Topic: special relativity

topics > Group: science

absolute vs. relative names
electricity and magnetism
event time
general relativity
history of science
Newtonian physics
the effect of scale
Subtopic: relativity as a principle up

Quote: the principle of relativity is that equations of mechanics hold in all frames of reference and that the speed of light is constant [»einsA9_1905]
Quote: religiousness A's absolute relationship to an absolute God results in despair at sustaining the relationship; all is leveled and relative [»dreyHL_1991]
Quote: the phases of the moon as seen from earth are the same as the phases of the earth as seen from the moon [»galiG_1632]
Quote: the law of relativity applies to the entire universe [»poinH_1902, OK]

Subtopic: measurement up

Quote: observation depends on coincidence in space and time, independent of a frame of reference; fundamental idea of relativity [»bohrN_1934]

Subtopic: synchronous up

Quote: clocks at rest relative to each other are synchronized if, by definition, the time for light to travel from A to B is the time for it to travel from B to A [»einsA9_1905]

Subtopic: space and time are relative up

Quote: experiments have shown that ether, i.e., absolute space, does not exist [»poinH_1902, OK]
Quote: whoever speaks of absolute space uses a meaningless phrase; space is relative to other objects, e.g., place du Pantheon [»poinH_1908, OK]
Quote: there is no absolute space, no absolute time, no simultaneity across distance, not even geometry; these concepts are no more than a language [»poinH_1902, OK]
Quote: a sharp distinction between space and time is only possible when velocities are much lower than the speed of light [»bohrN_1934]
Quote: space and time have meaning only if neglect interaction due to measurement; e.g., a blind man exploring a room with a stick [»bohrN_1934]

Subtopic: motion is relative up

Quote: motion is relative to things at rest; among things that share equally in a motion, motion is as if it did not exist [»galiG_1632]
Quote: Newton first stated the principle of relativity: the motions of bodies in a given space are independent of uniform motion of the space in a straight line [»feynRP_1963]
Quote: force is real; space, time, and motion are relative, a relationship [»leibGW4_1695]
Quote: the laws of motion must preserve the relative nature of motion
Quote: no special laws for equal bodies or bodies at rest; since rest is vanishingly small motion, and equality is vanishingly small inequality [»leibGW4_1695]
Quote: size, shape, and motion are relative to our perceptions; like color, heat, etc.

Subtopic: special relativity up

Quote: the principle of relativity is that equations of mechanics hold in all frames of reference and that the speed of light is constant [»einsA9_1905]
Quote: the length of a rod measured in the rest system differs from the length in a moving system [»einsA9_1905]
Quote: Einstein developed the special theory of relativity from the paradox of traveling at the speed of light; not from constructive efforts based on known facts [»einsA_1949]
Quote: the restricted principle of relativity is that natural phenomena follow exactly the same laws in all inertial co-ordinate systems [»einsA_1916b]
Quote: Newton's first law is only valid for inertial frames of reference; why should inertial frames have priority over other frames of reference? Newton saw this objection [»einsA_1916b]

Subtopic: special relativity as relative measurement up

Quote: experiments have reference to relations between bodies, not to space [»poinH_1902, OK]
Quote: the law of relativity: a system depends on the state of its bodies and their mutual distances; it does not depend on absolute position and orientation [»poinH_1902, OK]
Quote: geometric empiricism and measurement do not have a rational meaning; only the relations between measurements
Quote: Lorentz explained the Michelson experiments by supposing the velocity of light was constant while lengths depended on direction
Quote: the distance between two points is meaningless by itself; it depends on how distance is measured [»poinH_1908, OK]
Quote: four-dimensional space-time, the effect of motion on bodies and clocks, and the equivalence of energy and inert mass, follow from the interpretation of coordinates and time as products of measurement [»einsA_1934]

Subtopic: speed of light up

Quote: the word "simultaneous" requires the speed of light; sharper definitions are not possible; a constant speed of light does not contradict concepts of position, velocity, and time [»heisW_1927]
Quote: we can measure distance with light only if we suppose that the velocity of light is constant for all observers [»poinH_1908, OK]
Quote: measure the speed of light by measuring the round-trip delay over a large distance
Quote: light moves with the swiftest motion [»galiG_1638]
Quote: constant speed of light in inertial systems from Maxwell-Lorentz's electromagnetic equations for empty space; otherwise, could distinguish one inertial system from the others [»einsA3_1936]
Quote: if approach light at the speed of light, infinitely intense [»einsA9_1905]

Subtopic: special relativity and space time up

Quote: every description of an event or position of an object depends on coincidences with a rigid body of reference or, equivalently, a Cartesian system of co-ordinates [»einsA_1916b]
Quote: the only observables are space-time coincidences [»einsA_1916]
Quote: time is nothing but the form of our internal intuition; it has empirical reality but not absolute reality [»kantI_1781, OK]
Quote: universal agreement is possible for judgments of simultaneity, coincidence, and number [»campNR_1919, OK]

