Analog SFF, March 2008

by Dell Magazine Authors

  Did he have children?

  "Alas, no. A nephew. He works here sometimes.” Aaron sighed and offered me a seat at one of the beat-up tables lined down the middle of the bookstore. “My wife, blessed be her memory, died of the plague in ‘29. You heard of it? An awful time. My nephew will have this store when I join her. People will always need books."

  He chuckled and picked up a small battered disc from the floor. “Look at this! Cast aside and yet it holds someone's story. Some writer's hopes. Look! A romance, I think.” He studied the disc doubtfully. “I don't know if I have a reader that fits this anymore. It came from Earth with the first settlers. Do you think the one who wrote this ever dreamed it would travel to the stars and still be read so many years later?” Aaron smiled and carefully placed the possibly unusable disc on a shelf piled high with a variety of other e-books and data holders.

  He wasn't worried by the violence? One of the reasons our delegation was here was to try to broker a cease-fire, I explained. A few gestures of tolerance would deny the violent extremes of the Anubans most of their support.

  "Blessings on your task,” Aaron replied. “Worried? What can I do? I live with wisdom—” He waved at the books again. “—and am surrounded by human foolishness. Why would they hurt me? Who fears words?"

  I didn't see Aaron D'abu again for a couple of months, being engaged in fruitless negotiations with the government and those who claimed to represent the Anuban sect. Eventually I returned to Fraternity and stopped by the bookseller again. He greeted me as if we'd just parted yesterday and this time offered refreshment. “It did not go well?"

  No, I confessed, neither side wanted to be seen as giving in.

  "If my mother were here, she would speak with them. In my mother's time,” Aaron confided over a glass of hot, sweet tea, “the mayor of Fraternity was not a humble man. He thought himself wise above all, and criticism angered him. One day, his police came to this very shop and pointed to a new book, which mocked the mayor. Take it down, they said, or this shop will be closed."

  "'Why should I remove this book?’ my mother asked."

  "'It is not truthful,’ they told her."

  "'Should I take down the book next to it, then?’ my mother asked, which was a book saying good things about the mayor."

  "'No,’ they said, ‘for that book is truthful.’”

  "'But I must,’ my mother declared, ‘for the second book says the mayor is a fair and wise man, and such a man would not fear the words of those who disagree with him. If the mayor says I must hide such words, then the second book cannot be truthful, either.’”

  Aaron D'abu grinned at me. “The mayor's police argued, then called their supervisor, who called her supervisor, and so on. The next day the mayor himself came and sat here, at this very table, and drank tea with my mother. She told him of all this store held and he listened, and then he told his police to leave her alone, because he who does not fear the truth does not fear lies. That was my mother."

  He sighed and looked toward the back of the store. “She died there, seven years ago, among the words she treasured, taking inventory. It was as she wanted it. Her body was taken to the Garden of Memory, but her spirit remains here."

  Three months after that, occasional bombs were going off in Fraternity. Tensions kept rising, and both sides in the dispute were accusing us from Earth of favoring the other side instead of serving as honest brokers. A family had been massacred in a small town far to the north. Then two families in another town. Fighting began in Tvor City, radical Anubans striking and drawing retaliation against all Anubans, the radicals building support for themselves at the price of their own people's blood and the government hard-liners playing right into their hands.

  Wisdom seemed in short supply when I next visited Fraternity and sought out Aaron D'abu. There were fewer people on the street than I remembered, and Aaron seemed saddened. “Some people leave, others hide. They say the war is coming. I once told you of neighbors I had, good people. But they received threats. Death to Anubans. And they left, for their children's sake. I could not blame them."

  Had his business suffered?

  Aaron sighed heavily. “Business is not even as good as it was. Not like in the old days. People now say they are too busy for books. Too busy to read, while the world gallops toward the abyss! Perhaps the words of others would give them pause, make them think, give them new eyes to see all around them. Or maybe they fear all that and so avoid it."

