Humans evolved with gravity, and gravity affects human physiology and general health. Studies show that weightlessness has a number of negative health effects. Finding ways to mitigate these dangers is essential for long-distance space travel.Know More
All life on Earth evolved to live with the Earth's gravity, and humans are no exception. As a result, human muscles, bones and various systems depend on gravity to function properly. Before the United States and the USSR launched astronauts into space, they tried to study the effects of weightlessness on astronauts. While weightlessness can be simulated with parabolic motion in aircraft, the simulations last only minutes.
Short launches early in the development of space technology showed that people suffered from no ill effects on short trips. When astronauts spent longer periods of time in space, however, some health effects became clear. Humans lose muscle mass and cannot put it back on with exercise.
Experts often propose simulating gravity for lengthy stays on space stations and for long space trips. This is generally accomplished by using a spinning motion. While no existing space technology can accomplish this, it is fairly simple in practice, and these plans will likely be used if people need to spend years at a time in space on missions.Learn more about Physics
The specific gravity of mercury is 13.6. Specific gravity is also called relative density and is the ratio of the density of one substance to that of a standard substance such as water. Density is an object's mass per unit volume.Full Answer >
According to Wichita State University, Isaac Newton discovered gravity sometime during the summer of 1665. However, the book where Newton first wrote of this finding, "The Principia," was not published until July 5, 1687.Full Answer >
The specific gravity of diesel fuel oil varies between 0.81 to 0.96. Specific gravity of diesel fuel oil is recorded at 15.6 degree centigrade.Full Answer >
Friction is caused by the interactions between the sometimes microscopic roughness of different substances. As a result, friction is primarily affected by the "roughness" of an object. Friction is also affected by the mass or weight of the object as well.Full Answer >