A Dyson sphere is a hypothetical megastructure that encompasses a star and captures a large percentage of its solar power output. The concept is a thought experiment that attempts to imagine how a spacefaring civilization would meet its energy requirements once those requirements exceed what can be generated from the home planet's resources alone. Because only a tiny fraction of a star's energy emissions reaches the surface of any orbiting planet, building structures encircling a star would enable a civilization to harvest far more energy.
Faster-than-light travel and communication are the conjectural propagation of matter or information faster than the speed of light. The special theory of relativity implies that only particles with zero rest mass may travel at the speed of light, and that nothing may travel faster.
Hard science fiction is a category of science fiction characterized by concern for scientific accuracy and logic. The term was first used in print in 1957 by P. Schuyler Miller in a review of John W. Campbell's Islands of Space in the November issue of Astounding Science Fiction. The complementary term soft science fiction, formed by analogy to hard science fiction, first appeared in the late 1970s. The term is formed by analogy to the popular distinction between the "hard" (natural) and "soft" (social) sciences, although there are examples generally considered as "hard" science fiction such as Isaac Asimov's Foundation series, built on mathematical sociology. Science fiction critic Gary Westfahl argues that neither term is part of a rigorous taxonomy; instead they are approximate ways of characterizing stories that reviewers and commentators have found useful.
Superluminal communication is a hypothetical process in which information is conveyed at faster-than-light speeds. The current scientific consensus is that faster-than-light communication is not possible, and to date it has not been achieved in any experiment.
A tachyon or tachyonic particle is a hypothetical particle that always travels faster than light. Physicists believe that faster-than-light particles cannot exist because they are inconsistent with the known laws of physics. If such particles did exist they could be used to send signals faster than light. According to the theory of relativity this would violate causality, leading to logical paradoxes such as the grandfather paradox. Tachyons would exhibit the unusual property of increasing in speed as their energy decreases, and would require infinite energy to slow to the speed of light. No verifiable experimental evidence for the existence of such particles has been found.
A warp drive or a drive enabling space warp is a fictional superluminal spacecraft propulsion system in many science fiction works, most notably Star Trek, and a subject of ongoing physics research. The general concept of "warp drive" was introduced by John W. Campbell in his 1957 novel Islands of Space and was popularized by the Star Trek series. Its closest real-life equivalent is the Alcubierre drive, a theoretical solution of the field equations of general relativity.
There are several proposed types of exotic matter:
Galactic empires are a science fiction setting trope, in which most or all of the habitable planets in the setting's galaxy are ruled by a single centralized political entity. Galactic empires most frequently appear in works in the sub-genres of science fantasy and space opera, although they may appear in other sub-genres as well. Works featuring galactic empires may have them as the story's focus, chronicling the empire's growth and/or decline. Alternatively, they may merely serve as a backdrop against which the events of the story play out.
Asimov's Science Fiction is an American science fiction magazine edited by Sheila Williams and published by Dell Magazines, which is owned by Penny Press. It was launched as a quarterly by Davis Publications in 1977, after obtaining Isaac Asimov's consent for the use of his name. It was originally titled Isaac Asimov's Science Fiction Magazine, and was quickly successful, reaching a circulation of over 100,000 within a year, and switching to monthly publication within a couple of years. George H. Scithers, the first editor, published many new writers who went on to be successful in the genre. Scithers favored traditional stories without sex or obscenity; along with frequent humorous stories, this gave Asimov's a reputation for printing juvenile fiction, despite its success. Asimov was not part of the editorial team, but wrote editorials for the magazine.
In science fiction, hyperspace is a concept relating to higher dimensions as well as parallel universes and a faster-than-light (FTL) method of interstellar travel. Its use in science fiction originated in the magazine Amazing Stories Quarterly in 1931 and within several decades it became one of the most popular tropes of science fiction, popularized by its use in the works of authors such as Isaac Asimov and E. C. Tubb, and media franchises such as Star Wars.
