Planetary Radio: Space Exploration, Astronomy and Science - A Tribute to Philip Morrison

Episode Date: May 2, 2005

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Remembering Philip Morrison, this week on Planetary Radio. Hi everyone, welcome to Public Radio's travel show that takes you to the final frontier. I'm Matt Kaplan. Dr. Philip Morrison passed away on April 22nd at his home in Cambridge, Massachusetts. In his 89 years on this little planet, his mind and spirit encompassed the entire universe. We'll talk about the man and his legacy

with Harvard physicist and SETI researcher Paul Horowitz and former head of the Jet Propulsion Laboratory, Bruce Murray. That other Bruce, Bruce Betts, will also be here with another What's Up segment. And here's a quick look at some of the headlines circling our planet and others. You've probably heard that NASA has pushed back the launch date for space shuttle Discovery. The new window for the so-called return-to-flight mission is July 13 to 31. the so-called return-to-flight mission is July 13 to 31.

Deep Impact has found its deep space destiny. With almost two months to go till its spectacular collision, the probe has taken its first picture of Comet Tempel 1. You can see it at planetary.org. That's where you can also check up on those plucky, if slightly cranky, Mars rovers, Spirit and Opportunity. They continue to explore the surface of the red planet in spite of minor mechanical and software glitches. Opportunity was crossing some sandy ripples when it unexpectedly got caught in one of them, burying itself up to its hubcaps, or at least to where its hubcaps would be if it had any.

Principal investigator Steve Squires says the team will take its time figuring out how to extricate the rover. Q&A with Emily is up next. She's enjoying the world's first and biggest light show. It's far out, man. I'll be right back. Hi, I'm Emily Lakdawalla with questions and answers. A listener asked, what is the aurora? Polar aurorae are fantastic, colorful displays of light in the night sky.

They are the most visible effect of the solar wind on the Earth's atmosphere. Aurorae begin at the sun, which is continuously emitting energetic particles in all directions carrying with them the solar magnetic field traveling at speeds of hundreds of kilometers per second the solar wind blasts into the Earth's magnetic field solar wind particles can jump to the Earth's magnetic field lines the particles cascade down the magnetic field lines toward the poles where they collide with neutral atoms in the Earth's upper atmosphere. The collisions excite electrons. When the electrons drop back down into lower energy states, they emit colored light.

The Earth isn't the only planet that has such light shows. Stay tuned to Planetary Radio to find out more. Physically, Phil Morrison was a small man, bent by his childhood struggle with polio. But his mind seemed as large as the galaxy to those who had the good fortune to work with him, or who were educated by him. And according to the many friends whose lives he touched, his heart was just as big. Two of those friends recently joined us to talk about Dr. Morrison. Paul Horowitz is professor of physics and electronics at Harvard University and a leading SETI researcher.

Bruce Murray is professor emeritus of Planetary Science and Geology at Caltech, a founder and former chair of the Planetary Society and former head of the Jet Propulsion Laboratory. We focused our conversation on Phil Morrison's contributions to the search for extraterrestrial intelligence. You can read more about his very rich life and work at planetary.org. But any discussion of SETI should really start with something Dr. Morrison did more than 45 years ago. Paul, I want to start with you. What was it in 1959 that Phil Morrison did that was of such significance to SETI? Well, 1959 was the year in which the Cacone and Morrison paper,

very short paper, about three pages, came out in the international journal Nature. And the title of that paper, which I happen to have in front of me here, is Searching for Interstellar Communications. This very short paper basically laid out the framework for 40 years of SETI that followed, it pointed out that we are probably not alone, that other civilizations may exist, that the galaxy permits communications over distances comparable to its size, that is tens of thousands of light years up to perhaps hundreds of thousands of light years, and that then they go technically into a bit of a discussion of how one might communicate over those distances. The actual piece of history, as I understand it, behind this is that Cacconi came to Morrison to ask him whether

the gamma rays that were going to come out of their new particle accelerator up at Cornell there could be seen outside the Earth and might be a channel of communication. And Phil and Giuseppe followed this up and looked to see, in fact, could that be done? Even if not, is there a way it could be done? And what they did was they explored the whole electromagnetic spectrum and other possibilities and concluded that radio waves did indeed provide a channel, and in fact probably the best channel, at least from what they knew in 1959, and probably from what we still know. Electromagnetic waves consisting of either radio waves or light or something in between

could span the distance between stars in the galaxy. There's actually a rather interesting little comment in here in which they dismiss a visible light. This was, of course, before the invention of the laser. But they say here that if you wanted to operate in a visible or gamma ray, it would require either very great power or very complicated techniques, presumably arrays of searchlights. And, of course, we'll probably come back to this because nowadays there are lasers, and, in fact, it is a very good technique.

