The sweetest, saltiest love song about how sodium and chlorine fell in love…
A cute tune by the McGarrigle Sisters, telling the heartwarming story of salt – sodium and chlorine – falling in love.
Perfect for high school and university chemistry lectures, complete with valences, electron shells and ionic bonding of NaCl.
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
The easy part’s the answer
The resolution to the cadence, the final pose of the dancer
The hard work’s dynamic tension
build the elegant clash, the clarity in a question
World shaking shift of continental drift
Earthquaking violence from a pace so placid
The twist in dioxy-ribonucleic acid
Einstein astride a soaring light beam
Nothing’s as absolute as it seemed
The revelation comes at the speed of light
A universe of relative wrongs and rights
No more can you trust the rules you revere
Time stops, space shrinks as it all becomes clear.
by Phil Dooley, written for The Poet’s Guide to Science play.
First performed at Smiths Alternative in Canberra, August 24, 2018, as part of National Science Week.
Excited to be in Adelaide in 2019 for my first Fringe! Doing seven shows in six days, all at the Rob Roy Hotel, 106 Halifax St South Adelaide.
Tuesday 12th March: Physics in the Pub (booked out)
Wednesday 13 March – Solo Show
The Most Amazing Planet in the Universe – an Astronomer’s Ode to Earth
Thursday 14th March – Sunday 17th March
The Poet’s Guide to Science – a hilarious play of modern dilemmas, featuring working scientists
Tickets on sale now for shows in Canberra, Melbourne and Adelaide Fringe. Melbourne earlybird tickets on sale until the Friday 11 January – snap them up!
The Most Amazing Planet in the UniverseWe like to think we are special and we live on the only planet. But astronomers have recently discovered thousands of weird and wonderful planets orbiting other stars – there may be billions more.
But Earth is still the most amazing planet – the reasons why will surprise you.
If an alien were to visit, they would be astounded. Earth is shrouded in a corrosive and unstable gas, oxygen. Water regularly falls from the sky in liquid and even solid form (rocks falling from the sky?!).
And there are bizarre organisms covering the land that are green: logically, plants should be purple!
Dr Phil’s songs and stories will take you on a trip around the cosmos and reveal the surprising things that make our world special.
An uplifting show that will thrill you, entertain you and wow you.
Dr Phil is a physicist, entertainer, pianist and singer. He’s performed shows in Science shows and festivals around the world including Glasgow, Sydney, and London. By day he’s a science writer for Cosmos Magazine, New Scientist, Australian Geographic and more, and was selected for the 2018 Anthology of Best Australian Science Writing.
Catch the show in
Canberra: 29 January 2019, Smiths Alternative
Melbourne: 4 – 9 February 2019, The Butterfly Club
Adelaide Fringe: 13 March 2019, Rob Roy Hotel
It’s all about microfarts, angled pours and French women’s breasts. Have a happy new year!
Original published in Cosmos Magazine, 6 November 2018. This has attracted media attention – check my Phil Up On Science Live page for radio interview times.
Opening a bottle of champagne not only signifies the start of a celebration, but also uncorks a swathe of sophisticated physics phenomena that contribute to the special appeal of bubbly.
Just as the pop of a cork marks a change in mood, it also marks a sudden change for the champagne. Pressure that has been building for months during the fermentation process is quickly released and suddenly things are out of equilibrium. What makes champagne fun are the dynamic processes that bring the system back into balance – pops, bubbles and fizz.
But where did the pressure come from in the first place? The answer is micro-farts. The yeast introduced by the winemaker feeds on sugar in the wine, using its energy to power its life, and then ejects its waste: carbon dioxide.
In each bottle of sparkling wine, yeast microbes produce more than 10 grams of this gas. That equates, in the confines of the sealed bottle, to a pressure about three times that found inside a car tyre. Under these conditions most of the carbon dioxide dissolves in the wine.