  A sound of thunder rolled by and the shelves filled with books rattled slightly as if in momentary fright. The bookseller gazed out into the street, where a not-too-distant column of smoke could be seen rising over the buildings. “We came to this world, to this continent, to this city, to build things. And now too many just want to destroy what our mothers and fathers built. This will pass. I know it will. My books tell me it will. Another day will come.” Aaron grimaced. “My nephew has been drafted. He will fight. When he comes home, he has promised to come work here."

  Another few months and even the most optimistic among our delegation had to admit that we'd failed. Bombs were going off daily in cities and the death toll kept rising while both sides refused to compromise. Earth had no power to compel peace or reason, but was now being blamed in part for the ongoing violence, as if we could have somehow stopped what the people of this world seemed determined upon. We would leave and try to see what we could accomplish elsewhere.

  The decision was reached during a final meeting in Fraternity, so I resolved to say good-bye to Aaron D'abu before our delegation took its flight back to Bastet's spaceport the next morning. I'd finally buy some books from him, to help occupy the long trip to the next world on our schedule. As I walked toward the street on which his shop lay, I heard and felt and saw the explosion that rattled buildings all around me. Once I recovered, I started running, joining a crowd hastening to provide assistance.

  The oldest building in Fraternity was no more. Only rubble remained of the structure. From the size and shape of the crater before it, a vehicle loaded with explosives had been detonated in front of the building.

  I stumbled to a halt and stared at the devastation. Why?

  I must have said the question out loud, because a woman beside me shook her head. “The building belonged to a man who now commands an anti-Anuban militia.” She was crying, tears cutting paths through the bomb-birthed dust that had powdered her face. “Not ten minutes ago I came past here and greeted my friend Aaron. Have you ever noticed his bookstore?” I nodded. “All gone,” the woman mourned. “Aaron and all he treasured. And for what? Aaron had been threatened by some Anubans. I knew of it. They didn't like some of the books he sold, but Aaron wouldn't take anything off the shelves. But look where they put the bomb! They didn't even care the bookstore was there. They just wanted to destroy the building."

  And I truly didn't know at that moment which was worse: that people might deliberately destroy the bookshop of Aaron D'abu because they hated the ideas inside, or that they might heedlessly destroy it because they didn't care about the ideas it held.

  "It's a task of great honor, to sell books,” Aaron had once told me. “All of life, hope, death, and love is within my walls. It's a great responsibility, you know. We booksellers, we come and go. But the books, the ideas, those remain with us always for those who seek them."

  I left Bastet, wishing more people on that world had read the books that Aaron D'abu had once sold.

  Copyright (c) 2007 by John G. Hemry

  * * * *

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  Reader's Department: THE ALTERNATE VIEW: THERE'S A HOLE IN THE BOTTOM OF THE UNIVERSE! by John G. Cramer

  It's perhaps natural to think that our universe should be more or less the same in all directions, once we average out the lumpiness of stars, galaxies, galactic clusters, superclusters, etc. However, there's a growing body of evidence suggesting that this presumption is not true. There is now a strong suspicion that our universe may contain a gaping “hole” located in the constellation Eridanus. This all started several years ago with the observation that there was a pronounced “Cold Spot” in the data from the Wilkinson Microwave Anisotropy Probe (WMAP) that produced space-based measurements of the cosmic microwave background (CMB) left behind about 400,000 years after the Big Bang.

