Carl Sagan's Ithaca Memorial

As part of today's Carl Sagan memorial blogswarm (via) marking the tenth anniversary of Sagan's death, I thought I'd write, not about Carl Sagan directly, but about a memorial to him -- one that happens to be my favorite piece of public art in my home town of Ithaca, New York. Sagan, of course, taught at Cornell (located in Ithaca) for many years, which is his connection to the town; hence the location for the memorial.

The sculpture in question is the Sagan Planet Walk, a scale model of the solar system on a 5,000,000,000:1 scale. The sun is represented as a window in a large black monolith:

It's about six feet tall (I'm afraid the photos are just what I happen to have, I have no time today to go get new ones, and I didn't think to get a photo of someone standing next to it.) It's in the middle of the Ithaca Commons, a pedestrian-only walkway at the center of downtown Ithaca. The next for monoliths (which are each a bit smaller) are all on the same block. In fact, in the background of the photo above, you can see the Earth and Mars megaliths:

(The Venus monolith is directly behind the Sun monolith in this shot; Mercury is off to the left, beyond the edge of the photo.)

Each of the planets is represented by a slightly smaller grey monolith (except Pluto (yes, this was back before Pluto's demotion) which has a monolith matching that of the Sun, to anchor the other end of the Planet Walk). Here, for example, is the one for Mercury:

And here's the one for Jupiter:

The window in the center of each Monolith is identical in size to the window which represents the sun, in order to give a sense of scale. The actual planet is represented by a to-scale size model of the planet embedded in the window. In most cases, you can only see it by going right up to the window and looking very closely; it's often hard to tell the planet from a speck of dirt (although the planet is in the center of each window, and of course you can tell if you look closely enough.) But the larger planets you can see even from a few feet away. For example, here is an enlargement of the Jupiter window above:

And here is an enlargement for the Saturn window:

For Jupiter, they also include several moons (the four big ones, I think) and the Saturn window includes Triton; but you can't see them with the level of detail in these pictures. Incidentally, in those two pictures, Jupiter looks smaller than Saturn, but that's a result of the framing and angle of the photos; in the actual monument, Jupiter is quite clearly bigger than Saturn (aside from the latter's rings, which even things out a bit.)

On the front of each monolith is a plaque giving information about the planet. There's also a podcast by Bill Nye which you can listen to as you do the walk (although I've never heard it -- it's fairly new -- even though I've done the walk more than a dozen times from end to end, not counting passing it just strolling around town (we live near Uranus, so I go by parts of the walk all the time.))

What's really cool about the memorial, however -- it's purpose, really -- is not possible to capture in photos, and that's the visceral sense of the sheer size of the space, and of the extraordinary emptiness of it. It takes about half an hour to walk from the Sun (at the heart of downtown) to Pluto, right in front of the Sciencenter, the local science museum. But walking it you imagine almost all of it as empty, save for these tiny little specks of nothing captured in the windows. Even the sun seems tiny. It's dizzying: our universe is basically extended void, a vast amount of nothing, with just a few insignificant specks of fire and dust. It is, in a powerful sense which gets lost in the common use of the phrase, awe-inspiring.

And of course the distances vary greatly. It's a matter of moments to walk from the Sun to Mars; each of the other distances gets progressively longer, save for the Neptune - Pluto distance which is shorter (although still long on the Sun - Mars scale). Here is the official map from the Sciencenter web site:

You can get a slight sense of the distances from this map -- but not as well as you can from an ordinary astronomy textbook. What really works is the sculpture itself: putting the entirety on a human scale, so you can feel it, get the variations under your shoes and in your legs.

It is a marvelous memorial for the late, lamented Carl Sagan, who spent his life trying to educate the public about astronomy and science: a beautiful piece of public art that also serves to convey, on a marrow-in-the-bones level, the feeling of awe that our universe can inspire when looked at through science's lens.

But my favorite thing about the planet walk I don't have a photograph of. It isn't on the map; it isn't in Ithaca -- it doesn't even exist yet, and it probably never will. But there has been talk apparently about building a matching, to-scale monolith for Alpha Centauri, the nearest star to the Sun.

It would be in Hawaii.

I love to imagine that it will be built: making the Sagan Planet Walk one of the largest public sculptures in the world (since, after all, the space between the monoliths is an integral part of the sculpture), and boggling the mind with the true vastness and emptiness of this extraordinary cosmos that we live in.

In any event, next time you are in Ithaca (which, to be sure, is in the middle of nowhere -- it's not even directly on a major interstate -- so it may be a while for most of you) take the time to walk the planet walk. It's a wonderful bit of public art, and worth taking the time to appreciate properly. And a wonderful tribute to an amazing man.

In Memoriam
Carl Sagan
1934 - 1996

Update: Joel Schlosberg has now put up a post linking to the various entries of the blog memorial. Go there to check 'em out.