Re: Is the earth’s diameter increasing with time?
Peace OYMWA
Actually rotation speed of axis is not linked to the mass of the object. If anything the heavier planets in our solar system rotate faster than the inner smaller planets. Although their solar orbit lasts longer because they are further away, about their own axes they go faster. This is a combination of their density, gravitational effect of the primordial nebula formation and magnetism. And it’s not fully understood, but the principle is rooted in conservation of momentum if a big body is rotating and suddenly crunches together effectively increasing its density then it will rotate faster to conserve the momentum. You can try this out yourself sit on a rotating chair and spin around with your legs hanging out, while you are rotating slowly around tuck your legs in and you will increase in angular speed. This is because your angular momentum needs to be conserved and as your diameter reduces each particle of weight on your body gets more force because the distance from the centre has reduced. Delta Momentum = Mass x Delta (Velocity). Delta (Velocity) = Acceleration. Angular velocity works in terms of arc length so the arc length equal to larger radius means its angle would be small compared to the arc length of a smaller radius to cover the same distance in arc length. This results in a faster spin.
If you add the increase in weight - then the weight needs to come from somewhere - because according to Newtonian physics matter can neither be created nor destroyed. So if external matter enters the Earth (hopefully not because that would mean asteroid collisions) it depends on the angle and speed of impact that would deliver the speed to the rotation of the axis. It could in theory land in a certain way that would stop the spin of the Earth or reverse it.
But the moon orbiting the Earth and the Earth orbiting the Sun also has a huge factor … Think of a basketball player who spins a ball on his finger. He uses his free hand to spin the ball faster. So imagine that the free hand is like the moon that passes by the Earth twice a month once backwards with respect to the orbit of the Earth around the Sun and once forwards with respect to the orbit around the Sun. Each passing of the moon will have an effect like the hand turning the ball on the Earth and actually keeps the rotation going.