Instruct: Given a question, retrieve relevant passages that can help answer the question.
Query: How many nanoseconds are in a second?
A nanosecond (ns) is an SI unit of time equal to one thousand-millionth of a second (or one billionth of a second), that is, / of a second, or 10 seconds.
The Mahāsāṃghika, translated into Chinese as the "Móhēsēngzhī Lǜ" (Taishō Tripiṭaka 1425) describes several units of time, including "shùn" or "shùnqǐng" () and "niàn". According to this text, "niàn" is the smallest unit of time at 18 milliseconds and a "shùn" is 360 milliseconds. It also describes larger units of time, including a "tánzhǐ" () which is 7.2 seconds long, a "luóyù" () which is 2 minutes 24 seconds long, and a "xūyú" (), which is of a day at 48 minutes long.
In physics, a theoretical lower-bound unit of time called the Planck time has been proposed, that being the time required for light to travel a distance of 1 Planck length. The Planck time is theorized to be the smallest time measurement that will ever be possible, roughly 10 seconds. Within the framework of the laws of physics as they are understood today, for times less than one Planck time apart, one can neither measure nor detect any change. It is therefore physically impossible, with current technology, to determine if any action exists that causes a reaction in "an instant", rather than a reaction occurring after an interval of time too short to observe or measure.
In astronomy, the Julian year is a unit of time; it is defined as 365.25 days of exactly 86,400 seconds (SI base unit), totalling exactly 31,557,600 seconds in the Julian astronomical year.
Fast draw is one of the fastest sports in the world. Every time is measured under one second, from the signal to draw to when the timer is stopped. The current World Fast Draw Association (WFDA) record for Open Class Fast Draw in an event called Standing Balloons is .208 seconds - and that includes the time it takes to react, draw, fire and pop a balloon target at eight feet away. A world class competitor can draw and fire a shot in under half a second. Given that the average human reaction time is around 0.2 to 0.25 seconds, the round is over before most people can react. The reaction times of the best fast draw shooters is 0.145 seconds, which means that the gun is cocked, drawn, aimed (from the hip), and fired in just over 0.06 seconds. To establish a World Fast Draw Association record, a second shot must be fired in the same competition that is no more than 0.30 seconds slower than the first; this is intended to prevent a shot that anticipates the start signal from setting a record. In competitions where two rounds must be fired, at separate targets, less than 0.10 seconds separate the shots.
Nanoionic hard drives use nanoionic technology allowing for smaller devices while doing away with moving parts and the mechanical failures which are associated with previous HDD drives. Nanoionic hard drives are currently the most state of the art drives on the market and nanoionics was not utilized in hard drives until February 2014. Nanoionic devices were first proposed in 1992: "The results obtained show that it is possible to form arrays of electrochemical devices with single elements ~10 nm in size in the films". The basis of design of nanoionic devices is the creation of nanostructures with nanoionic parameter "λ" / "L" ~ 1, where "L" is the size of device structure, and "λ" is the characteristic size of specific region where the property of fast ionic transport is realized. “Possibilities to influence on these specific regions < λ > in a controllable manner may appear in short sized devices”. Ion - electronic hybrid devices should be considered as a step on a way to the future nanoelectronics-nanoionics (nanoelionics) that was first proposed in 1996.
The Julian year, as used in astronomy and other sciences, is a time unit defined as exactly 365.25 days. This is the normal meaning of the unit "year" (symbol "a" from the Latin "annus") used in various scientific contexts. The Julian century of days and the Julian millennium of days are used in astronomical calculations. Fundamentally, expressing a time interval in Julian years is a way to precisely specify how many days (not how many "real" years), for long time intervals where stating the number of days would be unwieldy and unintuitive. By convention, the Julian year is used in the computation of the distance covered by a light-year.
An Atom of time or "a-tom" (“indivisible” in Greek), refers to the smallest possible unit of time.
The following example concerns definitions of quantities and units. The (average) velocity ("v") of an object is defined as the quantitative physical property of the object that is directly proportional to the distance ("d") traveled by the object and inversely proportional to the time ("t") of travel, i.e., "v" = "kd"/"t", where "k" is a constant that depends on the units used. Suppose that the meter (m) and the second (s) are base units; then the kilometer (km) and the hour (h) are noncoherent derived units. The meter per second (mps) is defined as the velocity of an object that travels one meter in one second, and the kilometer per hour (kmph) is defined as the velocity of an object that travels one kilometer in one hour. Substituting from the definitions of the units into the defining equation of velocity we obtain, 1 mps = "k" m/s and 1 kmph = "k" km/h = 1/3.6 "k" m/s = 1/3.6 mps. Now choose "k" = 1; then the meter per second is a coherent derived unit, and the kilometer per hour is a noncoherent derived unit. Suppose that we choose to use the kilometer per hour as the unit of velocity in the system. Then the system becomes noncoherent, and the numerical value equation for velocity becomes {"v"} = 3.6 {"d"}/{"t"}. Coherence may be restored, without changing the units, by choosing "k" = 3.6; then the kilometer per hour is a coherent derived unit, with 1 kmph = 1 m/s, and the meter per second is a noncoherent derived unit, with 1 mps = 3.6 m/s.
