ChewbaccaD said:
What if the atoms that make up the sand are universes?
a reasonable estimate for the size of a grain of sand. The number they come up with is 8 per cubic millimeter. Let’s make life easier and round that up to 10. That means we’ll get 10 grains/mm3 X 109 mm3/m3 = 1010 grains/m3. Multiplying that by the volume of the universe (and if you’re feeling bored, think about how crazy that phrase is…) gives us 1090 grains of sand.
That’s right, if we fill the entire universe with grains of sand we’d still need 1010 universes to get a googol grains of sand.
Hmph. Okay, but how many atoms would that be?
To make things easier, let’s just make the universe one giant silicon crystal. Silicon has a density of 2.3 g/cm3 (again, Wikipedia is our friend), or 2.3 x 106 g/m3. Silicon has an atomic mass of 28 g/mol (the stable isotope of Silicon has 14 protons and 14 neutrons).
So, a cubic meter of silicon has
2.3 x 106 g/m3 / 28 g/mol X 6.022 1023 atoms/mol
=
4.95 X 1028 atoms/m3
Ooo, we may be on to something here.
Multiply that by the volume of the universe:
4.95 X 1028 atoms/m3 X 3 × 1080 m3 = 1.48 X 10109 atoms
= 1.48 X 109 googol atoms!