Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
24 Jan

Why the Night Sky Matters: The Ramifications of Light Pollution

Carrie and I are lucky enough to have a hot tub in our back yard, overlooking a pretty spectacular ocean and mountain view. We often soak for a while and talk about the day’s activities just before retiring to bed (I sometimes alternate with a quick plunge or two into our unheated pool). Last night we were taking advantage of the break between winter storms to “jacuze” when I noticed that the cloud cover had so dispersed the city lights of L.A. and Santa Monica that it lit up the sky even 20 miles out into Malibu. On an otherwise moonless night, it had become light enough to simulate dusk all over L.A.. Can you imagine the amount of manmade light it takes to have that effect? Of course, that got me thinking about all the ways in which light permeates our lives in ways both good and bad.

These days, mentioning the words “pollution” or “environment” raises hackles in some, perhaps most people. Political blinders go up, knee-jerk responses engage. Support for classically green renewables like wind or solar power usually comes with unequivocal and emotional disdain for any and all variations of nuclear. On the same token, those who question the legitimacy of anthropogenic global warming often display a lack of concern for the effects of fracking, industrial pollution, or rampant use of agricultural pesticides. Now, I’m not wading into that morass, mind you. This isn’t the place for that. I am, however, calling to attention the fact that both (albeit amorphous, roughly defined) groups have a major blind spot: light pollution. And it’s not that they reject it as a problem. It’s that they are simply unaware it even exists (maybe it’s all the bright lights).

So what exactly is light pollution?

Well, it’s not light as in mild, harmless, or barely-there. It’s not gentle pollution, and it’s nothing like “light to moderate drinking.” Light pollution is characterized by excessive amounts of artificial light. Light that shouldn’t be there, light that you can’t escape from. It’s light that fills city streets at night – all night – and extends upward to obscure our view of the stars. It’s the blinding white and blue light streaming from big screen TVs, laptops, and lamps, and it’s the little niggling lights that pepper the interiors of our homes, winking at us from Blu-ray players and gaming consoles and clock radios even as we (try to) sleep.

In other words, light pollution exists inside and outside our homes. It affects both the environment at large and the individual inhabitants within. It is micro and macro. In the modern world it is, for the most part, inescapable.

I won’t delve too deeply into the negative effects of artificial light on human health as it relates to circadian rhythm, because I’ve already covered those. Quickly, though, some of the research:

Night time exposure to blue (artificial) light can suppress melatonin production, thereby disrupting sleep, reducing quality of sleep, throwing off circadian rhythm, and even promoting certain cancers.

Computer light exposure at night affects circadian rhythm and cognitive performance.

Continuous light exposure might hamper our ability to process carbohydrates, particularly in the liver.

According to a large review titled “The Dark Side of Light at Night,” (PDF) shift workers (a proxy for night time light exposure) get more cancer, heart disease, and are more likely to be obese. They also experience great oxidative stress loads and have compromised immune systems. Shift workers might represent the extreme end of nighttime light exposure, but they show the potential negative ramifications of even constant low-level exposure for everyone else.

But besides all the measurable, objective, physiologically-harmful effects of too much artificial light, there are the intangibles. That’s what this post is really about. Who else was lucky enough to spend their childhood summer nights on the roof or in the open field, gazing up at the millions of stars set against the backdrop of eternity? I was, and it’s what I still look forward to most of all about camping. When I sneak away from the fire and catch a break in the canopy, I stop and stare up above at the stars, those same heavenly mysteries that got our ancestors thinking, poking, prodding, and striving for more. Though today I know that they represent far flung galaxies of eons past and that that bluish “star” is actually Venus, a planet covered by volcanoes and rocky deserts – while thirty thousand years ago mankind looked up and concocted wondrous tales of gods and celestial beasts – that knowledge is suddenly meaningless once I begin to gaze. I’m caught up, emotional, dare-I-say “spiritual” – a lot like how our ancestors must have felt when they looked up at night. I’m lost in the limitlessness. I’m a kid again, suddenly struck with the realization of just how small I am and of the extrinsic meaninglessness of it all. Nature, remember, is neutral, and it becomes evident that we create our own meaning – it’s actually intrinsic, it comes from within – and set our own path. It’s all on us, and I’m reminded of this essential fact because of that brief brilliant moment with the stars.