This section is based on the work of Jong-Ping Hsu and Leonardo Hsu. They decided to use the word "Taiji" which is a Chinese word meaning the ultimate principles that existed before the creation of the world. In SI units, time is measured in seconds, but taiji time is measured in units of metres — the same units used to measure space. Their arguments about choosing what units to measure time in, lead them to say that they can develop a theory of relativity which is experimentally indistinguishable from special relativity, but without using the second postulate in their derivation. Their claims have been disputed.
The transformations that they derive involve the factor formula_2 where β is the velocity measured in metres per metre (a dimensionless quantity). This looks the same as (but should NOT be conceptually confused with) the velocity as a fraction of light v/c that appears in some expressions for the Lorentz transformations. Expressing time in metres has previously been done by other authors: Taylor and Wheeler in "Spacetime Physics" and Moore in "Six Ideas that Shaped Physics".
One of the earliest occurrences of the word “atom” to mean the smallest possible unit of measuring time is found in the Greek text of the New Testament in Paul's . The text compares the length of time of the “atom” to the time needed for “the twinkling of an eye.” The text reads: “en atomo, en repe ophthamou” – the word "atom" is usually translated "a moment" - “In a moment, in the twinkling of an eye”. With that meaning it was later referred to in Medieval philosophical writings as the smallest possible division of time. The earliest known occurrence in English is in Byrhtferth's "Enchiridion" (a science text) of 1010–1012, where it was defined as 1/564 of a "momentum" (1½ minutes), and thus equal to 15/94 of a second. It was used in the "computus", the calculation used to determine the calendar date of Easter.
Magnetic fields are vector quantities characterized by both strength and direction. The strength of a magnetic field is measured in units of tesla in the SI units, and in gauss in the cgs system of units. 10,000 gauss are equal to one tesla. Measurements of the Earth's magnetic field are often quoted in units of nanotesla (nT), also called a gamma. The Earth's magnetic field can vary from 20,000 to 80,000 nT depending on location, fluctuations in the Earth's magnetic field are on the order of 100 nT, and magnetic field variations due to magnetic anomalies can be in the picotesla (pT) range. "Gaussmeters" and "teslameters" are magnetometers that measure in units of gauss or tesla, respectively. In some contexts, magnetometer is the term used for an instrument that measures fields of less than 1 millitesla (mT) and gaussmeter is used for those measuring greater than 1 mT.
A game consisted of four 15-minute quarters with a halftime intermission 20 minutes in length. The clock typically only stopped for time-outs, penalties, injuries, and official clarifications. Further stoppages occurred for incomplete passes and out of bounds during the final 90 seconds of the second and fourth quarters. A mandatory official's time-out, called a promotional timeout, was assessed after the first and third quarters and is 90 seconds in duration. Another mandatory official's time-out, called a warning period, was assessed with 90 seconds to play at the end of each half. The game could also be stopped for further promotional time-outs but not exceed 90 seconds per league rules.
Taking a day to be 24 hours, the smallest time unit, "prāṇa", or one respiratory cycle, equals 4 seconds, a value consistent with the "normal breathing frequency" of 15 breaths/min used in modern medical research. The Surya Siddhanta also described a method of converting local time to the standard time of Ujjain. Despite these early advances, standard time was not widely used outside astronomy. For most of India's history, ruling kingdoms kept their own local time, typically using the Hindu calendar in both lunar and solar units. For example, the Jantar Mantar observatory built by Maharaja Sawai Jai Singh in Jaipur in 1733 contains large sundials, up to 90 ft (27 m) high, which were used to accurately determine the local time.
The idea that ice ages cycles were predictable appears to have become conflated with the idea that another one was due "soon" - perhaps because much of this study was done by geologists, who are accustomed to dealing with very long time scales and use "soon" to refer to periods of thousands of years. A strict application of the Milankovitch theory does not allow the prediction of a "rapid" ice age onset (i.e., less than a century or two) since the fastest orbital period is about 20,000 years. Some creative ways around this were found, notably one championed by Nigel Calder under the name of "snowblitz", but these ideas did not gain wide acceptance.
British physicist Sir Alfred Brian Pippard wrote, "There is thus no justification for the view, often glibly repeated, that the Second Law of Thermodynamics is only statistically true, in the sense that microscopic violations repeatedly occur, but never violations of any serious magnitude. On the contrary, no evidence has ever been presented that the Second Law breaks down under any circumstances." However, there are a number of paradoxes regarding violation of the second law of thermodynamics, one of them due to the Poincaré recurrence theorem.