This paper ends with a wonderful little line here. They say the probability of success is difficult to estimate, but if we never search, the chance of success is zero. ability of success is difficult to estimate, but if we never search, the chance of success is zero. And I think it was this rousing call to go ahead and look for this kind of a signal that could indeed cross interstellar distances that energize the whole generation of us, including myself. I love that quote. And frankly, it could probably be applied to all of exploration and all of science, I imagine. But Bruce, what was it about Phil Morrison coming out with this paper, co-writing this paper, that was so important, that this question of, as you've said, legitimacy?

I was, at that point, a relatively young, inexperienced person in this whole business, just getting into it, but fascinated, like so many others, with the prospect of life elsewhere. its whole business, just getting into it, but fascinated, like so many others, with the prospect of life elsewhere. It just seemed logical to me that that should be the case, and then the possibility of searching for it became very interesting. The problem was that there was a group of people like that, Paul is a good example, who were all fired up, wanted to spend energy and time pursuing it,

but that among the scientific establishment, this was a sci-fi thing. This wasn't legitimate science to many people. But Morrison's special contribution was, because he was a very distinguished physicist, all on his own, well regarded by many, many other scientists, that he decided that, yes, it was an interesting topic, and it was warranted, all on his own, well regarded by many, many other scientists, that he decided that, yes, it was an interesting topic and it was warranted. And furthermore, he wrote this paper, which was published in a very distinguished international science journal.

And that changed everything in many ways, because it meant that people like Paul could legitimately, or could seek telescope time and other support and point to such a paper as the legitimate way to do it. It wasn't just their own personal hunch. And it's hard now to emphasize quite how important that really was. So ironically, Phil's most important thing, I think, was not so much in laying out the strategy, which he did. That would have been figured out eventually anyway.

But by using his credibility, which he was one of the few people who had it and wanted to, to enable this whole thing to get started probably 10 or 20 years earlier than it might have otherwise. Paul, did Phil Morrison's interest in SETI wane over the years, or did he continue to make contributions? No, I think, if anything, it waxed. Phil was a lifelong friend of SETI. He, for instance, chaired or led the study that led to the SP419 document about the search for extraterrestrial intelligence. Perhaps more interesting to those of us actually doing the search, he came up with just terrific ideas. For instance, in our radio search right here in Massachusetts using the radio dish that we took over, we started a search looking at this special frequency of the 21 centimeter line, the emission line of neutral hydrogen in space.

That is, by the way, the most abundant atom in the universe. And this line is used for radio astronomy to map out galactic arms and is surely known to radio astronomers everywhere, not just on our planet. We were looking at this line, which I should point out was suggested in the Kekonian-Marsen paper in 1959. But the line is a narrow line, and the question is, what do you do about the fact that your planet is moving relative to our sun, and that our sun is moving relative to other stars? Would the people at the other end compensate for that motion, or what? And Phil pointed out that this is a problem, and in those days when we couldn't

cover the entire radio spectrum, and that's still the case, you look for a simplifying principle. And he wrote me a wonderful letter. It must be in the late 80s, in which he said, sure, you could expect them to compensate for your Doppler shift, or you could compensate for their Doppler shift. By the way, this letter is typed out, and it's got a little cross out, and it's got little things drawn in it, and it's just a wonderful thing. But he says there is a universal frame that astronomers everywhere must be aware of, and that is the frame in which the blackbody radiation of the Big Bang is isotropic. It looks the same in every direction. At this time, it was becoming known how our motion relative to that reference frame, and he pointed out this is where you should look.

And this led to the experiment, which we called Meta, in particular its choice of radio frequencies at which to listen. We followed up on this and looked at three frequencies, one of which was this 21-centimeter line referenced to this magic frame. So Phil would come up with wonderful things. And when you thought you were all out of wonderful things, he came up with something completely new. We are paying tribute to one of the great figures in science,

one of the great human figures of our time, Phil Morrison, who passed away just a few days ago at the age of 89. Our guests are Bruce Murray and Paul Horowitz, and they will rejoin us as we continue the conversation right after this. This is Buzz Aldrin. When I walked on the moon, and they will rejoin us as we continue the conversation right after this. We're tracking near-Earth asteroids and comets. We sponsor the search for life on other worlds. And we're building the first-ever solar sail. You can learn about these adventures and exciting new discoveries from space exploration in The Planetary Report.

