How many cubic nanometers are in a cubic parsec?

Jun 13, 2016

$3.37394104 \times {10}^{76} {\text{nm}}^{3}$

Explanation:

A parsec is a distance measurement used in astronomy, defined as the distance at which one astronomical unit subtends an angle of one arcsecond. It's equal to

$\text{32,313,140,071,200 km}$

To convert kilometres (km) to nanometres (nm), we need to know that we move the decimal 3 places to the right for km to m, then another 9 for m to nm, so we're moving 12 in all:

$\text{32,313,140,071,200,000,000,000,000 nm}$

But we want cubic, so we cube this number to get (google couldn't deal with all the digits, so I got an approximation of):

${\text{3.37394104e76 nm}}^{3}$, which is

$337394104000000000000000000000000000000000000000000000$${\text{0000000000000000000000 nm}}^{3}$

I'll let the reader put in the commas.

Fun Fact - this number, the number of cubic nanometres in a cubic parsec, is approaching the number of elementary particles in the universe, currently theorized at ${10}^{80}$.