Centauri Dreams
Imagining and Planning Interstellar Exploration
Interstellar Flight Goes Mainstream
Paging back through Kelvin Long’s book Deep Space Propulsion (Springer, 2011) last night, I was reminded that Freeman Dyson had written about his disillusionment with nuclear pulse propulsion methods long after Project Orion was terminated. The passage is in his autobiographical account Disturbing the Universe (Basic, 1981), which caught Long’s attention and led him to reprint it. Here’s a snippet of Dyson’s reflections:
Sometimes I am asked by friends who shared the joys and sorrows of Orion whether I would revise the project if by some miracle the necessary funds were suddenly to become available. The answer is an emphatic no… By its very nature, the Orion ship is a filthy creature and leaves its radioactive mess behind it wherever it goes… Many things that were acceptable in 1958 are no longer acceptable today. My own standards have changed, too. History has passed Orion by. There will be no going back.
Long speculates that Dyson may simply have been referring to Orion as an Earth-launch vehicle, leaving open options for construction and deployment in deep space, but my own sense is that the passage above means just what it says. When I interviewed Dyson for Centauri Dreams (the book) back in 2003, he made it abundantly clear that he considered the matter closed. He criticized nuclear methods because they could use no more than one percent of the mass with any nuclear reaction, and said he was much more enthusiastic about laser and microwave beaming and pellet propulsion concepts like those first developed by Clifford Singer back in the ‘70s and later expanded significantly by Gerald Nordley.
Interstellar Flight in the Public Eye
Long covers the Orion concept in detail as well as Medusa, a remarkable attempt to fuse pulsed propulsion with sail technologies (we need to talk more about Medusa soon). But I was really digging into his book in relation to Robert Bussard, whose 1960 paper “Galactic Matter and Interstellar Flight” (citation below) is in my view the real marker for the emergence of interstellar studies. To be sure, there were key papers before this, including the significant contributions of Leslie Shepherd and Eugen Sänger, both of whom I want to talk about in coming days. But what you get with Bussard is an idea published in an academic journal that is found and brought emphatically into the public consciousness in ways that transform public thinking.
If the beauty of beamed propulsion is that it removes the need to carry huge stores of propellant, the advantage of Bussard’s ramjet concept was that it harvested what it needed from the medium. Bussard announced his intention to speed up interstellar travel times enormously:
… by abandoning the interstellar rocket entirely, turning to the concept of an interstellar vehicle which does not carry any of the nuclear fuel or propellant mass needed for propulsion, but makes use of the matter spread diffusely throughout our galaxy for these purposes. By rough analogy with its atmospheric counterpart we call this an interstellar ramjet. Other possible types might include, vehicles which carry all of the nuclear fuel on board and only use swept-up galactic matter as inert diluent added to the propellant stream analogous to the operation of ducted rockets in atmospheric ?ight and all variations between these two extremes. Study of the performance of these fuel-carrying vehicles is deferred to a future paper.
To my knowledge, Bussard never wrote this future paper — if I’m wrong about that, I hope someone will correct me. His ideas, of course, generated an influx of new concepts tweaking the ramjet and taking the idea of matter collection in deep space in entirely new directions.
We’ve looked at problems with the original Bussard design in these pages before, focusing especially on the proton/proton fusion reaction and the power needed to exploit it. A number of theorists have suggested workarounds, including Centauri Dreams regular Al Jackson, who in several papers explored a laser-powered ramjet design that I want to talk about next week. For today, though, the focus is on reaction to the Bussard paper of 1960, for it was quickly seized upon by science fiction writers and scientists alike. The book Intelligent Life in the Universe, co-authored by Carl Sagan and Iosif S. Shklovskii, focused on time dilation at relativistic velocities and the way to the stars seemed to open.
Time Dilation Takes Center Stage
Intelligent Life in the Universe came out in 1966, a greatly expanded version of Shklovskii’s original Russian text of 1962. It is the coupling of relativistic time dilation and the Bussard ramjet idea that seized the imagination of science fiction writers. Sagan and Shklovskii could show that at an acceleration of 1 g, only a few years (ship-time) is required to reach the nearest stars, while (as experienced again aboard the ship) only 21 years takes you to the galactic center, and 28 years to the Andromeda galaxy. There being no time dilation on the home planet, the elapsed time there as the star mission proceeds, for distances beyond about 10 light years, roughly equals the distance of the destination in light years. In other words:
…for a round-trip with a several-year stopover to the nearest stars, the elapsed time on Earth would be a few decades; to Deneb, a few centuries; to the Vela cloud complex, a few millennia; to the Galactic center, a few tens of thousands of years; to M 31, the great galaxy in Andromeda, a few million years; to the Virgo cluster of galaxies, a few tens of millions of years; and to the immensely distant Coma cluster of galaxies, a few hundreds of millions of years. Nevertheless, each of these enormous journeys could be performed within the lifetimes of a human crew, because of time dilation on board the spacecraft.
