“And God said, Let there be light: and there was light.”

It’s revealing that the first thing God creates, according to the Biblical book of Genesis, is light … or, in other words, energy. Whoever first conceived of that description and wrote it down had at least one thing right: light — our primary source of energy — is fundamental to everything else. Without it, to borrow two other words from Genesis, all of us here on Earth would quickly be cast into the darkness and the void.

Oil, the resource that’s enabled two-plus centuries of industrial and social advancement, is light energy embodied — the pressure-cooked energy concentrated by photosynthesizing organisms that captured the Sun’s power millions of years ago. So too are coal and natural gas. Even the newer sources of energy we’ve tapped into all owe their existence to the Sun. Wind energy wouldn’t exist without it (it’s solar heating of the atmosphere, coupled with the Earth’s rotation, that gives rise to air currents). Solar energy? Duh. Not even nuclear power would exist without a stellar ancestor in its past: any elements heavier than hydrogen were produced in the fusion engine of some star somewhere in the universe.

Some might want to make the case that wave and tidal energy owe more allegiance to the Moon than to the Sun. But think about it for a moment. Sun with no Moon = all the other forms of energy are still available to us. Moon with no Sun = the Earth is frozen solid, leaving waves and tides out of the picture.

Perhaps the most interesting thing about the energy we rely on today, though, is the fact that we’ve likely reached an inflection point, a moment (not literally, but not in geological time terms either) in which our understanding of and access to energy is undergoing a dramatic change. Global oil production might have peaked several years ago, according to some estimates. Even if it hasn’t yet, worldwide demand is going up while production at the rates we’ve come to depend on grows more and more difficult and costly. New sources — solar, wind, tidal, biofuel — are expanding their footprints, though they’re still a small proportion of our overall energy mix. Can we grow them fast enough to keep up as fossil fuels keep rising in price, contributing to sociopolitical havoc and becoming ever-harder to bring to market?

Depending on the answer, we could soon discover first-hand how truly fundamental — and hard to replace — our energy resources are to life as we know it.