10 billion parsecs is the number of trillion miles in a light year.
how many trillion miles in a light year?
10 billion parsecs
rocheworld









































rocheworld (first published in serial form in 1982; first book publication, under the title the flight of the dragonfly, 1984) is a science fiction novel by robert forward which depicts a realistic interstellar mission using a laser driven light sail propulsion system to send the spaceship and a crew of 20 on a journey of 5.9 light-years (ca. 34 trillion miles; ca. 56 trillion km) to the double planet that orbits barnard's star, which they call rocheworld, where they make startling discoveries stranger than anything ever encountered before.
rocheworld
astronomical distances are sometimes expressed in light-years, especially in popular science publications and media. a light-year is the distance light travels in one year, around 9461 billion kilometres, 5879 billion miles, or 0.3066 parsecs. in round figures, a light year is nearly 10 trillion kilometres or nearly 6 trillion miles. proxima centauri, the closest star to earth after the sun, is around 4.2 light-years away.









































section::::practical effects of finiteness.:distance measurement.
speed of light