In science fiction, a time viewer, temporal viewer, or chronoscope is a device that allows another point in time to be observed. The concept has appeared since the late 19th century, constituting a significant yet relatively obscure subgenre of time travel fiction and appearing in various media including literature, cinema, and television. Stories usually explain the technology by referencing cutting-edge science, though sometimes invoking the supernatural instead. Most commonly only the past can be observed, though occasionally time viewers capable of showing the future appear; these devices are sometimes limited in terms of what information about the future can be obtained. Other variations on the concept include being able to listen to the past but not view it.
Black holes, objects whose gravity is so strong that nothing including light can escape them, have been depicted in fiction since before the term was coined by John Archibald Wheeler in the late 1960s. Black holes have been depicted with varying degrees of accuracy to the scientific understanding of them. Because what lies beyond the event horizon is unknown and by definition unobservable from outside, authors have been free to employ artistic license when depicting the interiors of black holes.
Super Science Stories was an American pulp science fiction magazine published by Popular Publications from 1940 to 1943, and again from 1949 to 1951. Popular launched it under their Fictioneers imprint, which they used for magazines, paying writers less than one cent per word. Frederik Pohl was hired in late 1939, at 19 years old, to edit the magazine; he also edited Astonishing Stories, a companion science fiction publication. Pohl left in mid-1941 and Super Science Stories was given to Alden H. Norton to edit; a few months later Norton rehired Pohl as an assistant. Popular gave Pohl a very low budget, so most manuscripts submitted to Super Science Stories had already been rejected by the higher-paying magazines. This made it difficult to acquire good fiction, but Pohl was able to acquire stories for the early issues from the Futurians, a group of young science fiction fans and aspiring writers.
Soft science fiction, or soft SF, is a category of science fiction with two different definitions, defined in contrast to hard science fiction. It can refer to science fiction that explores the "soft" sciences, as opposed to hard science fiction, which explores the "hard" sciences. It can also refer to science fiction which prioritizes human emotions over the scientific accuracy or plausibility of hard science fiction.
Astonishing Stories was an American pulp science fiction magazine, published by Popular Publications between 1940 and 1943. It was founded under Popular's "Fictioneers" imprint, which paid lower rates than Popular's other magazines. The magazine's first editor was Frederik Pohl, who also edited a companion publication, Super Science Stories. After nine issues Pohl was replaced by Alden H. Norton, who subsequently rehired Pohl as an assistant. The budget for Astonishing was very low, which made it difficult to acquire good fiction, but through his membership in the Futurians, a group of young science fiction fans and aspiring writers, Pohl was able to find material to fill the early issues. The magazine was successful, and Pohl was able to increase his pay rates slightly within a year. He managed to obtain stories by writers who subsequently became very well known, such as Isaac Asimov and Robert Heinlein. After Pohl entered the army in early 1943, wartime paper shortages led Popular to cease publication of Astonishing. The final issue was dated April of that year.
In physics, a tachyonic field, or simply tachyon, is a quantum field with an imaginary mass. Although tachyonic particles are a purely hypothetical concept that violate a number of essential physical principles, at least one field with imaginary mass, the Higgs field, is believed to exist. Under no circumstances do any excitations of tachyonic fields ever propagate faster than light—the presence or absence of a tachyonic (imaginary) mass has no effect on the maximum velocity of signals, and so unlike faster-than-light particles there is no violation of causality. Tachyonic fields play an important role in physics and are discussed in popular books.
A tachyon is a hypothetical faster-than-light particle.
Disasters in popular culture includes real and fictional disasters, as depicted by the media, and are considered social events. Disaster movies made in Hollywood are part of the American pop culture. Catastrophe types can include hostile aliens, climate change/global warming, environmental disasters, financial crises, natural disaster, nuclear apocalypse, pandemics, super heros, terrorist attacks, zombies and other technological meltdowns.
Space travel, or space flight is a classic science-fiction theme that has captivated the public and is almost archetypal for science fiction. Space travel, interplanetary or interstellar, is usually performed in space ships, and spacecraft propulsion in various works ranges from the scientifically plausible to the totally fictitious.
Impact events have been a recurring theme in fiction since the 1800s.
