He made the first measurement of stellar parallax: 0. 3 arcsec for the binary star 61 Cygni.

Aberration should not be confused with stellar parallax, although it was an initially fruitless search for parallax that first led to its discovery.

61 Cygni is significant because Friedrich Wilhelm Bessel determined its parallax in 1838, the first star to have a known parallax.

With this work under his belt, Bessel was able to achieve the feat for which he is best remembered today: he is credited with being the first to use parallax in calculating the distance to a star.

Astronomers had believed for some time that parallax would provide the first accurate measurement of interstellar distances — in fact, in the 1830s there was a fierce competition between astronomers to be the first to measure a stellar parallax accurately.

According to Mohani Mohamed, the Arabian astronomer Alhazen ( 965 – 1037 ) made the first attempt at observing and measuring the Milky Way's parallax, and he thus " determined that because the Milky Way had no parallax, it was very remote from the Earth and did not belong to the atmosphere.

Among its results were determinations of the lunar and of the solar parallax ( Mars serving as an intermediary ), the first measurement of a South African arc of the meridian, and the observation of 10, 000 southern stars.

The first direct measurement of the distance to a star ( 61 Cygni at 11. 4 light-years ) was made in 1838 by Friedrich Bessel using the parallax technique.

It was one of the first stars whose distance was estimated through parallax measurements.

The first person to publish a star's parallax was Friedrich G. W. von Struve, when he announced a value of 0. 125 arcseconds ( 0. 125 ″) for Vega.

Thus most astronomers at the time, including Struve, credited Bessel with the first published parallax result.

Astronomers of the era expected that changes over time in the apparent separation and relative location of these stars would provide evidence for both the proper motion of stars and, by means of parallax shifts in their separation, for the distance of stars from the Earth ( a method first suggested by Galileo Galilei ).

* The first parallax measurement of the distance to Alpha Centauri is published by Thomas Henderson.

* 11th century — Ibn al-Haytham ( Alhazen ), an Arabian astronomer, refutes Aristotle's theory on the Milky Way by making the first attempt at observing and measuring the Milky Way's parallax,

Their measurement of γ Virginis in 1718 was the first made of the components of a double star and was directed towards the determination of stellar parallax.

The first successful measurement of stellar parallax was made by Friedrich Bessel in 1838 for the star 61 Cygni using a Fraunhofer heliometer at Königsberg Observatory.

Measurement of annual parallax was the first reliable way to determine the distances to the closest stars.

The first successful measurements of stellar parallax were made by Friedrich Bessel in 1838 for the star 61 Cygni using a heliometer.

He was also the first to measure the parallax of Vega, although Friedrich Bessel had been the first to measure the parallax of a star ( 61 Cygni ).

Some conversions from one system of units to another need to be exact, without increasing or decreasing the precision of the first measurement.

: A further argument is that relativistic difficulties about establishing which measurement occurred first also undermine the idea that one observer is causing what the other is measuring.

This is totally spurious, since no matter who measured first the other will measure the opposite spin despite the fact that ( in theory ) the other has a 50 % ' probability ' ( 50: 50 chance ) of measuring the same spin, unless data about the first spin measurement has somehow passed faster than light ( of course TI gets around the light speed limit by having information travel backwards in time instead ).

This method of measurement is inherited from the method used for the first generation of CRT television, when picture tubes with circular faces were in common use.

It is one thing to say that physical measurement of the first particle's momentum affects uncertainty in its own position, but to say that measuring the first particle's momentum affects the uncertainty in the position of the other is another thing altogether.

His announcement of Sirius's " dark companion " in 1844 was the first correct claim of a previously unobserved companion by positional measurement, and eventually led to the discovery of Sirius B.

Among the first investigations of ferromagnetism are the pioneering works of Aleksandr Stoletov on measurement of the magnetic permeability of ferromagnetics, known as the Stoletov curve.

In 2008 it was suggested that the Pharos was the vertical yardstick used in the first precise measurement of the size of the earth.

The psychometrician L. L. Thurstone, founder and first president of the Psychometric Society in 1936, developed and applied a theoretical approach to measurement referred to as the law of comparative judgment, an approach that has close connections to the psychophysical theory of Ernst Heinrich Weber and Gustav Fechner.

Slipher first reports on his measurement in the inaugural volume of the Lowell Observatory Bulletin.

* One time, as the referees were spotting the ball before a measurement to determine if the Chiefs got a first down, Stram yelled to the officials, " You didn't mark it right!

Then they made an exact, or ' strong ', measurement of the first polarization to see whether it had been disturbed by the second measurement.

The results of the first test can be treated as a baseline or control measurement ; all subsequent tests can then be compared to the baseline to indicate improvement.

* Friedrich Bessel makes the first accurate measurement of distance to a star.

In practical conditions and measurement, the multipath time is computed by considering as last impulse the first one which allows to receive a determined amount of the total transmitted power ( scaled by the atmospheric and propagation losses ), e. g. 99 %.

