Everest Puzzlers
1. Why is there more oxygen at low altitudes?
Earth is surrounded by an atmosphere, or blanket of air. Gravity--the force that pulls everything toward the center of the Earth--holds the atmosphere in place. At low altitudes, the atmosphere is pulled down strongly by gravity, and pushed down by the air above it. This packs down the oxygen, so you get more oxygen per breath than you would at high altitudes.
2. Why is Everest's air so dangerous?
The higher you climb, the less oxygen you get in each breath. Too little oxygen to the brain makes climbers weak and dizzy. Climbers may also get sick. Why?
Blood carries oxygen from the lungs to all parts of the body. Climbers hearts pump fast to spread the limited oxygen around
Extra blood flowing to the brain can lead to swelling. Brain swelling causes headaches, and sometimes blindness and death. Blood can also leak into the lungs, making it hard to breathe.
3. Why does it get colder the higher you climb?
The air and the ground absorb (soak up) rays from the sun. The air and ground warm up, then send out heat that warms you up.
On Everest, there's less air to trap the sun's heat. Also, light, shiny surfaces like ice reflect (bounce back) sunlight before it can soak in. The result: Less warmth for mountain climbers!
Source: Scholastic SuperScience
Earth is surrounded by an atmosphere, or blanket of air. Gravity--the force that pulls everything toward the center of the Earth--holds the atmosphere in place. At low altitudes, the atmosphere is pulled down strongly by gravity, and pushed down by the air above it. This packs down the oxygen, so you get more oxygen per breath than you would at high altitudes.
2. Why is Everest's air so dangerous?
The higher you climb, the less oxygen you get in each breath. Too little oxygen to the brain makes climbers weak and dizzy. Climbers may also get sick. Why?
Blood carries oxygen from the lungs to all parts of the body. Climbers hearts pump fast to spread the limited oxygen around
Extra blood flowing to the brain can lead to swelling. Brain swelling causes headaches, and sometimes blindness and death. Blood can also leak into the lungs, making it hard to breathe.
3. Why does it get colder the higher you climb?
The air and the ground absorb (soak up) rays from the sun. The air and ground warm up, then send out heat that warms you up.
On Everest, there's less air to trap the sun's heat. Also, light, shiny surfaces like ice reflect (bounce back) sunlight before it can soak in. The result: Less warmth for mountain climbers!
Source: Scholastic SuperScience
posted by James at 4:54 AM
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