Einsteinian time dilation had been considered long before this, of course, and it shows up in science fiction in early stories like Robert H. Wilson’s “Out Around Rigel,” which ran in Astounding Stories in December of 1931. But when Sagan and Shklovskii combined time dilation with a serious discussion of communications between galactic civilizations as enabled by Bussard-style ramjets, the notion went from utterly theoretical to a matter that mixed science with engineering. Bussard’s ideas went on to inspire a wave of ramjet-related studies, as we’ve already seen, and also inadvertently triggered the study of magnetic sails as braking devices.
Image: The Bussard ramjet, which opened serious speculation about attaining speeds close to c. Credit: Adrian Mann.
The Ramjet in Science Fiction
Meanwhile, we can think about the later science fiction that flowed from the Bussard ramjet. I usually cite Poul Anderson’s Tau Zero in that regard, a 1970 novel that grew out of a 1967 short story (“To Outlive Eternity,” which ran in Galaxy a year after Sagan and Shklovskii). But we can add to Anderson’s tale of a runaway starship the work of Larry Niven, who described Bussard vessels in his 1976 novel A World Out of Time:
The starships were Bussard ramjets. They caught interstellar hydrogen in immaterial nets of electromagnetic force, compressed and guided it into a ring of pinched force fields, and there burned it in fusion fire. Potentially there was no limit at all on the speed of a Bussard ramjet. The ships were enormously powerful, enormously complex, enormously expensive.
I pulled this quote from Technovelgy.com, which routinely looks at the intersection of science and science fiction. The first part of Niven’s novel appeared in Galaxy in 1971 as a short story called “Rammer,” another indication that Bussard’s notions were quickly embraced. Gregory Benford uses a greatly modified Bussard design in his Galactic Center novels, dodging the proton-proton fusion problem in well-vetted ways we’ll discuss next week. Sagan went on to refer to the ramjet in the popular television series Cosmos and the book that accompanied it, but the ultimate sign of Bussard’s ideas reaching full public awareness may have been the ‘Bussard collector’ used in the Star Trek universe as part of StarFleet’s propulsion paraphernalia.
It could be argued that much was coming together anyway by the early 1960s, and two years after Bussard described the ramjet, Robert Forward would put the idea of a laser-propelled lightsail into the public consciousness in an article in Missiles and Rockets. But I’ll give the nod to Robert Bussard, with a major assist from Sagan and Shklovskii, for turning the interstellar idea into public currency by suggesting that although the engineering was far beyond our skills, the basic physics did not rule out human travel to the stars. And if you’re a science fiction writer with a need to get around the galaxy quickly, Bussard will always be a contender.
The Bussard paper is “Galactic Matter and Interstellar Flight,” Astronautica Acta Vol. 6 (1960), pp. 179–94 (available online).
An Interstellar Provocation
It had never occurred to me that there was something the Graf Zeppelin and the Saturn V had in common. Nonetheless, a re-reading of Freeman Dyson’s paper “Interstellar Transport” confirms the obvious connection: Like the great airships of the 1930s, the Saturn V was huge and carried a payload that was absurdly small. Dyson, writing in 1968 fresh off the end of Project Orion, the rise of Apollo, and the triumph of chemical propulsion, had thought at one time that the US could bypass the Saturn V and its ilk, offering a fast track to the planets at a fraction of Apollo’s cost. The Atmospheric Test Ban Treaty of 1963 was a major factor in putting an end to that speculation.
I mentioned yesterday that I thought Dyson set about to be deliberately provocative in this piece, that he hoped to reach people who would have been unaware that interstellar distances could conceivably be crossed (thus his choice of Physics Today as his venue). To do that, he had to show that even reaching the Moon was a stretch for chemical methods, which he characterized as “…not bad for pottering around near the Earth, but… very uneconomic for anything beyond that.” While an Apollo mission to the Moon demanded staging and a huge mass ratio, an Orion vessel was built with only one stage, its mass ratio well under 10 even for long journeys out and around the Solar System.
Image: Dyson’s largest concept, a ‘super-Orion’ carrying colonists on an 1800 year journey. Credit: Adrian Mann.
