Dry quicksand is loose sand whose bulk density is reduced by blowing air through it and which yields easily to weight or pressure. It acts similar to regular quicksand, but it does not contain any water and does not operate on the same principle. Dry quicksand is an example of a granular material. Patterns in the sand Sand is a granular material made up of fine rock particles. ... Bulk density a property of particulate materials. ... This article or section does not adequately cite its references or sources. ... A granular material is a conglomeration of discrete solid, macroscopic particles characterized by a loss of energy whenever the particles interact (the most common example would be friction when grains collide). ...

Until recently, the existence of dry quicksand was doubted, and the reports of humans and complete caravans being lost in dry quicksand were considered to be folklore. This article does not cite any references or sources. ...

Scientific research

Writing in Nature, physicist Detlef Lohse and coworkers of University of Twente in Enschede, Netherlands allowed air to flow through very fine sand (typical grain diameter was about 40 micrometers) in a container with a perforated base. They then turned the air stream off before the start of the experiment and allowed the sand to settle: the packing fraction of this sand was only 41% (compared to 55–60% for untreated sand). ^[1] Nature is one of the most prominent scientific journals, first published on 4 November 1869. ... Articles with similar titles include physician, a person who practices medicine. ... Universiteit Twente is a university located in Enschede, Netherlands. ... Raadhuisstraat in Enschede, with the Grote Kerk in the background Enschede or Eanske in the local dialect (Twents) is a municipality and a city in the eastern Netherlands, in the province of Overijssel, in the Twente region. ... Look up air in Wiktionary, the free dictionary. ... A micrometre (American spelling: micrometer, symbol µm) is an SI unit of length equal to one millionth of a metre, or about a tenth of the diameter of a droplet of mist or fog. ... In crystallography, atomic packing factor or packing fraction is the fraction of volume in a crystal structure that is occupied by atoms. ...

Lohse found that a weighted table tennis ball (radius 2 cm, mass 133 g), when released from just above the surface of the sand, would sink to about five diameters. Lohse also observed a "straight jet of sand [shooting] violently into the air after about 100 ms". Objects are known to make a splash when they hit sand, but this type of jet has never been described before. Jan-Ove Waldner Table tennis (also commonly known as ping-pong) is a game in which two or four players hit a lightweight ball back and forth to each other with bats (also sometimes called racquets or paddles). ... Water bouncing upwards after water droplet hits it In fluid mechanics, a splash is a sudden disturbance to the otherwise quiescent free surface of a liquid (usually water) The disturbance is typically caused by a solid object suddenly hitting the surface, although splashes can occur in which moving liquid supplies...

Lohse concluded that

In nature, dry quicksands may evolve from the sedimentation of very fine sand after it has been blown into the air and, if large enough, might be a threat to humans. Indeed, reports that travellers and whole vehicles have been swallowed instantly may even turn out to be credible in the light of our results. ^[1]

“Natural” redirects here. ... Sedimentation describes the motion of particles in solutions or suspensions in response to an external force such as gravity, centrifugal force or electric force. ... Human beings are defined variously in biological, spiritual, and cultural terms, or in combinations thereof. ... The Trikke is a Human Powered Vehicle (HPV) This article is about the means of transport. ...

Occurrences in literature and otherwise

During the planning of the Project Apollo moon missions, dry quicksand on the moon was considered as a potential danger to the missions. It was not known if the surface of the moon was solid or a mile-deep layer of dust that would swallow the astronauts and their craft. The large plates at the end of legs of the Apollo Lunar Module were designed to reduce this danger, but the astronauts did not encounter dry quicksand. Project Apollo was a series of human spaceflight missions undertaken by the United States of America (NASA) using the Apollo spacecraft and Saturn launch vehicle, conducted during the years 1961 – 1975. ... The LEM flight instrumentation panel and front windows. ... Astronaut Bruce McCandless II using a manned maneuvering unit outside the U.S. Space Shuttle Challenger in 1984. ...

