by neufer » Mon Jul 08, 2013 8:58 pm
Ron-Astro Pharmacist wrote:
Speaking about stable systems, I’ve never understood Lagrangian points. Do moons cause them or are they an interaction between then planet and the moon? Since we like to put satellites in orbit at them, it seems like a place where matter might accumulate. They seem like a very unusual place in the space around us. Ron
http://en.wikipedia.org/wiki/Lagrangian_point wrote:
<<The Lagrangian points (also Lagrange points, L-points, or libration points) are the five positions in an orbital configuration where a small object affected only by gravity can theoretically be part of a constant-shape pattern with two larger objects (such as a satellite with respect to the Earth and Moon). The Lagrange points mark positions where the combined gravitational pull of the two large masses provides precisely the centripetal force required to orbit with them. L1, L2, and L3 positions are as stable as a ball balanced on the tip of a wedge would be stable: any disturbance will toss it out of equilibrium. The L4, and L5 positions are stable as a ball at the bottom of a bowl would be stable: small perturbations will move it out of place, but it will drift back toward the center of the bowl.
The Earth–Moon L4 and L5 points lie 60° ahead of and 60° behind the Moon as it orbits the Earth. They may contain interplanetary dust in what is called Kordylewski clouds; however, the Hiten spacecraft's Munich Dust Counter (MDC) detected no increase in dust during its passes through these points.>>
http://en.wikipedia.org/wiki/Peace_sign wrote:
<<What by the 21st century is the internationally recognized symbol for peace was originally designed in 1958 for the British nuclear disarmament movement by Gerald Holtom. Holtom, an artist and designer, made it for a march from Trafalgar Square, London to the Atomic Weapons Research Establishment at Aldermaston in England.
The symbol is a combination of the semaphore signals for the letters "N" and "D," standing for "nuclear disarmament". In semaphore the letter "N" is formed by a person holding two flags in an inverted "V," and the letter "D" is formed by holding one flag pointed straight up and the other pointed straight down. Superimposing these two signs forms the shape of the centre of the peace symbol. Holtom later wrote to Hugh Brock, editor of Peace News, explaining the genesis of his idea in greater depth:
"I was in despair. Deep despair. I drew myself: the representative of an individual in despair, with hands palm outstretched outwards and downwards in the manner of Goya's peasant before the firing squad. I formalised the drawing into a line and put a circle round it".
Ken Kolsbun, a correspondent of Holtom's, says that the designer came to regret the symbolism of despair, as he felt that peace was something to be celebrated and wanted the symbol to be inverted. Eric Austen is said to have "discovered that the 'gesture of despair' motif had long been associated with 'the death of man', and the circle with 'the unborn child'." Some time later, Peggy Duff, general secretary of CND between 1958 and 1967, repeated this interpretation in an interview with a US newspaper, saying that the inside of the symbol was a
"runic symbol for death of man" and the circle the
"symbol for the unborn child".
