Just as the speed of a massless particle of light in a vacuum is restricted by the Universe's upper speed limit, the massless distortions of spacetime would also be energy zipping along at top speed. Or, to be more precise, gravity moves at 299,792,458 metres per second, a rate we can just call c.
Kopeikin and Fomalont concluded that the speed of gravity is between 0.8 and 1.2 times the speed of light, which would be fully consistent with the theoretical prediction of general relativity that the speed of gravity is exactly the same as the speed of light.
As long as gravitational waves and photons have no rest mass, the laws of physics dictate that they must move at exactly the same speed: the speed of light, which must equal the speed of gravity.
Gravity is measured by the acceleration that it gives to freely falling objects. At Earth's surface the acceleration of gravity is about 9.8 metres (32 feet) per second per second. Thus, for every second an object is in free fall, its speed increases by about 9.8 metres per second.
"9.81 meters per second squared" means that objects on Earth will accelerate (or go faster) 9.81 meters every second, if they are in free fall, due to the pull of gravity.
As Jupiter moved between Earth and the quasar, the gravitational bending of Jupiter allowed us to measure the speed of gravity, ruling out an infinite speed and determining that the speed of gravity was between 2.55 × 10^8 and 3.81 × 10^8 meters-per-second, completely consistent with Einstein's predictions.
If an object is dropped from rest then . . . after 1 second its velocity is -9.8 m/s. after 2 seconds its velocity is -19.6 m/s. after 3 seconds its velocity is -29.4 m/s.
The first equation shows that, after one second, an object will have fallen a distance of 1/2 × 9.8 × 12 = 4.9 m. After two seconds it will have fallen 1/2 × 9.8 × 22 = 19.6 m; and so on.
The Earth's gravitational field extends well into space it does not stop. However, it does weaken as one gets further from the center of the Earth. The Shuttle orbits about 125 mi above the surface, roughly the distance between Jackson and Nashville!
If you are at the center of the earth, gravity is zero because all the mass around you is pulling "up" (every direction there is up!).
Astronomers agreed that the black hole was spinning really fast, but obviously not as faster than the speed of light — the universal speed limit.
Earth's gravity comes from all its mass. All its mass makes a combined gravitational pull on all the mass in your body. That's what gives you weight. And if you were on a planet with less mass than Earth, you would weigh less than you do here.
The speed of gravity is the same as the speed of light in a vacuum, and we know that we cannot go faster than that.
Nothing can travel faster than 300,000 kilometers per second (186,000 miles per second). Only massless particles, including photons, which make up light, can travel at that speed. It's impossible to accelerate any material object up to the speed of light because it would take an infinite amount of energy to do so.
Albert Einstein's theory of general relativity predicts that where gravity is stronger, time passes more slowly. That's called time dilation.
It's impossible to just “turn off” gravity. The only ways to simulate weightlessness or microgravity is to balance gravity's pull with another force, or to fall!
Previous research has shown that spending time in space causes bone density loss, immune dysfunction, cardiovascular issues such as stiffening of arteries, and loss of skeletal muscle mass and strength in both humans and rodent models. These changes resemble aging in people age on Earth, but happen more quickly.
That means people who live at high altitudes age a tad faster than those plodding through space-time at sea level. "Gravity makes us age slower, in a relative term," Chou said. "Compared to someone not near any massive object, we are aging more slowly by a very tiny amount.
Falling freely – at the same rate
If I drop a cannonball and a cricket ball, the cannonball will fall faster. Right Lines: All objects fall freely at the same rate irrespective of mass (provided the effects of air resistance can be ignored).
A typical skydiver in a spread-eagle position will reach terminal velocity after about 12 seconds, during which time they will have fallen around 450 m (1,500 ft).
Gravity will accelerate any object at a rate of 32 feet per second per second. But what do we do with that number? What it means is that if we fall for one second we'll reach a speed of 32 feet per second. After two seconds we reach 64 feet per second.
As every object will be out of balance for those 5 seconds, the earth's atmosphere will start to disappear, its core will expand with the heat of the sun, the surface of the earth will begin to crack, tidal waves will soar high and other sudden changes will start coming to life.
An artificial gravity level of 0.1 g can be achieved by a reasonably low rotation rate (5 rpm) at radius as low as 4 m (see Figure 2-04). Likewise at a radius of 4 m, about 15 rpm would be required to produce Earth gravity at the feet (although gravity would be 50% less at the head), or 21 rpm to produce 2 g.
The speed of light traveling through a vacuum is exactly 299,792,458 meters (983,571,056 feet) per second. That's about 186,282 miles per second — a universal constant known in equations as "c," or light speed.