Watching the bubbles: Beer, physics, and other thoughts

By Eric Peterson | Jan 29, 2017

There are about two and a half pints of carbon dioxide dissolved in a single pint of beer.

The bubbles are simultaneously rising and falling. They rise in columns from the center of the glass, hit the top, and displace surface beer to the sides, where it sinks to the bottom and drags bubbles down with it, creating a current as it drops. Then the process begins again.

They say that most beer drinkers enjoy a creative peak at a blood-alcohol level of 0.075 percent. That's about two pints for an averaged-sized man. Jennifer Wiley of the University of Illinois at Chicago backed this earth-shattering concept up with research. Turns out you're not at your problem-solving best when you're stone-cold sober: People at 0.075 percent could solve brainteasers more quickly and accurately than subjects who hadn't drank at all.

"We have this assumption, that being able to focus on one part of a problem or having a lot of expertise is better for problem solving," Wiley was quoted in Medical Daily in 2012. "But that's not necessarily true. Innovation may happen when people are not so focused. Sometimes it’s good to be distracted." Wiley also found that the creative benefits sadly diminish beyond that magical 0.075 percent threshold.

It makes perfect sense that some scientists feel beer is the basis of modern civilization. Rather than nomadic shepherds, people settled down, grew grain, and brewed beer, ultimately leading to New York City.

Then there's Rhett Alain, who attempted to model a head of foam on a beer for Wired magazine in 2009, and after a lot of complicated math, found it was a really hard thing to do.

Then a reader pointed out that Alain wasn't the first person to do such modeling. The European Journal of Physics published a research paper by A. Leike, "Demonstration of the exponential decay law using beer froth," in 2002. After a bunch of similarly complicated math -- including such equations as hth(t) = h(0) (1/t T) θ (T − t) -- Leike's work will really make you question if you don’t need a little more to get up to that ideal level of 0.075 percent.

There's something very quantum about that perfect level, to be sure, a feeling of being a quark that's unstuck in time and adrift in the universe, at least if you're doing it right.

A giant in the field, Niels Bohr was one of the first physicists to understand atomic structure. The great Dane was one of the fathers of quantum mechanics, and Carlsberg helped him establish the Institute of Theoretical Physics. The Copenhagen brewery, which set up its in-house lab in 1875, has a long history as a benefactor of scientists. When Bohr won the Nobel Prize in 1922, Carlsberg gave him a house next to the brewery and free beer for life, delivered via pipeline.

Bohr made many breakthroughs in quantum mechanics in the years that followed, and his work often straddled the line of science and philosophy. Heady stuff. And who knows how much the beer had to do with it?

Eric Peterson is editor of BreweryWeek. Contact him at