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Permutation City
''Permutation City'' is a 1994 science-fiction novel by Greg Egan that explores many concepts, including quantum ontology, through various philosophical aspects of artificial life and simulated reality. Sections of the story were adapted from Egan's 1992 short story "Dust", which dealt with many of the same philosophical themes. ''Permutation City'' won the John W. Campbell Award for the best science-fiction novel of the year in 1995 and was nominated for the Philip K. Dick Award the same year. The novel was also cited in a 2003 ''Scientific American'' article on multiverses by Max Tegmark. Themes and setting ''Permutation City'' asks whether there is a difference between a computer simulation of a person and a "real" person. It focuses on a model of consciousness and reality, the ''Dust Theory'', similar to the Ultimate Ensemble Mathematical Universe hypothesis proposed by Max Tegmark. It uses the assumption that human consciousness is Turing-computable: that consciousness ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greg Egan
Greg Egan (born 20 August 1961) is an Australian science fiction writer and amateur mathematician, best known for his works of hard science fiction. Egan has won multiple awards including the John W. Campbell Memorial Award, the Hugo Award, and the Locus Award. Life and work Egan holds a Bachelor of Science degree in Mathematics from the University of Western Australia. He published his first work in 1983. He specialises in hard science fiction stories with mathematical and quantum ontology themes, including the nature of consciousness. Other themes include genetics, simulated reality, posthumanism, mind uploading, sexuality, artificial intelligence, and the superiority of rational naturalism to religion. He often deals with complex technical material, like new physics and epistemology. He is a Hugo Award winner (with eight other works shortlisted for the Hugos) and has also won the John W. Campbell Memorial Award for Best Science Fiction Novel. His early stories feature s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virtual Reality
Virtual reality (VR) is a simulated experience that employs pose tracking and 3D near-eye displays to give the user an immersive feel of a virtual world. Applications of virtual reality include entertainment (particularly video games), education (such as medical or military training) and business (such as virtual meetings). Other distinct types of VR-style technology include augmented reality and mixed reality, sometimes referred to as extended reality or XR, although definitions are currently changing due to the nascence of the industry. Currently, standard virtual reality systems use either virtual reality headsets or multi-projected environments to generate realistic images, sounds and other sensations that simulate a user's physical presence in a virtual environment. A person using virtual reality equipment is able to look around the artificial world, move around in it, and interact with virtual features or items. The effect is commonly created by VR headsets consisting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paradise
In religion, paradise is a place of exceptional happiness and delight. Paradisiacal notions are often laden with pastoral imagery, and may be cosmogonical or eschatological or both, often compared to the miseries of human civilization: in paradise there is only peace, prosperity, and happiness. Paradise is a place of contentment, a land of luxury and fulfillment. Paradise is often described as a "higher place", the holiest place, in contrast to this World (theology), world, or underworlds such as Hell. In eschatological contexts, paradise is imagined as an Entering heaven alive, abode of the virtuous dead. In Christianity and Islam, Heaven is a paradisiacal relief. In old Egyptian beliefs, the underworld is Aaru, the reed-fields of ideal hunting and fishing grounds where the dead lived after judgment. For the Celts, it was the Fortunate Isles, Fortunate Isle of Mag Mell. For the classical Greeks, the Elysium, Elysian fields was a paradisiacal land of plenty where the heroic and ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synchronization
Synchronization is the coordination of events to operate a system in unison. For example, the conductor of an orchestra keeps the orchestra synchronized or ''in time''. Systems that operate with all parts in synchrony are said to be synchronous or ''in sync''—and those that are not are '' asynchronous''. Today, time synchronization can occur between systems around the world through satellite navigation signals and other time and frequency transfer techniques. Navigation and railways Time-keeping and synchronization of clocks is a critical problem in long-distance ocean navigation. Before radio navigation and satellite-based navigation, navigators required accurate time in conjunction with astronomical observations to determine how far east or west their vessel traveled. The invention of an accurate marine chronometer revolutionized marine navigation. By the end of the 19th century, important ports provided time signals in the form of a signal gun, flag, or dropping time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solipsism
Solipsism (; ) is the philosophical idea that only one's mind is sure to exist. As an epistemological position, solipsism holds that knowledge of anything outside one's own mind is unsure; the external world and other minds cannot be known and might not exist outside the mind. Varieties There are varying degrees of solipsism that parallel the varying degrees of skepticism: Metaphysical Metaphysical solipsism is a variety of solipsism. Based on a philosophy of subjective idealism, metaphysical solipsists maintain that the self is the only existing reality and that all other realities, including the external world and other persons, are representations of that self, and have no independent existence. There are several versions of metaphysical solipsism, such as Caspar Hare's egocentric presentism (or perspectival realism), in which other people are conscious, but their experiences are simply not ''present''. Epistemological Epistemological solipsism is the variety of ideali ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Economic Inequality
