Carl Sagan was famous for noting that there were more stars in the universe than grains of sand on every beach on earth. Is this true, and how do those numbers compare to the number of atoms in the human body or the estimated number of living insects on earth? Today we take a look at this 4-way comparison.
Stars vs Sand vs Atoms vs Insects
Although the stars-vs-sand comparison has been cited for decades, adding in the number of atoms in a human body and the estimated number of living insects on earth brings a new dynamic to the picture.
While the numbers below are only estimates, there is a clear winner in this grudge match of large numbers.
Grains of Sand
A page published by the University of Hawaii estimates that there are 7,500,000,000,000,000,000 grains of sand on all the beaches on earth. Another way to put that number is seven quintilian five hundred quadrillion, or simply 7.5 quntillion. Outer Places estimates the number much higher, at 5 sextillion.
Stars in the Universe
An article in Universe Today suggested a possible number of stars in the universe could be 1,000,000,000,000,000,000,000,000, or one septillion stars, far greater than the estimated number of grains of sand on all the beaches on earth. This is much higher than the number used by Outer Places, which places the number anywhere between 10 sextillion and 200 sextillion.
Atoms in the Human Body
Jefferson Lab estimated the number of atoms in a human weighing 70kg to be an astronomical number of 7,000,000,000,000,000,000,000,000,000 or seven octillion.
Number of Insects
Smithsonian has estimated the number of living insects on earth. The report notes that there are 30 million species of insects, totaling an estimated 10 quintillion individuals alive at any time, or 10,000,000,000,000,000,000.
If the massive numbers used above are confusing, here is another way to view these comparisons using the estimates above included:
- 7.5 quintillion = low estimate of grains of sand
- 10 quintillion = estimated number of living insects
- 5 sextillion = high number of grains of sand
- 10 sextillion = low estimate of stars in universe
- 1 septillion = high estimate of stars in universe
- 7 octillion = estimated atoms in a human body
Of course none of the numbers above are exact, and there are certainly other interpretations and other data from which additional conclusions can be based.
In our math grudge match of stars vs sand vs atoms in the human body vs number of living insects, we seem to have a clear winner, based on the numbers provided. While there in fact are more stars in the universe than grains of sand on all of earth’s beaches – as the decades-old comparison correctly states – there could also be more insects than the number of grains of sand, if the low estimate of sand is accurate.
Perhaps surprisingly, there are more atoms in a human body than all of the stars, sand, and insects combined.
Or simply put: atoms>stars>sand?>insects
Updated January 27, 2016
Originally published July 2015