WhatsNew2Day – Latest News And Breaking Headlines
Chances are you’ll open a bottle or two of champagne in just a few days to ring in the new year.
But what you may not appreciate when opening the fizz is that you are dealing with a supersonic mechanism similar to a powerful airplane.
So say Austrian scientists, who have finally revealed the fascinating physics behind drinking champagne.
They say a supersonic shock wave shoots gas through the bottle at speeds of up to 400 meters per second at -202°F (-130°C), much colder than even the North Pole.
Meanwhile, the cork is ejected at much slower speeds, but fast enough to cause serious injury if pointed in the wrong direction.
Time for a fizz lesson: Scientists say “complex supersonic phenomena” occur when you open your bottle of champagne on December 31
The gas that comes out of the champagne bottle is much faster than the cork. The point in this gas jet where the pressure changes abruptly is known as the Mach disk.
The new study was led by Lukas Wagner, a doctoral student at the Institute of Fluid Mechanics at the Vienna University of Technology.
Wagner and his colleagues say that “complex supersonic phenomena occur” every time a bottle of champagne is opened.
Champagne bottles are thicker and heavier than regular wine bottles to contain the immense pressure they contain.
This pressure is generated by the CO2 bubbles that are produced during fermentation and is why the cork has to be literally sealed with a wire cage (‘the ‘muselet’).
When it finally opens, the cap is pushed outward by the bottle’s compressed gas and flies off with a powerful bang, but the physics behind this is unclear, the team says.
Through complex computer simulations, they were able to calculate the behavior of the expelled cork and the flow of CO2 gas that accompanies it.
While the cork is ejected at about 20 meters per second, the gas flow is much faster: up to 400 meters per second, the team found.
Pictured is a visualization of the cork coming out of a champagne bottle in black. The champagne cork flies away at a relatively low speed: about 20 meters per second.
Therefore, the gas is officially supersonic, meaning it travels faster than the speed of sound (343 meters per second).
There is a point in the gas flow where the pressure changes abruptly, known as the “Mach disk”, as is also seen in supersonic aircraft.
“Very similar phenomena are known in supersonic airplanes or rockets, in which the exhaust jet leaves the engines at high speed,” said study author Stefan Braun, also from the Vienna University of Technology.
As for the audible pop when the bottle is opened, which often announces the start of the celebrations, this is a combination of two different effects.
On the one hand, the cork expands sharply when leaving the bottle, creating a pressure wave and, on the other, the supersonic gas jet generates a shock wave.
This is very similar to the well-known sonic boom phenomenon, which aviation experts are trying to eliminate to make quieter airplanes.
The study, posted on the preprint server. arXivcould be important for other applications involving gas flows, such as ballistic missiles, projectiles or rockets.
The cork is ejected at much slower speeds, but fast enough to cause serious injury if pointed in the wrong direction (file photo)
“In many technically important situations these are very solid flow bodies that interact strongly with a much faster gas flow,” the authors conclude.
Another team of researchers revealed earlier this year why champagne bubbles bubble perfectly straight, while beer bubbles do not.
It was discovered that larger bubbles and the addition of special proteins in the bubbles stabilize the bubble chains, allowing them to rise in a straight line.
Other research has shown that there are more bubbles in champagne than in beer, when comparing the same volume of both drinks.
This is because Champagne and other sparkling wines contain about twice as much dissolved carbon dioxide (CO2) from added sugar.