Orion could have managed this because the exhaust velocity of the debris from its nuclear explosions would be in the thousands of kilometers per second range instead of what the chemical rocket could offer with its paltry 3 kilometers per second. Dyson assumed the use of hydrogen bombs (“the only way we know to burn the cheapest fuel we have, deuterium”) and a conservative energy yield of one megaton per ton, going on to say this:
These numbers represent the absolute lower limit of what could be done with our present resources and technology if we were forced by some astronomical catastrophe to send a Noah’s ark out of the wreckage of the solar system. With about 1 Gross National Product we could send a payload of a few million tons (for example a small town like Princeton with about 20,000 people) on a trip at about 1000 km/sec or 1 parsec per 1000 years. As a voyage of colonization a trip as slow as this does not make much sense on a human time scale. A nonhuman species, longer lived or accustomed to thinking in terms of millenia rather than years, might find the conditions acceptable.
Anyone who has spent time in the absurdly pretty town of Princeton NJ, where Dyson has lived for years while pursuing his work at the Institute for Advanced Studies, knows why he coupled a familiar scene with something as joltingly unfamiliar as a starship. The choice is reflective of his method: Dyson expresses the results of his calculations in tableaux that are both publicly accessible and mind-jarring, as a look through almost any of his books will demonstrate (think, for example, of his idea of a life-form that might poke out from an inner sea onto the surface ice of a Kuiper Belt object, a kelp-like, mirrored being he christened a ‘sunflower’). Root one end of an idea in the everyday, the other in a mind-bending direction, and you make your point memorable, which is one reason Dyson has inspired so many young people to be scientists.
Remember, the intent here was to get the Orion idea into the public discussion, along with an interstellar implication that Orion’s original designers had never built into their thinking. Dyson always knew that if you put the idea out there, the next step is to get to work on the specifics, detail after patient detail, work that on the interstellar level would presumably involve many generations. When remembering Dyson’s involvement with Project Orion, I think about something he once told Stewart Brand (in a Wired interview):
You can’t possibly get a good technology going without an enormous number of failures. It’s a universal rule. If you look at bicycles, there were thousands of weird models built and tried before they found the one that really worked. You could never design a bicycle theoretically. Even now, after we’ve been building them for 100 years, it’s very difficult to understand just why a bicycle works—it’s even difficult to formulate it as a mathematical problem. But just by trial and error, we found out how to do it, and the error was essential.
It’s the same method we would have used for Orion if the project had proceeded, but the number of factors working against it proved insurmountable, and here one of Dyson’s greatest strengths — his ability to engage the public — was running up against a growing public distrust of nuclear technologies. But the point is that theory always couples with engineering practice, hammering on a problem until the best solution is reached. Unless, of course, the kind of bureaucracy that Dyson so disliked steps in to muzzle the research early on. A bit of that dislike comes across in the conclusion of “Interstellar Transport,” as he ponders what a starship would achieve:
By the time the first interstellar colonists go out they will know a great deal that we do not know about the places to which they are going, about their own biological makeup, about the art of living in strange environments. They will certainly achieve two things at the end of their century-long voyages. One is assurance of the survival of the human species, assurance against even the worst imaginable of natural or manmade catastrophes that may overwhelm mankind within the solar system. The other is total independence from any possible interference by the home government. In my opinion these objectives would make such an enterprise worthwhile, and I am confident that it will appear even more worthwhile to the inhabitants of our overcrowded and vulnerable planet in the 22nd century.
Dyson looked at questions of cost and energy production and assumed a continued economic growth of what today seems like a sizzling 4% per year. Working out the cost of the Orion starship (he figured 1011 dollars), he concluded that such a mission would be as economically feasible in the future some 200 years off as a Saturn V was in 1968. We can argue about such numbers (and be sure to check the comments from yesterday, where a fruitful discussion on the implications of exponential economic growth is continuing) but I suspect they are the first instance of a methodical prediction on when starflight will occur that most readers of Physics Today had ever encountered.
The paper thus comes into focus as a landmark in introducing a pulsed fusion concept to a wide audience, explaining its deep space potential, and calculating when an interstellar future might be possible. I can see why Greg Matloff considers it a key factor in the growth of the interstellar movement because of its broad audience and energizing effect. But tomorrow I’ll make the case for a slightly earlier paper’s even more profound effect on the public perception of interstellar flight, one that has played into our media imaginings of traveling among the stars ever since its publication.
Dyson’s paper “Interstellar Transport,” ran in Physics Today October 1968, pp. 41-45, and is available online.
