Time

qas: question: Time has long been a major point of study in which fields?
answers: text: religion, philosophy, and science

question: Fields such as business, industry, sports, science, and performing arts incorporate some notion of what into their measuring systems?
answers: text: time

question: What is an example of a simple definition of time?
answers: text: time is what clocks measure

question: Which three fields usually support performing arts?

question: What fields use measuring systems to check the weight of their products?

question: What does having rules in sports usually prevent?

question: What does science use to test a hypothesis?

question: What do athletes need to use to be aware of where their teammates are in a game?

question: Fields such as business, industry, sports, science, and performing arts incorporate some notion of what into their clocks?

question: What keeps everything from happening at different times?

question: What fields incorporate some notion of clocks into their measuring system?

question: What has long been a major subject of study in human sensation?

question: What does time measure?
context: Time has long been a major subject of study in religion, philosophy, and science, but defining it in a manner applicable to all fields without circularity has consistently eluded scholars. Nevertheless, diverse fields such as business, industry, sports, the sciences, and the performing arts all incorporate some notion of time into their respective measuring systems. Some simple definitions of time include "time is what clocks measure", which is a problematically vague and self-referential definition that utilizes the device used to measure the subject as the definition of the subject, and "time is what keeps everything from happening at once", which is without substantive meaning in the absence of the definition of simultaneity in the context of the limitations of human sensation, observation of events, and the perception of such events.

qas: question: According to one of the main viewpoints of time, time is part of the fundamental structure of what?
answers: text: the universe

question: The realist view of time is sometimes referred to as what?
answers: text: Newtonian time

question: What does the opposing view of time believe time is a part of?
answers: text: a fundamental intellectual structure

question: Who is divided about the structure of the universe?

question: In what order did Gottfried Leibniz believe events occur?

question: What kind of time did Gottfried Leibniz believe in, as a supporter of Sir Isaac Newton?

question: How was Immanuel Kant described, since he also believed in Newtonian time?

question: What did Sir Issac Newton believe that you could not do in time?

question: According to one of the main viewpoints of time, time is part of the view of what?

question: What is the realest view of time sometimes known as?

question: What does the opposing view of time believe the universe is a part of?

question: Who subscribed to the opposing view?

question: Who believe time is neither a structure or a view?
context: Two contrasting viewpoints on time divide many prominent philosophers. One view is that time is part of the fundamental structure of the universe—a dimension independent of events, in which events occur in sequence. Sir Isaac Newton subscribed to this realist view, and hence it is sometimes referred to as Newtonian time. The opposing view is that time does not refer to any kind of "container" that events and objects "move through", nor to any entity that "flows", but that it is instead part of a fundamental intellectual structure (together with space and number) within which humans sequence and compare events. This second view, in the tradition of Gottfried Leibniz and Immanuel Kant, holds that time is neither an event nor a thing, and thus is not itself measurable nor can it be travelled.

qas: question: Time is one of how many fundamental physical quantities?
answers: text: seven

question: Time is one of the fundamental physical quantities in which two systems?
answers: text: the International System of Units and International System of Quantities

question: What is an example of a quantity that time is used to define, mentioned in the paragraph?
answers: text: velocity

question: Investigations of what brought questions of space into questions about time?
answers: text: a single continuum called spacetime

question: Philosophy is one of how many fundamental physical quantities?

question: In what two systems is philosophy considered a fundamental physical quantity?

question: What is something else that philosophy is used to define?

question: What kind of experiments can be used when understanding philosophy?

question: Who first used philosophy to understand everyday affairs of life?

question: Philosophy is one of how many fundamental physical quantities?

question: Philosophy is one of the fundamental physical quantities in which two systems?

question: What is an example of a quantity that philosophy is used to define, mentioned in the paragraph?

question: Investigations of what brought questions of space into questions about philosophy?

question: What do questions about velocity have their roots in?
context: Time is one of the seven fundamental physical quantities in both the International System of Units and International System of Quantities. Time is used to define other quantities—such as velocity—so defining time in terms of such quantities would result in circularity of definition. An operational definition of time, wherein one says that observing a certain number of repetitions of one or another standard cyclical event (such as the passage of a free-swinging pendulum) constitutes one standard unit such as the second, is highly useful in the conduct of both advanced experiments and everyday affairs of life. The operational definition leaves aside the question whether there is something called time, apart from the counting activity just mentioned, that flows and that can be measured. Investigations of a single continuum called spacetime bring questions about space into questions about time, questions that have their roots in the works of early students of natural philosophy.

qas: question: What has been a prime motivation in astronomy and navigation?
answers: text: Temporal measurement

question: Periodic events and periodic motion have served as standards for what?
answers: text: Periodic events and periodic motion

question: What is the current international unit of time?
answers: text: the second

question: The electronic transition frequency of which element defines the second?
answers: text: caesium atoms

question: Time has personal value due to awareness of it's limited nature in what?
answers: text: each day and in human life spans

question: What groups have been occupied by understanding the life span of humans?

question: How important is a strong economy considered?

question: How do you define the method used for tracking heartbeats?

question: What do caesium atoms affect to make them shorter?

question: Why do scientists want to study caesium atoms?

question: What has been a prime motivation in units of time?

question: What have periodic events and transition frequency have served as standards for?

question: What is the current national unit of time?

question: Why does time have international value?

