How can humidity be 100

This may also be what accounts for the dirty dog smell. As water molecules evaporate from soggy dog fur, they carry with them smelly bacteria. Humidity brought us tonal language. Distribution of tonal languages red dots and non-tonal languages blue dots in the Phonotactics Database of the Australian National University. Darker shading on the map corresponds to lower average humidity.

Photo by Everett C. PNAS Our vocal cords are comprised of a pair of mucus membranes that stretch across the voice box, or larynx. They vibrate, controlling the air from the lungs that flows by as we speak or sing. The level of moisture in the air affects the elasticity of our vocal cords. Singers can tell you that it is harder to carry a tune in a dry environment.

More recently, researchers theorized that speech was one of many human behaviors adapted to fit environment. After looking at more than 3, languages, they discovered that tonal languages, like Chinese and Vietnamese, rarely developed in dry climates.

To understand how it worked, you need to know a thing or two about hair. In , Horace Benedict de Saussure, a Swiss physicist and geologist, made the first hair hygrometer, using a human hair to measure humidity. A single strand of hair has many layers. The inner layer is filled with proteins called keratins that bind to each other, giving shape to your luscious locks.

These proteins bind by forming tough disulfide bonds or weaker hydrogen bonds. You can thank hydrogen bonds for the funny way your hair dries naturally after getting out of the shower. Water molecules two hydrogens and an oxygen are soaked up by your hair and act as a bridge linking keratin molecules together in place.

These hydrogen bonds keep your hair fixed in shape until you wet it again, allowing new hydrogen bonds to form.

In high humidity, water molecules in the air find their way into straight strands. As hydrogen bonds connect keratin proteins, hair starts to fold back on itself and curl. Frizzy fly aways occur when hair folds back enough to break the cuticle — or the outer layer of hair that looks like dragon scales under a microscope. The drier the hair, the more likely it is to soak up moisture in the atmosphere. So damaged hair — scorched by curling irons or parched from over shampooing — is often treated with moisturizing salon products.

Enter hygrometer. Saussure attached one end of a inch piece of human hair to a screw. The rest of the strand he maneuvered through a pulley and attached to a weight. As the hair took on moisture, the strand curled and shortened moving the pulley and lifting the weight.

Saussure could then calculate how much humidity was in the air based on how much the weight moved. Instead, it looks at how much water vapor the air can hold at a certain temperature. When the humidity is at percent, it's holding the absolute maximum; that means no more water can evaporate because the atmosphere has reached its limit.

Humid days feel terrible in part because our sweat can't evaporate, making it feel much hotter outside. Things like temperature and pressure affect the air's capacity to hold water vapor; the hotter it is, the more vapor the air can hold. Humidity FAQ What is relative humidity?

Relative humidity is a percentage that represents the amount of water vapor in the air at a given temperature compared to the max possible water vapor amount at that same temperature. For instance, relative humidity of 25 percent means that air is at a quarter of its possible water vapor capacity. What is absolute humidity? The higher the air temperature is, the more water vapor it can potentially contain.

What's the difference between absolute humidity and relative humidity? Both readings measure water vapor levels in the air. However, relative humidity measures how much water vapor the air actually holds by comparing it to the maximum achievable amount at a given temperature.

In contrast, absolute humidity simply measures the total amount of water vapor air can hold without considering the temperature.

What is an uncomfortable level of humidity? Most people are comfortable with a relative humidity level of percent. Higher levels are uncomfortable because there's too much moisture in the air, making people sweaty and unable to cool down.

What causes high levels of humidity? High humidity which is anything over 50 percent or so is caused by high temperatures. What is it in antiperspirant that stops sweat? Why does your body temperature rise when you have a virus such as the flu? Sources Environmental Protection Agency.

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