As the cork is loosened the pressure of the gas in the bottle pushes it out. Cork speeds can reach more than 50 kilometres per hour, says Gérard Liger-Belair from University of Reims Champagne-Ardenne in France.
Liger-Belair has made a career of studying the physics of bubbly; for him a glass of champagne is “a fantastic playground”, although he insists he does not drink his experimental samples.
Instead, he enjoys a glass of champagne with laser tomography, infrared imaging, high-speed cameras and mathematical models.
His measurements show the speed of the cork depends on the temperature of the wine. The carbon dioxide is much less soluble at higher temperatures, which leads to a higher pressure inside the bottle and thus a faster launch speed.
At the perfect drinking temperature of eight to 10 degrees Celsius the corks pops out at around 40 kilometres per hour. His experiments extend only to 20 degrees Celsius, at which the speed is in the low fifties. Presumably, champagne warmer than that is inconceivable in France.
In the moments after the it pops, fleeting wisps of fog appear – another dynamic phenomenon. The sudden five-fold drop in the pressure of the gas in the neck of the bottle causes a temperature decrease of around 80 degrees Celsius. As it momentarily dips below minus-70, traces of water and alcohol in the gas condense into an evanescent mist that quickly evaporates as the gas approaches room temperature.
Next the fizz begins, as the carbon dioxide dissolved in the wine starts to escape. If one were to let the contents of the bottle go absolutely flat, it would take more than 10 hours and involve the release of more than six litres of gas.
A bad pour can let the fizz out too quickly, says Liger-Belair. He recommends a gentle stream into a tilted glass to preserve bubbles. Pouring into the middle of a vertical flute will stir up the wine and release too much carbon dioxide immediately.
Even with such precautions, there is an initial rush of bubbles. University of Tokyo physicist Hiroshi Watanabe was part of a team that used supercomputers to model how quickly bubbles of different sizes form in liquids, and how the different sizes interact.
“After many bubbles appear at the moment of uncorking a champagne [bottle], the population of bubbles starts to decrease,” Watanabe said in an interview with Smithsonian.com.
“Larger bubbles become larger by eating smaller bubbles, and finally only one bubble will survive.”
Bubbles are a vital part of the taste of champagne, say researchers from the Sorbonne University in Paris, France. As they burst, they throw droplets of wine into the air above the surface and enhance the drinking experience.
The scientists identified two mechanisms that produce droplets. First, as the surface of the bubble ruptures, it throws up dollops 50 times smaller than the radius of a hair. Then as the rounded bubble shape collapses, it sends up a jet of up to 10 slightly larger droplets.
“The tiny droplets ejected during bursting are crucial for champagne tasting as their evaporation highly contribute to the diffusion of wine aroma in air,” said Elisabeth Ghabache and her colleagues in a paper in the journal Physics of Fluids.
There’s been much debate about how champagne should be served. Some insist on a narrow flute, while others prefer a wide coupe.
Liger-Belair does not recommend the coupe, despite its claim to fame as being modelled on the left breast of French queen Marie Antoinette (or Napoleon’s wife Josephine, or model Kate Moss).
His gas chromatography and infrared images showed that flutes funnelled the aroma-carrying carbon dioxide more effectively into the headspace above the glass where the drinker can inhale it. But carbon dioxide’s acidic nature is actually an irritant if the concentration is too high, so Liger-Belair recommends the middle ground, a tulip shaped wine glass.
Exactly how the flavours interact with the nose and taste buds is a very individual thing. So the scientific thing to do – even if you don’t have infrared cameras and a gas chromatography set up – is to emulate Liger-Belair at your next celebration and perform your own experiments, one glass at a time.
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 …
Quite stoked to be on the cover of this little publication…
\The original article is here https://cosmosmagazine.com/physics/coming-clean-the-physics-of-doing-the-laundry
https://www.newsouthbooks.com.au/books/best-australian-science-writing-2018/
Hurrah – 1000 views on my Phil Up On Science YouTube channel for the Plastic Spaghetti video.