question: What is an example of a technologist?
context: Temporal measurement has occupied scientists and technologists, and was a prime motivation in navigation and astronomy. Periodic events and periodic motion have long served as standards for units of time. Examples include the apparent motion of the sun across the sky, the phases of the moon, the swing of a pendulum, and the beat of a heart. Currently, the international unit of time, the second, is defined by measuring the electronic transition frequency of caesium atoms (see below). Time is also of significant social importance, having economic value ("time is money") as well as personal value, due to an awareness of the limited time in each day and in human life spans.

qas: question: What is a mathematical tool used for organizing intervals of time?
answers: text: the calendar

question: What is a physical tool that tracks the passage of time?
answers: text: the clock

question: Which tool is used in day to day life?
answers: text: the clock

question: Which tool is used in periods longer than a day?
answers: text: the calendar

question: How is the number that marks the occurrence of an event obtained?
answers: text: by counting from a fiducial epoch—a central reference point

question: For how long does chronometry usually display a reference point?

question: What do fiducial epochs display at the same time?

question: What physical mechanism is used to count periods longer than a day?

question: What organizational mathmatical tool is used for a time period of less than a day?

question: What do people usually carry with them at all times?

question: What is a mathematical tool used for organizing intervals on clocks? 

question: What is a physical tool that tracks the passage of points?

question: Which tool is used in periods longer than an interval?

question: How is the number that marks the occurrence of an interval obtained?

question: What takes three distinct period forms?
context: Temporal measurement, chronometry, takes two distinct period forms: the calendar, a mathematical tool for organizing intervals of time, and the clock, a physical mechanism that counts the passage of time. In day-to-day life, the clock is consulted for periods less than a day whereas the calendar is consulted for periods longer than a day. Increasingly, personal electronic devices display both calendars and clocks simultaneously. The number (as on a clock dial or calendar) that marks the occurrence of a specified event as to hour or date is obtained by counting from a fiducial epoch—a central reference point.

qas: question: Artifacts from which era suggest that the moon was used to reckon time around 6,000 years ago?
answers: text: the Paleolithic

question: Which calendars were among the first to appear?
answers: text: Lunar calendars

question: How long were the original lunar calendars?
answers: text: either 12 or 13 lunar months (either 354 or 384 days)

question: Where did some of the other early forms of calendars originate?
answers: text: Mesoamerica

question: How many months were in a year in the original Mayan calendars?
answers: text: 18

question: During what time period did the Mesoamerican age appear?

question: When did the Mayan civilization first appear?

question: How many days did it take to date artifacts from the Paleolithic?

question: How many artifacts were found that connected the moon to Mayan culture?

question: What culture was the first create artifacts that were found?

question: Artifacts from which era suggest that the moon was used to reckon time around 12 years ago?

question: Which calendars were among the last to appear?

question: How long were the original lunisolar calendars?

question: Where did some of the other early forms of months originate?

question: How many seasons were in a year in the original Mayan calendars?
context: Artifacts from the Paleolithic suggest that the moon was used to reckon time as early as 6,000 years ago. Lunar calendars were among the first to appear, either 12 or 13 lunar months (either 354 or 384 days). Without intercalation to add days or months to some years, seasons quickly drift in a calendar based solely on twelve lunar months. Lunisolar calendars have a thirteenth month added to some years to make up for the difference between a full year (now known to be about 365.24 days) and a year of just twelve lunar months. The numbers twelve and thirteen came to feature prominently in many cultures, at least partly due to this relationship of months to years. Other early forms of calendars originated in Mesoamerica, particularly in ancient Mayan civilization. These calendars were religiously and astronomically based, with 18 months in a year and 20 days in a month.

qas: question: What was the most accurate clock-like device in the ancient world?
answers: text: the water clock, or clepsydra

question: A clepsyrda was found in the tomb of which Pharaoh?
answers: text: Egyptian pharaoh Amenhotep

question: Which inventors made significant improvements on the water clock up until the Middle Ages?
answers: text: Arab inventors

question: Which engineers came up with the first mechanical clocks?
answers: text: Chinese

question: When were the first mechanical clocks created?
answers: text: the 11th century

question: What device was invented by the ancient Greeks?

question: What mechanism was used to replenish water in a water clock?

question: What was another term used for a mechanical clock?

question: Why did the Chinese maintain timekeeping records in the 11th century?

question: For how long did the ancient Greeks make improvements to the water clock?

question: What was the most accurate clock=like device in Chaldea?

question: A clepsyrda was found in the tomb of which Greek?

question: which inventors made significant improvements on the water clock up until the ancient world?

question: Which engineers came up with the first clocks?

question: When were the first water clocks created?
context: The most precise timekeeping device of the ancient world was the water clock, or clepsydra, one of which was found in the tomb of Egyptian pharaoh Amenhotep I (1525–1504 BC). They could be used to measure the hours even at night, but required manual upkeep to replenish the flow of water. The Ancient Greeks and the people from Chaldea (southeastern Mesopotamia) regularly maintained timekeeping records as an essential part of their astronomical observations. Arab inventors and engineers in particular made improvements on the use of water clocks up to the Middle Ages. In the 11th century, Chinese inventors and engineers invented the first mechanical clocks driven by an escapement mechanism.

qas: question: Which device uses the flow of sand to measure time?
answers: text: The hourglass

question: How many hourglasses did Magellan use on each ship during his famous voyage across the globe?
answers: text: 18

question: What method did temples and churches use to measure time?
answers: text: Incense sticks and candles

question: Which abbot of St. Alban's abbey built a mechanical clock around 1330?
answers: text: Richard of Wallingford

question: Who is credited with the invention of the minute hand?
answers: text: Jost Burgi.

