
	Where results make sense

Topic: Weightlessness

In the News (Wed 3 Dec 08)

Damian Green

Sumner Redstone

Crimson Tide

Tommy Tuberville

Bill Clinton

Wayne Rooney

Vilasrao Deshmukh

Wake Forest

Grand Slam

Oklahoma State

	Zero Gravity Experience Weightlessness Parabolic Flights in the USA
		Weightless flights are offered in cooperation with ZeroG Corp and take place aboard a specially-modified and FAA certified Boeing 727 christened GForce One.
		During take-off and landings, you'll be safely strapped into standard airline seats and you'll hear the standard airline flight safety briefings from the flight crew.
		Each weightless adventure is a fantasy trip through the galaxy.
	www.incredible-adventures.com /zero-gravity-usa.html (551 words)

	The Physics Classroom
		Weightlessness is only a sensation; it is not a reality corresponding to an individual who has lost weight.
		Earth-orbiting astronauts are weightless for the same reasons that riders of a free-falling amusement park ride or a free-falling elevator are weightless.
		One might respond to this discussion by adhering to a second misconception: the astronauts are weightless because the force of gravity is reduced in space.
	www.physicsclassroom.com /Class/circles/U6L4d.html (2738 words)

	Weightlessness - Glasgledius (Site not responding. Last check: )
		Weightlessness is not due to an increased distance to the earth: the acceleration due to gravity at a height of, for example, 100 km is only 3% less than at the surface of the earth.
		Weightlessness means a zero g-force: acceleration is equal to gravity.
		Weightlessness for a more extended period of time is achieved in a spaceship outside the earth's atmosphere, as long no propulsion is applied; orbiting the earth this is the case except at moments that rockets are on for flight path corrections, and until reentry in the atmosphere.
	www.glasglow.com /E2/we/Weightlessness.html (601 words)

	Weightlessness (Site not responding. Last check: )
		Weightlessness Cynthia D'Souza De La Salle Institute 7423 N Sheridan A3 3455 S Wabash Ave Chicago IL 60626 Chicago IL 60616 (312) 508-5978 (312) 842-7355 Objectives: Mass remains constant but weight is the force with which the earth pulls the body to itself.
		Then gravity is not the reason for weightlessness, but the falling away at the same rate of the elevator.
		If their motion were suddenly stopped, their full weight would seem to return because their supports were pressing upwards into them.
	www.iit.edu /~smile/ph9507.html (556 words)

	weightlessness - HighBeam Encyclopedia
		weightlessness the absence of any observable effects of gravitation.
		This condition is experienced by an observer when he and his immediate surroundings are allowed to move freely in the local gravitational field.
		Three examples of situations where weightlessness is encountered are: (1) an elevator falling freely in a vacuum; (2) a space capsule orbiting the earth; (3) a spacecraft drifting in outer space with its engines off.
	www.encyclopedia.com /doc/1E1-weightle.html (565 words)

	Teachers' Domain: What Is "Weightlessness"?
		Surprisingly, however, an object does not need to be in outer space to experience the sensation of weightlessness.
		That is, the force of the earth's gravity acting on them is still 90 percent as strong as if they were on the earth's surface.
		Rather, weightlessness occurs because they and their spacecraft are free falling in gravity.
	www.teachersdomain.org /resources/phy03/sci/phys/mfw/zweightlessness (461 words)

	Space Brains: The Enrichments of Weightlessness
		Weightlessness causes the load-bearing tissues, bone and muscle, to atrophy, but, because mind-bearing tissue will be exercised in ways not even possible on Earth, weightlessness holds out the prospect of extraterrestrial mind expansion.
		The evolutionary changes that weightlessness will produce in brains will be due to the peculiar way in which brains develop, which weightlessness will exaggerate.
		Moreover, the neural enrichment that weightlessness promises stands to be augmented by the addition of new neurons throughout life.
	www.starlarvae.org /Space_Brains_The_Enrichments_of_Weightlessness.html (2310 words)