Dry quicksand was occasionally featured in literature. The 1966 movie African Gold (released abroad as Ride the High Wind) shows an actress being trapped in dry quicksand. Mindwarp (1990) also has an actress wandering into dry quicksand before being rescued. The movie 12 to the Moon (1960) shows a crew member being lost in moon dust similar to dry quicksand. In the film Lawrence of Arabia, a servant of T. E. Lawrence "drowns" in dry quicksand (this was never claimed to have happened in real life). The plot of the Arthur C. Clarke novel A Fall Of Moondust (1961) was based on the perils of working and travelling on a moon surface covered by a deep layer of dry quicksand, based on the actual risks considered during the planning of the Project Apollo missions. Year 1966 (MCMLXVI) was a common year starting on Saturday (link will display full calendar) of the 1966 Gregorian calendar. ... Year 1990 (MCMXC) was a common year starting on Monday (link displays the 1990 Gregorian calendar). ... Year 1960 (MCMLX) was a leap year starting on Friday (link will display full calendar) of the Gregorian calendar. ... Lawrence of Arabia is an award-winning 1962 film based on the life of T. E. Lawrence. ... Sir Arthur Charles Clarke, CBE (born 16 December 1917) is a British science-fiction author and inventor, most famous for his novel 2001: A Space Odyssey, and for collaborating with director Stanley Kubrick on the film of the same name. ... Year 1961 (MCMLXI) was a common year starting on Sunday (link will display full calendar) of the Gregorian calendar. ... Project Apollo was a series of human spaceflight missions undertaken by the United States of America (NASA) using the Apollo spacecraft and Saturn launch vehicle, conducted during the years 1961 – 1975. ...

The novel Dune features an Arrakian safety hazard called "sinks" by the Fremen natives, a pit filled with dust that swallows travelers. The movie and book The Princess Bride, featured "Lightning Sand" (described as being similar to quicksand, only dry where quicksand is wet), one of the three terrors of the Fire Swamp. Dry quicksand was also featured in the movies Mad Max: Beyond Thunderdome, and the 2004 Chinese film, Kekexili: Mountain Patrol. In the 1999 film The Mummy, dry quicksand buried Captain Winston Havlock and his crashed biplane. In the 1993 film Pure Luck Martin Short's character finds himself sinking in dry quicksand in Mexico before being rescued. Dune is a science fiction novel written by Frank Herbert and published in 1965. ... The Princess Bride is a 1973 novel written by William Goldman and originally published in the USA by Harcourt Brace Jovanovich. ... This article or section does not adequately cite its references or sources. ... Mad Max Beyond Thunderdome was a 1985 film, the 2nd sequel to the action movie Mad Max. ... shelby was here 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... (Redirected from 1999 film) See also: 1998 in film, other events of 1999, 2000 in film, list of years in film. Events April 7 - Star Wars fans begin lining up at movie theaters in Westwood and Hollywood to buy tickets for Star Wars, Episode I - The Phantom Menace May 3... The Mummy is a film written and directed in 1999 by Stephen Sommers and starring Brendan Fraser and Rachel Weisz, with Arnold Vosloo as the reanimated mummy of the title. ... An American film released in 1993. ...

Phillip J. Fry and Turanga Leela drive a (stolen replica) lunar rover from an amusement park into a pit of dry quicksand in the Futurama episode "The Series Has Landed". Philip J. Fry Philip J. Fry is the central character of the television series Futurama. ... Turanga Leela (referred to as simply Leela) is the primary female character in the animated television series Futurama. ... This article or section does not adequately cite its references or sources. ... Futurama is an Emmy Award-winning animated American sitcom created by creator of The Simpsons Matt Groening and developed by Groening and David X. Cohen for the Fox network. ... The Series Has Landed is the 2nd episode in series 1 of Futurama. ...

See also

• Fech fech

Fech Fech is a very fine powder caused by the erosion of clay-limestone terrain, pulverulent soil under a thin crust common in deserts. ...

References

1. ^ ^{a b} Detlef Lohse, Remco Rauhé, Raymond Bergmann, and Devaraj van der Meer. Creating a dry variety of quicksand. Nature 432, 689 - 690 (09 December 2004); doi:10.1038/432689a

External links

• Pictures of the quicksand experiment by Lohse et al