The earth has an average diameter of 7918 miles (12742 km). The deepest part of the ocean in the Mariana trench is approx 36070 feet (10994 m). The deepest part of the ocean is therefore approx one one thousandth of the diameter of the earth.

Now that 30 inch, 75cm sphere in the demo has an area 4 Pi r squared = 1.76 sq metre. The volume of water to cover the sphere to a depth of one thousandth of the diameter ie 0.75mm is (approx) 1.3l, which is more than typically respired in a day, let alone a single breath. (a figure of 400ml/day is quoted on quora.com)

Oh what a miserable grinch I am. Nice demo though.

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