question: Why does dust stick to stationary objects?
comment: Depending on the thing.... Things like tv screens and other electrical/electronic items could have a little bit of static electricity lingering on them.
passages: Most of the contamination to be found on the image sensor surface is caused by dust particles as small as just one micrometre (0.001 mm) adhering to it through electrical charges. The particles themselves carry a positive static electric charge, while the image sensor is negatively charged, which makes them attract each other. The same phenomenon can be observed on the surface of LCD and CRT monitor screens.
  
  BULLET::::1. Dust particles adhering through intermolecular force
   Section::::Physics.:Wear.:Rubbing Wear or Fretting.
  
  The rubbing wear occurs in systems subject to more or less intense vibrations, which cause relative movements between the surfaces in contact with the order of the nanometer. These microscopic relative movements cause both adhesive wear, caused by the displacement itself, and abrasive wear, caused by the particles produced in the adhesive phase, which remain trapped between the surfaces. This type of wear can be accelerated by the presence of corrosive substances and the increase in temperature.
  
  Section::::Physics.:Wear.:Erosion Wear.
   Section::::Risks and counter-measures.:In the workplace.
  
  Means have to be provided to discharge static from carts which may carry volatile liquids, flammable gasses, or oxygen in hospitals. Even where only a small charge is produced, it can result in dust particles being attracted to the rubbed surface. In the case of textile manufacture this can lead to a permanent grimy mark where the cloth comes in contact with dust accumulations held by a static charge. Dust attraction may be reduced by treating insulating surfaces with an antistatic cleaning agent.
  
  Section::::Risks and counter-measures.:Damage to electronics.
   Static cling
  
  Static cling is the tendency for light objects to stick (cling) to other objects owing to static electricity. It is common in clothing, but occurs with other items, such as the tendency of dust to be attracted to, and stick to, plastic items.
  
  Section::::Cause and prevention.
   Resistance affects electrical conditions in the dust layer by a potential electric field (voltage drop) being formed across the layer as negatively charged particles arrive at its surface and leak their electrical charges to the collection plate. At the metal surface of the electrically grounded collection plate, the voltage is zero, whereas at the outer surface of the dust layer, where new particles and ions are arriving, the electrostatic voltage caused by the gas ions can be quite high. The strength of this electric field depends on the resistance and thickness of the dust layer.
   Wear of metals occurs by plastic displacement of surface and near-surface material and by detachment of particles that form wear debris. The particle size may vary from millimeters to nanometers. This process may occur by contact with other metals, nonmetallic solids, flowing liquids, solid particles or liquid droplets entrained in flowing gasses.
   Adhesive wear can be found between surfaces during frictional contact and generally refers to unwanted displacement and attachment of wear debris and material compounds from one surface to another. Two adhesive wear types can be distinguished:
  
  BULLET::::1. Adhesive wear is caused by relative motion, "direct contact" and plastic deformation which create wear debris and material transfer from one surface to another.
  
  BULLET::::2. Cohesive adhesive forces, holds two surfaces together even though they are separated by a measurable distance, with or without any actual transfer of material.
   The type of mechanism and the amplitude of surface attraction varies between different materials but are amplified by an increase in the density of "surface energy". Most solids will adhere on contact to some extent. However, oxidation films, lubricants and contaminants naturally occurring generally suppress adhesion, and spontaneous exothermic chemical reactions between surfaces generally produce a substance with low energy status in the absorbed species.
   Dust reduction system
  
  A dust reduction system, or dust removal system, is used in several makes of digital cameras to remove dust from the image sensor. Every time lenses are changed, dust may enter the camera body and settle on the image sensor.
   Section::::Development.:Mechanics.
   In common with other interchangeable lens designs, DSLRs must contend with potential contamination of the sensor by dust particles when the lens is changed (though recent dust reduction systems alleviate this). Digital cameras with fixed lenses are not usually subject to dust from outside the camera settling on the sensor.
   As couplings wear they create wear particles. In some applications such as clean rooms or food handling this dust could be a contamination problem so in these applications the coupling should be enclosed to prevent the particles from contaminating other surfaces around it. But a more likely scenario is that the coupling has a better chance of getting contaminated from its environment. Obviously oil or grease should be kept away from the contact surface because they would significantly reduce the coefficient of friction which could drastically decrease the torque potentially causing failure. Oil mist or lubricated particles can also cause surface contamination. Sometimes paper dust or other contamination can fall in between the contact surfaces. This can also result in a loss of torque. If a known source of contamination is going to be present many clutch manufactures offer contamination shields that prevent material from falling in between the contact surfaces.
   Because of their low surface area, static cling causes fibers that have detached from an article of clothing to continue to stick to one another and to that article or other surfaces with which they come in contact. Other small fibers or particles also accumulate with these clothing fibers, including human and animal hair and skin cells, plant fibers, and pollen, dust, and microorganisms.
   Dust-Off was developed and introduced in 1970 by an employee at Falcon Safety Products who discovered that the pressurized blasts used to sound the alarm in the company’s signal horns could also remove dust from photography equipment and film without having to touch the surface.
   Many materials which we encounter during the day are dispersed media. For example, milk consists of oil drops dispersed in water, fog contains tiny water drops dispersed in air, shaving cream contains bubbles dispersed in a liquid, sand consists of solid grains in air and a kitchen sponge of bubbles dispersed in a solid.
   Microviscosity
  
  Microviscosity, also known as microscopic viscosity, is the friction experienced by a single particle undergoing diffusion because of its interaction with its environment at the micrometer length scale. The concept of microviscosity is intimately related to the concept of single particle diffusion and can be measured using microrheology. 
  
