NIST: Glasperlenspiel: New Test for Gravity

[bystander]

Glasperlenspiel: NIST Scientists Propose New Test for Gravity
National Institute of Standards and Technology | Physics Laboratory | 31 Aug 2010

A beam of laser light (red) should be able to cause a glass bead of approximately 300 nanometers in diameter to levitate, and the floating bead would be exquisitely sensitive to the effects of gravity. Moving a large heavy object (gold) to within a few nanometers of the bead could allow the team to test the effects of gravity at very short distances. [i](Credit: K. Talbott/NIST)[/i]

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A new experiment proposed* by physicists at the National Institute of Standards and Technology (NIST) may allow researchers to test the effects of gravity with unprecedented precision at very short distances—a scale at which exotic new details of gravity's behavior may be detectable.
laser light illustration

A beam of laser light (red) should be able to cause a glass bead of approximately 300 nanometers in diameter to levitate, and the floating bead would be exquisitely sensitive to the effects of gravity. Moving a large heavy object (gold) to within a few nanometers of the bead could allow the team to test the effects of gravity at very short distances.

Of the four fundamental forces that govern interactions in the universe, gravity may be the most familiar, but ironically it is the least understood by physicists. While gravity's influence is well-documented on bodies separated by astronomical or human-scale distances, it has been largely untested at very close scales—on the order of a few millionths of a meter—where electromagnetic forces often dominate. This lack of data has sparked years of scientific debate.
...
In an attempt to sidestep the problem, Geraci and his co-authors have envisioned an experiment that would suspend a small glass bead in a laser beam "bottle," allowing it to move back and forth within the bottle. Because there would be very little friction, the motion of the bead would be exquisitely sensitive to the forces around it, including the gravity of a heavy object placed nearby.

According to the research team, the proposed experiment would permit the testing of gravity's effects on particles separated by 1/1,000 the diameter of a human hair, which could ultimately allow Newton's law to be tested with a sensitivity 100,000 times better than existing experiments.

Actually realizing the scheme—detailed in a new paper in Physical Review Letters—could take a few years, co-author Scott Papp says, in part because of trouble with friction, the old nemesis of short-distance gravity research. Previous experiments have placed a small object (like this experiment's glass bead) onto a spring or short stick, which have created much more friction than laser suspension would introduce, but the NIST team's idea comes with its own issues.

Short-Range Force Detection Using Optically Cooled Levitated Microspheres

• Physical Review Letters 105 101101 (30 Aug 2010) DOI: 10.1103/PhysRevLett.105.101101

[neufer]

Won't radiation pressure from the reflection of the glass bead in the (large?) gold attractor simply repulse the glass bead?

<<_Das Glasperlenspiel_ (German for _The Glass Bead Game_) is the last work and magnum opus of the German author Hermann Hesse. Begun in 1931 and published in Switzerland in 1943, after being rejected for publication in Germany, the book was mentioned in Hesse's citation for the 1946 Nobel Prize for Literature.

Das Glasperlenspiel takes place at an unspecified date, centuries into the future. Hesse suggested that he imagined the book's narrator writing around the start of the 25th century. The setting is a fictional province of central Europe called Castalia, reserved by political decision for the life of the mind; technology and economic life are kept to a strict minimum. [The nymph Castalia who was transformed into an inspiration-granting fountain by the god Apollo.] Castalia is home to an austere order of intellectuals with a twofold mission: to run boarding schools for boys, and to nurture and play the Glass Bead Game, whose exact nature remains elusive and whose devotees occupy a special school within Castalia known as Waldzell. The rules of the game are only alluded to, and are so sophisticated that they are not easy to imagine. Playing the game well requires years of hard study of music, mathematics, and cultural history. Essentially the game is an abstract synthesis of all Arts and scholarship. It proceeds by players making deep connections between seemingly unrelated topics.

The novel follows the life of a distinguished member of the order, Joseph Knecht (the surname translates as "servant" or "squire"), as narrated by a fictional historian of the order. The text, written in a scholarly biographical style, chronicles the protagonist's decision to join the order, his mastery of the Game, and his advancement in the order's hierarchy to eventually become Magister Ludi, an honorary title reserved for the Game's finest player.

The beginning of the novel introduces the Music Master, the resident of Castalia who recruits Knecht as a young student. As the novel progresses, Knecht begins to question his (and others') loyalty to the order; he gradually comes to doubt that the intellectually gifted have a right to withdraw from life's big problems. Knecht comes to see Castalia [cASTalERISKia?] as a kind of ivory tower, an ethereal protected community, devoted to pure intellectual pursuits but oblivious to the problems posed by life outside its borders. This conclusion precipitates a personal crisis, and, according to his personal views regarding spiritual awakening, Knecht resigns as Magister Ludi and asks to leave the order, ostensibly to become of value and service to the larger culture. The heads of the order deny his request to leave, but Knecht departs Castalia anyway, initially taking a job as a tutor to his childhood friend Designori's energetic and strong-willed son, Tito. Only a few days later, the story ends abruptly with Knecht drowning in a mountain lake while attempting to follow Tito on a swim.

Freedman wrote in his biography of Hesse that the tensions created by the rise of the Nazi Party in Germany directly contributed to the creation of _Das Glasperlenspiel_ as a response to the oppressive times. "The educational province of Castalia, which provided a setting for the novel, came to resemble Hesse's childhood Swabia physically while assuming more and more the function of his adopted home, neutral Switzerland, which in turn embodied his own antidote to the crises of his time. It became the "island of love" or at least an island of the spirit." Freedman opined that in _Das Glasperlenspiel_ "

ontemplation, the secrets of the Chinese I Ching and Western mathematics and music fashioned the perennial conflicts of his life into a unifying design.">>

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Art (Glasperlenspieler/Knecht the dots) Neuendorffer

[Chris Peterson]

Won't radiation pressure from the reflection of the glass bead in the (large?) gold attractor simply repulse the glass bead?

A 300nm bead won't reflect 600nm photons. There will be a scattering effect, but it is almost exclusively forward and rearward, and I'd think manageable. At this scale, I expect they need to worry about the photons from thermal emission from the test mass. Although not stated, I guess this experiment will be conducted in the dark, in a vacuum, and in a supercooled environment.

[neufer]

Won't radiation pressure from the reflection of the glass bead in the (large?) gold attractor simply repulse the glass bead?

A 300nm bead won't reflect 600nm photons. There will be a scattering effect, but it is almost exclusively forward and rearward, and I'd think manageable. At this scale, I expect they need to worry about the photons from thermal emission from the test mass. Although not stated, I guess this experiment will be conducted in the dark, in a vacuum, and in a supercooled environment.

It all sounds pretty half baked to me.

[rstevenson]

It all sounds pretty half baked to me.

In the biz, that's known as Parbaking.

Rob