from sea level, the biosphere goes up about 9 km and down about 19 km. what is the thickness of the biosphere in meters?

4 answers

1 km = 1,000 meters
28 km = ?? meters
if I put a banna in the fridge will it turn black tommorow?
Try it and find out.
An interesting thing to try is does putting other ripe fruit with the banana speed up the 'going black' process? Alternatively does putting a ripe banana with other fruit speed up their ripening?