question: What did Richard of Wallingford use to circumnavigate the globe?

question: In what year did Ferdinand Magellan build a mechanical clock?

question: How many inventions were made by Galileo?

question: Where are pendulum driven clocks used now and also in the past to measure time?

question: Where are the temples and churches located that use pendulum clocks to measure time?

question: Which device uses minutes to measure time?

question: How many hourglasses did Galileo Galilei use on each ship during his famous voyage across the globe?

question: What method did temples and chruches use to measure the globe?

question: Which abbot of St. Alban's abbey built a mechanical clock around 1292?

question: Who made great advances in candles?
context: The hourglass uses the flow of sand to measure the flow of time. They were used in navigation. Ferdinand Magellan used 18 glasses on each ship for his circumnavigation of the globe (1522). Incense sticks and candles were, and are, commonly used to measure time in temples and churches across the globe. Waterclocks, and later, mechanical clocks, were used to mark the events of the abbeys and monasteries of the Middle Ages. Richard of Wallingford (1292–1336), abbot of St. Alban's abbey, famously built a mechanical clock as an astronomical orrery about 1330. Great advances in accurate time-keeping were made by Galileo Galilei and especially Christiaan Huygens with the invention of pendulum driven clocks along with the invention of the minute hand by Jost Burgi.

qas: question: Which timekeeping devices are the most accurate?
answers: text: atomic clocks

question: What method do atomic clocks use to measure seconds?
answers: text: the frequency of electronic transitions in certain atoms

question: Which system bases its unit of time on the properties of caesium?
answers: text: the International System of Measurements

question: How long has the International System of Measurements based the second on caesium?
answers: text: Since 1967

question: In what year were caesium atoms discovered?

question: What are microwaves the most accurate at doing?

question: What are microwaves also used to calibrate?

question: What system bases its unit of time on microwave properties?

question: How many cycles of radiation are in microwaves?

question: Which timekeeping devices are the least accurate?

question: What method do atomic clocks use to measure cycles?

question: Which system bases its unit of time on the properties of vibrations?

question: How long has the International System of Measurements based the second on years?

question: How does caesium deine the second?
context: The most accurate timekeeping devices are atomic clocks, which are accurate to seconds in many millions of years, and are used to calibrate other clocks and timekeeping instruments. Atomic clocks use the frequency of electronic transitions in certain atoms to measure the second. One of the most common atoms used is caesium, most modern atomic clocks probe caesium with microwaves to determine the frequency of these electron vibrations. Since 1967, the International System of Measurements bases its unit of time, the second, on the properties of caesium atoms. SI defines the second as 9,192,631,770 cycles of the radiation that corresponds to the transition between two electron spin energy levels of the ground state of the 133Cs atom.

qas: question: Which standard of time started with British Railways?
answers: text: Greenwich Mean Time

question: When was GMT adopted by British Railways?
answers: text: 1847

question: GMT used what instead of atomic clocks?
answers: text: telescopes

question: When did observations at the Greenwich Observatory cease?
answers: text: 1954

question: The terms GMT and Greenwich Mean Time are also used informally to refer to what?
answers: text: UT or UTC

question: In what year did British railways go into business?

question: What did the British railway stop using in 1954?

question: What did Greenwich Mean Time replace in 1847?

question: How constant is an atomic clock?

question: What happens when an atomic clock is not constant?

question: Which standard of time started with the International Astronomical Union?

question: When was GMT adopted by the International Astronomical Union?

question: The International Astronomical Union used what instead of atomic clocks?

question: When did observations at the Greenwich Observatory begin?

question: The term calibrated is also used informally to refer to what? 
context: Greenwich Mean Time (GMT) is an older standard, adopted starting with British railways in 1847. Using telescopes instead of atomic clocks, GMT was calibrated to the mean solar time at the Royal Observatory, Greenwich in the UK. Universal Time (UT) is the modern term for the international telescope-based system, adopted to replace "Greenwich Mean Time" in 1928 by the International Astronomical Union. Observations at the Greenwich Observatory itself ceased in 1954, though the location is still used as the basis for the coordinate system. Because the rotational period of Earth is not perfectly constant, the duration of a second would vary if calibrated to a telescope-based standard like GMT or UT—in which a second was defined as a fraction of a day or year. The terms "GMT" and "Greenwich Mean Time" are sometimes used informally to refer to UT or UTC.

qas: question: How many main viewpoints divide many philosophers?
answers: text: Two

question: The realist view states that time is part of the fundamental structure of what?
answers: text: the universe

question: The realist view is sometimes referred to as what?
answers: text: Newtonian time

question: The opposing view states that time is an intellectual concept that allows people to what?
answers: text: to sequence and compare events

question: How many viewpoints are there about different dimensions?

question: Gottfried Leibniz believed time is part of the fundamental structure of what?

question: What does the realist view believe don't exist of themselves?

question: What did Sir Isaac Newton believe time and space were the product of?

question: What did Sir Isaac Newton believe was the only way we can know objects?

question: How many main viewpoints divide many sequences?

question: Who subscribed to the third view?

question: What is another name for the second view?

question: What does the third view hold that?

question: Who believe in the third view?
context: Two distinct viewpoints on time divide many prominent philosophers. One view is that time is part of the fundamental structure of the universe, a dimension in which events occur in sequence. Sir Isaac Newton subscribed to this realist view, and hence it is sometimes referred to as Newtonian time. An opposing view is that time does not refer to any kind of actually existing dimension that events and objects "move through", nor to any entity that "flows", but that it is instead an intellectual concept (together with space and number) that enables humans to sequence and compare events. This second view, in the tradition of Gottfried Leibniz and Immanuel Kant, holds that space and time "do not exist in and of themselves, but ... are the product of the way we represent things", because we can know objects only as they appear to us.

