As a final post for the year, I thought I would channel some of my earlier holiday/energy crossovers (Halloween, Thanksgiving, and Christmas/Hanukkah/Kwanzaa all got energy-related analyses this year!) and have a fun and quick look at some energy figures associated with celebrating New Year’s Eve. Whether you head out to a wild and exclusive party, stay in and toast a quiet New Year with your family, or fall somewhere in between, you’re sure to stumble across one of the users of energy described here. So toast to a good 2017, and even better 2018, and learning more mostly-pointless but still-fun energy trivia!
Popping champagne and the Times Square Ball
A surprising amount of scientific research has been done on the science of champagne bottles– filling them, storing them, and opening them. Fortunately for the purposes of this article, there was even a fairly extensive research paper conducted on the physics of popping the cork of the champagne bottle.
According to the study published in the Journal of Food Engineering, the velocity that a champagne cork shoots out of a bottle of champagne varies based on the temperature of the champagne. Consistent with the idea that increased temperatures correlate with increased pressures, the study found that at 4 degrees Celsius the cork shot out at about 38 kilometers per hour (km/h), but that speed increased to about 48 km/h at 12 degrees Celsius and about 54 km/h at 18 degrees Celsius.
By consulting Wine Spectator, it appears the optimal temperature at which to serve champagne is 55 degrees Fahrenheit, or about 12.8 degrees Celsius. If we assume a roughly linear relationship between temperature and cork speed (as shown in the graph below), that would mean the ideal champagne bottle’s cork would pop at about 47.6 km/h.
The basic formula to calculate the kinetic energy of a moving object is 1/2 times mass times velocity squared. Plugging in the mass of the cork (which the study gave at about 10 grams) and the velocity (47.6 km/h or 13.2 meters per second), the cork has a kinetic energy of about 0.9 Joules (J).
While 0.9 J does not sound like that much (as discussed in the post about energy units, a single Joule is the energy required to lift an apple 1 meter off the ground), keep in mind that flying corks can still be dangerous, and if one hits you in the eye it can ‘cause a shockwave that can lead to hemorrhage, disruption of tissues, a cataract, even retinal damage.’
Also worth noting is that the flight of the champagne cork is only a small part of the energy in opening a champagne bottle. The same study that looked at the speed of the cork also found that only about 5% of the energy released when a champagne bottle is opened gets transferred to the kinetic energy of the cork, with the rest being converted to the ‘pop’ sound, a small amount of generated heat, and a cloud of gaseous carbon dioxide (CO2) gushing out of the bottle. If the 0.9 J behind the cork is only 5% of the total champagne opening energy, that would mean the total energy associated with the opening of a champagne bottle is about 17.5 J.
Given this knowledge, what if we wanted to calculate something ridiculous– like how many champagne corks popping it would take to power the Times Square Ball that’s dropped on New Year’s Eve (seems like this could loosely be the plot to an odd children’s book, or the first part of a plan hatched by a cartoon villain)? For the 100th anniversary of the Times Square Ball drop, the ball was updated with over 32,000 state-of-the-art LEDs, which made the lit up ball 80% more efficient than it previously had been with halogen bulbs. The end results is that the lit ball now only requires 50 kilowatt-hours (kWh) of energy for the New Year’s Even celebration. Converting that figure to Joules gives a total energy use of 180,000,000 J.
So what does that mean for our ‘power the Times Square Ball by opening champagne bottles’ scheme? If we’re harnessing the energy of just the corks flying out of the bottles (at 0.9 J per cork), then 205,687,545 bottles of champagne will need to be uncorked. Given that 2 million people attended the Times Square New Year’s Eve celebration to ring in 2017, that would mean every person in attendance would need to uncork just under 103 bottles of champagne each. BUT– if we instead are able to harness the entire energy from the champagne uncorking (which brings the total energy per bottle to 17.5 J), then only 10,284377 bottles of champagne are required, or just over 5 bottles per attendee of the Times Square celebration. That’s much more doable! In fact, the Guinness World Record for champagne bottles opened in one minute is 10, so all that’s left is for these misguided champagne powered villains to figure out is how to harness all that energy.
Party poppers and fireworks in Sydney
Another common feature to midnight celebrations are party poppers– those mini explosive doodads that explode with a loud bang and a pop of confetti and/or streamers when you pull on the string. Many people don’t realize that these party poppers actually contain explosive powder, though in small enough quantities that they are not legally considered fireworks and can thus be old in any grocery or party store. But given the limited firepower allowed, exactly how much energy is contained in these almost-fireworks that we give to children and drunken party-goers alike?
While most real firecrackers are limited by law to 50 milligrams (mg) of gunpowder, the party poppers that are sold in stores are capped out at 16 mg of gunpowder each. Given that gunpowder has a specific energy of 3.0 Megajoules per kilogram, we can calculate that each party popper contains 48 J of explosive energy.
Now what if we considered the firepower of these party poppers in the context of another explosive New Year’s Eve tradition– fireworks! Among the largest and most famous New Year’s Eve fireworks displays (also famous due it taking place in one of the earliest time zones to celebrate the New Year) is the annual Midnight Fireworks in Sydney, Australia. How many of the dinky party poppers would it take to equal the firepower in this massive fireworks display? This calculation is the most ‘back-of-the-envelope’ type one here, but some reasonable estimates can be made.
First, start with the knowledge that the Midnight Fireworks to celebrate 2017 in Sydney featured 8 metric tons of fireworks. Then take the rule of thumb that the explosive flash powder of fireworks makes up about 25% of the weight of the overall weight of the fireworks, leading to an estimate that the Sydney fireworks required 2 metric tons (or 2 million grams) of explosive flash powder. Combine that with with energy density of flash powder of 9,196 Joules/gram to arrive at an estimated energy content of the Sydney Midnight Fireworks of 18.292 Gigajoules, or 18.392 billion J.
Over 18 Gigajoules is a massive amount of explosive energy, an an equally impressive number of party poppers. Given each party popper supplies 48 J of energy, you’re looking at 383,166,667 total party poppers. What would be required for those in attendance at the Sydney fireworks display to match the firepower of the fireworks with party poppers (yes, our cartoon villain with poorly designed schemes has come back and is trying to take over the world with party poppers!)? Since the 2017 fireworks display in Sydney clocked in at 12 minutes long, that means the crowd of people popping party poppers would need to average 31,930,556 party poppers per minute. Combine that figure with the attendance of the Sydney Midnight Fireworks (which was about 1.5 million) to find that, in order for the crowd in attendance to equal the firepower of the actual fireworks, each person would need to pop just over 21 party poppers per minute. While a party popper every 2.82 seconds for 12 minutes by 1.5 million different people seems like a crazy high number, the Guinness World Record for party poppers popped in a minute (because of course that’s a record) is 78 in one minute. As such, the 1.5 million in attendance would only need to go at 27% of the world record pace– once again, totally doable. Though be careful, because the party poppers are also known to cause ocular injury— especially when a million and a half people are each firing off over 250 poppers each in such close proximity.
Sources and additional reading
About the author: Matt Chester is an energy analyst in Washington DC, studied engineering and science & technology policy at the University of Virginia, and operates this blog and website to share news, insights, and advice in the fields of energy policy, energy technology, and more. For more quick hits in addition to posts on this blog, follow him on Twitter @ChesterEnergy.