists laid out the seemingly impossible tasks.

The basic concept was clear: a stable laser beam bouncing between mirrors in a vacuum.

When a gravitational wave came past and warped the space between the mirrors, it would momentarily disturb the stability of the laser.

Surpassing scientific challenges

Gravitational waves are vibrations of space and time themselves, one part of Einstein’s 1916 General Theory of Relativity.
Gravitational waves are vibrations of space and time themselves, one part of Einstein’s 1916 General Theory of Relativity.

But the practicalities were not so simple.

“Everything needed to be roughly a factor of 1000 more powerful or sensitive than we had at the time,” Bachor recalls.

Laser technology was weak. Nobody knew how to build a good enough mirror, it had to be massive and perfectly smooth, and with losses less than one part in a billion.

The experiment would need to be enormous, preferably 10 or more kilometres long.

Damping out vibrations from the environment was another huge challenge. The smallest earth tremor, or a passing truck, threatened to obliterate the tiny ripples from distant spacequakes.

But they didn’t know the size and shape of the ripples they were searching for, says Professor Susan Scott, from the Research School of Physics and Engineering (RSPE).

“We really had no idea of the enormity of the task which lay ahead of us. We were searching for a needle in a cosmic haystack, extremely faint signals in very noisy data.

“We had early meetings with submarine intelligence experts but we quickly realised we were facing a much more daunting task than theirs,” she said.

But, as in 1916, the scientists were not discouraged.

“The amazing thing was that the mood at the end of the conference was ‘Let’s go for it,’ ” Bachor says.

“We were eternal optimists. These people were pioneers who had seen the progress over the previous 20 years. We trusted that the technology would evolve.”

The start of a technological revolution

Over the next 20 years technological revolution after technological revolution achieved the impossible.

But political realities posed a big obstacle to progress.

The Russians quickly realised they could not afford to build an experiment.

The UK could not find the land and teamed up with Germany to build a smaller experiment, GEO 600, only 600 metres long. Japan set up small experiments in disused mines.

Australia had the land but lost out on funding against stiff competition from more developed astronomy projects, such as the Square Kilometre Array, which could guarantee data.

The gravitational astronomy world’s hopes lay with the two four-kilometre long experiments at the Laser Interferometer Gravitational-Wave Observatory (LIGO) at either end of the US, and the French-Italian Virgo project.

The nations apportioned the tasks, and set to work.

Over the next 20 years technological revolution after technological revolution achieved the impossible.

Joining the hunt as an honours student in 1996, Daniel Shaddock, was dismayed by the challenge.

“When I first heard about the sensitivity needed for gravitational waves, I thought that’s crazy, we’re never going to see them,” said Shaddock, now a professor in the RSPE.

“But you start working through the challenges and before you know it, you’re in a position where you have the measurement technology that you need.”

Also drawn to the quest was Dutch student Bram Slagmolen, who travelled around the globe in 1999 to work with McClelland.

“We’ve done things I wouldn’t have dreamed of back then,” says Slagmolen, now a research fellow at ANU and the leader of the Australian Consortium for Interferometric Gravitational Astronomy.

“Although the final experiment would be on a large scale and hideously complex, we ran little experiments that gave us understanding and allowed us to go the next step.”

In Italy, the Virgo experiment was dogged by technical hitches, but by mid-2015, LIGO scientists – including many Australians led by McClelland – believed their twin US experiments could start, and flicked on the many systems required to isolate Einstein’s elusive echoes of intergalactic impacts.

The Universe delivers an extraordinary result

ANU Vice-Chancellor Brian Schmidt AC and Australian Chief Scientist Dr Alan Finkel AO at the gravitational waves discovery media event. Photo by Stuart Hay.
ANU Vice-Chancellor Brian Schmidt AC and Australian Chief Scientist Dr Alan Finkel AO at the gravitational waves discovery media event. Photo by Stuart Hay.

Then the Universe delivered something truly extraordinary.

The team had estimated they might have to spend a couple of years sifting through their data to find matched sets of tiny wobbles from outer space.

But while they were still doing final tests with simulated data, still days away from the first official science run, the detector twanged with a signal so clear that the team could see it above the background without any filtering.

“The signal matched perfectly to the predicted pattern of two black holes colliding, but it was so strong we thought it must be a blind injection of a simulated signal, ” Scott says.

“We were aware very quickly that this was not the case and so this signal that had thundered into our detectors was probably real, and from surprisingly large black holes.”

A long time ago in a galaxy far, far away, there had been an invisible collision that had unleashed more energy than any other event humans had witnessed.

The peak power had been 50 times that of total output of every star in the visible universe.

There was no accompanying flash of an explosion.

After a trip of 1.3 billion years across the cosmic pond, the ripples had died down so much that they moved LIGO’s mirrors by about one thousandth of the diameter of a proton.

The signal was imperceptible to normal humans but clear as a bell in the detector in Louisiana and then, seven milliseconds later, in the Washington State detector.

Just the beginning of gravitational wave physics

It’s like the moment when Galileo first turned a telescope towards the skies and started a new epoch of astronomy.

McClelland’s search is not over now their tool is working.

“This is just the beginning,” he says.

“It’s like the moment when Galileo first turned a telescope towards the skies and started a new epoch of astronomy. Here we shall begin a whole new and fundamentally different way of observing the Universe.”

Bram Slagmolen was jubilant.

“I was always convinced we would see them, it was just a question of when,” he says.

“We’ll definitely see more now, by the end of the year we should have multiple detections, in the bag, it will be fabulous for the whole community.”

Aside from observing the antics of invisible black holes, gravitational waves help scientists see further back in time than conventional astronomy, says McClelland’s colleague Professor Susan Scott.

“This is a big deal. One of our holy grails is to understand the beginning of the Universe.”

And so another search begins.

Continue Reading Wave of the Century

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