**Pushing gravity
** Modified 1-11-09

We analyse the force and power required to keep the earth in orbit from two points of view. First, the tension on a steel cable give a sense of scale of the huge forces involved. Then we look at a Pushing Gravity force which has a long and interesting history.

**Tangent velocity:**

**vt = circumference/period = 2*pi*au/year = 2*pi*149.598E9_m/31.56E6_s = 29,785.9_m/s, **the tangent velocity of the earth in orbit.
**149.598E9_m = au,** the average distance between the centers of the earth and sun. The year is expressed in seconds.

**Centripetal force:**

To deflect the mass of the earth, **Mer = 5.9722E24_kg,** from her inertial, straight line path, requires a centripetal force of,

**mass*velocity ^{2}/radius = Mer*vt^{2}/au = 5.9722E24_kg*(29,785.9_m/s)^{2}/149.598E9_m = 3.5418E22_kg*m/s^{2}.**

**Force resisted by steel:**

Ultimate strength is quoted force per unit of cross section area (N/mē). The SI unit of stress is the pascal, where **1_Pa = 1_N/m ^{2} = 1_kg/(m*s^{2})**. The ultimate tensile strength of AISI 1018 Steel is

**Radial velocity:**

To keep her in orbit also requires a centripetal radial velocity of,

**2*Au/Year = 2*149.598E9_m/31.56E6_s = 9,481.45_m/s**

**Power to keep earth in orbit:**

The power required to keep the earth in an orbit, to be applied each second, in the absense of gravity, would be,

**force * velocity = power
centripetal force * radial velocity = Watts
Mer*vt**

To find the minimum mass required to generate this power, we divide by c

**Pushing gravity:**

The force required to keep the earth in orbit is provided by the impulse of unseen waves or particles with mass or energy which come in from every direction and which are stopped by everything which has gravity. Space is supposed filled with these unseen particles. Objects shadow each other from these particles and are pushed together by the impulse of the particles. The impact of these particles must generate a lot of heat.

**Solar output power:**

**Earth's insolation = 1,366_W/m ^{2},** The solar output received at the earths orbit.

**Pushing gravity power required:**

The power to keep the earth in orbit, by means of pushing gravity 3.357E26_W, is more than twice the total solar output of 1.2805E26_W. This is as unrealistic, one might say silly, as the steel cable.