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Why is blood red instead of blue?
The veins under your skin look blue, but the blood inside is red: bright when it carries oxygen, darker when it doesn't. The blue comes from how skin scatters light.
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The veins under your skin look blue, but the blood inside is red: bright when it carries oxygen, darker when it doesn't. The blue comes from how skin scatters light.
Tap to go on, or swipe →