Further, the corpuscular radiation, i.e., the solar-wind protons, must sputter away the surface atoms of the dust and cause a slow diminution in size, with a resultant increase in both the Poynting-Robertson effect and the ratio of the repulsive force to the gravitational force.

The Poynting-Robertson effect causes the semi-major axis of orbits to diminish more rapidly than the semi-minor axis, with a consequent tendency toward circular orbits as the particles move toward the sun.

De Jager ( 1955 ) has calculated the times required for these particles to reach the atmosphere under the influence of the Poynting-Robertson effect, which in this case causes the orbits to become more and more eccentric without changing the semi-major axis.

The solar-electromagnetic- and corpuscular-radiation pressure and the associated Poynting-Robertson effect increase in effectiveness as the particle size decreases and modify the distribution and limit sizes to larger than a few microns.

The Poynting-Robertson effect forces the dust into more circular ( but still elongated ) orbits, while spiralling slowly into the Sun.

* March 30-John Henry Poynting ( born 1852 ), English physicist, discovered the Poynting-Robertson effect and developed the Poynting vector.

* September 9-John Henry Poynting ( died 1914 ), English physicist, discoverer of the Poynting-Robertson effect and the Poynting vector.

They are differentially disturbed by the planets, in particular Jupiter and to a lesser extent by radiation pressure from the sun, the Poynting – Robertson effect, and the Yarkovsky effect.

Recent work tries to take into account the roles of differences in parent bodies and the specifics of their orbits, ejection velocities off the solid mass of the core of a comet, radiation pressure from the sun, the Poynting – Robertson effect, and the Yarkovsky effect on the particles of different sizes and rates of rotation to explain differences between meteor showers in terms of being predominantly fireballs or small meteors.

Such feeble pressures are able to produce marked effects upon minute particles like gas ions and electrons, and are important in the theory of electron emission from the Sun, of cometary material, and so on ( see also: Yarkovsky effect, YORP effect, Poynting – Robertson effect ).

* Poynting – Robertson effect

Dust and possibly water ice from this belt migrates inward because of drag from the stellar wind and a process by which stellar radiation causes dust grains to slowly spiral toward the star, known as the Poynting – Robertson effect.

All other similarly stable regions in the Solar System have been found to contain objects, although non-gravitational forces such as radiation pressure, Poynting – Robertson drag and the Yarkovsky effect may have depleted the vulcanoid area of its original contents.

The inner edge is not sharply defined: objects closer than 0. 06 AU are highly susceptible to Poynting – Robertson drag and the Yarkovsky effect, and even out to 0. 09 AU vulcanoids would have temperatures of 1, 000 K or more, which is hot enough for evaporation of rocks to be the limiting factor in their lifetime.

The Poynting – Robertson effect, also known as Poynting – Robertson drag, named after John Henry Poynting and Howard Percy Robertson, is a process by which solar radiation causes a dust grain in the Solar System to slowly spiral into the Sun.

In 1937 Robertson described the effect in terms of general relativity.

Since the gravitational force goes as the cube of the object's radius ( being a function of its volume ) whilst the power it receives and radiates goes as the square of that same radius ( being a function of its surface ), the Poynting – Robertson effect is more pronounced for smaller objects.

Also, since the Sun's gravity varies as whereas the Poynting – Robertson force varies as, the Poynting – Robertson effect also gets relatively stronger as the object approaches the Sun, which tends to reduce the eccentricity of the object's orbit in addition to dragging it in.

For particles much smaller than this, radiation pressure, which makes them spiral outwards from the Sun, is stronger than the Poynting – Robertson effect that makes them spiral inward.

For rocky particles about half a µm in diameter, the radiation pressure equals gravity, and they will be always blown out of the Solar System even though the Poynting – Robertson effect still affects them.

# REDIRECT Poynting – Robertson effect

He used his frustration from the incident to good effect however, as he beat Dominic Dale, Robertson, Graeme Dott and Robert Milkins to reach the final of the World Open, his first since the 2006 Welsh Open.

From the IAC minutes of the 4th December and the earlier CIA documents it appears clear that the Robertson Panel was the outcome of recommendation ( a ) of the IAC decision but that this formed part of a wider intended programme of action aimed at enabling rapid positive identification of UFOs from an air defense perspective ( i. e. identifying actual Soviet aircraft from misidentified natural phenomena or other conventional objects ) and a desire to reduce reporting of UFOs, which were seen as clogging up air defense communication channels and created the risk of exploitation of this effect.

