One never considers the vastness of space. Here are some hints to help one reflect on its immensity.

The distance from the sun to earth is one astronomical unit, taking eight minutes for light to travel. One astronomical unit equals about 150 million kilometres (93 million miles).

Another way of looking at it: the astronomical unit is a bit more than eight light minutes in distance.

Quite by coincidence, the number of astronomical units in one light year and the number of inches in one mile are virtually the same. For general reference, there are 63,000 astronomical units in one light year and 63,000 inches in one mile. This wonderful coincidence enables us to bring the light year down to earth. If we scale the astronomical unit – the earth-sun distance – at one inch, then the light-year on this scale represents one mile.

The closest star to earth, other than the sun, is Alpha Centauri at some 4.4 light years away. Scaling the earth-sun distance at one inch places this star at 4.4 miles (seven kilometres) distant.

Scaling the astronomical unit at one inch, here are distances to various stars, star clusters and galaxies:

Alpha Centauri: four miles (closest star: four light years = 4 x 93,000,000 x 63,000 ) miles; Sirius: nine miles; Vega: 25 miles; Fomalhaut: 25 miles; Arcturus: 37 miles; Antares: 600 miles. Its massive size would swallow up most of the solar system. Pleiades open star cluster: 440 miles; Hercules globular star cluster (M13): 24,000 miles; centre of (our) Milky Way galaxy: 27,000 miles; Great Andromeda galaxy (M31): 2,300,000 miles; Whirlpool galaxy (M51): 37,000,000 miles*; Sombrero galaxy (M104): 65,000,000 miles*.

*Remember this is scaled down: one inch = 93 million miles.

And all this vastness of the cosmos, some would say created itself out of nothing!