Beginnings of the Interstellar Idea
My time off last week really was refreshing, although it coincided with the same heat wave that has kept the Eastern US under duress for many days now, especially dangerous for those who lost power because of severe storms. Fortunately, I used part of my time to fly to San Jose to participate in Steve Durst’s Galaxy Forum (sponsored by the International Lunar Observatory Association), where I spoke on destinations in the outer Solar System and beyond as we make our first tentative steps into the galaxy. It was a good gathering, with lively talk from Seth Shostak, Jon Lomberg, Tony Cardoza (who signs people up to travel on future flights with Virgin Galactic), and Durst himself. It was also a pleasure to meet Centauri Dreams regular Alex Tolley. Blissfully, the temperatures never got out of the low 70s, with a refreshing breeze that made walking around downtown a pleasure.
Miles, my older son, lives near San Francisco and the trip was also a wonderful chance to reconnect. I can recall walking around the Air and Space Museum in Washington with him when he was just a boy, talking about the various planetary missions and speculating about what might come next. In our San Jose conversations, we talked about the attention now being paid to interstellar flight and what has changed over the years, ideas I reflected on while flying back to the East Coast. It’s really only been in the past 50 or 60 years that scientists and engineers have focused on the problems of interstellar flight, and even then mostly as extra projects in their spare time.
How exactly did the idea grow in the scientific community, and who were the early players? In an essay on fusion propulsion in the Johnson/McDevitt book Going Interstellar, Greg Matloff fixes on Freeman Dyson as a pioneer in what we could call the ‘interstellar movement.’ Dyson had been working with Ted Taylor on Project Orion, which saw its high-water mark in the early 1960s as a propulsion system that could take astronauts on interplanetary journeys, and do so not in the cramped quarters of an Apollo-style capsule but aboard a massive vehicle that could hold a crew of a hundred or more. Orion used the explosion of nuclear devices behind a massive pusher plate to drive the vehicle, ruling out launch from Earth, but there were serious studies of using Orion principles in a Saturn rocket upper-stage, a design that could not only reach Mars in about a month but could carry greenhouses, livestock and building materials.
Image: Freeman Dyson in earlier times, when Orion ideas were in the air and all things seemed possible. Credit: New York Times.
When the Atmospheric Test Ban Treaty (1963) made Orion obsolete, Dyson wanted to save the idea, fearing it would be buried in some government vault and never resurrected. Matloff sees a cunning strategy in what happened next:
Being a physicist, Dyson planned to publish a paper describing the potential of Orion in a journal. But most physics, astronomy, and astronautics journals have circulations of only a few thousand. He chose to publish in Physics Today, a semi-popular monthly organ of the American Institute of Physics. Many public and university libraries subscribe to this magazine — its monthly readership would therefore be much larger than that of more technical physics journals. Dyson planned a paper that would outline the concept of Orion in visionary terms, and do so in a manner that would not violate his oath of secrecy.
And there’s the key, to get the Orion idea out to the public, which Dyson could do by using openly available information, such as the publicly available yield in equivalent megatons of a deuterium-fueled thermonuclear explosive. Going on to develop the Orion idea, Dyson could show that a fusion-pulse ‘worldship’ could reach the nearest stars in approximately 1800 years, carrying a colony of 20,000 to settle on whatever new worlds would be found at destination. The Dyson colony ship had an acceleration time of 500 years, to be repeated in the deceleration phase, but a much leaner Orion-based design could reach velocities of 10,000 kilometers per second, arriving at the Alpha Centauri stars in a scant 130 years.
Image: An interplanetary Orion departs for Mars. Credit: Adrian Mann.
It was the decision to make the Orion concept visible that distinguished Dyson’s approach. He had labored in Bomber Command for the RAF during World War II, an experience that made him all too aware of how a sluggish bureaucracy can stifle creativity and prevent needed change. I believe that Dyson’s starship ideas were deliberately provocative as he attempted to spark interest in the general public in a propulsion scheme he saw primarily as an interplanetary technology — he would later come to see Orion’s demand for nuclear explosives as both dangerous and impractical. But the key was to get across the fact that working within the laws of physics, a craft could be designed that could, in theory, cross the interstellar divide.
Dyson’s paper “Interstellar Transport” ran in Physics Today in October of 1968 (pp. 41-45), and it’s still a classic of interstellar studies. Tomorrow I want to dig into it in a little more detail, as we’ve never really gone through it in these pages. But I don’t want to stop with Dyson. There are a number of scientists whose early contributions helped to launch this field. Some honed their skills on the intractable problems of power and distance in scientific journals, seeing where the equations led under a variety of novel propulsion schemes, while others saw their work transformed as it entered popular culture, an outcome that few could have anticipated. All of them transformed our thinking as interstellar flight began to be seen as a remote but real possibility.