	Astrobiology: The Living Universe - Physiological Effects of Weightlessness
		Another negative consequence of weightlessness is the effect zero-gravity has on the cardiovascular system.
		Because of the impact weightlessness has on the human body, it is obvious to see why astronauts must be at the peak of fitness.
		The key difference between the symptoms of aging and the health of astronauts is that the changes in astronauts are, for the most part, reversible.
	library.thinkquest.org /C003763/index.php?page=adapt02 (1147 words)

	Weightlessness (Site not responding. Last check: )
		The phenomenon of "weightlessness" occurs when there is no force of support on your body.
		The "weightlessness" you may feel in an aircraft occurs any time the aircraft is accelerating downward with acceleration 1g.
		It is possible to experience weightlessness for a considerable length of time by turning the nose of the craft upward and cutting power so that it travels in a ballistic trajectory.
	hyperphysics.phy-astr.gsu.edu /hbase/mechanics/hump.html (288 words)

	weightlessness
		The condition of zero-gravity (zero-g) or microgravity experienced by all spacecraft and their occupants when in orbit, in any other state of free fall, or traveling through space at constant speed.
		Weightlessness can be of great benefit in certain areas of research and manufacturing, and large construction work in space.
		On the other hand, long-term exposure to weightlessness has adverse health effects, including muscular deconditioning and bone demineralization.
	www.daviddarling.info /encyclopedia/W/weightlessness.html (205 words)

	SparkNotes: SAT Physics: Weightlessness
		There is a popular misconception that astronauts in satellites experience weightlessness because they are beyond the reach of the Earth’s gravitational pull.
		For example, say that a weightless astronaut is eating lunch as he orbits the Earth in the space station.
		If the astronaut releases his grasp on a tasty dehydrated strawberry, then the berry, like your pen, floats in midair exactly where it was “dropped.” The force of gravity exerted by the Earth on the strawberry causes the strawberry to move in the same path as the spaceship.
	www.sparknotes.com /testprep/books/sat2/physics/chapter11section4.rhtml (533 words)

	Highbeam Encyclopedia - Search Results for weightlessness
		weightlessness Condition experienced by an object on which the force due to gravitation is neutralized.
		Such an object is said to have zero gravity and no weight; it floats and cannot fall.
		Weightlessness can be experienced in space and during free fall.
	www.encyclopedia.com /SearchResults.aspx?Q=weightlessness (750 words)

	Weightlessness (Site not responding. Last check: )
		Man readily adjusts to weightlessness and it is this inherent adaptability which causes the problem.
		Associated with this, during bed rest, immersion in water or the weightlessness of space flight is a progressive loss of circulatory reflexes so important in maintaining blood pressure.
		Incorporating the LBNP into a sleeping chamber for use throughout the sleep period might prove an acceptable way to protect the circulatory system.Other measures include the combined use of salt retaining hormones and fluid in the few hours prior to de-orbit to help return the blood volume and body fluids to normal.
	www.spacedoc.net /weightlessness.html (992 words)

	Lesson 35--Rotating Frames of Reference in Space and on Earth
		This lesson continues to explore rotating frames of reference, focusing on the weightless environment in space and on a qualitative discussion of the Coriolis force.
		Stories and extensions: The "Vomit Comet" airplane used by NASA to simulate weightlessness; "artificial gravity"; in a rotating space station; the swirl of draining sinks and of storms, north and south of the equator.
		Every one here must have already heard of "weightlessness" in space, and has probably seen on TV astronauts floating weightlessly in the "zero g" environment of the space shuttle.
	www-istp.gsfc.nasa.gov /stargaze/Lrotfram.htm (1622 words)

	Gravity Creates Weightlessness?
		It is a very common misconception that when astronauts are in orbit they are weightless because they are somehow far enough from the earth that the force of earth's gravity does not pull on them.
		The feeling or impression of weightlessness comes from the lack of a force from the ground (normal force) having to push on your feet to keep you up.
		When that force is gone, we feel say we feel "weightless." In fact, whenever a person is in freefall they feel weightless even though gravity is still causing them to have weight.
	regentsprep.org /Regents/physics/phys01/accgravi/nogravsm.htm (375 words)