The timestamps printed on the photos in the NASA press release do not correspond to the actual time that the shadow was imaged, rather they represent the "image start time" of a vertically much larger original image. Mars Global Surveyor orbits Mars in a Sun-synchronous polar orbit with orbital period 117.65 minutes, moving from south pole to north pole, and continuously points its camera straight down. The result is an image in the form of a very long thin vertical strip, where the pixels in the top part of the image are imaged nearly one hour after those in the bottom part of the image. In principle the image could be as much as 43200 pixels high, but "downtrack summing" is used to merge adjacent lines. For instance, a downtrack summing factor of 27 causes every 27 lines to be merged into one, resulting in an image 1600 pixels high. Thus to determine the actual time that the Phobos shadow was imaged, it is necessary to locate the original image and measure how many pixels from the bottom of the image the shadow is found and add the corresponding offset to the image start time.
The scientific study of the nervous system increased significantly during the second half of the twentieth century, principally due to advances in molecular biology, electrophysiology, and computational neuroscience. This has allowed neuroscientists to study the nervous system in all its aspects: how it is structured, how it works, how it develops, how it malfunctions, and how it can be changed. For example, it has become possible to understand, in much detail, the complex processes occurring within a single neuron. Neurons are cells specialized for communication. They are able to communicate with neurons and other cell types through specialized junctions called synapses, at which electrical or electrochemical signals can be transmitted from one cell to another. Many neurons extrude a long thin filament of axoplasm called an axon, which may extend to distant parts of the body and are capable of rapidly carrying electrical signals, influencing the activity of other neurons, muscles, or glands at their termination points. A nervous system emerges from the assemblage of neurons that are connected to each other.
Relativistic speed refers to speed at which relativistic effects become significant to the desired accuracy of measurement of the phenomenon being observed. Relativistic effects are those discrepancies between values calculated by models considering and not considering relativity. Related words are velocity, rapidity, and celerity which is proper velocity. Speed is a scalar, being the magnitude of the velocity vector which in relativity is the four-velocity and in three-dimension Euclidean space a three-velocity. Speed is empirically measured as average speed, although current devices in common use can estimate speed over very small intervals and closely approximate instantaneous speed. Non-relativistic discrepancies include cosine error which occurs in speed detection devices when only one scalar component of the three-velocity is measured and the Doppler effect which may affect observations of wavelength and frequency.Relativistic effects are highly non-linear and for everyday purposes are insignificant because the Newtonian model closely approximates the relativity model. In special relativity the Lorentz factor is a measure of time dilation, length contraction and relativistic mass increase of a moving object.
X-rays range in wavelength from 10 to 0.01 nanometers; a typical wavelength used for crystallography is 1 Å (0.1 nm), which is on the scale of covalent chemical bonds and the radius of a single atom. Longer-wavelength photons (such as ultraviolet radiation) would not have sufficient resolution to determine the atomic positions. At the other extreme, shorter-wavelength photons such as gamma rays are difficult to produce in large numbers, difficult to focus, and interact too strongly with matter, producing particle-antiparticle pairs. Therefore, X-rays are the "sweetspot" for wavelength when determining atomic-resolution structures from the scattering of electromagnetic radiation.
A rugby union game is divided into two halves of 40 minutes (or shorter for lower-grade games, and breaks given halfway through each half if playing conditions are considered to be extreme) separated by a half time period of up to 15 minutes in an international match. Most notably, a rugby union game will continue after the scheduled end of a half (half-time or full-time) until the ball becomes dead - any occurrence that would have play restart with a scrum or lineout, or when a team scores. This has led to some "nail-biting" finishes where teams losing by only a small margin work their way towards scoring, and games can go on several minutes over time. Something similar can occur at the end of either half in American football, though usually for only a few seconds of additional time, because a play that begins before the half expires continues until the ball is dead regardless of whether there is any time left on the clock. In both sports, the clock is also stopped during substitutions and for injuries, so the referee does not need to add stoppage time as is done in soccer/Association football. American football games are made up of four quarters of 15 minutes each (less at the high school and youth levels), but the clock stops and starts according to specific rules, so that a 15-minute quarter lasts much longer.
Multiples of seconds are usually counted in hours and minutes. Fractions of a second are usually counted in tenths or hundredths. In scientific work, small fractions of a second are counted in milliseconds (thousandths), microseconds (millionths), nanoseconds (billionths), and sometimes smaller units of a second.
An everyday experience with small fractions of a second is a 1-gigahertz microprocessor which has a cycle time of 1 nanosecond. Camera shutter speeds usually range from second to second.
Just as the second forms the basis for other units of time, the light-second can form the basis for other units of length, ranging from the light-nanosecond (299.8 mm or just under one international foot) to the light-minute, light-hour and light-day, which are sometimes used in popular science publications. The more commonly used light-year is also presently defined to be equal to precisely light-seconds, since the definition of a year is based on a Julian year (not Gregorian year) of exactly 365.25 days, each of exactly SI seconds.
One picosecond is equal to 1000 femtoseconds, or 1/1000 nanoseconds. Because the next SI unit is 1000 times larger, measurements of 10 and 10 second are typically expressed as tens or hundreds of picoseconds. Some notable measurements in this range include:
Units of time based on orders of magnitude of the second include the nanosecond and the millisecond.