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Hubble Telescope Service Mission Featured in 'Hubble 3D' IMAX Movie Aided By ...
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Hubble Telescope Service Mission Featured in 'Hubble 3D' IMAX Movie Aided By ...
In May of 2009, when the future of the Hubble space telescope was hinging on delicate repairs performed by NASA astronauts using ATK's Mini Power Tool, ATK turned to a trusted source for precision components required for the job. Now ATK and Timken play
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Analysts believe that the launch of the new Japanese solar sail demonstrator Ikaros evidences the fact that the dawn of a new type of space exploration is upon us. They say that the spacecraft proved beyond a reasonable doubt that the technology is
Hubble Telescope Service Mission Featured in 'Hubble 3D' IMAX Movie Aided By ...
CANTON, Ohio, Sept. 2 /PRNewswire/ -- In May of 2009, when the future of the Hubble space telescope was hinging on delicate repairs performed by NASA astronauts using ATK's Mini Power Tool, ATK turned to a trusted source for precision components required
God unnecessary to create universe: Hawking
In his previous book, A Brief History of Time, Hawking had appeared to accept the possibility of a creator, saying the discovery of a complete theory would allow humans to 'know the mind of God.' (Canadian Press)Physicist Stephen Hawking says God wasn't
Caltech mineral physicists find new scenery at Earth's core-mantle boundary
Using a diamond-anvil cell to recreate the high pressures deep within the earth, researchers at the California Institute of Technology (Caltech) have found unusual properties in an iron-rich magnesium- and iron-oxide mineral that may explain the
Hubble Telescope Service Mission Featured in 'Hubble 3D' IMAX Movie Aided By ...
See more news releases in: Automotive, Computer Electronics, Oil & Energy, Aerospace & Defense, Machine Tools, Metalworking and Metallury, Contracts, New Products & Services CANTON, Ohio, Sept. 2 /PRNewswire/ -- In May of 2009, when the future of the
Kablam! | Bad Astronomy
This image is stunning. And not just because, well, it?s all explodey and stuff: [Click to explodenate.] The three panels show a 1986 test of a Tomahawk cruise missile. The missile traveled 640 km (400 mile) low over the terrain to detonate
Hubble Telescope Service Mission Featured in 'Hubble 3D' IMAX Movie Aided By ...
See more news releases in: Automotive, Computer Electronics, Oil & Energy, Aerospace & Defense, Machine Tools, Metalworking and Metallury, Contracts, New Products & Services CANTON, Ohio, Sept. 2 /PRNewswire/ -- In May of 2009, when the future of the
Science Spin September 2010
TO VIEW THE DIGITAL ISSUE CLICK ON THE COVER Wind and wave Big plans for the west coast could be more important for the economy than the gas, and within a few years Irelan d could be exporting power to Europe.   Exploring the depths of Fermanagh At
Hubble Telescope Service Mission Featured in 'Hubble 3D' IMAX Movie Aided By ...
Hubble Telescope Service Mission Featured in 'Hubble 3D' IMAX Movie Aided By Timken® Precision Bearings
Lineagen, Inc. Selected to Present at the 2010 Genetic Risk Factors for Autis...
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Stephen Hawking: No Need for God in the Creation of the Universe
One of the most famous scientists in the world says that given the laws of gravity, there was no need of a divine intervention for the creation of the Universe.Stephen Hawking says in The Grand Design, a book co-written with American physicist Leonard
In vitro assembly of cubic RNA-based scaffolds designed in silico
AbstractThe organization of biological materials into versatile three-dimensional assemblies could be used to build multifunctional therapeutic scaffolds for use in nanomedicine. Here, we report a strategy to design three-dimensional nanoscale scaffolds

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More About Static Electricity

In electrostatics conditions of charge need not be 'static' and unchanging. Instead 'static' implies that the dynamic portion is being ignored, and we analyze frozen snapshots of the situation. In electrostatics we study e-fields, voltage, and charge but ignore any currents and magnetism which may also be present. Because of its relationship and interaction with magnetism, the two fields are often combined as electromagnetism.

The electrostatic approximation
The validity of the electrostatic approximation rests on the assumption that the electric field is irrotational: From Faraday's law, this assumption implies the absence or near-absence of time-varying magnetic fields:

In other words, electrostatics does not require the absence of magnetic fields or electric currents. Rather, if magnetic fields or electric currents do exist, they must not change with time, or in the worst-case, they must change with time only very slowly.