Ken Kolsbun in his "biography" of the peace symbol wrote that, "In an attempt to discredit the burgeoning anti-war movement, the John Birch Society published an attack on the peace symbol in its June 1970 issue of American Opinion", calling the symbol "a manifestation of a witch's foot or crow's foot", supposedly icons of the devil in the Middle Ages. A national Republican newsletter was reported to have "noted an ominous similarity to a symbol used by the Nazis in World War II".>>
Art
Neuen
Dorffer
[quote="Ron-Astro Pharmacist"]
Speaking about stable systems, I’ve never understood Lagrangian points. Do moons cause them or are they an interaction between then planet and the moon? Since we like to put satellites in orbit at them, it seems like a place where matter might accumulate. They seem like a very unusual place in the space around us. Ron[/quote][quote=" http://en.wikipedia.org/wiki/Lagrangian_point"]
[float=right][img3="[b][color=#FF0000][size=150]The New Horizons Nominal Trajectory will pass
close to the [/size][/color][/b][url=http://en.wikipedia.org/wiki/Hilda_family][b][color=#FF0000][size=150]unstable L3 Lagrangian point.[/size][/color][/b][/url]"]http://planetary.s3.amazonaws.com/assets/images/9-small-bodies/2013/20130517_newhorizons_shbots.jpg[/img3][/float]<<The Lagrangian points (also Lagrange points, L-points, or libration points) are the five positions in an orbital configuration where a small object affected only by gravity can theoretically be part of a constant-shape pattern with two larger objects (such as a satellite with respect to the Earth and Moon). The Lagrange points mark positions where the combined gravitational pull of the two large masses provides precisely the centripetal force required to orbit with them. L1, L2, and L3 positions are as stable as a ball balanced on the tip of a wedge would be stable: any disturbance will toss it out of equilibrium. The L4, and L5 positions are stable as a ball at the bottom of a bowl would be stable: small perturbations will move it out of place, but it will drift back toward the center of the bowl. [b][color=#0000FF]The Earth–Moon L4 and L5 points lie 60° ahead of and 60° behind the Moon as it orbits the Earth. They may contain interplanetary dust in what is called Kordylewski clouds; however, the Hiten spacecraft's Munich Dust Counter (MDC) detected no increase in dust during its passes through these points.[/color][/b]>>[/quote][quote=" http://en.wikipedia.org/wiki/Peace_sign"]
[float=right][img]http://upload.wikimedia.org/wikipedia/commons/d/d0/Lagrangian_points_equipotential.gif[/img]
[img]http://upload.wikimedia.org/wikipedia/commons/thumb/4/4f/Peace_symbol.svg/200px-Peace_symbol.svg.png[/img][/float]<<What by the 21st century is the internationally recognized symbol for peace was originally designed in 1958 for the British nuclear disarmament movement by Gerald Holtom. Holtom, an artist and designer, made it for a march from Trafalgar Square, London to the Atomic Weapons Research Establishment at Aldermaston in England.
The symbol is a combination of the semaphore signals for the letters "N" and "D," standing for "nuclear disarmament". In semaphore the letter "N" is formed by a person holding two flags in an inverted "V," and the letter "D" is formed by holding one flag pointed straight up and the other pointed straight down. Superimposing these two signs forms the shape of the centre of the peace symbol. Holtom later wrote to Hugh Brock, editor of Peace News, explaining the genesis of his idea in greater depth:
[b][i] "[color=#0000FF]I was in despair. Deep despair. I drew myself: the representative of an individual in despair, with hands palm outstretched outwards and downwards in the manner of Goya's peasant before the firing squad. I formalised the drawing into a line and put a circle round it[/color]"[/i][/b].
Ken Kolsbun, a correspondent of Holtom's, says that the designer came to regret the symbolism of despair, as he felt that peace was something to be celebrated and wanted the symbol to be inverted. Eric Austen is said to have "discovered that the 'gesture of despair' motif had long been associated with 'the death of man', and the circle with 'the unborn child'." Some time later, Peggy Duff, general secretary of CND between 1958 and 1967, repeated this interpretation in an interview with a US newspaper, saying that the inside of the symbol was a [b][i]"[color=#0000FF]runic symbol for death of man[/color]"[/i][/b] and the circle the [b][i]"[color=#0000FF]symbol for the unborn child[/color]"[/i][/b].
Ken Kolsbun in his "biography" of the peace symbol wrote that, "In an attempt to discredit the burgeoning anti-war movement, the John Birch Society published an attack on the peace symbol in its June 1970 issue of American Opinion", calling the symbol "a manifestation of a witch's foot or crow's foot", supposedly icons of the devil in the Middle Ages. A national Republican newsletter was reported to have "noted an ominous similarity to a symbol used by the Nazis in World War II".>>[/quote]
Art [b][color=#0000FF]N[/color][/b]euen[b][color=#0000FF]D[/color][/b]orffer