The Curious Case of Custard

“Could Jesus walk on custard?” Stephen Fry asked his assembled guests.

Fry – a writer, comedian, and actor- is the host of a British TV panel/game show called QI (Quite Interesting). The object of the show is to answer both esoteric and seemingly obvious questions, but points (tabulated by an incomprehensible scheme) are deducted from contestants giving obvious and “non-interesting” answers. The show’s guests/contestants are generally British comedians and actors, most of them returning to the show many times.

Each of the contestants took a chance at answering the question, each one giving their answer a humorous spin. Eventually, Stephen Fry answered the question himself, saying that not only could Jesus walk on custard, but the guests could, he could – in fact, everyone could.

It’s true. Custard (uncooked imitation custard, like Bird’s) has the properties of a non-Newtonian fluid, meaning that the more pressure you apply to the fluid, the more resistance it exerts on you. Try this the next time you make custard: in a large mixing bowl, take a spoon and slowly slide it into the custard mix. The spoon easily slides in and you can stir the mix. Now, remove the spoon slowly and this time jab it quickly into the mix. The custard resists the spoon! If you let the spoon sink into the mix, you can try the same action in reverse – try to quickly pull the spoon out. You’ll be surprised at the strength of your dessert!

What this means is that if you had enough custard, you could walk on it, as Jon Tickle from the UK show Braniac: Science Abuse shows below. Note that for this to work, you must be exerting continuous, instantaneous pressure on the custard: stop walking, and you sink!

Now, who’s hungry?

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