Girls' World

Science Stumpers

GW gives you the lowdown on some of the world’s most mind-boggling mysteries!

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WHY CAN’T ASTRONAUTS BREATHE IN SPACE? — Jane, 10, FL

On Earth, humans live in the tropospher­e where the air is thick and breathable. But air gets thinner and thinner the higher up you go, and by the time astronauts break through the atmosphere and reach space, the air becomes so thin that they aren’t able to breathe. But thankfully, scientists and engineers have figured out a way for astronauts to “breathe” in space: Water is brought up to the Internatio­nal Space Station and then split into oxygen and hydrogen. The oxygen from the water is then vented into the space cabin for astronauts to breathe in, while the unbreathab­le hydrogen is vented out!

IS SUGAR REALLY SO BAD FOR MY TEETH? — Gwenny, 8, AZ

You’ve probably been warned that eating sugary sweets will “rot your teeth,” but it turns out that sugar itself isn’t the real culprit behind tooth decay. Cavities are formed when bacteria in the mouth digest debris left on your teeth after you eat. Such debris might come from sugar-filled snacks like cookies and candy, but they can also come from healthy foods like whole grains, vegetables and fruits. If you don’t brush your teeth after eating, bacteria in your mouth will produce an acid that combines the debris with saliva to form plaque. It’s actually this plaque — not sugar — that rots your teeth. So as long as you brush your teeth after eating a sugary treat, your teeth should stay healthy!

HOW COME SOME PEOPLE SNORT WHEN THEY LAUGH? — Bibi, 11, NC

Laugh-snorting occurs when air is exhaled through the nose instead of through the mouth. It’s kind of like snoring: When air is restricted in your nose or your throat, it creates something called “airflow turbulence.” As air quickly moves in or out, it causes vibrations in the surroundin­g tissues that result in the snorting sound! Opening your mouth whenever you laugh is one way to redirect the air and prevent snorting, but consciousl­y changing a laugh is harder than it might seem. So remember: People who snort when they laugh probably can’t help it — and they don’t need to!

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