When the input is a pure sine wave, the measurement is most commonly the ratio of the sum of the powers of all higher harmonic frequencies to the power at the first harmonic, or fundamental, frequency:

Incidentally, the first public performance of the poem was on August 14, 1888, by actor De Wolf Hopper, on Thayer's 25th birthday.

However, the Daleks return in " Bad Wolf "/" The Parting of the Ways " ( 2005 ), and subsequently in " Army of Ghosts "/" Doomsday " ( 2006 ), " Daleks in Manhattan "/" Evolution of the Daleks " ( 2007 ), " The Stolen Earth "/" Journey's End " ( 2008 ) and " Victory of the Daleks " ( 2010 ), the penultimate of these being the series 4 finale where Davros also returns, and the final of these being the first time the Eleventh Doctor meets the Daleks.

Universal's horror cycle continued into the 1940s, these included The Wolf Man ( 1941 ), not the first werewolf film, but certainly the most influential, as well as a number of films uniting several of their monsters.

The first Board of Directors included Monica Hargraves, Dan Cogan, Margaret McCasland, Erica Van Etten, Greg Spence Wolf, Bob LeRoy, LeGrace Benson, Wally Woods, Jennifer Elges, and Donald Stephenson.

The cyclic variation of the number of sunspots was first observed by Heinrich Schwabe between 1826 and 1843 and led Wolf to make systematic observations starting in 1848.

The first Trojan discovered, 588 Achilles, was spotted in 1906 by the German astronomer Max Wolf.

Maximilian Franz Joseph Cornelius Wolf ( 1890 )— the discoverer of the first Trojan

The first recognized discovery of a Trojan occurred in February 1906, when astronomer Max Wolf of Heidelberg-Königstuhl State Observatory discovered an asteroid at the Lagrangian point of the Sun – Jupiter system, later named 588 Achilles.

In 1958 Wolf Vostell becomes the first artist who incorporates a television set into one of his works.

Werewolves are often depicted as immune to damage caused by ordinary weapons, being vulnerable only to silver objects, such as a silver-tipped cane, bullet or blade ; this attribute was first adopted cinematically in The Wolf Man.

* In 919, the first use of gunpowder in battle occurred with the Chinese Battle of Lang-shan Jiang ( Wolf Mountain River ), where the naval fleet of the Wen-Mu-King defeated Chien Yuan Kuan because Wen had used ' fire oil ' ( huo yóu, 火油 ) of gunpowder-fuse ignited flamethrowers to burn Chien's fleet.

The first non-native to re-settle in the area may have been a trader named Guillory, who might have had a trading-post near Wolf Point on the Chicago River in around 1778.

During this time, Wiesbaden became Protestant with the nomination of Wolf Denthener as first Lutheran pastor on January 1, 1543.

In 2365, the Federation had first formal contact with the Borg Collective, who threatened the existence of the Federation at the Battle of Wolf 359.

Wolf first used Staats ' time-out procedure in a 1964 published study dealing with the behavioral treatment of a child.

In the Battle of Langshan Jiang ( Wolf Mountain River ) in 932, the naval fleet of the Wenmu King of Wuyue defeated the fleet of the Kingdom of Wu because he had used ' fire oil ' ( huo yóu, 火油 ) to burn his fleet ; this signified the first Chinese use of gunpowder in warfare, since a slow-burning match fuse was required to ignite the flames.

It became a hit for the channel, spawning many future stars in both music and acting during its nine-year run, including Martika ( who went by her real name of Marta Marrero in the show's first season ), eventual Party of Five co-stars Scott Wolf and Jennifer Love Hewitt ( billed as Love Hewitt ), and Stacy Ferguson ( later known as " Fergie " of The Black Eyed Peas ).

King and Howlin ' Wolf made their first recordings at his studio.

Burkesville is the first city downstream from Wolf Creek Dam.

The universality of Sirius lore, even the Pawnee tribe of North America, and others, referred to Sirius as the ' Wolf Star ', indicates this Sothic Mythos may have extremely ancient roots, perhaps as old as the first humans to migrate from Africa.

His Principles for Oral Narrative Research, recently translated by K. Wolf and J. Jensen, Bloomington, Ind., 1992, was first published ( in Danish ) in 1921, after Olrik's early death ( Nogle grundsætninger for sagnforskning ).

* Wolf ( 1994 ): the country home of Laura ( Michelle Pfeiffer ) where Jack Nicholson's character first becomes a wolf, which appears on the DVD cover

Before being named Bucyrus in 1908, the city was called first Wolf Butte and then Dolan, which was ultimately rejected due to similarity with Doland, South Dakota.

Brookville was first established in 1832 when Warren Estabrook opened a general store just north of the present-day intersection of Main and Wolf Creek Streets.

David Aspen was the first white settler to live within the borders of what is now Wolf Township.