qas: question: What are the earliest texts of Indian/Hindu philosophy?
answers: text: The Vedas

question: How long ago are the earliest texts of Indian/Hindu philosophy dated?
answers: text: back to the late 2nd millennium BC

question: How long does each cycle of birth and destruction of the universe last according to Ancient Hindu texts?
answers: text: 4,320 million years

question: Which ancient Greek philosophers wrote essays on the concept of time?
answers: text: Parmenides and Heraclitus

question: Aristotle defined time as "number of movement in respect of the before and after" in which book?
answers: text: Book IV of his Physica

question: For how long has the Timaeus existed?

question: In what year did Plato write Book IV of his Physica?

question: What cycles did Aristotle write about in the Timaeus?

question: What Greek philosophers wrote the Vedas?

question: What did Hundu cosmology identify time with?

question: What are the earliest texts of Heraclitus philosophy?

question: How long ago are the earliest texts of Heraclitus philosophy dated?

question: How long does each cycle of birth and destruction of the universe last according to Ancient Indian texts?

question: Which ancient Indian philosophers wrote essays on the concept of time?

question: In which book did Paramenides define time as "number of movement in respect of the before and after?"
context: The Vedas, the earliest texts on Indian philosophy and Hindu philosophy dating back to the late 2nd millennium BC, describe ancient Hindu cosmology, in which the universe goes through repeated cycles of creation, destruction and rebirth, with each cycle lasting 4,320 million years. Ancient Greek philosophers, including Parmenides and Heraclitus, wrote essays on the nature of time. Plato, in the Timaeus, identified time with the period of motion of the heavenly bodies. Aristotle, in Book IV of his Physica defined time as 'number of movement in respect of the before and after'.

qas: question: Who commented on the nature of time in Book 11 of his confessions?
answers: text: St. Augustine of Hippo

question: By what does St. Augustine of Hippo begin to define time?
answers: text: by what it is not rather than what it is

question: What does Augustine call time in Confessions 11.26?
answers: text: a “distention” of the mind

question: How is memory defined as?

question: How does St. Augustine define memory?

question: In what book does St. Augustine reflect on how memory works?

question: What does St. Augustine say when someone asks him about memory?

question: Where is a similar approach of defining memory also taken?

question: Who commented on the nature of time in Book 26 of his confessions?

question: By what does St. Augustine of Hippo begin to define memory?

question: What Does Augustine call memory in Confessions 11.26?

question: Who calls memory a distention of the mind?

question: Who ruminates on the nature of approaches?
context: In Book 11 of his Confessions, St. Augustine of Hippo ruminates on the nature of time, asking, "What then is time? If no one asks me, I know: if I wish to explain it to one that asketh, I know not." He begins to define time by what it is not rather than what it is, an approach similar to that taken in other negative definitions. However, Augustine ends up calling time a “distention” of the mind (Confessions 11.26) by which we simultaneously grasp the past in memory, the present by attention, and the future by expectation.

qas: question: In what did Immanuel Kant describe time as a priori intuition that allows humankind to understand sense experience?
answers: text: the Critique of Pure Reason

question: What did Kant portray space and time to be?
answers: text: both are elements of a systematic mental framework

question: Kant thought of time as a fundamental part of what?
answers: text: an abstract conceptual framework

question: What type of measurements are used to quantify the duration of events?
answers: text: temporal measurements

question: What type of measurements are used to quantify the distances between objects?
answers: text: Spatial measurements

question: How did Immanuel Kant describe the mind?

question: What does the mind allow us to do according to Immanuel Kant?

question: What framework is the mind a part of?

question: What did Kant also think of the mind as a part of?

question: How do we process with our minds according to Kant?

question: In what did Immanuel Kant describe measurement as a priori intuition that allows humankind to understand sense experience?

question: What did Kant portray measurement and time to be?

question: Kant thought of measurement as a fundamental part of what?

question: What type of measurements are used to quantify the number of events?

question: What type of measurements are used to quantify the distance between measurements?
context: Immanuel Kant, in the Critique of Pure Reason, described time as an a priori intuition that allows us (together with the other a priori intuition, space) to comprehend sense experience. With Kant, neither space nor time are conceived as substances, but rather both are elements of a systematic mental framework that necessarily structures the experiences of any rational agent, or observing subject. Kant thought of time as a fundamental part of an abstract conceptual framework, together with space and number, within which we sequence events, quantify their duration, and compare the motions of objects. In this view, time does not refer to any kind of entity that "flows," that objects "move through," or that is a "container" for events. Spatial measurements are used to quantify the extent of and distances between objects, and temporal measurements are used to quantify the durations of and between events. Time was designated by Kant as the purest possible schema of a pure concept or category.

qas: question: Who suggested that humankind does not exist inside time, but is time?
answers: text: Martin Heidegger

question: The relationship to the future is the state of anticipating what?
answers: text: a potential possibility, task, or engagement

question: What is considered a qualitative experience rather than a quantitative one?
answers: text: The present

question: According to Heidegger, what can we do, in our thoughts?
answers: text: step out of (ecstasis) sequential time.

question: Who thought that people are the possibilities they search for?

question: A linear relationship with time is the state of what?

question: How is the past defined instead of being quantitative?

