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It's so obvious [br]that it's practically proverbial.

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You can't unboil an egg.

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Well, it turns out you can, sort of.

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What thermal energy [br]does to the eggs' molecules,

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mechanical energy can undo.

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Eggs are mostly made [br]of water and proteins.

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The proteins start off [br]folded up into intricate shapes,

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held together by weak chemical bonds.

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Adding heat disrupts those bonds,

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allowing the proteins to unfold,[br]uncoil, unwind and wiggle freely.

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This process is called denaturing.

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The newly liberated proteins [br]bump up against their neighbors

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and start to form [br]new bonds with each other,

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more and more as the heat increases,

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until finally, they're so entangled[br]that they gel into a solid mass,

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a boiled egg.

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That entanglement might look [br]permanent, but it's not.

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According to a chemical idea

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called the principle [br]of microscopic reversibility,

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anything that happens, [br]like egg proteins seizing up,

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can theoretically unhappen[br]if you retrace your steps.

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But adding more heat will tangle[br]the proteins further,

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and cooling them down[br]will only freeze them,

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so here's the trick:

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spin them around ridiculously fast.

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I'm not kidding.

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Here's how it works.

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First, scientists dissolve [br]boiled egg whites in water

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with a chemical called urea,

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a small molecule that acts as a lubricant,[br]coating the proteins' long strands

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and making it easier for them [br]to glide past each other.

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Then, they spin that solution [br]in a glass tube

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at a breakneck 5000 rotations per minute,

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making the solution [br]spread out into a thin film.

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Here's the key part.

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The solution nearest[br]the wall spins faster

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than the solution closer to the middle.

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That difference in velocity [br]creates sheer stresses

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that repeatedly stretch [br]and contract the proteins

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until eventually they snap back[br]into their native shapes and stay there.

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By the time the centrifuge stops spinning,

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the egg white is back [br]in its original unboiled state.

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This technique works [br]with all sorts of proteins.

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Bigger, messier proteins can be[br]more resistant to being pulled apart,

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so scientists attach [br]a plastic bead to one end

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that adds extra stress[br]and encourages it to fold up first.

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This unboiling method won't work[br]with a whole egg in its shell

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since the solution has to spread[br]throughout a cylindrical chamber.

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But the applications go way beyond[br]uncooking your breakfast, anyhow.

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Many pharmaceuticals consist of proteins[br]that are extremely expensive to produce,

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partly because they get stuck [br]in tangled up aggregates,

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just like cooked egg whites

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and have to be untangled and refolded[br]before they can do their jobs.

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This spinning technique has the potential

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to be an easier, cheaper [br]and quicker method

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than other ways to refold proteins,

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so it may allow new drugs to be made[br]available to more people faster.

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And there's one more thing [br]you need to keep in mind

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before trying to uncook all of your food.

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Boiling an egg is actually[br]an unusual cooking process

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because even though it changes the way[br]proteins are shaped and bound together,

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it doesn't actually change [br]their chemical identity.

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Most types of cooking are more like[br]the famous Maillard reaction,

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which makes chemical changes

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that turn sugars and proteins[br]into delicious caramel crunchiness

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and are a lot harder to undo.

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So you might be able to unboil your egg,

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but I'm sorry to say [br]you can't unfry it...yet.