Subtopic: special relativity and clocks up

Quote: moving clocks are slower than stationary ones; for example a clock at the equator is slightly slower than an identical clock at one of the poles [»einsA9_1905]
Quote: everyday experience fails to differentiate between "simultaneously seen" and "simultaneously happening"; i.e., the difference between local time and time
Quote: objective time requires a local time (clock) that is extended to events in the whole space [»einsA3_1936]
Quote: in a rotating disk or gravitational field, the speed of a clock depends on its location [»einsA_1916b]
Quote: clocks move slower in a moving system; construct a clock by bouncing light perpendicular to the motion; to the stationary observer, the light follows a longer, zigzag path and the clock ticks are slower [»feynRP_1963]
Quote: if ideal clocks go at the same rate, they always go at the same rate; e.g., sharp spectral lines from atoms of the same chemical element; a foundation of 4-d space-time
Quote: if one clock behaved differently than another in a moving system, could distinguish the systems; hence all clocks behave the same
Quote: the frequency that an atom absorbs or emits light depends on its position in a gravitational field, just as a clock on a rotating disk depends on its distance from the center [»einsA_1916b]
Quote: Adams confirmed that spectral lines shift toward red in a strong gravitational field; predicted by Einstein
Quote: on a rocket ship a clock at the head runs faster than one at the tail; the same thing happens in a gravitational field, the higher clock runs faster [»feynRP_1964]
Quote: an altitude difference of 20 meters at the earth's surface speeds up a clock by two parts in 10^15; tested experimentally with the Mossbauer effect

Subtopic: special relativity and simultaneous events up

Quote: space and time must be interlocked because simultaneous events are relative; 'now' is inconsistent at a distance [»feynR_1965]
Quote: all judgments of time concern simultaneous events [»einsA9_1905]
Quote: simultaneous events in a stationary frame are not simultaneous in a moving frame; even if measure lightning flashes at the midpoint of two locations [»einsA_1916b]
Quote: since distance measures depend on simultaneous events; length depends on the frame of reference [»einsA_1916b]

Subtopic: frame of reference up

Quote: in the general theory of relativity the space-time metric only applies to small regions of a gravitational field
Quote: we impose the frames of time and space on nature because we find them convenient [»poinH_1905, OK]
Quote: mathematical analysis is primarily the study of temporal and spatial frames
Quote: mathematical analysis is a language for learning the internal harmony of the world, the only true objective reality
Quote: if special relativity was false, there would be an absolute frame of reference and physical systems would depend on their relationship to the rapidly moving earth; such effects are not seen [»einsA_1916b]
Quote: motion is relative to a frame of reference; a dropt stone follows a straight line in a stationary frame and a parabolic curve in a moving frame [»einsA_1916b]
Quote: simultaneity depends on the frame of reference; synchronous clocks in a stationary system are not synchronous in a moving system [»einsA9_1905]
Quote: the only purpose of a system of reference is to help describe the totality of coincidences in space-time
Quote: if a box is at rest inside another box, the two spaces are the same; not true if the boxes move relative to each other [»einsA_1916b]
Quote: there are an infinite number of spaces which are in motion relative to each other

Subtopic: Lorentz transformation up

Quote: with the Lorentz transformation, x=ct holds in a stationary frame and the transformed equation, x'=ct', holds in a moving frame of reference [»einsA_1916b]
Quote: when relativity was discovered, the electromagnetic laws already accounted for relativistic effects

Subtopic: space time up

Quote: space and time do not stand alone; only space-time has an independent reality [»minkH9_1908]
Quote: physical laws should relate world-lines, the histories of substantial points through space-time [»minkH9_1908]
Quote: physical reality consists of space-time events; no rational division into a 3-d space and a time continuum; laws of nature must correspond [»einsA_1956, OK]
Quote: physicists have changed the concepts of time and space to fit experience; were a priori
Quote: time and space are a priori; both are necessary conditions for the possibility of appearances [»kantI_1781, OK]

Subtopic: space up

Quote: space is relative to a body; it is all possible continuations of a body by adjacent bodies [»einsA_1956, OK]

Subtopic: space vs. time up

Quote: events outside of the light cone from event P have a time-like relation to P; those inside have a space-like relation [»einsA_1956, OK]
Quote: Newtonian physics assumes the existence of a real universe; relativity and quantum mechanics are based on observability

Related Topics up

Topic: absolute vs. relative names (12 items)
Topic: electricity and magnetism (53 items)
Topic: event time (45 items)
Topic: general relativity (47 items)
Topic: history of science (52 items)
Topic: Newtonian physics (79 items)
Topic: physics (51 items)
Topic: the effect of scale (17 items)
Topic: time
(49 items)

Updated barberCB 5/05
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