Aside from the fact that everything falls at a speed of 9.8 m/s2, what do we know about gravity? These gravity facts will explain what this force does for us and what would happen if it did not exist.
Planets are weighed by their gravitational pull, according to scientists.
You may be wondering how we have all these measurements for planets when it appears impossible to measure objects in space, let alone massive objects like planets. However, things changed in 1797 with Lord Henry Cavendish’s experiment. Scientists can now calculate the weight of a planet based on the time it takes for objects to orbit it and the distance those objects are from the planet thanks to his discoveries.
Cavendish devised a test using two 150 kg lead balls (planets) and two smaller spheres (moons). He calculated the gravitational attraction between these elements. Cavendish discovered the missing piece of Newton’s gravitational puzzle, the value of G – the amount that relates the gravitational force between two bodies to their masses and distance – through his experiment. Cavendish was also the first man to attempt weighing a planet using the new value of G. He calculated the Earth’s mass as six billion trillion tonnes using Newton’s equation and the value of G.
Gravity is as weak as a fridge magnet.
When you place a dime-sized magnet on a fridge, it generates enough electromagnetic force to overcome gravity and stick to it.
Gravity and weight are not synonymous.
One of the most overlooked gravity facts is that astronauts do not have weight in space, despite the fact that the force of gravity in space is 90% of the force an astronaut experiences on Earth. The force we feel on a surface is defined as weight (like on a chair or a bed). As a result, astronauts in space are weightless.
Galileo Galilei demonstrated that gravitational acceleration is constant by using… the Tower of Pisa?
Galileo Galilei, an Italian scientist, dropped two spheres of varying masses from the Leaning Tower of Pisa in the 14th century. He did this to show how their mass had no effect on their descent time, and they all fell at the same time.
Galileo discovered that the objects fell with the same acceleration, according to Galileo’s student Viviani. With that, he disproved Aristotle’s earlier theory of gravitational acceleration, which stated that objects fall at rates proportional to their mass.
When you accelerate, your weight shifts.
When you run, you strain because the Earth’s gravity pulls you toward its core, but the ground you’re running on pushes up and perfectly matches this force.
This interaction of forces is what causes you to feel heavy. When you reach the top of a roller coaster, the chair presses harder against your body, opposing gravity and making you feel heavier. However, as the coaster begins to descend, your body feels lighter. This is why you feel weightless for a brief moment before descending. These weight fluctuations are referred to as ‘g-force.’
Some bacteria thrive in microgravity.
Bacteria grown in a NASA Space Shuttle stuck together in shapes never seen before on the ground and survived at much higher densities. This is not the same behavior as identical bacteria on Earth.
Dark energy works in opposition to gravity.
Gravity is a weak force that is incapable of holding the entire universe together. The universe has been expanding since the Big Bang. Dark energy opposes the pull of gravity in the universe. Gravity is only strong over short distances, but dark energy is thought to be evenly distributed, accelerating the expansion of the universe while preventing gravity from pulling everything back together.
Gravity has an infinite range.
Although gravity is the weakest of the four fundamental forces, it has an infinite range. Its strength diminishes rapidly as objects get closer together, but its reach is theoretically infinite.
Artificial gravity is created by spinning motions.
The outer walls of a spinning fair ride provide an inward center-seeking force that keeps riders moving in a circle. This sensation of constant momentum is known as centripetal force, and it feels similar to gravity.
On Mars, you weigh nearly three times less than you do on Earth.
Because all of the atoms in your body are the same size, mass is a fixed property. Your mass remains constant whether you are on Earth, in space, or on the Moon. However, the gravitational pull of other planets differs from that of Earth. As a result, your mass will be the same, but your weight will differ.
Astronauts train for space travel in planes.
The sky, next to outer space, is the closest thing we have to defying gravity. Planes make a parabolic arc (a quick up-and-down motion) to induce weightlessness, allowing astronauts to train for space travel.
The solar system will collapse if gravity is not present.
Planets and moons would cease to orbit their parent bodies and drift away in a straight line if gravity did not exist.
The sun, on the other hand, suffers a more dire fate: without gravity in the solar system, the sun would explode in minutes.
The sun is constantly under pressure. It is so massive that gravity compresses its core, causing it to heat up and burn hydrogen. The sun is in equilibrium due to the pressures of gravity and radiation.
Without gravity, there will be no force to keep the intense pressure at the sun’s core in check. The sun’s chemical reactions will be disrupted by the sudden loss of gravity, causing it to expel extremely hot gas across the solar system.