The Planetary Report is the Society's full-color magazine. It's just one of many member benefits. You can learn more by calling 1-877-PLANETS. That's toll-free, 1-877-752-6387. And you can catch up on space exploration news and developments at our exciting and informative website, planetarysociety.org. The Planetary Society, exploring new worlds. We are talking about Dr. Philip Morrison

on Planetary Radio this week. We don't often do tributes, but we sure felt that this was someone who had earned this many times over. And we have two very special guests who did cross paths with Dr. Morrison. Paul Horowitz is Professor of Physics

and Professor of Electrical Engineering at Harvard University, a SETI pioneer in his own right. Bruce Murray is the former chairman of the Planetary Society, also co-founder, professor emeritus of planetary science and geology at Caltech, where he's been on the faculty since 1960. And, of course, he was the director of the Jet Propulsion Lab from 1976 to 1982. Bruce, let's come back to you. You said, and this is a recent quote on hearing of the passing of Phil Morrison,

the world is a diminished place without Phil's imagination and vision. It seems that there was much more behind that than the passing of a great mind. Yeah, I think, again, you need to look back in time, in DeFill's time, which I only partly overlapped with. He was already a big gun, a big figure from World War II, the Manhattan Project, and which a number of physicists like him rose to great prominence and leadership. What was unusual about him was his willingness to embrace new ideas and look at things in unusually innovative ways. And SETI was, in particular, a really bizarre new idea at that point.

If it had just been some brash young scientist pushing this, it wouldn't have gone nearly so well. Paul, I want to quote from something that you wrote on the passing of Dr. Morrison, because it's really lovely, and I don't know what you'll have to add to this, but here it is. Phil was that rarest of things, a sensible visionary. It was his ability to link good sense to bold visions that made him a pioneer in the search for extraterrestrial intelligence. His intellect was gentle and brilliant, and his remarks on any subject were insightful and always surprising. The world is diminished by his passing. You also talked about his overarching warmth and compassion.

I wish I had overlapped more with Phil. The kinds of things I saw were, for example, for 20 or 30 years, he wrote all the book reviews in Scientific American. What was really remarkable about those, and I gather that that was two or three books a month he would review, he read something like 30 books a month. His little house was absolutely chock-a-block full of these books. And when you go and visit, he would often, Phil would come down to the library and would pick out several books that would be appropriate for our children at that age.

Maybe they were six or ten, and say, I think this is a good book for you. Phil wrote those reviews, each one as if that was his field of expertise. He wrote it with the knowledge and the breadth of perspective that just sounded absolutely genuine, and it was a mind like Phil's that could do that. But when you came to his house, it was his spirit as much as his mind that enveloped you. He would smile in a wonderful way and when he would say something that was unexpected, he would look at you with that little bit,

sort of a slightly impish grin and just wait until you caught his meaning, which was always subtle. And then he'd give this wonderful smile and you just felt as if you were entering a very warm and intelligent place. caught his meaning, which was always subtle. And then he'd give this wonderful smile, and you just felt as if you were entering a very warm and intelligent place. I so miss those book reviews in Scientific American, and the column that he and his wife wrote after he gave up the book review position. They were part of my introduction to the love of science.

Bruce, Dr. Morrison, also participated directly in the Planetary Society. He was a member of the advisory board? Yes, from the beginning. And he was not just a member. He was the person who could always, you know, your go-to man, could always count on his help in a cheerful and effective way. And he would channel his energies into things like the Planetary Society, which helped us enormously.

And it was this generosity of spirit and imagination together that I think so many people missed. And that was the basis of my comment about how much we're diminished by his passing. It isn't just his science, not even just his advocacy for SETI, but it was his general ability and willingness and warmth to give to so many different elements of our technological society that needed this kind of support. He was a wonderful man, and I'm not sure who the young Philip Morrisons of today are, and who, when they pass, will be remembered the same way. You know, that was very much my next question. Whether there is anybody out there now who has the stature

or might approach the stature of a Phil Morrison, I certainly would put him up there with another colleague of yours, Carl Sagan. Well, Phil and Carl were friends and similar in many things, but very different fundamentally. friends and similar in many things, but very different fundamentally. Phil was an accomplished, respected physicist from the World War II era, and he brought that credibility to new fields like our own. Carl was a bright, young upstart who was trying to create fields.

