Image of the day

From the
ATWB Customer Gallery


My Account

New to Astromart?

Register an account...

Need Help?

Wild Card 002.1 "Defending Our Planet from Invasions from Space" PLUS a LOT More!

Posted by Rick Shaffer   06/14/2004 12:00AM

This column has evolved, and so has its numbering system. I intended to write just two columns a month, but I’m having just too much fun doing this, and I find that I need a weekly “column fix”, so I’ve been writing one column per week. What’s happened is that I’ve enumerated each pair of columns as “Wild Card 00X” and “Wild Card 00X.1”. I’m doing this to show that each pair of columns is linked by subject. However, not every word of the “.1” edition of a column will be linked to the first one in the series. That’s the case with this one. We start out with a subject that is linked to the previous column, more about SETI:


In 1959, Guissepe Cocconi and Philip Morrison wrote a letter to “Nature” magazine suggesting to their colleagues that searching for evidence of extraterrestrial intelligence is a worthy subject for scientific research. They also conjectured that the region of the microwave spectrum near 1421 MHz would be the logical place to begin the search. That broke the ice, and there have been several searches over the years since then then, both here in the US and elsewhere. As I wrote last week, I briefly worked on one effort for NASA/JPL in the 1980s.

We’re now in a situation in which the US government has no official connection to any effort to detect extraterrestrial intelligence. I’m not interested in criticizing the efforts of the various private organizations that are now “doing SETI”. I simply don’t know enough about their efforts to critique them. I do know that there’s one way I and anyone else who owns a reasonably-fast computer can be part of one effort to do SETI. That’s SETI at Home. You can search on that subject to find out more.

Instead of critiquing what’s being done now, I’d like to try to get you to think about SETI not as a scientific study, but, rather, as an exercise in military intelligence. Here’s my rationale:

Classical military intelligence operates from one central premise: That we (whoever “we” are….) must know what any enemy might be able to do to us. So an intelligence analyst isn’t interested in what any enemy “would” do, but only what that enemy “could” do For example, the various US intelligence services continually analyze the military capabilities of every country in the World, enemy and ally alike. And, every other service worthy of the name is doing the same.

Would the principality of Monaco attack the United States of America? It’s unlikely in the extreme. But, an analyst in each of several different intelligence services certainly has that principality as part of his or her responsibility. Monaco may have only a thin folder, but that folder certainly exists.

I contend that our species needs to regard any threat from space in the same way our intelligence services regard the military threat posed by other countries. We shouldn’t, and maybe we can't know what any alien species WOULD do to us, either maliciously or accidentally. Rather, we should concentrate on what “they” COULD do to us."

Step ONE in assessing what threat extraterrestrial species might be to Humanity is to find out if those species actually exist! We can’t actually search our entire Galaxy for extraterrestrials. Our technology isn’t that advanced. But we do have the technology to detect radio signals from other civilizations as technologically advanced as our own, if they’re within, say, 300-500 light-years of Earth. And, if a civilization is much more advanced, and if it’s still using radio signals to communicate, we might detect it from much farther away.

What might we do if we detected signals from an extraterrestrial civilization? I’d have to think about that for a good while, and I’m not convinced that my conclusions would be of any particular use. I’d rather hear the opinion of a large group of folks from a wide variety of specialties. (And, what fun it would be to be a “fly on the wall” as those folks discussed what, if anything, we should do, IF….!)

I am convinced of one thing, though. If we find no evidence of ET within a bubble 500 light-years of Earth, that distance would mean that we’d be at lower risk of what another civilization “could” do to us than if we find a close neighbor.


I doubt if anyone would argue that fairly large rocks more than occasionally get run over by a “bus” called the Earth. If you doubt this, take a trip to Northern Arizona and visit Meteor Crater. I suggest that the probability of the Earth being invaded by extraterrestrials is smaller than the probability that a rock large enough to end Human Civilization will hit the Earth. But, regardless of the nature of the threat, we Humans need to start thinking as much about defending our planet and our species from various threats from space as we do about defending our various countries’ borders from invasions by the military forces of other countries. I would think that’s something on which all Humans can agree.