	Adverse Effects of Weightlessness
		Muscle loss may be accompanied by a change in muscle type: rats exposed to weightlessness show an increase in the amount of "fast-twitch" white fiber relative to the bulkier "slow-twitch" red fiber.
		In 1987, rats exposed to 12.5 days of weightlessness showed a loss of 40 percent of their muscle mass and "serious damage" in 4 to 7 percent of their muscle fibers.
		In weightlessness, the muscular effort required to reach for and grab an object is reduced.
	www.permanent.com /s-nograv.htm (1461 words)

	Weightlessness, Weightlessness occurs when there is no gravitational pull on a body..., by Manpreet, General Science ...
		Weightlessness occurs when there is no gravitational pull on a body...
		Under the conditions of weightlessness it is possible to conduct certain scientific experiments that are impossible on earth.
		Scientists have been conducting experiments to find out whether a woman may become pregnant in weightlessness condition- and if so, what could be the effect of zero gravity on such children.
	www.4to40.com /earth/science/print.asp?article=earth_science_weightlessness (447 words)

	Cnes - What is weightlessness?
		When picturing an astronaut, most of us probably see someone hanging upside down inside a spacecraft, their hair standing on end and trying to catch a drink like Tintin’s faithful companion Captain Haddock, who watches his whisky curl into a ball in Explorers on the Moon.
		In weightlessness you have the impression of floating, while in fact you are falling; you think you are in a vacuum, but in fact you are breathing
		Weightlessness, also often called zero gravity, is in fact an ideal, theoretical state that does not exist in practice.
	www.cnes.fr /web/1064-what-is-weightlessness.php (0 words)

	Scientific American: Feature Article: Weightlessness and the Human Body: September 1998
		But only in the past few years have scientists begun to understand the body's responses to weightlessness, as the data--the cumulative experience of nearly 700 people spending a total of 58 person-years in space--have grown in quantity and quality.
		The direct and indirect effects of weightlessness precipitate a cascade of interrelated responses that begin in three different types of tissue: gravity receptors, fluids and weight-bearing structures.
		Also affected, for example, are the immune system (the various physical and psychological stresses of spaceflight probably play roles in the immunodeficiency experienced by astronauts) and the multiple systems responsible for the amount and quality of sleep (lighting levels and work schedules disrupt the body's normal rhythms).
	www.msu.edu /user/flaniga9/0998white.html (3770 words)

	Holland Lab Scientist Explores Health Effects of Weightlessness
		Shi and his research team were recently awarded a grant for more than $375,000 from the National Space Biomedical Research Institute (NSBRI) to continue their research on the effect of stress on the immune system in a ground-based, animal model of simulated weightlessness.
		This unusual condition of weightlessness is one reason for health problems that astronauts commonly experience.
		According to Shi, the weightless conditions that astronauts experience on space flights are in many ways physiologically analogous to the stress that results when humans are physically restrained-appropriately called restraint stress, which has been demonstrated to cause an increase in the amount of opioids produced by the body.
	www.redcross.org /news/bm/holland/010313wtless.html (1368 words)

	Mass, Weight, and Weightlessness (Site not responding. Last check: )
		Weightlessness can be achieved in one of two ways.
		weightlessness is the type of weightlessness we associate with space flight.
		Seeing astronauts weightless leads to a commonly-held misconception that gravity stops acting beyond the Earth's atmosphere.
	www.astro.virginia.edu /class/skrutskie/astr121/notes/weight.html (224 words)