Electrostatic potential
Because the electric field is irrotational, it is possible to express the electric field as the gradient of a scalar function, called the electrostatic potential (also known as the voltage). Thus, the electrostatic potential Φ is related to the electric field E by the equation:

Charge separation by contact
The presence of surface charge imbalance means that the objects will exhibit attractive or repulsive forces. This surface charge imbalance, which leads to static electricity, can be generated by touching two differing surfaces together and then separating them due to the phenomena of contact electrification and the triboelectric effect. Rubbing two non-conductive objects generates a great amount of static electricity. This is not just the result of friction; two non-conductive surfaces can become charged by just being placed one on top of the other. Since most surfaces have a rough texture, it takes longer to achieve charging through contact than through rubbing. Rubbing objects together increases amount of adhesive contact between the two surfaces. Usually insulators, i.e., substances that do not conduct electricity, are good at both generating, and holding, a surface charge. Some examples of these substances are rubber, plastic, glass, and pith. Conductive objects only rarely generate charge imbalance except, for example, when a metal surface is impacted by solid or liquid nonconductors. The charge that is transferred during contact electrification is stored on the surface of each object. Static electric generators, devices which produce very high voltage at very low current (such as the Van de Graaf generator or Wimshurst machine) and used for classroom physics demonstrations, rely on this effect. Note that the presence of electric current does not detract from the electrostatic forces nor from the sparking, from the corona discharge, or other phenomena. Both phenomena can exist simultaneously in the same system.

Triboelectric series
The triboelectric effect is a type of contact electrification in which certain materials become electrically charged when coming into contact with another, different, material, and are then separated. The polarity and strength of the charges produced differ according to the materials, surface roughness, temperature, strain, and other properties. It is therefore not very predictable, and only broad generalizations can be made. Amber, for example, can acquire an electric charge by friction with a material like wool. This property, first recorded by Thales of Miletus, suggested the word "electricity", from the Greek word for amber, ēlektron. Other examples of materials that can acquire a significant charge when rubbed together include glass rubbed with silk, and hard rubber rubbed with fur.

Electrostatic generators
The presence of surface charge imbalance means that the objects will exhibit attractive or repulsive forces. This surface charge imbalance, which leads to static electricity, can be generated by touching two differing surfaces together and then separating them due to the phenomena of contact electrification and the triboelectric effect. Rubbing two non-conductive objects generates a great amount of static electricity. This is not just the result of friction; two non-conductive surfaces can become charged by just being placed one on top of the other. Since most surfaces have a rough texture, it takes longer to achieve charging through contact than through rubbing. Rubbing objects together increases amount of adhesive contact between the two surfaces. Usually insulators, e.g., substances that do not conduct electricity, are good at both generating, and holding, a surface charge. Some examples of these substances are rubber, plastic, glass, and pith. Conductive objects only rarely generate charge imbalance except, for example, when a metal surface is impacted by solid or liquid nonconductors. The charge that is transferred during contact electrification is stored on the surface of each object. Static electric generators, devices which produce very high voltage at very low current and used for classroom physics demonstrations, rely on this effect.

Note that the presence of electric current does not detract from the electrostatic forces nor from the sparking, from the corona discharge, or other phenomena. Both phenomena can exist simultaneously in the same system.

Charge neutralisation
Natural electrostatic phenomena are most familiar as an occasional annoyance in seasons of low humidity, but can be destructive and harmful in some situations (e.g. electronics manufacturing.) When working in direct contact with integrated circuit electronics (especially delicate MOSFETs), or in the presence of flammable gas, care must be taken to avoid accumulating and discharging a static charge.

'Static' electricity
Static can be a serious nuisance in the processing of analog recording media, because it can attract dust to sensitive materials. In the case of photography, dust accumulating on lenses and photographic plates degrades the resulting picture. Dust also permanently damages vinyl records because it can be embedded into the grooves as the stylus passes over. In both cases, several approaches exist to combat such dust deposition. Some brushes, particularly those with carbon fiber bristles, are advertised as possessing anti-static properties. Also available are handheld static guns which shoot streams of ions to discharge static on records and lenses. Static electricity is a class of phenomena involving objects with a net charge; typically referring to charged objects with voltages of sufficient magnitude to produce visible attraction, repulsion, and sparks.

Natural electrostatic phenomena are most familiar as an occasional annoyance in seasons of low humidity, but can be destructive and harmful in some situations (e.g. electronics manufacturing.) When working in direct contact with integrated circuit electronics (especially delicate MOSFETs), or in the presence of flammable gas, care must be taken to avoid accumulating and discharging a static charge (see electrostatic discharge).

Note that the presence of electric current does not detract from the electrostatic forces nor from the sparking, from the corona discharge, or other phenomena. Both phenomena can exist simultaneously in the same system.

Static electricity is an important element in the biological process of pollination by bees, since the charge on a bee's body helps to hold pollens to it.