  * * * *

  Let's start by reviewing the cosmic microwave background. Shortly after the initial Big Bang, when fast exponential inflation had stopped, our universe settled down to a slower and steadier rate of expansion. As more space became available to hold the energy in it, the universe cooled to a nearly perfect “liquid plasma” saturated with energy, in which quarks and gluons behaved as free particles. As the cooling progressed, the gluons thinned out and the quarks clumped into composite mesons, protons, and neutrons. For some reason that remains obscure, there was a slight excess of protons and electrons over their antimatter equivalents (antiprotons and positrons). During the high-density stages of the early universe, nearly all of the antimatter particles paired off with their matter counterparts to annihilate, leaving behind the surviving matter particles and producing a universe populated almost exclusively by matter. The cooling universe was then a “soup” dominated by free electrons and protons. In this environment, a photon of light, strongly influenced by any encounter with a charged electron or proton, could travel only a short distance without being absorbed or scattered by one of the free charged particles. But as the cooling progressed, the negative electrons and positive protons tended to pair off to make electrically neutral hydrogen atoms. The free charged particles, which easily absorb photons, were replaced by light-transparent neutral atoms. The murky black “soup” of the early universe became crystal clear.

  The photons of the early universe had energies characteristic of the light emitted from a hot object (the universe) at a temperature of about 2,900 K. (Here, K means “kelvin” and specifies the absolute temperature in Celsius degrees above absolute zero.) As long as the universe was murky black, these photons were trapped by repeated emission and re-absorption. However, the transformation to a transparent universe released them from this trap, and they became free photons. These liberated photons have been traveling through the universe ever since, and we detect them today as the cosmic microwave background radiation. However, as the universe expands and space itself stretches, the wavelengths of these CMB photons also stretch until they are now microwave photons characteristic of a very cold object with a temperature of 2.73 K instead of visible light photons characteristic of a hot object with a temperature of 2,900 K. We observe these CMB photons today as microwaves emitted from a “surface” that has not existed for the last 13 billion years.

  There has been a recent flurry of activity to sweep the sky and map the CMB photon intensity vs. angular position on a fine scale. WMAP has produced such a mapping, producing an orange-tinged bluish map that has become well known in science articles and book cover art. In a localized area on the right and well below the map's center there is a particularly cold region, quite dark as compared to the blue, yellow, and orange regions of most of the rest of the map. This region is called the “WMAP Cold Spot,” and it lies in the river constellation Eridanus.

  When a feature like this is obvious to the naked eye, there is a fairly good chance that it is significant. The question that is raised is whether the Cold Spot is just an expected fluctuation in the intensity of the CMB, or whether it is non-statistical and might be an indication of something particularly interesting going on. The answer is that it is definitely not a simple statistical fluctuation. A group working the Physical Institute of Cantabria in Spain and at Purdue University has carefully analyzed the WMPA data and has concluded that the Cold Spot is not compatible with normal Gaussian fluctuations of the CMB.

  * * * *

  * * * *

  Recently two groups, one at the University of Minnesota and the other at Cavendish Labs in England and in Lausanne, Switzerland, have carefully examined the data from the National Radio Astronomy Very Large Array Sky Survey (NVSS), which looked at 82% of the sky visible from the VLA in New Mexico and catalogued more than 1.8 million individual radio sources. The groups studied this extragalactic survey, looking for structure at the Cold Spot location. Both groups have found a sizable dip in source population and radio brightness at just the location of the WMAP Cold Spot.

  The implication of these results is that the Cold Spot is not a characteristic of the CMB itself, but instead it is a phenomenon that happens as the CMB photons pass through the universe on the way to our detectors. The combined WMAP and NVSS data suggest that along the line of sight to the Cold Spot, there is an enormous volume containing almost no stars, galaxies, or gas. A physical process called the integrated Sachs-Wolfe Effect, the gravitational wavelength shift of photons as they pass through varying gravitational fields in an expanding universe, is probably responsible for the cold spot. As photons of light fall into the gravity well of a massive object like a galactic cluster, they gain energy and are blue-shifted. On emerging from the gravity well, such photons would lose the energy gained, except that, due to the accelerated expansion effect of the large quantity of dark energy in the universe, there is a net repulsion acting and it is a bit easier to get out of the gravity well, so that not all of the gained energy is removed. The net result is that CMP photons that pass through regions containing significant mass arrive at our detectors with a bit more energy on the average than those passing through regions of the universe that are relatively empty. Therefore, the CMB radiation should appear cooler along a line of sight passing through a large “empty” region. In effect, the CMB radiation is weighing the universe along the various lines of sight.

