Champagne is one of the most popular alcoholic beverages in the world. But underneath its sleek veneer hides some fascinating and potentially fatal secrets.
It also happens to share a thing or two with rockets!
What makes champagne pop?
The reason champagne pops are actually for some fascinating scientific reasons. It involves high speeds, a giant drop in pressure and oscillating gas.
Champagne, while bottled, contains a lot of dissolved carbon dioxide. This dissolved gas creates internal pressures within the bottle that varies depending on the temperature that the champagne has been stored.
"At rest" the upward pressure of the dissolved carbon dioxide gas is not enough to overcome the frictional force between the cork and bottle (as well as any cork net that may be present).
When you start to twist the cork out, this frictional force is converted from static friction to kinetic friction. The kinetic frictional values are low enough for the internal pressure to overcome them.
At this point the cork is accelerated out of the bottle and, if left to its own devices, can shoot out. This can be quite fast too.
How fast do corks come out of a champagne bottle?
Some home experiments have shown that corks can be shot out of a bottle in excess of 12 meters per second. But for some more scientific rigor, look no further than the work of Friedrich Balck at the Clausethal Technical University in northwest Germany.
After vigorously shaking a bottle of bubbly, with a recorded pressure of 2.5 bars, he was able to expel the cork at 40 kilometers per hour or 11 meters per second.
Not too shabby.
What is the pressure inside a champagne bottle?
As we have already mentioned, the pressure inside a champagne bottle is caused by dissolved carbon dioxide within the liquid. This build-up of gas is the result of secondary fermentation in the beverage, technically called en triage.
During this process, cane sugar and more yeast are added to each bottle. The cane sugar and yeast produce alcohol and also carbon dioxide as byproducts.
This also happens to be the reason that champagne corks are so thick when compared to other wine bottle corks.
Some research into this has shown that pressure can range from between 4 and 6 atmospheres or 0.41 n/mm2 to 0.62 n/mm2.
"The sources I encountered ranged the pressure of champagne from 4 to 6 atmospheres or in layman's terms, typically between 60 to 90 pounds per square inch.
According to USA Today, a pressure of this magnitude is only seen from double-decker bus tires and champagne. This is the reason why you should never point a champagne bottle at someone unless you really mean to hurt them." - The Physics Factbook.
What do popping champagne bottles and rockets have in common?
So, without further ado, here are some reasons that champagne and rockets are similar. This list is far from exhaustive and is in no particular order.
1. Both rockets and popping champagne produce Mach disks
Amazingly, a close examination of popping champagne has shown some striking similarities to supersonic jet streams -- as seen in rockets.
Researchers recently published an article in Science Advances that showed very clear evidence of the formation of Mach disks similar to that of rocket plumes. The plumes were seen in the jet of freezing CO2 just at the point when the bottle is first opened.
For best results, the study found, the bottles needed to be stored at 20 degrees Celsius. The jet of carbon dioxide ejected during popping was recorded at being -90 degrees Celsius.
‘The conditions needed to create such shock waves are drastic, but in the very first millisecond following cork popping, all the conditions are met,’ study lead Gérard Liger-Belair told Decanter.com.
"The velocity of gases expelled from the bottleneck reaches almost Mach 2, twice the velocity of sound."
Amazing, but it must be noted that the experiment was only conducted on bottles stored at between 20 and 30 degrees Celsius for 72 hours before filming. This is well above what would be considered the ideal serving temperature.
2. Both rockets and popping champagne release CO2
As we have already seen, champagne gets its explosive power from dissolved carbon dioxide. When the cork is popped a large amount of that carbon dioxide is liberated in an explosive and delightful pop.
But some rockets also generate carbon dioxide as they power their way into the heavens. However, these emissions are pretty negligible when compared to other forms of transportation.
“The rocket business could grow by a factor of 1,000 and the carbon dioxide and water vapor emissions would still be small compared to other industrial sources,” Martin Ross, a senior project engineer at the Aerospace Corporation who studies the effects of rockets on the atmosphere, told The Verge in an interview.
3. Both rockets and champagne experience Rayleigh scattering
Rayleigh scattering, named after its discoverer the British physicist Lord John Rayleigh, is mainly elastic scattering of light, or other EM radiation, without changing the wavelength by tiny particles or other mediums.
It is this effect that gives the sky its blue coloration since blue light is scattered more efficiently than other wavelengths like red. Rayleigh scattering is what gives the emissions from a popping champagne bottle it's blue hue too.
With champagne, this is caused by transient heterogeneous freezing of gas-phase CO2 on ice water clusters as it leaves the bottleneck.
Rayleigh scattering is also a useful tool for rocket scientists.
Various methods have been developed to help understand the gas-density temperature of rocket exhaust plumes. By using a Fabry-Perot interferometer and argon-ion lasers, scientists can determine the gas temperature using the phenomena of Rayleigh scattering.
4. Both champagne and rockets obey Newton's Third Law
Rockets, at the very basic level, work via the principle of Newton's Third Law. This is basically the principle that "for every action, there is an equal and opposite reaction".
So, by blasting tons of hot gas out of the rear, the rocket is propelled in the opposite direction (usually skywards). A similar thing happens when you pop a bottle of champagne.
As the cork is expelled at high speed from the end of the bottle, the bottle itself should experience an "equal and opposite" reaction away from it. Of course, since you tend to be holding the bottle (and it is relatively heavy compared to the cork), we don't really notice it.
5. Both champagne corks and some rockets are bubble-powered
And finally, for a bit of fun, did you know you can actually power a small homemade rocket using bubbles in a similar fashion to champagne cork popping?
By combining effervescing antacid tablets ad water inside a paper rocket, you can amaze your friends and family with the power of rocket science (and some chemistry).
NASA seemed to love the idea too and created a handy little guide if you want to try it for yourself?