Friday, November 01, 2002

The Ultimate Sky

by Joel Marks
Published in Sky and Telescope 104:5 (10), November 2002

Every fall semester when I am teaching my philosophy classes, which are mostly sections of introductory ethics, I am reminded of Immanuel Kant's exclamation, "Two things fill the mind with ever-increasing wonder and awe … the starry heavens above me and the moral law within me." For this is the season when M31 rises to the top of the sky for all to see on a clear dark night, and I cannot resist telling my students all about it and, conditions permitting, taking them outside to see it.

The reception I receive is both gratifying and discouraging. There is no question that most of the students enjoy the break in routine from arguing about right and wrong. They are in fact genuinely curious about the stars. And the story I have to tell them has got to be at least tied for first place as the greatest ever told: How the very same Immanuel Kant whom we study in the philosophy course was one of the first to postulate the correct identity of the Andromeda Nebula, perhaps by analogy to Galileo's discovery of the stellar nature of the Milky Way (which is a story in itself, of course); how this informed inference was spectacularly confirmed in the Twentieth Century, thereby opening up the floodgate of galaxies; how immense these objects are (I do a Carl Sagan with the numbers) and hence the universe in toto; and so on.

To cap it off I roll open my giant Palomar poster of the Andromeda Galaxy and its companion galaxies. I point out that this is "an actual unretouched photograph"; that the stars filling the frame are in our galaxy; that to somebody residing on a planet in M31, we would look just like this picture (pointing to our location two-thirds out from the central bulge); that when we see the bulge as a tiny smudge in the sky, we are seeing something utterly unique in our (naked-eye) visual experience (from the Northern Hemisphere, anyway), namely, an object that lies outside the Milky Way galaxy; that our unaided eyes therefore have the capacity to see 2.3 million light-years into the distance; hence also, that we can literally look into the prehistoric past; etc., etc. M31 is the ultimate wonder that has been revealed to us by science, as far as this amateur astronomer is concerned.

But while I am getting carried away, I also recognize the tragedy that underlies my ability to "wow" my university students in this way: Hardly any of them has ever heard about any of this stuff. They have never taken an astronomy course, and probably never will. Astronomy is simply not considered to be a part of their basic education. Their location in the physical scheme of things has been known only up to a point, say, Earth, Solar System, without the rest of it: Milky Way, Local Group, Universe. It's like forever being a child who learns that she lives on Joralemon Street in Brooklyn Heights, but not that Brooklyn Heights is in New York, the United States, North America.

I feel so sad for the vast majority of people, who are never exposed to this particular reason to wonder. But it is also a drag on the continued uncovering of these revelations, since they depend upon funded research, hence, public support, hence, public understanding. I do my bit in my courses, but something much more wide-reaching and direct is called for.

I know one thing that would do it. I would like to see some enterprising geek invent goggles that would do for Andromeda what Galileo's spyglass did for the Milky Way -- just point it up at the sky and look through it to see the glory of Creation! For perhaps the most marvelous fact of all about M31 is that it is BIG -- that is, not only physically, but also phenomenally. Its angular dimension in our sky is huge – at least eight full moons across. Imagine seeing that whenever you looked up! If people could view such spectacles simply by donning a pair of spectacles (especially if it were cheap), then I think we would see the dawn of a new age.

I also think this points to a general fact about astronomy that is often lost on people who fail to reflect on the obvious, or, more precisely, on the implications of things already known. (This is my forte as a philosopher, you see.) It is commonly assumed that what telescopes do is to magnify. So when we see these gorgeous images of galaxies and nebulae and whatnot deep-sky objects, we think it is the enlarging power of the observing instrument that has done the trick.

But equally important in astronomical observation is light-gathering power. It struck me one day (many years ago), probably when reading an issue of this very magazine, that the angular sizes of many of the discoveries discussed were quite large. M31 is not at all unique in this regard, and is even dwarfed by other objects (just one of countless examples: The September Sky and Telescope, on page 17, announced the discovery of a 10-degree-long tail for the globular cluster, Palomar 5).

Imagine, then, if some inexpensive, enhanced-CCD goggles would instantly show us all of these marvels. I wonder what that sky would look like! I have no doubt it would blow everybody's mind -- permanently.

One more thing: I would insist that at least part of the proceeds from the sale of these goggles go to the International Dark-Sky Association. This would help ensure that future generations would be able to view the starry sky sans goggles and thus be every bit as awed and inspired as we and our predecessors have been.
P.S. I would like to see somebody like Bradley Schaefer do a comprehensive inventory of large-angular objects in our sky and illustrate the results on a Sky and Telescope all-sky gatefold map. Compare also this "modest proposal" in Planetarian v31 n4 p4 December 2002.