On 17 September 2009 it was announced that Justice Anthony Randerson, at the time the Chief High Court Judge, would be appointed to the Court of Appeal with effect from 1 February 2010 to replace the retiring Justice Bruce Robertson.

* 1937 – The Marihuana Tax Act of 1937 is passed in America, the effect of which is to render marijuana and all its by-products illegal.

Known as a major facet in the study of quantum hydrodynamics and macroscopic quantum phenomena, the superfluidity effect was discovered by Pyotr Kapitsa and John F. Allen, and Don Misener in 1937.

The new Constitution of Ireland ( Bunreacht na hÉireann ) repealed the 1922 Constitution, and came into effect on 29 December 1937.

Fritz Zwicky posited in 1937 that the effect could allow galaxy clusters to act as gravitational lenses.

In spite of widespread speculation that Roberts only agreed to join the court's majority in upholding New Deal legislation, such as the Social Security Act, during the spring of 1937 because of the court packing plan, Hughes wrote in his autobiographical notes that Roosevelt's court reform proposal " had not the slightest effect on our court's decision " in the Parrish case and that the delayed announcement of the decision created the false impression that the Court had retreated under fire.

The Irish Free State was reconstituted as " Ireland on 29 December 1937, when the present-day Constitution of Ireland came into effect.

During his time in St. Louis, Erhard read two books which were to have a marked effect on him: Think and Grow Rich by Napoleon Hill ( 1937 ) and Psycho-Cybernetics by Maxwell Maltz ( 1960 ).

It was used to great effect in the longer format Popeye cartoons Popeye the Sailor Meets Sindbad the Sailor ( 1936 ) and Popeye the Sailor Meets Ali Baba's Forty Thieves ( 1937 ).

On the 29 December 1937 the new " Constitution of Ireland " came into effect, renaming the Irish Free State to simply " Éire " or in the English language " Ireland ".

Since 1937, in applying the factual test in Jones & Laughlin to hold a broad range of activities sufficiently related to interstate commerce, the Supreme Court has exercised little independent judgment, choosing instead to defer to the expressed or implied findings of Congress to the effect that regulated activities have the requisite " economic effect ".

Others considered Curzio Malaparte and Melchior Wańkowicz ( with their championing of the effect of minor detail imbued with the force of a metaphor ) to have been Kapuściński's literary models and stylistic precursors within a genre that in Poland had previously such eminent exponents as Ksawery Pruszyński ( 1907 – 1950 ), Zbigniew Uniłowski ( 1909 – 1937 ), and Maria Sten ( 1917 – 2007 ).

In 1936 he joined the RAF, becoming an Acting Pilot Officer with effect from and with seniority of 31 January 1937 and a Pilot Officer on 16 November 1937, learning to fly at No. 2 Flying Training School at RAF Scopwick in Lincolnshire.

This had little effect on the Birous output: before 1937, Janco and his brother designed some 40 permanent or temporary structures in Bucharest, all of them located in the northern and central areas ( the " Yellow " and " Black " sectors, as they were known at the time ).

The peak of the repressions was during the great Purge of 1937 – 8, and it had the effect of greatly slowing down production in 1937.

On 9 June 1937, the offending references to manual labourers, mechanics, artisans and menial duties were deleted from the ARA rules ; Henley's rules were changed the following day, coming into effect from the 1938 regatta.

Article 2 and Article 3 of the Constitution of Ireland ( Bunreacht na hÉireann ) were adopted with the constitution as a whole on 29 December 1937, but completely revised by means of the Nineteenth Amendment which took effect on 2 December 1999.

Hamilton and Morgan never appear on screen together in this film ; however, her earlier appearance in the 1937 film Saratoga is a colloquy with Morgan regarding her use of a cosmetic product he invented ( with side glances and eye rolls by Morgan as to its effect on her " beauty ").

His Matura trip of 1937 to the Riviera, which included underwater hunting and photography, had a formative effect on him.

In 1937 Papez theorized that a circuit including the hippocampal formation and the cingulate gyrus constitutes the neural substrate of emotional behavior, and Klüver and Bucy reported that, in monkeys, resection involving the hippocampal formation and the amygdaloid complex has a profound effect on emotional responses.