The temperature of Cygnus X-1 from Hawking radiation is roughly a billionth of a degree above absolute zero.
We've moved from computers with a trillionth of the power of a human brain to computers with a billionth of the power.
We may be cousins to the worm, at the billionth remove; but we are not brothers.
The vibrations which thus occasion light are, at a mean, 555 in the billionth of a second.
Thus, to trace it, the autopsy doctors would have to find, separate or segregate a billionth bit of the mass under observation.
1680s, from French billion (originally byllion in Chuquet's unpublished "Le Triparty en la Science des Nombres," 1484; copied by De la Roche, 1520), from bi- "two" (see bi-) + (m)illion. A million million in Britain and Germany (numeration by groups of sixes), which was the original sense; subsequently altered in French to "a thousand million" (numeration by groups of threes) and picked up in that form in U.S., "due in part to French influence after the Revolutionary War" [David E. Smith, "History of Mathematics," 1925]. France then reverted to the original meaning in 1948. British usage is truer to the etymology, but U.S. sense is said to be increasingly common there in technical writing.