This may sound like a riddle, but thanks to chemistry it’s actually possible.
When an egg is boiled, the albumen around the yolk turns white. That’s because the heat has caused the proteins within it to tangle up randomly.
In 2015, a team of chemists in the US and Australia showed they could reverse the process. They added urea to liquefy the boiled egg whites, then put them in a vortex device to pull apart the proteins and return them to their original state.
It may sound like a party trick, but the technique has important applications in repairing faulty proteins used in medicine and industry.