I don’t regard the above as a political statement, because I’m neither endorsing a particular party nor a candidate. I just think that all of us should be asking political candidates to tell us their views on “planetary defense” as well as how they plan to defend the particular country in which we reside. I certainly leave it up to you to decide if a candidate’s answer will lead to your giving him or her your vote.


Many scientists who are interested in SETI contend that the problem of communicating with extraterrestrial intelligence (CETI) is a bigger nut to crack than being successful in SETI. This has been a recurring theme in SciFi as well. The reason is that extraterrestrial intelligence may be so alien to us that “they” might as well be a programmable VCR! (Whatever we might say to them, “their” response would be a big, red, flashing “12:00”!)

We might also find that the classic cartoon caption:

“Take me to your leader.” gets “lost in translation”, and becomes,

“Take me to your liter.” or, “Take me to your gallon.” and finally, “Where’s the nearest milk jug?”

Lately, though, we humans have gained practice in communicating with other species here on Earth. Almost everyone is aware of the work that’s been done in communicating with Great Apes and with certain breeds of Dolphins. Just in the last few days, though, the results of new research with “man’s best friend” the Dog, have been published. It seems that what dog fanciers among us have known for generations has now been proven scientifically: dogs understand radically more different human words than the majority of us would have supposed, up to a vocabulary of about 200-words (and counting). And the researchers have identified the process through which dogs learn to understand human speech, which they call “fast mapping”.

If you’d like to know more about this, just google on “border collie human speech” or go to Slashdot.

Oh, yeah. I called several Cats I know for comment on this story. None could be bothered to return my calls….


Fellow member Harry Aiello sent me an email that asks a couple of very good questions:

AielloQ1: “How do you get almost 3" of eye relief out of rifle scopes when 20-mm is cause for celebration in a telescope eyepiece?”

The answer to this one is to remember that riflescopes operate at very low powers and cover small fields relative to those we use in the typical telescope. So, the “cone of bundles” of parallel light emerging from the eye lens of a rifle scope is much steeper than it would be in an astronomical telescope. Since there’s no need for a shallow cone, the eye relief can be made very long.

Another way of thinking about this is to simply scan in the diagram I used in the original discussion of the exit pupil of “Wild Card 001”. It’s a 2X telescope. If you take the scan and stretch it out until the exit pupil is 3” back of the eye lens, you would create a fair 2X rifle scope. (The only part missing would be the lens or lenses that would erect the image.) So, a low power instrument with a very narrow field can have a very long eye relief.

AielloQ2: The best eyepiece I have ever seen personally is one in a Canon 10x30 IS binocular. Why? How?

Congrats on your Canon binocs, Harry! The “why” would seem to be that Canon has decided that they can make a decent pile of money selling innovative, extremely well-made optics for the sports, birding, security, and astronomy markets. (And, if “your” particular market isn’t on the list, I apologize. I’ll try to work you into a future column.)

The “how” isn’t perfectly clear, because I don’t have the design specs in front of me. Nor have I been allowed into the collective heads of the folks who designed your binoculars. But it’s well known that the best binoculars are designed as a system. So, the designer would take into account the following:

1. The aberrations of the objective lens. (Chromatic aberration, spherical, coma, astigmatism and flatness of field would be the ones that would be of main concern.) (Also note that more and more bino objectives feature more than the traditional two elements. They’ve begun to resemble telephoto lenses!)

2. The aberrations introduced by the prisms. (Chromatic and spherical would predominate here.)

3. The aberrations introduced by the eyepiece. (Chromatic, spherical, astigmatism, and flatness of field.)

Then the designer would actually allow the objective to have a lot of spherical aberration, so long as it is equal to, and of an opposite sign to the spherical aberration of the prisms. If he or she can do that, spherical aberration would vanish. The designer would follow the same path in dealing with all the other aberrations. (In actual fact, this is done with an optical design program that can try hundreds of combinations of lens and prism parameters within certain predefined limits. This “blunderbuss” approach is what computers do really well.)

It’s likely that the designer of your Canon binocs actually came up with a radically-better design than the one you own. However, it’s just as likely that it required optical glass that only Bill Gates could afford to put in his binoculars, or that it required extremely strict manufacturing tolerances, which would mean that too many optics would be rejected along the way. So, the designer had to continue working until what emerged was a design that could be made with less expensive glasses and with broader manufacturing tolerances.

