Oxygen levels for fire

For billions of years, Earth existed without a single flame. It’s a concept almost impossible to imagine in a world where fire is integral to human life. But Earth’s history tells a fascinating story about how fire became possible—and it’s more recent than you might think. While neighboring planets like Venus boast fiery volcanoes, actual fire, as we know it, has never existed … [Read more...] about People Are Just Learning That For Billions Of Years, There Was No Fire On Earth