question: What is broken when we are stuck in sequential time?

question: What are we able to do when stuck in sequential time?

question: Who suggested that humankind does not exist inside the present, but is the present?

question: What is considered a quantitative experience rather than a qualatative one?

question: What can we do in the present according to Heldegger?

question: Who said we do not exist in the future?

question: What are we able to forget?
context: According to Martin Heidegger we do not exist inside time, we are time. Hence, the relationship to the past is a present awareness of having been, which allows the past to exist in the present. The relationship to the future is the state of anticipating a potential possibility, task, or engagement. It is related to the human propensity for caring and being concerned, which causes "being ahead of oneself" when thinking of a pending occurrence. Therefore, this concern for a potential occurrence also allows the future to exist in the present. The present becomes an experience, which is qualitative instead of quantitative. Heidegger seems to think this is the way that a linear relationship with time, or temporal existence, is broken or transcended. We are not stuck in sequential time. We are able to remember the past and project into the future—we have a kind of random access to our representation of temporal existence; we can, in our thoughts, step out of (ecstasis) sequential time.

qas: question: Minkowski spacetime combines the three dimensions of space with what?
answers: text: a single dimension of time

question: In Minkowski spacetime, how can distances in space be measured?
answers: text: by how long light takes to travel that distance

question: What are two events in Minkowski spacetime separated by?
answers: text: by an invariant interval

question: The invariant interval between events is independent of what?
answers: text: of the observer (and his velocity)

question: The invariant interval that separates two events in Minkowski spacetime can either be what?
answers: text: space-like, light-like, or time-like

question: What are light years combined with in Minkowski spacetime?

question: How are bodies in space measured?

question: How are independent observers separated?

question: What are some characteristics that are applied to bodies in space?

question: What will events that have a time-like separation always be in some frame of reference?

question: What does Minkowski spacetime combine the three dimensions of time with?

question: In Minkowski spacetime, how can time be measured?

question: What are two events in Minkowski spacetime connected by?

question: What is the invariant interval between time is independent of?

question: What may the same observer calculate?
context: The theory of special relativity finds a convenient formulation in Minkowski spacetime, a mathematical structure that combines three dimensions of space with a single dimension of time. In this formalism, distances in space can be measured by how long light takes to travel that distance, e.g., a light-year is a measure of distance, and a meter is now defined in terms of how far light travels in a certain amount of time. Two events in Minkowski spacetime are separated by an invariant interval, which can be either space-like, light-like, or time-like. Events that have a time-like separation cannot be simultaneous in any frame of reference, there must be a temporal component (and possibly a spatial one) to their separation. Events that have a space-like separation will be simultaneous in some frame of reference, and there is no frame of reference in which they do not have a spatial separation. Different observers may calculate different distances and different time intervals between two events, but the invariant interval between the events is independent of the observer (and his velocity).

qas: question: What Newtonian concept can be used in the formulation of an idea for the synchronization of clocks?
answers: text: concept of "relative, apparent, and common time"

question: In which century did physicists encounter problems with the understanding of time?
answers: text: the late nineteenth century

question: The behavior of which two phenomena caused physicists to encounter problems with their understanding of time in the late 19th century?
answers: text: the behavior of electricity and magnetism

question: Which famous scientist resolved these issues?
answers: text: Einstein

question: In what year did Einstein encounter problems with using electricity?

question: Who's concept can be used to synchronize the use of electricity?

question: What did physicists use to solve the problems of electricity synchronization?

question: What did the use of the speed of light by Newton lead to?

question: What concept by Einstein can be used to synchronize electricity in classical mechanics?

question: What Newtonian concept can be used in the formulation of an idea for the understanding of clocks?

question: In which century did physicists encounter problems with the understanding of electricity?

question: Which famous scientist struggled with these issues?

question: The behavior of which two phenomena caused physicists to encounter problems with their understanding of clocks in the late 19th century?

question: How did Einstein resolve the two different observers?
context: In non-relativistic classical mechanics, Newton's concept of "relative, apparent, and common time" can be used in the formulation of a prescription for the synchronization of clocks. Events seen by two different observers in motion relative to each other produce a mathematical concept of time that works sufficiently well for describing the everyday phenomena of most people's experience. In the late nineteenth century, physicists encountered problems with the classical understanding of time, in connection with the behavior of electricity and magnetism. Einstein resolved these problems by invoking a method of synchronizing clocks using the constant, finite speed of light as the maximum signal velocity. This led directly to the result that observers in motion relative to one another measure different elapsed times for the same event.

qas: question: Historically, time has been closely related with what?
answers: text: space

question: In which of Einstein's two theories do time and space merge into spacetime?
answers: text: special relativity and general relativity

question: According to Einsteins two relativity theories, the concept of time depends on what?
answers: text: the spatial reference frame of the observer, and the human perception

question: A crew in a spaceship travelling nearly the speed of light will not notice the change in what?
answers: text: in the speed of time on board their vessel

question: How will the above mentioned spaceship appear to a stationary observer?
answers: text: the spaceship appears flattened in the direction it is traveling

question: What have a crew's thought processes usually been related to?

question: What is it called when a spaceship flies though space?

question: What does a space crew's thought processes depend on?

question: Flying through what makes the crew appear flattened out to each other?

question: What will an observer not notice the change of when watching a spaceship fly by?

question: Historically, what has been related to clocks?

question: In which of Einstein's two theories do time and clocks merge into spacetime?

question: According to Einstein's two relativity theories, what depends on the concept of clocks?