He wasn't the veteran master of some other well-respected field, and that was a real problem for Carl. It was because of the support of people like Phil that Carl could be more successful. Paul, we are almost out of time. Paul Horowitz at Harvard University. But it would be a shame, with this tribute to Phil Morrison, who might be considered one of the founding fathers of SETI, if we didn't at least get a very quick update on your SETI research activities. And, of course, we'll have to have you back for a more in-depth examination or update sometime soon.

But how are things going? And particularly I'm curious about optical SETI. Matt, if I could just add a comment to Bruce's last comment before I launch into that, and that is that are there people like Phil around? Who is the next Phil Morrison? You know, he was of a generation of, let me put it this way, Phil was stooped in stature, but he was a giant among humans. And the giants that came out of the World War II experience,

the ones I know, of course, the scientists, people like Ed Purcell, Norman Ramsey, Vicky Weisskopf, Oppenheimer, and Morrison. Something about that experience of working together in that intense effort at a critical time for the world made those people giants. I don't know if I see anyone on the horizon like Phil Morrison. Now, to answer your question about the optical study. Very quickly, I'm afraid. Yeah.

We've looked at 15,000 observations. We've looked at 5,000 stars. We are joined with Princeton in this effort. We have found no simultaneous pulse from the two observatories, and we published this in a paper in the APJ in last autumn, October of 2004. And we are now getting ready to launch an all-sky rather than a targeted search

to look at the entire northern sky, and we expect to have this running before the year's end. Paul, can we indeed have you on again soon to give us a little fuller explanation of what you're up to there at Harvard as the search for extraterrestrial intelligence continues? I'd be happy to do so as long as it's not past midnight my time, which I get very stupid. We'll avoid that, I promise. Paul Horowitz is Professor of Physics and Professor of

Electrical Engineering at Harvard University. Also the author of a classic in the field, The Art of Electronics. Bruce Murray is a co-founder and former Chairman of the Planetary Society, Professor Emeritus of Planetary Science and Geology at Caltech, also the former head of the Jet Propulsion Laboratory.

Bruce, I want to thank you as well for joining us today. It's been a pleasure. And we will be back with Bruce Betts and What's Up right after this return visit from Emily. I'm Emily Lakdawalla back with Q&A. The fantastic light shows of polar aurora aren't just confined to the Earth. In fact, any planet with an atmosphere and a magnetic field has an aurora. Mars and Venus have atmospheres but no magnetic field, and for Mercury it's the other way around, so the Earth's is the only aurora in the inner solar system. Beyond Mars, though, there's plenty of activity. The aurorae on Jupiter

and Saturn are particularly spectacular, though their activity is most visible in ultraviolet, not visible light. Aurori have been observed on the planets Uranus and Neptune, and also the moons Titan and Triton. Aurori have even been observed on Io, which has no permanent atmosphere. Its frequent volcanic eruptions can create a temporary atmosphere, which means that an observer braving the violent environment on Io could sometimes see auroral lights all the way down to the ground. Got a question about the universe? Send it to us at planetaryradio at planetary.org.

And now here's Matt with more Planetary Radio. Time for What's Up on Planetary Radio. Dr. Bruce Betts is here. He's the director of projects for the Planetary Society, and he joins us every week. Don't eat that microphone. I'm hungry. Just say hi. You can eat right after this.

All right. Hi, everyone. What's up, Bruce? What's exciting is our big, bright friend Venus is is back playing with us in the evening sky. It's up just for a little while right after the sun sets, but it's so darn bright you'll still be able to see it in the west or west-southwest, looking like an extremely bright star-like object. It will keep getting higher as the weeks progress after sunset. Jupiter, looking extremely bright as well but not as bright, will be in the southeast at dusk and headed up towards the south as the month goes along in the evening sky. And Saturn still hanging with us for another month or two.

Low in the west also in the evening sky, though not as low as Venus. But looking kind of yellowish and fun to look at through a telescope. And it is going away in the next couple of months. So if you get a chance, take a look at it. In the pre-dawn sky, you can see Mars. Mars up there in the southeast looking kind of yellowish-reddish in the pre-dawn sky. We've got something coming up. Just give people a heads up.

In late May, May 23rd and 24th, at least as seen from some parts of the globe, the moon occults Scorpius's bright star Antares, which is a beautiful red star, and the moon passes in front of it, and you can see it disappear and then reappear again. So that's something you can find more information out there on the web if you look for star occultations, but that's May 23rd and 24th. This week in space history, on May 5th, 1961, Alan Shepard became the first american in space on his

suborbital flight moving on to random space facts neutrinos i love neutrinos me too they're so weird right now coursing through your body matt and everyone else listening to this, are tens of billions, if not hundreds of billions of neutrinos. But wait, per second. These are these weird, weird, weird subatomic particles that do not interact with stuff. They do not like to play with, they do not play well with others. So they just course through your body. Most of them are coming from the sun. The sun puts these bad boys out.

