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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