question: A crew in a spaceship traveling nearly the speed of sound will not notice the change in what?

question: How will the spaceship appear to an observer traveling at the same speed?
context: Time has historically been closely related with space, the two together merging into spacetime in Einstein's special relativity and general relativity. According to these theories, the concept of time depends on the spatial reference frame of the observer, and the human perception as well as the measurement by instruments such as clocks are different for observers in relative motion. For example, if a spaceship carrying a clock flies through space at (very nearly) the speed of light, its crew does not notice a change in the speed of time on board their vessel because everything traveling at the same speed slows down at the same rate (including the clock, the crew's thought processes, and the functions of their bodies). However, to a stationary observer watching the spaceship fly by, the spaceship appears flattened in the direction it is traveling and the clock on board the spaceship appears to move very slowly.

qas: question: How does the crew on board the spaceship perceive the stationary observer?
answers: text: slowed down and flattened along the spaceship's direction of travel

question: The crew's perception of what is different from a stationary observer?
answers: text: time

question: What the crew perceives as seconds might be seen as how long to a stationary observer?
answers: text: hundreds of years

question: What remains unchanged in both the cases of the spaceship crew and of the stationary observer?
answers: text: causality

question: How is the future perceived as by the crew?

question: Where does the future appear flattened and slowed according to the crew?

question: Why does the future appear this way to the crew?

question: Why does the crew believe that the universe is traveling slowly?

question: How long would it take for a spaceship to cross the universe?

question: How does the crew board the spaceship perceive the traveling observer?

question: The crew's perception of what is different from the ship?

question: What the crew perceives as seconds might be seen as how long to a moving observer?

question: What remains unchanged in both the cases of the spaceship crew and of the moving observer?

question: What is the set of events to which a moving observer can send light signals?
context: On the other hand, the crew on board the spaceship also perceives the observer as slowed down and flattened along the spaceship's direction of travel, because both are moving at very nearly the speed of light relative to each other. Because the outside universe appears flattened to the spaceship, the crew perceives themselves as quickly traveling between regions of space that (to the stationary observer) are many light years apart. This is reconciled by the fact that the crew's perception of time is different from the stationary observer's; what seems like seconds to the crew might be hundreds of years to the stationary observer. In either case, however, causality remains unchanged: the past is the set of events that can send light signals to an entity and the future is the set of events to which an entity can send light signals.

qas: question: Who showed, in his thought experiments, that people travelling at different speeds measured time differently?
answers: text: Einstein

question: In what case do these effects become much more noticeable?
answers: text: for objects moving at speeds approaching the speed of light.

question: How long do most subatomic particles exist for in a lab?
answers: text: a fixed fraction of a second

question: Einstein showed how what could be altered by high speed motion?
answers: text: both temporal and spatial dimensions

question: What subatomic particle was discovered by Einstein?

question: What slows down for a spacial demension's frame of reference?

question: What did Einstein show that light could be warped by?

question: When at rest, how fast is a dimension's velocity?

question: What seems to shorten in the presence of a spatial dimension?

question: Who showed, in his thought experiments, that people traveling at different speeds measured light differently?

question: In what case do these effects become much more relative?

question: How long do most subatomic particles exist for in a warp?

question: Einstein showed how what could be altered by fixed particles?

question: What exist for a second in a lab?
context: Einstein showed in his thought experiments that people travelling at different speeds, while agreeing on cause and effect, measure different time separations between events, and can even observe different chronological orderings between non-causally related events. Though these effects are typically minute in the human experience, the effect becomes much more pronounced for objects moving at speeds approaching the speed of light. Many subatomic particles exist for only a fixed fraction of a second in a lab relatively at rest, but some that travel close to the speed of light can be measured to travel farther and survive much longer than expected (a muon is one example). According to the special theory of relativity, in the high-speed particle's frame of reference, it exists, on the average, for a standard amount of time known as its mean lifetime, and the distance it travels in that time is zero, because its velocity is zero. Relative to a frame of reference at rest, time seems to "slow down" for the particle. Relative to the high-speed particle, distances seem to shorten. Einstein showed how both temporal and spatial dimensions can be altered (or "warped") by high-speed motion.

qas: question: What laws do not specify an arrow of time?
answers: text: the laws of physics

question: The direction of the arrow of time is sometimes what?
answers: text: arbitrary

question: Which law states that entropy must increase over time?
answers: text: the Second law of thermodynamics,

question: The violation of what implies that there should be a small counterbalancing time asymmetry?
answers: text: CP symmetry

question: The standard description of measurement in quantum mechanics is what?
answers: text: time asymmetric

question: In what directions do the laws of entropy allow light to go?

question: What does quantum mechanics determine about entropy?

question: What needs to be preserved according to quantum mechanics?

question: Which law says that CPT symmetry must increase over time?

question: In particle physics what should there be to preserve entropy?

question: What laws specify as an arrow of time?

question: The direction of the past is sometimes what?

question: Which law states that entropy must increase in the past?

question: The violation of what implies that there should be a small counterbalancing difection asymmetry?

question: What is the standard description of direction in quantum mechanics?
context: Time appears to have a direction—the past lies behind, fixed and immutable, while the future lies ahead and is not necessarily fixed. Yet for the most part the laws of physics do not specify an arrow of time, and allow any process to proceed both forward and in reverse. This is generally a consequence of time being modeled by a parameter in the system being analyzed, where there is no "proper time": the direction of the arrow of time is sometimes arbitrary. Examples of this include the Second law of thermodynamics, which states that entropy must increase over time (see Entropy); the cosmological arrow of time, which points away from the Big Bang, CPT symmetry, and the radiative arrow of time, caused by light only traveling forwards in time (see light cone). In particle physics, the violation of CP symmetry implies that there should be a small counterbalancing time asymmetry to preserve CPT symmetry as stated above. The standard description of measurement in quantum mechanics is also time asymmetric (see Measurement in quantum mechanics).