And they have been crucial to our understanding of the deep interior of the sun and such things. But we don't have time for more of that. But the random space fact for today, right now, there are billions of these suckers going through you. And I also mentioned one other point, a strange point I had from an astrophysics professor at Stanford, which was that on average, even with these billions per second, your body will absorb or even just scatter one neutrino in your entire lifetime. He pointed out that you also die only one time in your lifetime. Coincidence?

You be the judge. Death by neutrino. On to our trivia contest. Neutrino. On to our trivia contest. We asked you, what was the last of the robotic surveyor series that explored the moon prior to Apollo for the United States? How did we do, Matt? Tons, tons of entries. All of them correct.

I don't think anybody got it wrong. And a number of people who felt properly chastised by your trick question last week, they mostly loved that about the nine wheels and Lunok one. Lunok one. Lunokod one. Lunokod one, sorry. Another moon question this week. Yes, which means moon fish in Russian.

Is that true? No, not at all. You had me going there. That would be Lunokod. Yeah. Yeah. Okay. That was the joke.

I get it. Jeffrey Williams, he not only sent us the correct answer, he is not the winner this week, I'm afraid. He didn't send us his address, but look at this. He sent us a whole table describing all of the Surveyor missions. So thank you for that, Jeffrey. It made for interesting reading. But here's our winner, Maurice Sluka, longtime listener, longtime entrant in the space trivia contest here on What's Up. Maurice said Surveyor 7 landed January 10, 1968 at Tycho Crater.

Maurice wrote to us from Prince George, British Columbia, and that is where we will be sending not a Planetary Radio t-shirt, but one of those lovely solar sail posters. Congratulations, Maurice. Radio t-shirt, but one of those lovely solar sail posters. Congratulations, Maurice. Indeed. Commemorating the upcoming Planetary Society Cosmos 1 solar

sail mission, coming soon to a planet near you. Find out more at planetary.org slash solar sail. But in the meantime, answer the following trivia contest so you can win a beautiful Cosmos 1 solar sail poster. Back on neutrinos, what are the three flavors of neutrinos?

Vanilla, chocolate, and strawberry. Oh, God, now I've come up with a new question. I'm sorry. I do that now and then. I just forget myself. Okay. See if you can come up with three other flavors. Now, there's three different types of neutrinos.

What are they called? Go to planetary.org slash radio to find out how to email us your answer and win in our fabulous contest. Neapolitan neutrinos. Get those entries into us by May 9, May 9, 2 p.m. Pacific time. And you will be entered in this latest space trivia contest on WhatsApp. I always try to kind of separate off the strawberry neutrinos. I know.

Nobody likes them. No one likes them. They're probably the ones that killos. It just doesn't work for me mixed in. Nobody likes them. No one likes them. They're probably the ones that kill you. Just out of spite. Is there anything else we should know about before we say goodbye? Yes, there is. We have a new contest here at the Planetary Society, the Great Comet Crater Contest,

Deep Impact Spacecraft. NASA's Deep Impact will slam an 800-pound ball of copper into Comet Tempel 1 on July 3rd or 4th, depending on your time zone. We ask you to guess how big the crater will be formed by the impactor, and we have lots of information for you that will help you make an intelligent, educated guess, or you can just guess randomly. In any case, go to planetary.org, and you'll find a link to enter our comet contest and

we've got prizes for that. The big grand prizes are actually pieces of the material they made the spacecraft from, engraved with spiffy stuff. That's fun. So just go to the website and check it out. Bigger than a bread box is probably a legal entry, but not a very

smart one. Well, strangely, we ask for entries in meters. But if you want to convert, that's fine. I suppose it would be about one. Say goodnight, Bruce. Goodnight, Bruce. Thank you, everyone. Go out there, look up at the night sky, and think about the nature of light.

Thank you, and goodnight. Bruce Betts. He's the director of projects for the Planetary Society. He shines a light on us every week right here on What's Up. Next week we'll salute the passing of Star Trek Enterprise as the series sails off into an interstellar sunset.

Planetary Radio is a production of the Planetary Society. Write to us at planetaryradio at planetary.org. Have a great week, everyone.