Cracker jokes and custard chemistry: ways to smuggle science into Christmas | Science

Christmas may seem like a time to switch off and suspend disbelief, but there are plenty of ways to introduce a little science into the celebrations.

We asked experts about their best at-home experiences to challenge your friends and family.

A sweet science

Matthew Cobb, professor of zoology at the University of Manchester, suggests choosing a candy like candy and, with your eyes closed and holding your nose, putting it in your mouth and chewing it, keeping your mouth closed.

“See if you can tell how sweet something tastes. You’ll probably just say ‘sweet’ and maybe have a vague idea of ​​something else,” says Cobb. “After five seconds, remove your fingers from your nose and you should feel a sudden sensation that will allow you to correctly identify the aroma.”

A more extreme version of this experience, he says, involves grating an onion and an apple separately, then tasting each on a spoon with your eyes closed and your nose held firmly. “They should taste the same, until you take your fingers out of your nose.”

Cobb says such experiments show how flavor consists largely of smell and not taste. “When we chew, volatile odors emitted by food travel up into our nose from the back of our mouth, where they stimulate our olfactory neurons,” he explains, adding that it is the combination of taste and smell that produces flavor.

“Without smell, things don’t taste much. We all discovered this during the first Covid outbreak, when people temporarily lost their sense of smell.”

Have fun

With crackers a Christmas staple, Sophie Scott, professor of cognitive neuroscience at University College London, suggests experimenting to see what might influence whether or not people laugh at a (terrible) joke.

“First, try reading these jokes for yourself and see if you laugh at them,” she says. “Second, read the jokes to someone else – maybe in a room full of people.”

Scott says to watch and see if anyone laughs — including you — when you get to the punchline, or if they respond in another way, like by groaning. She notes that although we associate laughter with jokes and humor, we laugh primarily for social reasons.

“You’re 30 times more likely to laugh if there’s someone else with you than if you’re alone,” she says. “What this means for cracker jokes is that a joke read by someone alone is much less likely to make them laugh than the same joke read – or heard – in company. And laughter is amplified by social connection, so the more you know and like the people you’re with, the more laughter there will be.”

Get stuck into the festive poultry

If you’re eating a turkey or other bird for your Christmas meal, take the time to explore the carcass.

“We had a Thanksgiving dinner a few weeks ago and I bought a huge turkey, cooked it for a few hours and lovingly basted it every 30 minutes or so,” says Steve Brusatte, professor of paleontology and evolution at the University of Edinburgh. “Mostly so that it’s delicious, but also so that the meat comes off the bones enough that I can remove the bones and show my wife and six-year-old son the shoulder area. »

This allowed Brusatte to demonstrate how the different bones come together to move the wing up and down, and how the huge elastic triangle stores energy when the wings beat.

“It’s a simple thing you can do with a roast turkey or chicken: look at the bones and understand how they fit together and move, which gives a better understanding of biomechanics and flight movements than I’ve ever seen in any textbook in my many years of study,” he says. “And then you get a delicious meal afterwards.”

Professor Sue Black, a forensic anthropologist, anatomist and academic at the University of Oxford, also recommends dissecting the party bird to understand the anatomy of movement.

“Boil the carcass so that only the bones remain and you have a 3D puzzle to reconstruct,” she says.

Christmas Chemistry

Salt is commonly spread on sidewalks in winter and there is a simple experiment that can help explain why.

“You’ll need 500ml of whole milk or cream, five egg yolks and 125g of sugar. A little vanilla never hurts,” says Andrea Sella, professor of inorganic chemistry at UCL.

“Whisk them together, then heat them almost to a boil until the mixture begins to thicken. Let it cool to room temperature. Meanwhile, remove some ice from the freezer. Either crush it, like an alchemist, with a mortar and pestle, or grind it in a blender like a modernist.”

Next, he says, grab two plastic bags – ideally zip-top bags. “Drop some of your crushed ice in one and add a generous amount of salt. In the second, pour some of your custard mixture, adding sprinkles, nuts or pieces of fruit. Seal it [second bag] and put it in the first.

“Now crush the ice cream and salt together, along with the custard in the bag. The temperature will plunge to -10°C or even lower. In just a few seconds, you will have ice cream, a soft (and delicious) solid.”

Sella explains that this happens because dissolved salt prevents liquid water molecules, produced when ice melts, from refreezing on the remaining ice.

“So the ice cream keeps melting and steals the heat from the custard (and your fingers),” he says. “It’s practical magic – also known as science.”

Festive day

“One of the most surprising little science experiments you can do at home is called Buffon’s Needle, but for party purposes let’s call it Buffon’s Pine Needles. It’s a way of approximating the value of ϖ,” says Kit Yates, professor of mathematical biology and public engagement at the University of Bath.

First, take a bunch of pine needles and select as many as possible that are approximately the same length (L). “Let’s say you manage to find a total (T) pine needles of similar size. You will also need a piece of paper with lines drawn indicating distance. W spaced apart – further apart than the length of your needles,” says Yates.

Scatter the pine needles, without aiming, on your sheet of lined paper then count the number of needles that cross one of the lines. This number is C.

Once you’ve counted, you can find your approximation of ϖ by plugging your numbers into this formula: ϖ ≈ 2LT/CW

“What I like about this is that it shows how ϖ seems to appear in really unusual places,” says Yates. “It almost seems like magic, but it’s just probability in action on your living room floor.”