There are wide varieties of economic inequality, most notably income inequality measured using the distribution of income (the amount of money people are paid) and wealth inequality measured using the distribution of wealth (the amount of wealth people own). Besides economic inequality between countries or states, there are important types of economic inequality between different groups of people. Important types of economic measurements focus on wealth, income, and consumption. There are many methods for measuring economic inequality, the Gini coefficient being a widely used one. Another type of measure is the Inequality-adjusted Human Development Index, which is a statistic composite index that takes inequality into account. Important concepts of equality include equity, equality of outcome, and equality of opportunity. Whereas globalization has reduced global inequality (between nations), it has increased inequality within nations. Income inequality between nations peak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recession
In economics, a recession is a business cycle contraction when there is a general decline in economic activity. Recessions generally occur when there is a widespread drop in spending (an adverse demand shock). This may be triggered by various events, such as a financial crisis, an external trade shock, an adverse supply shock, the bursting of an economic bubble, or a large-scale Anthropogenic hazard, anthropogenic or natural disaster (e.g. a pandemic). In the United States, a recession is defined as "a significant decline in economic activity spread across the market, lasting more than a few months, normally visible in real GDP, real income, employment, industrial production, and wholesale-retail sales." The European Union has adopted a similar definition. In the United Kingdom, a recession is defined as negative economic growth for two consecutive quarters. Governments usually respond to recessions by adopting expansionary macroeconomic policies, such as monetary policy, incr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commodity
In economics, a commodity is an economic good, usually a resource, that has full or substantial fungibility: that is, the market treats instances of the good as equivalent or nearly so with no regard to who produced them. The price of a commodity good is typically determined as a function of its market as a whole: well-established physical commodities have actively traded spot and derivative markets. The wide availability of commodities typically leads to smaller profit margins and diminishes the importance of factors (such as brand name) other than price. Most commodities are raw materials, basic resources, agricultural, or mining products, such as iron ore, sugar, or grains like rice and wheat. Commodities can also be mass-produced unspecialized products such as chemical substance, chemicals and computer memory. Popular commodities include Petroleum, crude oil, Maize, corn, and gold. Other definitions of commodity include something useful or valued and an alternative ter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungibility
In economics, fungibility is the property of a good or a commodity whose individual units are essentially interchangeable, and each of whose parts is indistinguishable from any other part. Fungible tokens can be exchanged or replaced; for example, a $100 note can easily be exchanged for twenty $5 bills. In contrast, non-fungible tokens cannot be exchanged in the same manner. For example, gold is fungible because its value doesn’t depend on any specific form, whether of coins, ingots, or other states. However, a unique item such as a gold statue by a famous artist would not be considered fungible. In short, a thing is fungible when all equivalent amounts of that thing are interchangeable. Fungible commodities include sweet crude oil, company shares, bonds, other precious metals, and currencies. Fungibility refers only to the equivalence and indistinguishability of each unit of a commodity with other units of the same commodity, and not to the exchange of one commodity for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trust Fund
A trust is a legal relationship in which the holder of a right gives it to another person or entity who must keep and use it solely for another's benefit. In the Anglo-American common law, the party who entrusts the right is known as the "settlor", the party to whom the right is entrusted is known as the "trustee", the party for whose benefit the property is entrusted is known as the " beneficiary", and the entrusted property itself is known as the "corpus" or "trust property". A ''testamentary trust'' is created by a will and arises after the death of the settlor. An ''inter vivos trust'' is created during the settlor's lifetime by a trust instrument. A trust may be revocable or irrevocable; an irrevocable trust can be "broken" (revoked) only by a judicial proceeding. The trustee is the legal owner of the property in trust, as fiduciary for the beneficiary or beneficiaries who is/are the equitable owner(s) of the trust property. Trustees thus have a fiduciary duty to manage th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hash Function
A hash function is any function that can be used to map data of arbitrary size to fixed-size values. The values returned by a hash function are called ''hash values'', ''hash codes'', ''digests'', or simply ''hashes''. The values are usually used to index a fixed-size table called a ''hash table''. Use of a hash function to index a hash table is called ''hashing'' or ''scatter storage addressing''. Hash functions and their associated hash tables are used in data storage and retrieval applications to access data in a small and nearly constant time per retrieval. They require an amount of storage space only fractionally greater than the total space required for the data or records themselves. Hashing is a computationally and storage space-efficient form of data access that avoids the non-constant access time of ordered and unordered lists and structured trees, and the often exponential storage requirements of direct access of state spaces of large or variable-length keys. Use of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lossy Compression
In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size for storing, handling, and transmitting content. The different versions of the photo of the cat on this page show how higher degrees of approximation create coarser images as more details are removed. This is opposed to lossless data compression (reversible data compression) which does not degrade the data. The amount of data reduction possible using lossy compression is much higher than using lossless techniques. Well-designed lossy compression technology often reduces file sizes significantly before degradation is noticed by the end-user. Even when noticeable by the user, further data reduction may be desirable (e.g., for real-time communication or to reduce transmission times or storage needs). The most widely used lossy compression al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