qas: question: Stephen Hawking makes a connection between time and what?
answers: text: the Big Bang

question: In which publication does Hawking say that any events that existed before the Big Bang would not be accessible to us?
answers: text: A Brief History of Time

question: What does Hawking suggest started with the big bang?
answers: text: time

question: Hawking also states that questions about what happened before the Big Bang are what?
answers: text: meaningless

question: Which philosopher has criticized Hawking's formulation?
answers: text: Aristotelian philosopher Mortimer J. Adler

question: What does Mortimer J. Adler think time has a connection with?

question: What book was written by Mortimer J. Adler?

question: What does Adler believe that questions about what happened before the Big Bang are?

question: Who has been criticized by Hawking for his stance on the Big Bang?

question: What kind of philosophy did Steven Hawking believe in?

question: What does Stephen Hawking make a connection between nothing and?

question: In which publication does Hawking say that any events that existed before the Big Bang would be nothing?

question: Which philosopher has praised Hawkings formulation?

question: What did Hawking say would not have an effect on the present time frame?

question: What did Hawking say time ended with?
context: Stephen Hawking in particular has addressed a connection between time and the Big Bang. In A Brief History of Time and elsewhere, Hawking says that even if time did not begin with the Big Bang and there were another time frame before the Big Bang, no information from events then would be accessible to us, and nothing that happened then would have any effect upon the present time-frame. Upon occasion, Hawking has stated that time actually began with the Big Bang, and that questions about what happened before the Big Bang are meaningless. This less-nuanced, but commonly repeated formulation has received criticisms from philosophers such as Aristotelian philosopher Mortimer J. Adler.

qas: question: The Big Bang model is solidly established in what?
answers: text: cosmology

question: How much is known about the early states of the universe?
answers: text: i

question: Which theorems require the existence of a singularity at the beginning of time?
answers: text: The Penrose–Hawking singularity theorems

question: These theorems have to assume what theory is correct?
answers: text: general relativity

question: These theorems state that general relatively must break down before what?
answers: text: before the universe reaches the Planck temperature

question: What does the Planck temperature require the existence of?

question: When does the Planck temperature show a singularity existed?

question: What will happen to the idea of the Planck temperature in the future?

question: What does the Planck temperature assume is correct?

question: When must quantum gravity break down?

question: The Penrose-Hawking model is solidly established in what?

question: How much is known about the early states of singularity theorems?

question: Which theorems require the existence of a singularity at the beginning of temperature?

question: These theorems have to assume what singularity is correct

question: These theorems state that a singularity must break down before what?
context: While the Big Bang model is well established in cosmology, it is likely to be refined in the future. Little is known about the earliest moments of the universe's history. The Penrose–Hawking singularity theorems require the existence of a singularity at the beginning of cosmic time. However, these theorems assume that general relativity is correct, but general relativity must break down before the universe reaches the Planck temperature, and a correct treatment of quantum gravity may avoid the singularity.

qas: question: How long has time travel been a topic in science fiction?
answers: text: since the 19th century

question: Traveling which direction in time has never been verified and presents many problems?
answers: text: backwards

question: A time machine is known as any technological devise that is used for what purpose?
answers: text: to achieve time travel

question: How long has space been a plot device in fiction?

question: What does the idea of traveling in space present?

question: What was space travel thought to be in the 19th century?

question: What did authors go beyond in the 19th century when writing fiction?

question: What are some devices thought to be when in the process of invention?

question: How long has time travel been a topic in theory?

question: Traveling which direction in time has never been verified and presents earthbound problems?

question: A theoretic problem is known as any technological devise that is used for what purpose?

question: What was a plot device in the 18th century?

question: What does not persist in some way?
context: Time travel is the concept of moving backwards or forwards to different points in time, in a manner analogous to moving through space, and different from the normal "flow" of time to an earthbound observer. In this view, all points in time (including future times) "persist" in some way. Time travel has been a plot device in fiction since the 19th century. Traveling backwards in time has never been verified, presents many theoretic problems, and may be an impossibility. Any technological device, whether fictional or hypothetical, that is used to achieve time travel is known as a time machine.

qas: question: What is another solution to the problem of temporal paradoxes?
answers: text: paradoxes cannot arise simply because they have not arisen

question: In several works of fiction, what ceases to exist in the past which causes paradoxes not to arise?
answers: text: free will

question: What paradox cannot be enacted because it is a fact that your grandfather was not killed before your parent was conceived?
answers: text: the grandfather paradox

question: What principle elaborates more on the view described?
answers: text: the Novikov self-consistency principle.

question: What is a solution to the Novikov self-consistency principle?

question: What can be changed by time travelers according to Novikov?

question: What principle further elaborates on how fiction can change history?

question: What is the Novikov self-consistency principle considered to be?

question: What paradox is formed when a person has free will?

question: What is another solution to the problem of hypothetical future?

question: In several works of fiction, what ceases to exist in the past which causes decisions not to arise?

question: What paradox cannot be enacted because it is a fact that your grandfather was not killed before your grandfather was conceived?

question: What principle elaborates less on the view described?