Revealing The New Universe and a Shared Cosmology
By Larry Klaes
Larry Klaes, a frequent Centauri Dreams contributor and commenter, here looks at a new book that explores humanity’s place in the cosmos. Is there a way to rise above our differences of outlook and perspective to embrace a common view of the universe? The stakes are high, for technology’s swift pace puts the tools of exploration as well as destruction in our hands. C.P. Snow explored the gulf between science and literature 50 years ago, but as Larry notes, the division may be broader still as we confront the possibility of intelligent life other than ourselves.
Just about anyone who has even taken the time to go outside on a clear night and stare up at the starry firmament over their head (assuming it is also largely free of the relatively recent artificial impediment called light pollution) has often been moved in rather profound ways by the sight, whether they are astronomically inclined or not. This feeling can be summed up, I think, by this quote from the artist Vincent van Gogh: “When I have a terrible need of – shall I say the word – religion. Then I go out and paint the stars.”
The Universe – or, I should say, what we can see with unaided vision, which amounts to several thousand stars (including the Sun), the Moon, and a few neighboring planets as viewed from Earth – seems to have always evoked such “spiritual” thoughts and feelings since the time of our very distant ancestors: There is the plausible theory that some of the animal drawings found in many of the caves of prehistoric Europe actually represent star patterns. The heavens were where the most powerful gods resided, both visible and hidden. The skies were also home to what various cultures considered their best members, once they passed on from this life (usually their rulers and warriors).
Then science came along and did its level best to end all this superstitious nonsense.
Oh, it all started out innocently enough. Some ancient Greek thinkers like Thales of Miletus simply removed the supernatural elements from the natural explanations for the nature of the world. Others like Democritus considered all gods to be the products of limited and flawed human imaginations and that only “atoms and the void” made up the real Universe. One man named Aristarchus of Samos went as far to say that Earth was a mere planet circling the Sun, which was just one of those numerous points of light in the night sky.
However, the ideas of these guys never quite caught on with most of humanity, which needed to know in their hearts that not only were they more than just a temporary collection of elements, but that someone or something out there considered them to be very special despite their often very obvious limitations and flaws. Thus for most of the next few thousand years, the West stuck largely with religion for their comforting answers, which did not have and often even rejected any solid evidence for the proof of its legitimacy.
Things started to really get torn apart culturally when the Renaissance and the Enlightenment came along. The turning point for this change is often cited as the day that the Roman Catholic Church told the Italian astronomer Galileo Galilei to stop supporting the ideas of one Nicholas Copernicus (who was influenced by the aforementioned Aristarchus) and anything else that seemed to contradict what was written in the Bible – or else.
Although Galileo essentially complied with the Church authorities, the ball named science began to really get rolling after this event and gained speed in the following centuries. Among those who did the most to solidify science as the main way to view the Cosmos in those early days of the so-called modern era was Sir Isaac Newton, who showed that it was gravity which kept Earth orbiting the Sun rather than fly off into the void and not bands of angels pushing our planet around our star via God’s Will.
Ironically, Newton was also a devout Christian who intensely studied the Bible to determine, among other things, that the world would come to an end in the year 2060. This was not terribly strange, however, as most scholars of his time and place did not see a division between science and religion; they assumed that God had made the Universe and science was the divinely inspired way for humanity to learn how He did it.
Eventually, though, as science and technology gained a stronger footing in civilization, the division between empirical and spiritual knowledge grew to the point that even today, the general public tends to feel torn and alienated by the perceived coldness and fact-only basis of science and the emotion-based ideas of religion and spirituality. Many folks often end up choosing one viewpoint or the other, conflicting with the other side and their own thoughts and feelings in the process. The results are a current society that is a living paradox, one that has a firmer grasp on how the Universe began than before along with the tools required to make this possible, while at the same time remaining focused on our home world, our baser immediate needs, and holding onto beliefs which our ancient forbearers would still recognize.
Can the two sides be reconciled before our society is presumably wrecked by the cultural clash, and if so, how?
In 2011, Yale University Press released a book titled The New Universe and the Human Future: How a Shared Cosmology Could Transform the World. The authors of this work are Nancy Ellen Abrams and Joel R. Primack, both professors at the University of California, Santa Cruz, who also happen to be a married couple.
As the subtitle of their work states, Abrams and Primack think that a “shared cosmology” could break this conflict our species is currently in: If we would all just agree on the origin and composition of the Cosmos as stated by modern science, and especially our place in it all, we will not only save ourselves but become truly universal beings with unlimited horizons and a renewed and vibrant sense of being, one that van Gogh with his need for religion via the celestial realm might have found comforting.