  Although sizable empty regions of the universe have been observed before in deep-sky surveys, the region that has produced the Cold Spot appears to be much larger. It appears to be an unusually large “supervoid,” perhaps 1,000 times larger than the largest empty regions previously detected. The Cold Spot Supervoid is estimated to be around six to ten billion light years from the Earth, at a red-shift factor of about z=1, and to have a diameter of around one billion light years. It is perhaps worth noting that no computer simulations of the formation and evolution of the universe have ever predicted a void of such a size.

  * * * *

  What could cause the Cold Spot Supervoid? I have not seen any speculations in the astrophysics literature as to its origin. The prevailing view seems to be that if it is there, then “it just happened."

  However, since this is a science-fiction magazine, let me indulge in a bit of SF related speculation. Some years ago I recall having a discussion about negative mass objects and cosmic voids with my good friend, the late Dr. Robert W. Forward. Bob Forward, for reasons that those familiar with his work will understand, was interested in the possibility that large concentrations of negative mass might exist in the universe. He noted that if there happened to be an object somewhere in the universe, perhaps a natural worm-hole mouth, that had a very large negative mass, then it would tend to repel all of the positive mass in the region, pushing it far away and sweeping out a large empty region in the universe.

  Since we now know about the dominant dark energy in the universe, we can now add to Bob Forward's speculation by noting that the integrated Sachs-Wolfe Effect would work backwards for photons that were climbing the gravity “mountain” of a negative mass objec
t (the inverse of a gravity well) and would cool the photons passing through a region dominated by negative mass.

  We have learned from general relativity that, given some quantity of negative mass, we could build space-time metrics that allow one to do all sorts of cool SF-related faster than light gymnastics. Therefore, if we need some negative mass to construct wormholes, warp drives, Krasnikov tubes, and so on (see earlier AV columns in this series), there is now a good place to look for it. Just get in your hypervelocity starship and head for the WMAP Cold Spot.

  Copyright (c) John G. Cramer

  AV Columns Online: Electronic reprints of about 140 “The Alternate View” columns by John G. Cramer, previously published in Analog, are available online at: www.npl.washington.edu/av.

  * * * *

  References:

  The WMAP Cold Spot:

  "Detection of non-Gaussian Spot in WMAP,” M. Cruz, E. Martinez-Gonzalez, P. Vielva, and L. Cayon, Mon.Not. Roy.Astron.Soc. 356 29-40 (2005), available online at www.arxiv.org/ PScache/astroph/pdf/0405/0405341v2.pdf

  "Extragalactic Radio Sources and the WMAP Cold Spot,” L. Rudnick, S. Brown, and L. R. Williams; Astrophysics Journal (2007, to be published); available online at www.arxiv.org/ pdf/0704.0908.

  "Probing dark energy with steerable wavelets through correlation of WMAP and NVSS local morphological measures,” J. D. McEwen, Y. Wiaux, M. P. Hobson, P. Vandergheynst, and A. N. Lasenby, 2007, submitted to Mon.Not.Roy.Astron.Soc. available online at www.arxiv.org/PScache/arxiv/pdf/0704/0704.0626v1.pdf

  Copyright (c) 2007 by John G. Cramer

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  Reader's Department: IN TIMES TO COME

  Not too many years ago we heard a lot of talk about “nuclear winter": the devastating global climate change that might follow a large-scale nuclear war. That talk largely died out with the collapse of the Soviet Union at the end of the 1980s, but recently a new concern has arisen: what aftereffects might we expect from a “small” nuclear war? The question is uncomfortably timely, with the proliferation of unpredictable powers too small to mount a “superpower” type of attack, but unpredictable and quite capable of mayhem on a lesser scale. The consequences are far from negligible, as Richard A. Lovett shows in next month's science fact article on “Nuclear Autumn."