If we allow light pollution to progress unabated, we lose that relationship. Many of us have, for all intents and purposes, already lost it – if we ever had it at all. But at least the opportunity remains. I mean, the stars are still there, if you get the heck out of Dodge. And if you can drag your kid outside city limits to shift his gaze from smart phone upward toward the relatively untouched sky, he might learn something about what it means to be human. Strip away all the luxuries and technology and just stick a modern city dweller in an open meadow in the middle of nowhere in the black of night and direct his or her attention skyward. If only for a moment, he’ll be like Luke Skywalker staring out at the night sky in “A New Hope” (with fewer suns) and thinking of rebel fleets and hyperspace travel.

That brings me to my final beef with light pollution: the extinguishing of a potent source of inspiration for greatness. From the ancients using astronomy to align their superstructures, to Newton drawing on the movement of celestial bodies to formulate basic theories of physics, to poets and authors and other artists (“Starry Night,” anyone?) creating work after a night spent stargazing, we do and have done great things with regular access to unfiltered night skies. I tend to think we have a lot ahead of us, too, if we’d give ourselves the chance. Misappropriation or lack of funding is the oft-cited cause of the US space program’s sorry state, but I feel like a lack of public fervor for all things stellar is at the root of it. People just don’t – or can’t – look up and marvel at the amazing ocular feast residing above anymore, and so they don’t dream of visiting it. Public officials don’t feel pressured to support it (besides, there are far more lucrative things to be doing with our tax money, like subsidizing their friends). Kids don’t seem to dream about becoming astronauts. I dunno about you, but that’s sad to me. The childhood version of Mark Sisson figured there’d be interstellar commercial travel and permanent bases on Mars by 2012. Adult version of Mark Sisson is highly disappointed that there is neither (but he hasn’t quite lost hope).

But we can’t go out and bust street lights with slingshots; we’re not extreme Luddite/Dennis the Menace hybrids. We can, however, make changes to the immediate environment. Our homes and our habits can change. So, if there’s an action item to be derived from this post, I guess it’s this: turn off the lights, go outside, preferably somewhere remote, look up, and take it all in. Take your kids with you. Foster the innate human obsession with the stars. Watch young eyes light up and mind-expanding thoughts of eternity and possibility germinate in growing brains. Then, set them loose and see where they go and what they do. I bet it’ll be pretty good.

Who else loves – nay, needs – the stars? Who else imagines how great things would be if we could actually step outside our living quarters, look up, and see the galaxies laid out before us in excruciating detail? Who else wishes that stargazing was no longer the strict province of campers and hunters and country-living? I realize that progress is inevitable and civilization butts heads with nature, but there’s got to be a better way.


Chime in the comment section. Let everyone hear about your love for the stars. And if your relationship with the cosmos has grown stale (or you’re a stargazing virgin), then get out and see them (so you know what we’re all blabbering about)!

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. What an awesome post. This is one of my big beefs. Why do we have to have so many lights on at night?
    My husband and son do some research in Burkina Faso, Africa, out in a village in the back of beyond with no electricity. There, near the equator, when the sun sets, it goes down really fast and it gets dark, really dark, like instantly. My son came home raving about the stars.
    I grew up in the mountains of New Mexico where there is very little light pollution, and we woudl go backpacking and just sleep out under the stars. I remember all those nights just gazing up and watching satellites and planes cruise across the heavens.
    Now, there’s an app for the iPhone called skygazer – you point it at the sky and it tells you what the constellations are. I would have loved to have that back then!!

    Gydle wrote on January 24th, 2012
  2. Thank you for writing this and for not making me feel totally alone. I’ve been pondering over this for quite some time, and I actually mailed the city council, asking them to please consider street lights with motion-sensors on them for all of the reasons you mentioned above. They didn’t even bother to reply. *sigh*

    Jeanette wrote on January 25th, 2012
  3. In the summertime I love to admire the beautiful sky and all the stars from our galaxy. It raises my level of consciousness, it talks and tells you that you are part of something bigger than you could ever imagine. We have evolved and we need lighted cities and communities, but once in a while find darkness and take a peak at the beautiful Cosmos and let it talk to you.

