Are planets really held by balance between centrifugal and centripetal forces? What about this explanation.?

Question

Is that still taught? That those forces would by chance happen to end up in exact balance in perpetuity is not credible. I believe it's electrical forces, like electrons around the nucleus. See also my question on gravity. This universe is based on electromagnetism.

Keep in mind I'm talking about revolution not rotation.

Emmanual Velikovsky was a writer in the 1950s or 60s, who examined alternate explanations. He was from Russia but I don't know if he was ethnically Russian or Jewish. He was not accepted by the "establishment", but that proves nothing. In the book Earths In Collision, which I have, he refers to historical accounts where another heavenly body passed by earth, and exchanged an electric charge with it. Then the length of the year changed from 360 days to an uneven 365. It means the orbit moved farther from the sun. So orbits would be controlled by electromagnetic forces.

Answer 1

It is in such exact balance because of the way it was created over many 100 million years before the earth and other planets even existed. The dust which later came to be the solar system was attached to each other by gravitational forces, and the dust cloud started spinning because it had some directional speed and "missed" the center of the point of what was later to become the center of the solar system. As more dust was collected and the cloud got bigger the entire system ended up as a giant spinning disc which was prevented from falling into itself by centrifugal forces. As even more dust is collected the majority is collected at the center of gravity like water spinning down the drain to create sufficient mass to become the sun, and the dust which did not reach the center of the spinning disc create local maximums, and eventually collapsed under gravitational forces into planet -- each planet inheriting some of the spinning nature of all the material they were made up of and hence were spinning on their own, which still maintaining a circular orbit around the center of the spinning disc which is now the sun .....

Gravitational and centrifugal forces is more than sufficient to explain both how the hole thing can into existence as well as how it maintains stability -- electromagnetism, while being a great force, only works on near sub-atomic particles -- at least it does not work long distance, as well as the power is just not there to create anything which would cause a cont ant field to explain anything.

Answer 2

The electrons are also held into balance by centripetal/centrifugal force. Actually it's not a balance, it's a single force.

When you have an object A in orbit around another object B, then A has inertia, which makes it want to keep moving forward.

A -> keeps going straight (no orbit)


B

If A wants to be held in orbit, there needs to be a force pulling it towards the center.

A -> inertia
|
v (centripetal force)
B

That means that the net force on it, after combining these, is bent towards the center:

A -> F1 is inertia
| \
| -> Total force is bent inwards
v F2 is centripetal
B

(Apologies for the crude diagrams).

This F2 force, we call centripetal. It is the difference between the orbit path, bending inwards, and the straight inertia path spinning outwards. If you spin an object on a string, the tension in the string is the centripetal force. For an electron around a nucleus, the force is electrical attraction. For the planets around the sun, the force is gravity.

Magnetism is not strong enough to hold the planets together, at that scale. You know that a small refrigerator magnet will lift a pin off a table, even though the gravity AND magnetism of the entire world is holding the pin to the ground. So the earth's magnetism is weak, but electromagnetism is strong on small scales. If it's that much more effective in your hand than on the earth, then it is so much better at atomic scales.

Don't think about how the forces ended up in balance - you're thinking backwards. Think about the planet, flying at a certain speed:

A --> whee I'm a planet

And it sees the sun.

A --> I'm still going straight
|
V
B but the sun has gravity.

Then depending on where it is, it will find a natural orbit. Perhaps the orbit will be fast or slow, elliptical or circular. But the *final orbit* depends on the *planet's mass, initial speed, and distance to the sun*, not the other way around. If the earth's speed in space slowed down, then the inwards gravitational force (acting as the centripetal force) would be larger than the forward motion, and it would pull the planet inwards. This attraction will move the earth faster, and then make it move farther from the sun. This is how an elliptical orbit is formed.

Answer 3

Um, not exactly. There really is no such thing as a centrifugal "force," first of all: what you experience as a force shoving you outward is simply your own inertia resisting the force pulling you toward the center of your axis of rotation. A centripetal force is that center-pulling force, whether it be gravity or some physical force exerted through some connecting piece. The momentum of a planet orbiting the sun wants to keep it travelling in a straight line out into space, but the gravity exerted on the planet by the sun pulls it inwards, curving its path into an elliptical orbit initially theorized and observed by Sir Isaac Newton and later verified by... well, every other astronomer since.

If we were to do the calculations (and I really don't have the patience to try to type them out here), we can calculate that electromagnetism simply cannot exert enough force to keep planets in orbit -- it's very strong on a human or microscopic scale, but when applied to the macroscopic or astronomical scale, it simply doesn't work as well as gravity, which is relatively weaker but exerts much more effectively over long distances. This dichotomy has been one of the reasons why the Unified Field Theory that some physicists have sought ever since Einstein postulated it could be found has been so difficult to pin down in practice -- the four fundamental forces of the universe don't all fit into a neat box, so far as we've been able to calculate.

Answer 4

Simple. If it didn't work as theorized, we would not have artificial satellites - they are governed by the same rules as any other orbiting body.

The people in the ISS can adjust orbital height simply by applying short bursts of thrust one way or the other. Changing speed alters the "centrifugal moment", and the space station takes up a new orbit until the balance is again made with the Earth's gravity.

If the theory was wrong, this would not work.

Answer 5

The universe is based on four fundamental interactions: Electomagnetism, weak nuclear force, strong nuclear force and gravity.

Gravity is created by mass in a direct proportion, meaning the greater the mass the greater the force of gravity. Stars, planets, solar systems and galaxies are held in balance by gravity.

The particles that make up that mass are affected by and in turn affect electromagnatism. But there is no direct evidence that show electromagnetic fields having an affect on gravity, whereas gravity can affect electromagnatism (light) if its force is great enough.

So I would say no. Planets are not held in balance by centrifugal and centripetal forces. In fact, any centrifugal force felt on a rotating planet is being exerted by gravity itself and yet gravity would still exist and exert the same force if the planet were not rotating.

Answer 6

There is actually only one force at work, and that is the centripetal force, or gravity. This can be likened to swinging a ball attatched to a string around in a circle. The ball (planet) wants to go in a straight path, but you (whatever its orbiting) won't let it because you're constantly pulling it inward (centripetal means inward) with your string (gravity).

Answer 7

There is only centripetal force. It means a force directed to the center is needed to maintain the circular (elliptical) orbit. The needed force has been delivered by gravitation. (So it is NOT an equilibrium !!))

Answer 8

You all missed the fact that it's NOT perfect for all perpetuity. Some planets have spun onto their sides. The earth is slowly falling into the sun, etc...

Answer 9

I think you should read that book by Sir Wayne Newton, or whatever his name is.

Answer 10

I believe it's our knowledge from the pictures