Image: The Carina Nebula in visible light. Credit: NASA.
So, do the authors have The Answer to Life, the Universe, and Everything Else? Well… like the world in which we reside, the results are at once both clear and more complex than a single resolution can provide.
The core of the concern held by Abrams and Primack – that industrial humanity has gotten away from its original ancestral views of the heavens and needs to reconnect with its cultural roots in order to truly make it in the Universe – is one I have long agreed with. Science via technology may know far more about the true makeup and actions of the stars and other worlds in space than our ancestors could even imagine, but modern civilization and its various trappings have also made many of us less aware of what goes on in the sky than our forbearers.
This disconnect has brought us to a strange state where we have the knowledge and ability to literally reach the stars, yet only a fraction of the resources and funding from our civilization goes to space exploration and science education. This has also led us to still act as if Earth is the focal point of existence and will somehow continue to sustain humanity even as we are now over seven billion in number and climbing literally every second. In essence, many individuals are intellectually aware of our true place in the Cosmos, but culturally we are still in the huts and caves, distracted into thinking otherwise by the smooth surfaces and shiny toys in those dwellings.
With The New Universe, Abrams and Primack make a mighty and interesting intellectual effort to explain our long history with the Cosmos and reconnect us with the heavens through modern science with some religious symbolism and ideas that simultaneously try not to turn science into yet another religion in the process. This effort is an outgrowth of their earlier collaborative book, The View from the Center: Discovering Our Extraordinary Place in the Cosmos (Riverhead Books, New York, 2006), and based on their participation in the Terry Lecture Series at Yale University in October of 2009.
The authors recognize that for as much as we have evolved in knowledge and technology since first emerging from the trees and savannahs several million years ago, our biology is still deeply connected to those tribal ancestors rooted in small communities and seeing the world as both infused and controlled by the supernatural.
We are still very much social animals, loyal to the views and beliefs of our groups, which vary across the planet. Abrams and Primack not only want to unite these disparate views through modern cosmology – the Universe started with the Big Bang, almost all of the Cosmos is composed of Dark Matter and Dark Energy – but they want it done NOW.
Their urgency comes from the view that the Twenty-First Century is a pivotal point in human history. We have the comprehension and the ability to know how existence really works and the means to lift ourselves out of the tribal mindset that is eating away at our planet’s resources and wrecking Earth’s environment. However, we only have so long to use our modern skills and tools before civilization loses its literal and collective fuel along with its focus, falling into a Dark Age that our descendants may never truly recover from. Or perhaps we may even drop all the way to the extinction of our species, taking many other living residents of this planet along with us.
I tend to agree with the authors of The New Universe that we are on the edge of either greatness or doom with our global society. I think that before the end of this century, humanity has to shed those ancient cultural and even instinctual views and behaviors which make us continue to act like we are still in little disconnected villages where the collective view of the world ends at our local horizons and warring on other groups will only have consequences for the enemy. We also need to be more aware of the potential threats from beyond Earth as well, such as from the planetoids and comets that wander out Sol system which could one day strike our world and cause devastation on a global scale.
This edge we are perched upon may not have enough leeway to allow us to wake up only when impending disaster appears. Would we be able to build a Worldship to conduct a celestial rescue of at least a portion of our species, for example, if most people remain ignorant of what is in the Universe and disconnected from it and have failed to support an infrastructure in space which would be required for the construction and operation of a giant vessel for carrying many humans safely across the Milky Way galaxy for thousands of years?
One beef I have with The New Universe is their attitude towards extraterrestrial life, especially the intelligent kind. It is clear that Abrams and Primack are in the camp that says Earth may harbor the only intelligent life in all of existence (or at least this Universe), although they throw in the word “possibly” and its proper variations each time the subject of its reality is mentioned. As with the Rare Earth folks, they too think that simple organisms may dwell on many worlds throughout space, but as life becomes more complex, so too the odds of it happening, until biological evolution comes to the human species, where the odds of making more than one version of us on another planet seem astronomical – or so they claim.
Image: Our place in the Universe. Credit: Yale University.
I get the distinct feeling that Abrams and Primack deliberately downplay the possibility for ETI to keep the focus on our species and civilization, which they already feel has had so many cosmic demotions in the last few centuries that the one which says we are just one of many intelligences in the Universe might somehow bring us down socially – despite the fact that the idea of aliens of all types has been an integral part of human society for generations now. While these fictional beings are often lacking in strong scientific integrity, they are part of our culture and they have created a level of cosmic awareness that likely did not exist in prehistoric times.