    Paul Alexander wrote on January 25th, 2012
  4. Ah, Mark, way to make my homesickness worse!

    I grew up in the country. Apart from growing and raising everything we ate, the nature was just amazing. My favourite time was August, when we’d have shooting stars, and we’d go out into the clearing with the neighborhood kids to watch the night sky…there was also a really tall tree in one of our neighbour’s land – I think it was a sycamore – and we used to sneak in at night through a crack in his fence, and challenge eachother as to who could climb up the highest. The one who won was the ‘king’ or ‘queen’ of the stars for the week! The good old days…

    Milla wrote on January 25th, 2012
  5. I am a volunteer adult leader with the Boy Scouts (highly recommended), and one of the highlights of our monthly camping trips is stargazing. The Milky Way is often visible and meteors are not uncommon. We almost always do an Aug. 12 meteor shower campout where we stay up all night and watch one of the best meteor showers of the year, the Perseids. The Geminids on Dec 12-13 are also good. Folks at work often ask me why I would go out on a campout with fifteen teenage boys. The answer is that is it a relaxing break from civilization. The night sky is a big part of that.

    Damien Gray wrote on January 25th, 2012
  6. Comet Hale-Bopp anyone? That was a pretty spectacular time.

    It’s on my life list to see the Northern Lights and the Southern Cross sometime before I croak.

    Todd wrote on January 25th, 2012
  7. I live in a very tourisy beach community which means there are hotels and restaurants and the like just at sand’s edge. The night time lights on these businesses cause the sea turtle hatchlings to become disoriented and they crawl out of their nest and toward the businesses instead of following the moon into the sea. Many, many, many endangered turtle hatchling species are smooshed by cars because they’re trying to cross the road to get to the light. It’s so sad that our community can’t do more to protect the turtles. They do lower the streetlights and shade the beach side of them, but most of the businesses and condos/homes keep their lights blazing.
    Also, because there are fewer sea turtles there are way more jelly fish in the water and washing up on shore because sea turtles eat jelly fish. There is hardly a day anymore that the dangerous marine life flag isn’t flying on the lifeguard stands.

    kiss wrote on January 25th, 2012
  8. I absolutely love the night sky. Living in New Mexico I can find some truly dark skies and the beauty of the milky way is really evident. One simple thing the average homeowner can do is install down lighting for their outside lights. These light fixtures direct the light down and not up where it pollutes the sky. If you truly want to make a difference you will do it!

    Michelle wrote on January 25th, 2012
  9. My parents have a small acreage about 8 miles north of a smallish community AND for some reason, there was never a yard light put in so the yard is always very dark unless the moon is blazing. After a visit, if I’m leaving after sundown, the visibility of the stars always stops me in my tracks. They are breathtaking.

    Looking back at my childhood, growing up mostly on farms and acreages, those moments spent star gazing have stuck with me. It really is a very special thing to stop and awe at the stars.

    musajen wrote on January 25th, 2012
  10. I grew up in the rural-ish midwest, and had the good fortune to often visit places even more rural. I still remember how beautiful the stars were when I was growing up, and the awesomeness of learning how they move through the sky, learning to tell the time of night from the season and the positions of the stars.

    Now I live in Chicago, and every so often on a clear night I’ll look up and say “Oh, look! The star is out tonight!” And I try at least once a month to go somewhere far enough away that the light pollution from the city isn’t so bad, but it’s difficult around here; it takes a few hours to get to anything near as dark as what I grew up with.

    Via wrote on January 25th, 2012
  11. A couple weeks ago the observatory of which I am associated ( and the local park commission jointly presented the premier of a film called The City Dark, A Search For Night On A Planet That Never Sleeps. The film, created by amateur astronomer Ian Cheney, asks, “What happens when we lose the night?” While planning for the event, we discovered that Dr. David Blask of Tulane University of New Orleans (only 50 miles away) is featured in the film discussing his research with Dr. Robert Dauchy on the effects of light on circadian rhythms. We invited them to the presentation. They had not seen the film and accepted. They discovered that light exposure retards melatonin levels. Rats were injected with cancer cells. The rats that had lowered melatonin levels developed cancers. Those with higher levels experienced few instances. They concluded the light exposure of shift workers may account for the higher cancer rates among those workers.

