the dark-adapted eye

Like many people, I breathed a huge sigh of relief when the news broke that Hubble was going to be repaired and rescued. In my opinion, this is one of the best decisions NASA has ever made, right up there with going to the moon, and developing the space shuttle. Hubble is probably the most beloved project NASA's ever had, literally outshining the Apollo project in the trove of spectacular images we have amassed from its gaze. If you want to turn kids on to science, there are few better ways than to show them some of Hubble's photos of the phenomena of deep space. For wow-factor alone, Hubble's cheap at twice the price, especially in this day and age of omnipresent light pollution. (Apropos of nothing and rather serendipitously, I'm listening to a 1926 recording of Holst's "The Planets" as I write this, and I keep waiting for Orson Welles to interrupt the broadcast with the news that Martians have invaded Earth. Of course, now the work will have to be titled "The Planets and One Dwarf Planet.")

<old fogey alert>When I was a kid, all I had to do was walk out the door and look up on a clear night to be completely overwhelmed and awestruck by the wonder of the night sky. Now, even though the neighborhood is not much more built up than it was in the 70s, all the new neighbors, and some of the old, insist on lighting their yards throughout the night. Former city dwellers as most of them are, they see danger lurking in the darkness, when in truth it's mostly raccoons, and the lights don't scare them one bit.</old fogey alert> This severely cuts down on the viewing pleasure in my former front yard. And now that I live in the City That Never Sleeps (which means it's much more the City of Lights than Paris could ever hope to be), I'm excited when I can actually manage to pick out a lone constellation somewhere, or even a particularly bright star (which is just as likely to be a satellite). Comet Hale-Bopp delighted me for the several months I could see it, especially when it appeared to be hanging directly over my house, coma erupting upward like a fountain. But most kids growing up now don't even know what they're missing in the night sky. Hubble is an excellent way to counteract some of that loss. But only some of it. There's no real substitute for getting out at night with a pair of binoculars, a small telescope, or even your nekkid eyes and looking up into the sky.

But doing that is becoming increasingly difficult, if not impossible, due to light pollution. The scale of the problem, ironically enough, is clear from the "before" and "during" pictures of the 2003 East Coast Blackout taken by NOAA satellites . During the blackout in NYC it was amazing to see the night sky smack in the middle of the city. It might almost have been worth the trek to the top of one of the high-rises to get roof access for a little stargazing. I'm sure most of us who live here have pretty much forgotten what the night sky looks like, embraced by the artificial glitter of neon and sodium lights. Light pollution is a serious enough problem that several international organizations and national advisory groups have formed to combat it, such as the International Dark-Sky Association. The Prairie Astronomy Club has some handy guidelines to help reduce light pollution in your own back yard, so to speak. I'm actually rather fond of Iceland's way of dealing with it, though.

Phil Plait scooped me on this ages ago over at Bad Astronomy, but it was such a brilliant (forgive the pun) idea, that I wanted to mention it again. For a half hour in September, all the streetlights in Reykjavik were turned off so people could get a clearer view of the sky. According to space artist Bjorn Jonsson who lives there, though, most of the light pollution is actually from other sources, not streetlights. I don't doubt this. Coming in over the city for a night landing at LaGuardia, streetlights are the least prevalent of light sources (though some of the most easily seen, especially in the middle of empty parking lots). Anyway, it's a great idea, and I'd love to see a voluntary half hour lights out, though that's unlikely in New York. But I wonder sometimes what we're losing with this disconnection from the night sky.

When I was starting to write this post, I noticed that Jennifer has categories for both astrophysics and cosmology, but not astronomy. Plain old visual astronomy seems to have lost some of its coolness factor, and morphed in much the way the study of literature has turned into literary theory. Theory seems to have much more attraction for the best and brightest than long freezing nights peering out at light collected through meticulously ground slabs of glass. Old fashioned visual astronomy seems to be drifting back into the domain of dedicated amateurs with their backyard telescopes, while the pros concentrate on radio astronomy in wavelengths not visible to the unaided human eye. Don't get me wrong: it's very cool stuff, bursting with new discoveries—like the 6-million-light-year-wide remnants of the ring recently spotted with the VLA—but for beauty and romance and sheer awe, I think it lacks something. "Listening" to space seems counterintuitive to me.