While it is true that we have no present scientific proof of extraterrestrial life and that any ETI which do exist are probably many light years from Earth, it does not help the cause of the authors to downgrade the possibility of life elsewhere, especially if they are serious about humanity becoming truly cosmically aware. The level of awareness they are asking for goes beyond just taking care of our planet. It means that our curiosity, drive, and even survival will cause us to move first beyond our home world and eventually our planetary system into the wider galaxy. Our knowledge of what exists among the 400 billion other star systems of the Milky Way contains many serious gaps, including the amount and types of alien life. ETI may or may not be an immediate concern for our species, but as students of the Universe, Abrams and Primack should know better than to dismiss something that could have a major effect on humanity in one form or another.
In regards to their views on ETI and the recent Centauri Dreams article on the hypothetical intelligence of stars, the authors discussed this subject and the possibility of galaxies and even the Universe as living entities in the FAQ chapter, which was clearly honed from the Q&A portions of their lectures and earlier book. Their answer is that galaxies are too large to be intelligent, in that it would take many thousands of years for the stars to communicate among themselves and millions of years for galaxies to talk to each other, assuming their thought waves or equivalents move no faster than light speed.
For those who wonder exactly who this book is for, the authors have said that it is essentially for everyone, while Primack also declared in one interview that The New Universe is aimed at the high school student both literally and intellectually. With the study of the heavens often being a great intellectual equalizer, educated folks of almost all ages who may be novices when it comes to astronomy and history – or who need some educational refreshers or just want our cosmological history presented in a concisely written package – will also find this work quite useful.
The fact that The New Universe is deliberately not some dry recitation of astronomy and history, makes a noble effort to reconcile the two cultures as defined by C. P. Snow, and implores its participants to care for our planetary home may ironically alienate some readers; however, the book’s title makes it clear up front what one is getting into, so the choice – just as it is with humanity when it comes to our place in the Cosmos – is ultimately yours.
The companion Web site for The New Universe, which includes among the information video presentations made specifically for the book, is here.
Summer Comes to Green Town
Summer in Green Town, Illinois back in 1928 opened like this:
“It was a quiet morning, the town covered over with darkness and at ease in bed. Summer gathered in the weather, the wind had the proper touch, the breathing of the world was long and warm and slow. You had only to rise, lean from your window, and know that this indeed was the first real time of freedom and living, this was the first morning of summer.”
Thus the beginning of Ray Bradbury’s Dandelion Wine, which I re-read not long after the author’s death. With catastrophic fires in the American west and triple-digit heat along the Atlantic seaboard, summer has indeed come, and so has a brief summer holiday for Centauri Dreams. Although I won’t have months ahead of me the way Bradbury’s character Douglas Spaulding did, I am looking forward to a week off. This site is now approaching its eighth anniversary and I’m ready for a break, one that will give me time to catch up on reading, do necessary work around the house, and take care of a couple of speaking engagements. I also plan to have some time to do nothing but put my feet up and relax.
“The bleak mansions across the town ravine opened baleful dragon eyes. Soon, in the morning avenues below, two old women would glide their electric Green Machine, waving at all the dogs. “Mr. Tridden, run to the carbarn!” Soon scatting hot blue sparks above it, the town trolley would sail the rivering brick streets.”
It’s not 1928 anymore, but Bradbury somehow makes that seem irrelevant. And although I’m certainly not twelve like Douglas Spaulding, a July morning with thunderstorms brewing takes me right back to how it felt. Expect the next Centauri Dreams post on July 9, one week from today. I’ll keep an eye on the site and will moderate comments when possible. Otherwise, for the next week I’ll be disappearing into Green Town. See you soon.
Private Funding for Asteroid Telescope
Asteroids are certainly having their moment in the press, what with the combined attention being paid first to Planetary Resources and its plans for asteroid mining, and now the B612 Foundation, with a plan that in some ways tracks the Planetary Resources model. As announced yesterday, B612 intends to build a space telescope using private funding and launch it into a Solar orbit, from which it can carry out discovery and mapping operations targeting asteroids that might pose a threat to the Earth. You’ll recall that Planetary Resources also has an ambitious agenda in terms of developing a series of small space telescopes.