  Understanding microviscosity requires an understanding of viscosity and diffusion i.e. macroscopic viscosity and bulk diffusion and where their assumptions break down at the micro to nanometer scale where physicists are still trying to replace phenomenological laws with physical laws governing the behavior of single particle mobility. 
   When cleaning equipment it is near impossible to remove all the loose molecules. It is almost certain that traces of the chemical used to clean the equipment will remain on its surfaces, forming a microscopically thin layer.
   Dust particles are generated by the disturbance/agitation of rock/mineral, dry grain, timber, or fiber material. The particles generated can range in size from 1μm to 100μm, and can "become airborne depending on their origin, physical characteristics and ambient conditions."
  
  Section::::Occupational Dust.:Occupational Dust Examples.
  
  Types of dust present in the occupational setting include:
  
  BULLET::::- Rock/mineral dusts
  
  BULLET::::- Metallic dusts
  
  BULLET::::- Chemical dusts
  
  BULLET::::- Grain and produce dusts
  
  BULLET::::- Molds and spores
  
  Section::::Occupations and Dust Hazards.
  
  Section::::Occupations and Dust Hazards.:Mining.
   Digital single-lens reflex cameras (DSLR) are particularly vulnerable to this issue, since the interior of the camera is exposed during lens changes unlike other forms of digital cameras, and the image sensor is fixed, unlike a film camera. Even the tiniest (micrometre-size) dust particles or other contaminants that settle on the face of the image sensor (individual pixels of which have dimensions on the order of ~5 micrometres) may cast shadows and thus become visible in the final image as more or less diffuse grey blobs, depending on aperture.
   Fragmentary or trace evidence is any type of material left at (or taken from) a crime scene, or the result of contact between two surfaces, such as shoes and the floor covering or soil, or fibres from where someone sat on an upholstered chair.
   In situations where two surfaces with areas below the micrometer scale come into close proximity (as in an accelerometer), they may adhere together. At this scale, electrostatic and/or Van der Waals and hydrogen bonding forces become significant. The phenomenon of two such surfaces being adhered together in this manner is also called stiction. Stiction may be related to hydrogen bonding or residual contamination.
  
  Section::::Automobiles.
   Generally, adhesive wear occurs when two bodies slide over or are pressed into each other, which promote material transfer. This can be described as plastic deformation of very small fragments within the surface layers. The asperities or microscopic high points (surface roughness) found on each surface affect the severity of how fragments of oxides are pulled off and added to the other surface, partly due to strong adhesive forces between atoms, but also due to accumulation of energy in the plastic zone between the asperities during relative motion.
   BULLET::::- Characteristics of dust – Moderate to heavy concentrations of many dusts (such as dust from silica sand or metal ores) can be abrasive to dry centrifugal collectors. Hygroscopic material can blind bag collectors. Sticky material can adhere to collector elements and plug passages. Some particle sizes and shapes may rule out certain types of fabric collectors. The combustible nature of many fine materials rules out the use of electrostatic precipitators.
   Trace evidence
  
  Trace evidence is created when objects make contact. The material is often transferred by heat or induced by contact friction.
   Fugitive dust acquires an electronic charge when dispersed in the air. Spraying an oppositely charged water fog can be used to effectively control dust in an industrial setting. If so charged, less water is needed to cause the particulate matter to drop from the air. This method has been tested with many materials including silica flour, sulfur dioxide, and fly ash.
  
  Section::::See also.
  
  BULLET::::- Asian dust
  
  BULLET::::- Bull dust
  
  BULLET::::- Coal dust
  
  BULLET::::- Occupational dust exposure
  
  Section::::Further reading.
  
  BULLET::::- PM 10 and Fugitive Dust in the Southwest Ambient Impact, Sources and Remedies, US Environmental Protection Agency
  
presuppositions: Dust sticks to stationary objects.
corrections: Dust sticks to some but not all stationairy objects based on their properties, such as those that carry static electricity. 
raw_presuppositions: Dust sticks to stationary objects. Dust sticks to stationary objects.
raw_corrections: Dust sticks to some but not all stationairy objects based on their properties, such as those that carry static electricity.  Dust only sticks to stationary objects if they have lingering static electricity on them.