"Relativity teaches us the connection between the different descriptions of one and the same reality." -A. EinsteinGravity By Gladys Palacio Velez
What is Gravity?Answer: Nobody truly knows what gravity is.But thanks to scientists throughout history we know how gravity behaves and it’s effects. In 1687 Sir Isaac Newton proposes his law of gravitation in which it states that every body in the universe attracts all other bodies with a force that is directly proportional with their masses and inversely proportional with its Sir Isaac Newton distance.
Microgravity Is there gravity in space? YES! Some people are confused that their isn’t any gravity in space because we see astronauts doing flips in mid-air and their hair standing up, meanwhile, in Earth everything sticks to the floor. Microgravity is one-millionth (1 x 10^-6) of Earth’s gravity. Microgravity isn’t all about being able to cool tricks in air but it also brings negative effects to the human body in: • Musculoskeletal • Neural system • Cardiovascular
Creating Microgravity A Microgravity Environment is obtained when any object is found in the state of free fall. Free fall = “the (one-dimensional) motion of any object under the influence of gravity only.” Examples of microgravity environments: Flying Parabolic Arcs Neutral Buoyancy Laboratories These examples given are used to train astronauts to learn how to work in the microgravity environment in space to perform the missions. All objects free fall at the same rate of acceleration regardless of their mass.
Artificial Gravity Artificial gravity is the varying of apparent gravity via artificial means, particularly in space, but also on the Earth. Methods for generating artificial gravity: • Rotation • Linear Acceleration • Mass • Magnetism • Gravity Generator • Buoyancy The importance of artificial gravity in space is protect the astronauts from the This device would spin at a harmful effects of being subjected to speed that would simulate microgravity for prolonged periods of time. the gravitational pull of Earth.
Gravity Probe B Launched on April 20, 2004GP-B is a mission to experiment that tests Einsteins 1916 general theory of relativity.The GP-B used four spherical gyroscopes, a telescope, and a star to measure two effects from Einstein Theories: • geodetic effect = the amount by which the Earth warps the local spacetime in which it resides. • The frame-dragging effect = the amount by which the rotating Earth drags its local spacetime around with it.
Einstein Theories are correct! Einstein’s General Theory of Relativity states that space and time are relative entities, interwoven fabric whose curvature is gravity. “Every one of the planets and stars and galaxies causes a depression that can attract or deflect passing smaller objects.” - Joanne Baker, 50 Physics Ideas After analyzing the data obtained by the GP-B for 5 years, scientists from NASA confirmed this theory.
Gravity Assist It’s the use of the relative movement and gravity of a planet or other celestial body to alter the path and speed of a spacecraft, typically in order to save propellant, time, and expense. Gravity assistance can be used to accelerate, decelerate and/or re-direct the path of a spacecraft. Before every space mission a trajectory needs to be designed for when sending a spacecraft.The trajectories that enabled NASAs twin Voyager spacecraft to tour the four gas giant planets and achieve velocity to escape our solar system had to use gravity assist.
Importance of Gravity in our Daily Life Without gravity we couldn’t live in the world we know because gravity is everywhere! Gravity is what keeps are bones functioning to be capable of giving support to our weight. It keeps satellites orbiting Earth so we can have communication. By understanding how gravity behaves we’ve been able to expand our knowledge in the universe and in our own planet and develop ground breaking technology. And soon enough we’ll reach Mars and asteroids.
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