Or maybe not, now that I think about it. My dad worked on an Air Force flight line in Northern Michigan when I was growing up, and every now and then when he was working nights, our phone would ring after dark and Mom would come into my room, bundle me up in a jacket and take me out to see the Northern Lights at Dad's behest. Although the Aurora Borealis is technically an atmospheric phenomenon that occurs when the solar wind's electrons collide with atoms in the Earth's upper atmosphere, charging them and making them fluoresce, it was still part of the night sky show to me. Discovering later that it was the solar wind making those curtains of light ripple and hiss did nothing to detract from the sensation that a little of the night sky was falling to earth. And the fact that you could hear it . . . well, that was just too cool for words. And what that, and the other nights of stargazing in my yard, started was a life-long enthusiasm for space, which expressed itself in the usual geeky ways: membership in Star Trek fandom, a diet high in saturated science fiction, a fascination with science. It's the latter that's really important, of course, and this is where Hubble comes in.

Hubble is one of those great geeky toys that the public loves. They may not see the tangible benefits from it because astronomy, cosmology, and astrophysics are still very much sciences of knowledge for its own sake. It's hard to make the vast majority of people care about, say, the existence of gravitons, but show them a photo like this one (Planetary Nebula NGC 6543):

. . . and it's hard not to be amazed by what's out there in all that dark, whether that dark is dark matter, dark energy, or just the absence of light in familiar wavelengths. In educational value alone, Hubble continues to pay for itself, even with rescue missions to keep it going for another ten years. I don't think we could ask for a better ambassador between the depths of space and our increasingly night-blind selves.

P.S. Don't forget to see what Jennifer is up to over at the AIP Industrial Physics Forum blog.

Comments

[Phil Plait, aka The Bad Astronomer]

[swoon]

[Quasar9]

Words are words, music is music, pictures are pictures, maths is maths, ...
All things which attract people in different ways
All things which interest people in different ways

Praise & platitudes is said to be like
"Music to the ears"
Some photography and music us said to be
"Candy for the Mind"
and some images are simply "eye candy"

Newspapers & magazines are full of words (and even images) no one has time to read thoroughly
The Internet & blogosphere has enabled anyone and everyone to be a writer, journalist, publisher, editor.
I have nine hundred & ninety nine channels of tv pumping out stuff all day I would need 999 lives to watch (including umpteen repeats, and the many alternative versions of the same 'news' or scoops)

There is a lot out there - more than any one mind can absorb. I remember when anyone could list the major makes and models of cars, you try to do that now. I remember when anyone could list the most famous bands and album tracks, you try and do that now. I remember when anyone could list the most famous soccer stars. you try to do that now. There was a time one could list the most famous hollywood stars and films, you try now - they are almost as many as the 'mamed' Stars in the skies.

Nowdays you can do a PhD
not just in every branch of science -
but in every sub-group speciality within, whether it be in surgery, medicine, pharmacy, chemistry, bio-chemistry, physics, cosmology or asyt-physics

One could be a PhD in Star Trek Movies
One could be a PhD in Star Gate
One could even be a PhD in Lost

Have we reached the pinnacle of the Tower of Babel again, more tv channels than people (audience), more PhD courses than students? more things to say by more people, less people interested in what is being said

[Huw Lynes]

let me be the first of many pedants to point out that since Pluto was discovered in 1930 it won't be included in your 1926 recording of the Planet Suite.

The pluto part of the suite was written by british composer Colin Matthews many years after Holst's death.

[LucysGranddaughter]

". . . and it's hard not to be amazed by what's out there in all that dark, whether that dark is dark matter, dark energy, or just the absence of light in familiar wavelengths."

