by Gregory Benford (Centauri Dreams note: Gregory Benford was kind enough to send along the following, which is the text of a speech he delivered at the Advanced Space Propulsion Conference in Aosta, Italy last June. A modified version of this talk is to appear shortly in the Journal of the British Interplanetary Society. Dr. Benford's extraordinary career as physicist and science fiction author needs no introduction here, but Centauri Dreams readers are also urged to have a look at his new Benford & Rose Web site, written in collaboration with UC-Irvine professor of ecology and evolutionary biology Michael R. Rose. Herewith Dr. Benford's thoughts on space exploration as human imperative). There are three forms of chimpanzees: the common chimp, the bonobo, and us. We are the only chimp who got out of Africa. That experience reflects and probably laid down the deep human urge—indeed, our signature: the urge to restlessly move on, explore, exploit. Natural selection gives us a...

"A manuscript I wrote on January 14, 1918 ... and deposited in a friend's safe ... speculated as to the last migration of the human race, as consisting of a number of expeditions sent out into the regions of thickly distributed stars, taking in a condensed form all the knowledge of the race, using either atomic energy or hydrogen, oxygen and solar energy... [It] was contained in an inner envelope which suggested that the writing inside should be read only by an optimist." -- Robert Goddard, "Material for an Autobiography," (1927), available in Pendray, G. E. and Goddard, E. C. (Eds.), The Papers of Robert H. Goddard (New York: McGraw Hill, 1970).

Is science fiction a predictive medium, or is it, as I have opined before in Centauri Dreams, a diagnostic form of writing, telling us more about the times we live in than any purported future it describes? The question is occasioned by SF writer and scholar James Gunn, whose essay "Tales from Tomorrow," available online and in the August/September issue of Science & Spirit, synopsizes the evolution of science fiction from Mary Wollstonecraft Shelley's attempt to "...unfold to the world the deepest mysteries of creation" to recent work like Greg Egan's Permutation City, where the mysteries of uploading human personalities into computers take center stage. Here Gunn discusses the development of the genre in the early magazines, as edited by Hugo Gernsback and the legendary John Campbell: While there were few science fiction books to speak of until 1946, what evolved through magazines like Gernsback's was a literature of ideas and, more important, a literature of change and...

"The space program stands with the cathedrals and pyramids as one of the great 'central projects' of history, epic social feats embodying the worldview of a culture and the spirit of an age. On the launch pads, the rockets point heavenward like Gothic spires. Searchlights intersect on a waiting ship to form a great candescent pyramid, ablaze on the black horizon like some alien encounter, radiating light to the heavens. To reach for the heavens seems almost the signature of the central project. The pyramid was called the 'stairway to heaven,' the cathedral the 'gate of heaven.' The archetype is in Genesis: 'let us build us a city and a tower, whose top may reach unto heaven.' "Literature on the pyramids, cathedrals and moon shots has tended to miss the significance not only of great height as the signal feature of central projects, but also their function as means through which whole cultures have found symbolic expression. Writers often pay lip service to the official rationales --...

The possible asteroid belt around the star HD69830, covered here in a recent entry, caused several days of pondering and a scouring of the Centauri Dreams library. This exoplanetary belt seems to be 25 times as dense as our own, and as close to its parent star as the orbit of Venus is to ours. That would make for an unforgettable celestial display every night, a belt of light cutting across the sky. The idea of a 'ringed star' finally drew forth the memory: an old Murray Leinster story called "Proxima Centauri." Published in the March 1935 issue of Astounding Stories (an issue in which future Astounding editor John Campbell would have two stories, one of them under his pseudonym Don A. Stuart), "Proxima Centauri" tells the story of the Adastra, a vast starship a mile in diameter as it makes the first interstellar crossing. Ahead in the viewfinders, Proxima Centauri reveals itself to be surrounded by a glowing ring that comes into view long before the planets in the Proxima system....

