Some funny physics numbers

The energy you need each day, provided by food, is about 2000 kCal = 8.36 MJoules This is the energy needed to move by 10 meters up a weight of 83 tons (about 20 elephants).
The distance between our sun and the closest star is 4.5 light-year which is about 4.2 10¹⁶ meters. Suppose you have a good space engine of today, whose celerity is 50000 km/h (15 km/s). Then you would need 88787 years to reach this star (alpha Centauri).
Take 1 cm3 of air. Count the number of molecules in it. You obtain around 3.10¹⁹. With your magic stick, replace aech molecule by a sand grain. You obtain 30 billions of tons of sand, that is sufficient to cover entirely a country like France with a 6 cm thick beach.
Every human being on earth output about one liter of water, which goes from 37oC to 20oC. Considering around 5 billions of human beings, we obtain a caloric energy:
Q = 5.10⁹ x 1 x (37-20) = 3.56 10¹⁴ Joules = 5 bombs of 20 kilotons (Hiroshima) every day.
It is the energy produced every day by mankind in the toilets.

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times since Nov. 4th 1999.