	ASGSB 2005 Abstracts - Adverse Effect of Simulated Weightlessness on Mechanotransduction in MG-63 Osteosarcoma Cells (Site not responding. Last check: )
		Objective This study was aimed to explore the relationship of Shc and AP-1/TRE in MG-63 cells mechanotransduction and to survey its functional alteration in simulated weightlessness.
		As to the MG-63 cells cultured in simulated weightlessness by using clinostat, mechanical stimulation by 1.5 Pa FSS resulted, after 15 min, in increased amount of luciferase activities in cells transfected with pcDNA3.
		This abnormal mechanotransduction might contribute to osteopenia induced by weightlessness observed in crewmembers.
	www.asgsb.org /programs/2005/118.html (298 words)

	Space: A Bad Influence on Microbes? - Space - RedOrbit
		Using modern advances in biotechnology and the weightlessness provided by the International Space Station (ISS), they plan to explore the changes in gene expression experienced by microbes in the true weightlessness of spaceflight.
		Cells feel a slight shear as they move through the liquid--a difference from true weightlessness that could affect their behavior--but like cells in orbit, they avoid becoming flattened on the bottom of the container.
		Whether performed in true or simulated weightlessness, this line of research could help unravel the genetic basis of infection--a bit of knowledge that would help astronauts and land-lovers alike to live a little healthier.
	www.redorbit.com /news/stories/1/2003/12/03/story003.html (940 words)

	Effects of Simulated Weightlessness on the Repair of Lower-Limb Bone Fractures and on the Number of Bone-Derived Stem ...
		This diminished level was reflected in a maximum hard callus volume that was only 22 percent of the WB group and a rate of hard callus formation that was only 19 percent of the WB group.
		In this case, this group exhibited a maximum hard callus volume that was only 34 percent of the WB group and a rate of hard callus formation that was only 28 percent of the WB group.
		Thus, a simulated weightlessness situation may be caused by a reduction in the existing number of functional preosteoblasts and osteoblasts available for immediate use to repair bone trauma.
	www.nsbri.org /Research/Projects/viewsummary.epl?pid=169 (1126 words)

	Amusement Park Physics -- Physics Glossary
		The weight of an object is expressed in pounds in the U.S. A 180-pound person is experiencing a force of gravitational attraction to the earth equal to 180 pounds.
		She no longer feels the external force of the seat and subsequently has a brief sensation of weightlessness.
		In this context, weightlessness is a sensation and not an actual change in weight.
	www.learner.org /exhibits/parkphysics/glossary.html (1550 words)

	ESA Portal - Floating in weightlessness – on Earth
		Ever since astronauts started playing games in space, for instance catching morsels of food floating in weightlessness conditions, the general public knows that the saying is not necessarily true.
		A capsule containing an experiment is allowed to drop down the structure and will experience weightlessness for 1.5 seconds before its fall is cushioned in a 1.75 metre deep pit filled with PVC spheres.
		The ESTEC drop tower is not primarily used for scientific research but as a demonstrator of gravitational effects for students and an interested public and to explain the function of the Zarm drop tower at the University of Bremen in Germany.
	www.esa.int /esaCP/SEMEPX2IU7E_index_0.html (749 words)

	Weightlessness (Godwin) by Francis Godwin from The Man in the Moone
		Weightlessness (Godwin) by Francis Godwin from The Man in the Moone
		This appears to be the first description of the idea of weightlessness in space.
		During the 19th century, Jules Verne probably influenced more people with his description of weightlessness, in his novel From The Earth To The Moon.
	www.technovelgy.com /ct/content.asp?Bnum=683 (263 words)

	ESA Portal - Focus On - Experience weightlessness onboard the 'Zero-G' Airbus
		Today, scaled down versions of just such a runaway elevator are the single most accessible way for scientists to experiment with weightlessness.
		Operated for ESA by the French company Novespace, the aircraft is specially flown so that its passengers and cargo experience longer periods of free-falling weightlessness - but in a survivable fashion.
		Flying level at about 6000 metres the weightlessness manoeuvre – known as a parabolic arc – begins when the aircraft is sent into a steep 45 degree climb on full engines.
	www.esa.int /export/esaCP/SEM8WZ8YFDD_FeatureWeek_0.html (1026 words)

Try your search on: Qwika (all wikis)