I was witness to epiphany -- someone else's. At the end of a rugged day on a forest fire in Colorado, I should've been snuggled in a sleeping bag, but was distracted. Our camp sprawled in a high, remote meadow.

The Milky Way was dense and bright, like a sun-drenched cloud. Stars seemed poised at the ridge crests, almost in touch. After dusk I strolled beyond a pool of lantern light into the glare of the galaxy. I stared at the sky, unwilling to surrender to sleep.

On the second night I was trailed by Y.T., a Vietnam veteran who over the prior two days had related horrifying, mesmerizing tales. He'd seen everything, but not the night sky, not like this.

When he asked what I was looking at, I pointed. There was M31, the Andromeda Galaxy, a faint patch of light visible with the naked eye, a maelstrom of 1 trillion suns, and two-and-a-half-million light years away.

That steered us into talk of cosmic distance and time -- we were seeing Andromeda as it was when homo sapiens did not exist.

There was Polaris, the north star, target of the Earth's axis. To measure the distance of Polaris above the horizon is to measure your latitude.

But our planet wobbles as it spins, so the north celestial pole migrates around the northern sky in a cycle of 25,000 years. Using the handle of the Big Dipper as a guide, I showed Y.T. the dim star Thuban in the constellation Draco -- it was the north star when the Egyptians built the Great Pyramid at Giza, and millennia hence it will be again.

We turned, and just rising was the Pleiades star cluster, or Seven Sisters, a stunning thicket of sapphires in our own galactic neighborhood, a mere 400 light years distant. Dominating all was the Milky Way itself, an effulgent tide of stars and dust spanning the sky.

When I explained that this arc of light was the central plane of our home galaxy, spread across a hundred thousand light years, and that we were gazing in at it from the hinterland of one of its spiral arms, Y.T. slumped into the grass, favoring the leg whose kneecap he left in Southeast Asia. He laid back and swept his eyes from horizon to horizon.

"But," he said, "but ..." A pause. "Wow ..." His face shone in the palpable glow of the Milky Way. His lips parted, mouthing a second, silent "wow." He'd found his place in the universe.

After our tour of duty, everyone scattered to their home states, never to reassemble. But around Christmas I got a letter from Y.T. He mentioned our forays under the stars, and how he was now learning the constellations with his kids. He wrote: "It was a great gift you gave me, man."

Wow.

It was gratifying to offer such a present, but it was only possible because we'd enjoyed a truly dark night sky. Such a valuable natural resource is not readily available to most of the humans on the planet.

When "light pollution" was first raised as an issue, it seemed a jest, an effete tree-hugger crusade. Couldn't see the Milky Way from downtown or out in the 'burbs? So what? Maybe you could catch it on "Star Trek" or "Nova". Besides, all that artificial light wasn't toxic, was it?

Actually, it is.

In 2007, the World Health Organization listed shift work as a carcinogen. (As someone who worked swing shifts for a decade, that resonates.) In 2009, the American Medical Association, not renowned for "new age" leanings, produced a resolution stating that unshielded street lights are a "public health hazard."

Research on "light at night" (LAN) tags it as a cause of sleep disorders linked to disruption of circadian rhythms. In that role, LAN contributes to hypertension, diabetes, obesity, cardiac problems and attention-deficit disorder.

It also enhances air pollution. In 2010, a scientist at the National Oceanic and Atmospheric Administration presented data indicating that human-caused sky-glow "reduces a naturally occurring nitrate radical that helps cleanse the atmosphere of exhaust and ozone." A brighter night sky is a filthier sky.

The unnatural "twilight" created by the electric mist of our lamps also has a negative impact on wildlife, by affecting feeding patterns, migratory navigation, and mating habits of everything from birds to insects. Recent observations show that even trees may be damaged.

What is so curious about light pollution is its mindlessness. As much as we wish to, say, clean up the emissions from coal-fired power plants, few doubt the necessity of the electricity they produce -- there is method to the madness, a tradeoff.

Not so with indiscriminate outdoor lighting. Think your "security" light keeps you safer?

A report to Congress in 1997 indicated "there is no conclusive correlation between lighting and crime." I know that if I were prone to burglary, the premises I'd sack would be those lit up. How better to discern: Is there a Doberman on the porch?

Where did the kids leave the tricycle, basketball or anything else I might trip over? Is there anything outside worth stealing? Are all the windows locked? Security lights would be a boon, illuminating my scouting yet providing deep shadows -- via contrast -- to mask my approach.

Besides, statistics testify that the majority of property crimes occur during daylight, or inside lighted buildings.

And why do we brightly illuminate streets and highways that are already in the path of our headlights? Apparently to be wasteful.

The International Dark-Sky Association estimates we squander $3 billion annually in the United States on unnecessary and/or inefficient outdoor lighting, amounting to 58,000 gigawatts of energy producing 15 million tons of carbon dioxide, and thus contributing to global climate change.

But what an easy problem to fix! Just switch off the useless lights, which is most of them. They are artifacts of cheap electricity and fear of the bogeyman.

When I was a child, I insisted on sleeping with a lamp lit in the room, but finally consented to darkness when a friend pointed out that the light allowed the bogeyman to see me. For those lights deemed necessary, make sure they're shielded so energy is not wasted lighting up the sky or the bellies of passing aircraft, but is focused on the ground.

Phase out conventional lamps in favor of LEDs, and if you must have a "security" light, wire it to a motion detector. (It startles the raccoons.)

In 1989, at the urging of the local astronomical community, the Board of Supervisors of Coconino County, Ariz., which includes Flagstaff and the Lowell and U.S. Naval Observatories, passed an ordinance that limited the quantity of light shed on each acre of land.

To convince the county, astronomers conducted a photometric study of Flagstaff and discovered that merely by shielding and aiming existing lights, the wattage could be reduced (and money saved) with no sacrifice of illumination.

To date, about 300 localities in the United States have similar lighting laws, primarily motivated by finances, but also by a conservation ethic, and to protect a natural resource (darkness) important to local interests such as tourism or observatories, not to mention public health.

The United Kingdom, Italy, Slovenia and the Czech Republic all have national laws to curb the wasteful deployment of light.

I support all that -- it's no-brainer common sense and certainly a win-win proposition, but back to Y.T. and my primary motivation: Under that fabulous night sky he encountered what I call astronomical happiness. It's joy in the presence of beauty; awe before the pulpit of sheer magnitude; wonder at cosmic enigmas.

Best of all, it's a passage beyond the self. We are needy self-absorbed, biological creatures whose fundamental instinct is for survival and propagation. Any time we can transcend the tyranny of our genes is precious, and a dark night sky is a portal to transcendence. The stars say: Get real -- notice the scope of the universe.

Your daily concerns are not trivial, but assign them a cosmic perspective. In this terrestrial barracoon it's a blessed privilege to be friends with the stars, capable of plumbing the celestial matrix and saying: Wow.

But to see the light it needs to be dark.

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Peter M. Leschak is the author of "Ghosts of the Fireground," "Letters from Side Lake" and other books. He lives in Side Lake, Minn.