Today’s Wonder of the Day was inspired by karris from AL. karris Wonders, “can you breath underwater and why” Thanks for WONDERing with us, karris!
Since human beings can't breathe under water like fish can, you're going to need to hold your breath if you plan to spend much time below the surface. When kids play in the pool, at the lake or even in the bathtub, it's usually not long before a contest breaks out to see who can hold their breath the longest underwater.
Holding your breath underwater isn't just a kids' game, though. Extreme athletes known as freedivers regularly have the same kinds of contests. This practice is known as static apnea. Apnea means a temporary stoppage of breathing and freedivers practice in order to increase the amount of time they can stay underwater without coming up for air.
Stéphane Mifsud of France currently holds the static apnea record with a time of 11 minutes 35 seconds. Can you imagine holding your breath for that long? Wow! To get a sense of how long that is, set a timer for 11 minutes 35 seconds and wait for it to expire. It's a long time, isn't it? To put it in perspective for a friend, see how high you can count during that time.
Believe it or not, there actually have been people who have held their breath for even longer than 11 minutes, though. The Guinness Book of World Records has a special category for holding your breath underwater. Unlike the freedivers who practice static apnea, the Guinness guidelines allow contestants to breathe pure oxygen for up to 30 minutes prior to their attempt.
Most people in good health can hold their breath for approximately two minutes. Experts believe that even a little bit of practice can increase that amount of time quite a bit. However, they also warn that depriving your body of oxygen can have many negative effects, so don't make a habit of holding your breath for very long!
When you hold your breath, carbon dioxide (the gas you normally breathe out) builds up inside you. Eventually, this gas must be released and a reflex causes your body's breathing muscles to spasm. These spasms hurt and usually cause you to gasp for air after just a couple of minutes.
When Guinness World Record chasers breathe pure oxygen before holding their breath, they do so to force as much carbon dioxide out of their bodies as possible. The extra oxygen also helps them to go longer without breathing.
Being underwater also helps to fight the body's natural reactions. Like dolphins and whales, our bodies instinctively conserve oxygen when we go underwater. This reaction — called the diving reflex — helps to conserve the oxygen in our bodies and enables us to hold our breath even longer.
Of course, if you want to explore underneath the sea, you're going to want to spend more than just a few minutes underwater. Divers who want to spend an extended amount of time underwater usually use scuba gear.
“SCUBA" was originally an acronym for Self-Contained Underwater Breathing Apparatus. Today, scuba is used as a regular word to refer to the practice of using special gear to breathe underwater while diving.
The first scuba gear was developed during World War II for U.S. combat divers, who were called frogmen. Frogmen used devices called rebreathers to stay underwater for extended periods of time while on underwater military missions.
Today, scuba divers use tanks of compressed air that attach to their backs. These tanks provide air to a device called a demand valve regulator. Scuba divers breathe through a mouthpiece attached to the regulator. It can take some time to adjust to breathing underwater this way, which is why people who want to become scuba divers must have special training before being certified to scuba dive.