Solar System Sunlight and Scripture

Most of you reading this are not practicing Christians, but almost all have seen a Christian Bible, probably the most common book in the world in all its many variants. The following is about math and ratios and the physical characteristics of a common artifact, not religion. Still, if this example helps a practicing Christian understand the scale of the solar system, this page has done its job.

I am looking at a 1962 Cokesbury edition of the Revised Standard Version of the Holy Bible, my Christmas present in 1964. The pages are 126 by 178 mm, and there are 1178 pages (both sides of each leaf), including white spacer pages, illustrations, indexes, study aids, and maps. Total page area is 126 x 178 x 1178 = 26420184 square millimeters, approximately 265 square meters.

A typical main-text period (full stop) is approximately 0.6 millimeters in diameter (using a dial micrometer and magnifier). That is 0.28 square millimeters. The total page area in "full stops" is 265/0.28e-6 or (approximately) 1 billion full stops.

The average radius of the Earth is R_E=6371 kilometers, and the average distance from the Sun to the Earth is R_S=149,600,000 kilometers. At the Earth's distance, the Sun lights up a sphere with an area of 4 \pi R_S^2 , while the Earth intercepts sunlight with an area of \pi R_E^2 . The ratio of these areas is 4 \pi R_S^2 / \pi R_E^2 ~=~ 4 ( R_S / R_E )^2 ~ ≈ ~ 2.2e9 or about 2 billion.

The Earth intercepts half as much of the Sun's total output as one period occupies compared to an entire Christian Bible.

Giant Jupiter intercepts about ten times as much sunlight as the Earth. Slightly larger Venus, at 72% of the distance from the Sun, intercepts 2.7 times as much sunlight. Tiny Mercury, Mars, the asteroids, and the rest of the distant planets combined intercept less sunlight combined than the Earth does. Combined, all the orbiting mass of the solar system "blacks out" about 8 full stops worth of sunlight. All the rest of the sunlight blows out into the vast universe, never to touch matter again, redshifting down to thermal noise.

That is either very humbling ... or an immense goad to our long-term spacefaring ambitions. We can increase the life-and-mind potential of the solar system a billion-fold - and there are 100 billion more stars in our home "Milky Way" galaxy alone. The human mind boggles - but someday those vast energy resources will power superhuman minds capable of comprehending the opportunities that await "us".

Compared to that, it is absurd to risk global annihilation over a mere hundred cubic kilometers of petroleum in the middle east.