What’s ironic is that, if you removed the eyepiece of your binoculars and used it in your telescope, you might be very dissatisfied with its performance! The reason should be obvious: your telescope doesn’t suffer from the aberrations present in “the rest” of your binocular. Rather, it suffers from its own set of peculiar aberrations. And, they may or may not be compensated by those in your binoc eyepiece.

QuickNote01: I haven’t mentioned one aberration that’s often allowed to run wild in binoculars, expecially wide angle binocs. That’s distortion, the aberration that turns a right-angle grid of lines into a pincushion or a barrel-looking pattern. Many users of binoculars don’t seem to find this aberration objectionable, so many designers ignore it. However, some designers use eyepieces that are often used in wide angle binocs to present normal-field images with no distortion. These types of eyepieces are called “orthoscopic”, because they present right angle patterns as right angle pattern. But an Orthoscopic eyepiece (with a capital “O”) is a particular design attributed to Ernst Abbe of Zeiss fame. The Orthoscopic eyepiece is orthoscopic. So are most Plossls.

QuickNote02: Al Nagler has certainly engaged in some of the kind of system design I’ve mentioned above. His Paracor lens makes a well-figured fast paraboloid into an extremely sharp catadioptric telescope. Does he design his Nagler and other premium wide-angle eyepieces to eliminate the residual aberrations present when the Paracor is used in a fast Newtonian? Some folks suspect that he does. Only he knows, and I’ll bet he’s not going to tell us!


(When Herb York advertised for folks to contribute to AstroMart, he stated explicitly that authors could engage in self-promotion. There’ll be time for that later. This section is about shameless promotion of some friends of mine.)

The predominant view of rock musicians is that they’re all drugged-out hedonists. And, if they’re not that, they must at least be one-dimensional, and that dimension must be music. I don’t know enough rock musicians to tell if the “one-dimensional, drugged-out hedonist” definition fits most of them. But I do know one “bigtime” rock musician pretty well, and I’ve met his partner in their band. Both are interesting, broad-spectrum Humans, and both are interested in Astronomy in particular, and the Universe in general. Their songs reflect that interest.

The band is called “Cracker”, and they’ve been recording and performing since 1991. Their music is a fusion (but not the “cold” kind!) of rock, punk, country, and jazz, with some salsa, garage, and observatory influences. They recorded 5 CDs for Virgin records, appear on several others, and now distribute their music themselves. You can buy their stuff at Pitch-A-Tent records. Just google on that….

My friend Johnny Hickman plays lead guitar, mandolin, harmonica, yodels and sings backup and lead vocals, and is the writer or co-writer of most of their songs. Johnny has a background both as a house painter and as a musician. Recently, he’s branched out into writing scores for motion pictures. He wrote the score for the movie “River Red”, and is working on another score for the same director. Johnny’s wrapping up his first solo album, so you can look for it this Fall. His side band, “CrazySloth” is based here in Sedona, AZ, where I live, and features his brother, Cap Capella, on keyboards. (It was definitely a treat to have a really good band practice in my living room!) Cap’s also an amateur astronomer, which is how I met him, and, of course, he’s a good friend as well. (Cap does the excellent “star walk” for beginners at our annual astronomy festival here in the Verde Valley of N AZ). I’m privileged to call Johnny Hickman and his wife Soraya my friends.

David Lowery is the other principal performer in Cracker. He plays rhythm guitar and sings lead and backup vocals, as well as writing most of the songs with Johnny. David’s eclectic style reflects his education. He has an MS in Mathematics! David has also produced albums for the Counting Crows and other bands, and was a co-star of the motion picture “River Red”.

Cracker tours a LOT! To find out where they’re appearing next, just google on “CrackerSoul”. That site also will tell you when they’re appearing on TV.

NEXT WEEK: Wild Card 003 is entitled “Mr. Strehl Takes His Ratio to TelescopeVille”. I hope you’ll enjoy it.

RICK SHAFFER is an astronomer, writer, teacher, and designer/builder of telescopes and museum exhibits. He lives and works in Sedona, AZ, where he can often be seen dining at the local Subway outlet with his 20” Newtonian, Dora.