''Probability Sun'' is a 2001

science fiction Science fiction (often shortened to sci-fi or abbreviated SF) is a genre of speculative fiction that deals with imaginative and futuristic concepts. These concepts may include information technology and robotics, biological manipulations, space ...

novel by American writer

Nancy Kress Nancy Anne Kress (born January 20, 1948) is an American science fiction writer. She began writing in 1976 but has achieved her greatest notice since the publication of her Hugo- and Nebula-winning novella '' Beggars in Spain'' (1991), which becam ...

, a sequel to her 2000 publication '' Probability Moon''. It was followed in 2002 by ''

Probability Space In probability theory, a probability space or a probability triple (\Omega, \mathcal, P) is a mathematical construct that provides a formal model of a random process or "experiment". For example, one can define a probability space which models ...

'', which won the John W. Campbell Memorial Award. The novel concerns a military expedition to the planet World, where aliens live who have developed a strange form of

telepathy Telepathy () is the purported vicarious transmission of information from one person's mind to another's without using any known human sensory channels or physical interaction. The term was first coined in 1882 by the classical scholar Frederic ...

collective unconscious In psychology, the collective unconsciousness () is a term coined by Carl Jung, which is the belief that the unconscious mind comprises the instincts of Jungian archetypes—innate symbols understood from birth in all humans. Jung considered th ...

, "shared

reality Reality is the sum or aggregate of everything in existence; everything that is not imagination, imaginary. Different Culture, cultures and Academic discipline, academic disciplines conceptualize it in various ways. Philosophical questions abo ...

", which causes piercing " head-pain" whenever "Worlders" attempt to hold strongly differing opinions. However, the expedition concerns a crash-landed alien artifact in the planet's crust which has uncharted powers, and may be the key to humanity winning a war against the "Fallers", a

genocidal Genocide is violence that targets individuals because of their membership of a group and aims at the destruction of a people. Raphael Lemkin, who first coined the term, defined genocide as "the destruction of a nation or of an ethnic group" b ...

alien race.

Setting

The ''Probability'' trilogy takes place in a

galaxy A galaxy is a Physical system, system of stars, stellar remnants, interstellar medium, interstellar gas, cosmic dust, dust, and dark matter bound together by gravity. The word is derived from the Ancient Greek, Greek ' (), literally 'milky', ...

that has been colonized by humans. This was made possible by the space tunnels, a network of FTL warp gates that were created by a now-lost progenitor race. Humanity is not united under a common government and political system; instead, the various governments in the Solar System and beyond have united as the "Solar Alliance Defense Network" in light of the war against the Fallers. The Terrans have also discovered a number of alien races, most of them vastly similar in body format, living conditions and even

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

, leading to the hypothesis that the aforementioned progenitor race seeded the galaxy with sentient life, which then evolved according to the conditions on each planet. Of the known alien races, humanity is the only one that has reached space. Humanity's understanding of the space tunnels is very limited, but several peculiar traits have been discovered. For one: if Ship A enters Tunnel 1, exits Tunnel 2 and then turns around and enters Tunnel 2 again, it will emerge from Tunnel 1 again... Unless Ship ''B'' emerges from Tunnel 2 in the interim, at which point Ship A will instead emerge from wherever Ship B entered. (The single tunnel leading to World is #438, which gives an idea of how carefully passage through heavily used tunnels must be coordinated.) For two, objects can only enter the Tunnel if they are below a certain mass, about 100,000

ton Ton is any of several units of measure of mass, volume or force. It has a long history and has acquired several meanings and uses. As a unit of mass, ''ton'' can mean: * the '' long ton'', which is * the ''tonne'', also called the ''metric ...

s; anything larger will actually fit into the aperture, but will collapse and explode. The threshold of what the tunnel can handle is determined by the object's

Schwarzschild radius The Schwarzschild radius is a parameter in the Schwarzschild solution to Einstein's field equations that corresponds to the radius of a sphere in flat space that has the same surface area as that of the event horizon of a Schwarzschild black ho ...

. Finally, nobody knows how the tunnels work. At all. Macro-level

quantum entanglement Quantum entanglement is the phenomenon where the quantum state of each Subatomic particle, particle in a group cannot be described independently of the state of the others, even when the particles are separated by a large distance. The topic o ...

has been proposed, but it is so far out of the realm of current physics that nobody believes it. The space tunnels also lead to the discovery of the Fallers, an alien race who refused to establish communications and immediately launched a war, which they are winning. No Faller has been captured alive—they prefer to suicide or

kamikaze , officially , were a part of the Japanese Special Attack Units of military aviators who flew suicide attacks for the Empire of Japan against Allied naval vessels in the closing stages of the Pacific campaign of World War II, intending to d ...

—but

forensic Forensic science combines principles of law and science to investigate criminal activity. Through crime scene investigations and laboratory analysis, forensic scientists are able to link suspects to evidence. An example is determining the time and ...

examination of corpses indicate they evolved separately from humans, instead of being seeded by the progenitors. Like humanity, they were not an interstellar race until the discovery of a space tunnel in their system, though they have been closing the gap quickly. Unlike humans, they did not discover the tunnel independently; it was, in fact, a Terran craft emerging into their home system that catapulted them onto the interstellar stage. The ''Probability'' novels shares two technological quirks with another of Nancy Kress' trilogies, the ''Beggars'' trilogy: in both stories, use of both

genetic modification Genetic engineering, also called genetic modification or genetic manipulation, is the modification and manipulation of an organism's genes using technology. It is a set of technologies used to change the genetic makeup of cells, including th ...

and behavior-regulating neuropharmacological drugs is commonplace. "Genemods" are applied ''

in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

'', whereas those who adhere to the "Discipline" administer "neuropharms" daily to control their

neurotransmitter A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a Chemical synapse, synapse. The cell receiving the signal, or target cell, may be another neuron, but could also be a gland or muscle cell. Neurotra ...

balances, in a mix that can be altered depending on the activities of one's day and the mood one hopes to approach it with.

Plot synopsis

While the human race struggles at war with the Fallers, an advanced alien race, an artifact is discovered which might be the key to a lost science, be a weapon itself, or a doomsday device.

Reception

Both Kirkus Reviews and Publishers Weekly gave the book favorable reviews.

References

{{reflist 2001 American novels 2001 science fiction novels American science fiction novels Works by Nancy Kress