    Merrill Hess wrote on January 25th, 2012
  12. Great article, I miss the sky :(

    ZenBowman wrote on January 26th, 2012
  13. Oh My! Love stars so much, that they are tatooed in multiple places on my body…I feel blessed to live somewhere that still gets pitch black, and on a clear night, the sky leaves me speachless and still, no matter what my hurry…I always stop to look in awe.

    lisa wrote on January 26th, 2012
  14. I was born and grown up in the very north of Sweden. Altough I moved elsewhere, being rather urbanized today, in my heart I’ll always be that little boy who got a glimpse of this marvellous world we live in.
    The seeds of my being aware of the infinite cosmos were sown when watching the first Russian Sputnik, speeding over the sky back in October 1957.

    I remember my father and me together experiencing this remarkable event at that time.

    Now reading about the solar storms I also recall those amazing, colourful Aurora Borealis curtains, sweeping back and forth across the starry, cold winter night skies.
    As aside, the Finnish word for these northern lights(revontulet)can be translated as “the fire of the fox”). (Firefox 😉

    As someone mentioned here earlier, the summers above the polar circle are quite the opposite. The midnight sun, throwing its reddish, sharp light over the landscape, somehow shortens my need for sleep.
    In fact, these are often the times when I find myself most alive and creative.

    Later on, in the twilight of August, the full moon looks like an orange;
    a very beautiful sight indeed.

    Luckily the air in the north is still very clean. So, unless there are clouds, the whole universe seems to be twinkling before your eyes.

    The best month to get lost in the cosmos is September. At that time the evenings are dark again, but still warm enough for such an adventure.

    However I do not own a telescope, but contemplating the Milky Way through an ordinary 7X50 binocular is also quite awesome.



    Jim wrote on January 27th, 2012
  15. I love this article. As someone who supports the paleo lifestyle and also dabbles in amateur astronomy, it’s nice to see these two issues converge somewhere besides my own mind. I’ve seen the milky way but I have to travel very far to do so, it’s sad and I long to live in a world where I can see unpolluted skies by just stepping outside my home. I’ve never seen the kind of skies that I hear sailors and people who’ve been to *really* remote places talk about, and don’t know if I ever will :(

    Craig wrote on January 27th, 2012
  16. I never knew that the pollution in the night sky could actually cause sleep disruption and cause some cancers! Thanks for the warning! This blog is so helpful!

    Suzanne wrote on January 28th, 2012
  17. I moved out to the country a few years ago, fully looking forward to a nice, dark sky. I had one, for a little while, until my neighbors across the road moved in and re-activated their always-on-at-night, supplied-by-the-power-co-op street lamp. (Which brings me to another point: you’d think the electric company would stand behind their supposed promotion of responsible energy usage and instead suggest people get motion-sensing lights instead of always-on lights!)

    I don’t understand why anyone would want a freakin’ street light in their driveway, right outside their house. The thing lights up rooms inside my house, I can only imagine what it does to theirs.

    I wonder if I could ever convince them to turn it off.

    Charlie wrote on January 29th, 2012
  18. Great!

    Michele Shimizu wrote on January 30th, 2012
  19. Great post! I think a great addition to the primal living movement would be to commit to turning off the lights at night. In my neighborhood, not only do the street lamps shed way too much excess light at night, but on top of that it has become extremely trendy in suburbia to use night lights as part of your landscaping. I know this can be useful for seeing your way to the door, but let’s be honest, you need that about .001% of the time. Let’s start a movement to use motion sensor lights only, and start bringing back the stars, and our circadian rhythms.

    Ryan wrote on February 1st, 2012
  20. I use to live in the country out in the farmland area, I never saw so many stars, it took me back to when i was a child in the early 70’s.
    Now I am married and live in Key West, husband refuses to move. The light pollution is terrible and the noise the bar down the road till 3am. I long for the quiet and darkness of the night sky twinkling. Sigh, someday.

    Faye wrote on January 2nd, 2014

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