question: Why can paradoxes arise?
context: Another solution to the problem of causality-based temporal paradoxes is that such paradoxes cannot arise simply because they have not arisen. As illustrated in numerous works of fiction, free will either ceases to exist in the past or the outcomes of such decisions are predetermined. As such, it would not be possible to enact the grandfather paradox because it is a historical fact that your grandfather was not killed before his child (your parent) was conceived. This view doesn't simply hold that history is an unchangeable constant, but that any change made by a hypothetical future time traveler would already have happened in his or her past, resulting in the reality that the traveler moves from. More elaboration on this view can be found in the Novikov self-consistency principle.

qas: question: What type of drugs can impair the judgement of time?
answers: text: Psychoactive drugs

question: Stimulants lead humans to overestimate what?
answers: text: time intervals

question: What causes humans to underestimate time intervals?
answers: text: depressants

question: The level of what is the reason stimulants and depressants change human perceptions of time?
answers: text: The level of activity in the brain of neurotransmitters

question: Such chemicals do what to the firing of the brain's neurons?
answers: text: either excite or inhibit the firing of neurons

question: What do rats not understand?

question: What does a decreased firing rate allow more of in the brain?

question: What does the presence of neurons impair the judgement of in rats?

question: What can neurons lead humans and rats to overestimate?

question: What causes rats to underestimate dopamine levels?

question: What type of drugs can impair the judgement of events?

question: Stimulants lead humans to underestimate what?

question: What causes humans to estimate time intervals?

question: The level of what is the reason stimulants and depressants change human perceptions of neurons?

question: Such events do what to the firing of the brain's neurons?
context: Psychoactive drugs can impair the judgment of time. Stimulants can lead both humans and rats to overestimate time intervals, while depressants can have the opposite effect. The level of activity in the brain of neurotransmitters such as dopamine and norepinephrine may be the reason for this. Such chemicals will either excite or inhibit the firing of neurons in the brain, with a greater firing rate allowing the brain to register the occurrence of more events within a given interval (speed up time) and a decreased firing rate reducing the brain's capacity to distinguish events occurring within a given interval (slow down time).

qas: question: The use of time is important in understanding what?
answers: text: human behavior, education, and travel behavior

question: What is a developing field of time related study?
answers: text: Time-use research

question: Time use is always changing with advances in what?
answers: text: technology

question: Travelling to work has been observed to be about how long for a large number of cities over a long period?
answers: text: 20–30 minutes one-way

question: The use of technology is important in understanding what?

question: What is a developing field of technology related study?

question: Time use is always changing with long periods of what?

question: Traveling home has been observed to be about how long for a large number of cities over a long period?

question: What changes with education?
context: The use of time is an important issue in understanding human behavior, education, and travel behavior. Time-use research is a developing field of study. The question concerns how time is allocated across a number of activities (such as time spent at home, at work, shopping, etc.). Time use changes with technology, as the television or the Internet created new opportunities to use time in different ways. However, some aspects of time use are relatively stable over long periods of time, such as the amount of time spent traveling to work, which despite major changes in transport, has been observed to be about 20–30 minutes one-way for a large number of cities over a long period.

qas: question: What is another way of phrasing "time order"?
answers: text: chronological order

question: What never precedes cause because of causality?
answers: text: effect

question: In what ways can a sequence of events be presented?
answers: text: in text, tables, charts, or timelines

question: What may the description of events include?
answers: text: a timestamp

question: A sequence of events used to describe a sequential path can be referred to as what?
answers: text: a world line

question: What is another way of phrasing "sequence of events"?

question: What never precedes cause because of timelines?

question: In what ways can a sequence of relationships be presented?

question: What may the description of relationships include?

question: What can a sequence of relationships used to describe a sequential path be referred to as?
context: A sequence of events, or series of events, is a sequence of items, facts, events, actions, changes, or procedural steps, arranged in time order (chronological order), often with causality relationships among the items. Because of causality, cause precedes effect, or cause and effect may appear together in a single item, but effect never precedes cause. A sequence of events can be presented in text, tables, charts, or timelines. The description of the items or events may include a timestamp. A sequence of events that includes the time along with place or location information to describe a sequential path may be referred to as a world line.

qas: question: Uses of sequences of events include what?
answers: text: stories, historical events (chronology), directions and steps in procedures, and timetables

question: What may a sequence of events be used to describe?
answers: text: processes in science, technology, and medicine

question: The use of what occurs in fields as diverse as machines, documentaries, or computer simulation?
answers: text: a sequence of events

question: What is a specific example of a sequence of events?
answers: text: the timeline of the Fukushima Daiichi nuclear disaster

question: Uses of sequences of order include what?

question: What may a sequence of order be used to describe?

question: The use of what occurs in history as diverse as machines, documentaries, or computer simulation?

question: What is a specific example of a sequence of history?

question: What may a sequence of history be focused on?
context: Uses of a sequence of events include stories, historical events (chronology), directions and steps in procedures, and timetables for scheduling activities. A sequence of events may also be used to help describe processes in science, technology, and medicine. A sequence of events may be focused on past events (e.g., stories, history, chronology), on future events that must be in a predetermined order (e.g., plans, schedules, procedures, timetables), or focused on the observation of past events with the expectation that the events will occur in the future (e.g., processes). The use of a sequence of events occurs in fields as diverse as machines (cam timer), documentaries (Seconds From Disaster), law (choice of law), computer simulation (discrete event simulation), and electric power transmission (sequence of events recorder). A specific example of a sequence of events is the timeline of the Fukushima Daiichi nuclear disaster.