But it IS hard to be amazed by stuff we can't see...dark energy, dark matter, parallel universes and string theories...it's the pretty, perceive-able pictures, after all, that have hoisted Hubble so high into public regard.

[Mick]

Astronomy made me the geek I am (that's a good thing :) )
Pictures like hubbles certainly catch a seven year olds interest... and science has a habit of interconnecting with itself, leading to an intrest in nuclear physics in stars, optics in telescopes etc.

[TBB]

Nice post, Lee. Regarding light pollution, at least in cities like New York City, the avian groups are out there at night counting dead birds that get disoriented from the skyscrapers' office lights. They are constantly trying to get the buildings to turn off their upper lights, which only works in favor for night-sky enthusiasts as well.

I once picked up the Urban Almanac, which has a bunch of astronomy-related information for city dwellers (though obviously more focus on the moon, which *can* be seen). It's pretty much an "appreciate nature for the cement-bound" calendar book:
http://tinyurl.com/create.php

[Astroprof]

It's really a shame that throughout history, mankind has been able to go outside and look up and see the stars. Today, few have that opportunity. Only a tiny percentage of people in the industrialized world have ever seen a dark sky.

[Lee Kottner]

TBB, is this the book you meant? http://tinyurl.com/y4bpal? I'd seen this before, being a faithful Utne reader (even back when it was the Utne Reader!) I see they're not making a 2007 edition, which is kind of sad. One of the things I'd meant to add to this post before the hour got so late was an anecdote about a guy with a telescope on Second Avenue in the East Village that I ran into one night, selling peeks at the rings of Saturn for a buck. So you can see a few things even in the light pollution here. It was well worth the money. This guy was from outside the city somewhere, but there's another amateur astronomer here with a blog called Top of the Lawn http://topofthelawn.blogspot.com/ that's worth a look.

Huw, thanks for the "pedantic" correction. ;^) As you can see, my knowledge of both classical music and astronomy is fairly superficial, and you've added to my personal trove of knowledge. I'm wondering now if Holst isn't due for another rewrite, or at least a return to the original. Oh the dilemma! What's a conductor to do? At least it's no longer a struggle between scientific accuracy and musical purity.

Lucy's Granddaughter, that's the beauty of the Hubble pictures: that they can lead to curiosity about the things we can't see, as Mick said.

[TBB]

Yes, Lee, sorry, I was skrinking the Amazon link and messed up. (Your link isn't working either, btw.)I meant: http://tinyurl.com/yhc4lh Too bad they aren't doing a 2007 issue.

The 2nd Ave guy sounds like a good entrepreneur - great idea!

[Stephen]

In 1997, I setup a 60 mm spotting scope on a tripod, and showed passers by comet Hale-Bopp. I even took pictures. The light pollution in downtown Philadelphia was high, but Hale-Bopp was very, very bright.

http://www.uitti.net/stephen/astro/index.shtml

This year, at Halloween, I set up the same scope on my West facing front porch, and offered kids a "free look at Jupiter". One older girl, really a chaparone, was the only enthusiastic viewer. But, next year, I'm going to bring out the 10 inch cannon. Jupiter will once again be setting in the West.

[Stephen]

I thought, from the title, you might metion just what the dark adapted eye can see. My favorite quote, from the Dancing Wu Li Masters, and from the Tao of Physics is this:

The dark adapted eye can detect a single photon.

Since photons are quantum particles, they are a way to experience quantum events directly. It isn't that easy. There are technical problems. Half an hour of dark adapting. The statistical nature of emitting just one photon, etc. So maybe most of us won't get to see a single photon after all. I'm amazed it can be done at all.

I hear conflicting things about the quantum efficiency of human eyes. Anywhere from 5% to 65%. One thing is true. The dynamic range of brightness that a human eye achieves routinely beats out even very expensive film or digital photography. For example, during a solar eclipse (where the Moon blocks the Sun), the human can see the disk of the Moon illuminated by reflected light from the Earth, and it can see the solar corona. But for photography, you have to take two pictures and splice them together.

[liebe]

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