"From time to time, alarm has been expressed at the danger of a 'sensory deprivation' in space. Astronauts on long journeys, it has been suggested, will suffer the symptoms that afflict men who are cut off from their environment by being shut up in darkened, soundproofed rooms. "I would reverse this argument: our culture will suffer from sensory deprivation if it does not go into space. There is striking evidence of this in what has already happened to the astronomers and physicists. As soon as they were able to rise above the atmosphere, a new and often surprising universe was opened up to them, far richer and more complex than had ever been suspected from ground observations. Even the most enthusiastic proponents of space research never imagined just how valuable satellites would actually turn out to be, and there is a profound symbolism in this. "But the facts and statistics of science, priceless as they are, tell only a part of the story. Across the seas of space lie the new raw...

The death of Hans Bethe has been covered by the media worldwide, and William J. Broad's obituary in the New York Times seems among the most thorough and accurate of the accounts of his life. But to me, Bethe will always be seen through Richard Feynman's eyes, and I think Broad misses the point of the one Feynman anecdote he tells. Feynman first worked with Bethe at Los Alamos during the days of the Manhattan Project, and he recalls the physicist's openness to debate, and his focus on the issue at hand rather than personality. Here, Feynman has just arrived in Los Alamos, and work had just begun, as told in the wonderful Surely You're Joking, Mr. Feynman! (New York: W.W. Norton, 1984): "Every day I would study and read, study and read. It was a very hectic time. But I had some luck. All the big shots except for Hans Bethe happened to be away at the time, and what Bethe needed was someone to talk to, to push his ideas against. Well, he comes in to this little squirt in an office and...

It seems fitting that the crater named Parsons is on the Moon's dark side. It's named after John W. Parsons, a youthful rocket builder who joined Texan Frank Malina in the early experiments that would lead to the creation of the Jet Propulsion Laboratory. Parsons, Malina and a childhood friend named Ed Forman patched together equipment from junkyards and at one point tried to script a movie about going to the Moon, hoping that selling it to Hollywood would fund their idea of launching a rocket to Earth's upper atmosphere. The three formed the Rocket Research Group at the Guggenheim Aeronautical Laboratory at Caltech, where Theodore von Kármán, the Laboratory's director, gave them lab space and campus equipment to pursue their dreams. This was back in the 1930's, when the group's rocket motors were being tested at the Arroyo Seco near Pasadena. Around that time, Chinese graduate student Tsien Hsue-shen (who would go on to become the father of Chinese rocketry) joined the team,...

Be aware of Time Bandits, an article by Jim Holt in the March 2 New Yorker, which studies the relationship between Albert Einstein and mathematician Kurt Gödel, now best known for his incompleteness theorems. The first of these, as Holt writes, "...demonstrates that no logical system can capture all the truths of mathematics." Here's a sample from this fascinating piece, discussing what happened when Gödel took on the relationship of space and time: What Gödel found was the possibility of a hitherto unimaginable kind of universe. The equations of general relativity can be solved in a variety of ways. Each solution is, in effect, a model of how the universe might be. Einstein, who believed on philosophical grounds that the universe was eternal and unchanging, had tinkered with his equations so that they would yield such a model—a move he later called "my greatest blunder." Another physicist (a Jesuit priest, as it happens) found a solution corresponding to an expanding universe...

How do we create our image of other worlds? The obvious answer -- through instrumentation on space probes -- is inadequate, because the raw data sent back by our spacecraft has to be assembled into the final images we see. Consider Hubble, which uses filters recording different wavelengths of light, and then combines them to create the image. Nor do we need confine ourselves to visible light, since we also get images in the infrared, and views filtered in whatever way will maximize science, like some of Cassini's radar images of Titan. Instead of just seeing an image, we assemble it. What you would see if you were actually there, in other words, isn't necessarily what you get. I notice that Elizabeth Kessler, a doctoral student in the University of Chicago's Committee on the History of Culture, has presented her work on Hubble and artistry at the annual meeting of the American Association for the Advancement of Science in Washington. The title of her talk, "Hubble's Vision: Imaging,...