NASA, it’s true, is already searching for Earth-crossing asteroids, and between ground-based efforts and space-borne missions like the Wide-Field Infrared Survey Explorer, thousands of asteroids that pass near the Earth have been discovered. But what the B612 Foundation is calling Sentinel will be dedicated to finding the smaller objects whose effect could still be catastrophic. I see that Ed Lu, a seasoned astronaut who is now chairman and CEO of the Foundation, has the most recent impact in mind when he describes the mission:
“The orbits of the inner solar system where Earth lies are populated with a half million asteroids larger than the one that struck Tunguska (June 30, 1908), and yet we’ve identified and mapped only about one percent of these asteroids to date. During its 5.5-year mission survey time, Sentinel will discover and track half a million Near Earth Asteroids, creating a dynamic map that will provide the blueprint for future exploration of our Solar System, while protecting the future of humanity on Earth.”
Image: Fallen trees at Tunguska, in a photo taken in 1927, long after the event. Credit: Wikimedia Commons.
Tunguska was, of course, a catastrophe we dodged, but only because it fell in a relatively unpopulated area of Siberia. Theories differ as to exactly what the object was, but whatever struck this remote region created the largest impact event in recorded history. The explosion knocked down trees over an area covering 2150 square kilometers. We can only imagine what would happen if an explosion of this size took place over a large metropolitan area.
Thus the 5.5-year mission of Sentinel, to be built by Ball Aerospace and the team behind the Spitzer and Kepler space telescopes. The plan is to catalog 90 percent of the asteroids larger than 140 meters, with the capability of discovering objects as small as 30 meters in diameter. As to Tunguska-sized objects (40-meters wide), B612 thinks it can find 50 percent of them.
The 1.5 ton telescope works in the infrared with a 50-centimeter mirror, with survey operations to scan the entire night half of the sky every 26 days to identify moving objects. Sentinel will orbit between Earth and Venus, scanning the skies near the Earth’s orbit with the Sun at its back. After a five year period of development and testing, launch aboard a SpaceX Falcon 9 is expected in 2017-2018.
Image: Projected orbit for Sentinel. Credit: B612 Foundation.
The man most identified with the B612 Foundation is Apollo 9 astronaut Rusty Schweickart, who founded it and now serves as chairman emeritus. Says Schweickart:
“For the first time in history, B612’s Sentinel Mission will create a comprehensive and dynamic map of the inner solar system in which we live – providing vital information about who we are, who are our neighbors, and where we are going. We will know which asteroids will pass close to Earth and when, and which, if any of these asteroids actually threaten to collide with Earth. The nice thing about asteroids is that once you’ve found them and once you have a good solid orbit on them you can predict a hundred years ahead of time whether there is a likelihood of an impact with the Earth.”
Even better is the fact that getting to a dangerous asteroid in plenty of time — a decade or more is preferable — leaves us with a variety of options for deflecting its course, something we’d have little time to manage in cases like that of the recent close pass by asteroid 2012 LZ1, which turned out to be fully a kilometer wide and made its approach scant days after its discovery. The more eyes on the sky the better, for the deflection options, studied by the B612 Foundation itself ever since its founding in 2002, include slow-acting trajectory changers like ‘gravity tractors,’ in which a spacecraft deflects the object using only its gravitational field as it orbits the asteroid.
What lightens the hearts of space enthusiasts is the fast pace of development for projects like these now that commercial launches are becoming a reality. Sentinel will be able to take advantage of advances in computing as well as our accumulated experience with infrared sensing, but it wouldn’t be in the cards if it weren’t for the launch capability provided by the Falcon 9. It also relies on the combined efforts of scientists, entrepreneurs and venture capitalists, along with the individual contributions needed to raise the several hundred million dollars needed. Speaking of which, the B612 Foundation donation page is open for business.
It’s interesting to put the fund-raising effort in the context of other attempts to fund major projects, as Ed Lu did when talking to Alan Boyle before the news conference announcing Sentinel in San Francisco. Boyle discussed the matter in his Cosmic Log column:
Lu pointed out that the estimated cost of the mission, amounting to a few hundred million dollars, was comparable to the cost of building a performing arts center, a museum, or a planetarium like the one where today’s briefing was being held. The San Francisco Museum of Modern Art, for example, has raised more than $437 million in its current capital campaign. “There are 50 to 100 projects larger than ours going on at any time in the United States, and nobody bats an eye,” he said.
And as Lu went on to recall, some of the observatories that are at the heart of astronomy’s history were built with private financing, including the Lick Observatory, the Keck Observatory and Palomar. The guess here, given our crowd-source mentality in a time of government cutbacks, is that the B612 Foundation will indeed raise enough money to fly this mission, serving as a precedent for other such efforts. The Planetary Society’s LightSail comes to mind, but private and commercial space efforts of all kinds are clearly on a fast upward trajectory.
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