Dark energy and centrifugal forces

Question

So looked it up when the thought occurred to me and ended up on this site where I read this: Does a similar concept like centrifugal force exist for the whole universe?, but now I want to ask to those more learned than myself, not if dark energy is created by centrifugal forces but instead if it is created in the place/moment when centrifugal forces find balance with gravitational forces as in orbit for example where push and pull are not directly felt. A sort of field of balanced or null resonance?

Answer 1

No.

I'm sorry, this is almost a meaningless question, its just physics words mixed up. But I'll try to explain why, maybe that's the best I can do.

Physicists are not naive. They understand concepts like centrifugal/centripetal force (the former is a kind of illusory "force" due to a rotating frame, the latter is a "real" force), having originated them. They understand why they suggest some form of dark energy may exist, having originated that idea too.

The former and latter have zero point zero to do with each other. I'll try to explain what each is, then hopefully that'll make sense.

Centripetal force is very simply - a force that pulls towards a (usually) fixed point, whatever direction the object is. The earth's gravity is a good example of this. Any genuine, centrally directed, honest-to-god force. Note that any time you travel in a curve, something will be applying a centripetal force. For example when a roundabout turns with you on it, the grip on the bars and friction on the seat are pulling you centrally as they hold you in place, which is why you aren't falling off. When your car turns round a bend, the friction of road to rubber tires keeps it moving in a curve as if moving around some central point of the curve. And, of course, satellites, planets and moons moving in a curve due to gravity.

Centrifugal force is an illusory, or "pseudo" force we seem to experience, throwing us outward from a curved path. For example when a child is on a roundabout and they feel they are being thrown off it, or a car goes round a bend and we are pressed towards the outside side of the car. What's going on there is, that the edge of the roundabout or the car, are being forced to travel in a curved path. But we aren't the roundabout or car, so our bodies try to go straight on. When you are in a car going round a bend, or on a roundabout, "straight on" seems to be away from the roundabout or towards the outside of the curve. If you draw your "straight on" path, and the path you're being forced to follow on the roundabout or in the car, you'll see that. So it seems that a force is pulling us away from the middle. But in reality we are moving straight, and the place we are, is what's curving away. Not us. There is no force pulling us to the outside. It just seems like there is. That's why its called a pseudo force. Its an illusion caused by being in on on an object that's following a curved not straight path.

Dark energy is a term used by physicists to describe something they know is going on, but don't yet understand. Its "dark" in the sense we know something's going on. We know some ways it behaves. We have evidence for its existence. But we dont yet know what it's made of, or its structure, so we don't know how to directly measure and see it. Its "dark" to our current instruments (a bit like how your eyes can't detect X rays or gravity). We don't know what it is, we just know something is there, and we give it the name "dark energy" until we have a better understanding to give it a proper name. What we know is, the universe is expanding. Normally you'd expect the expansion to.slow down, because of gravity if anything. This expansion was slowing down for billions of years..... and then something started to have more impact on its expansion, and overcame gravity, and the universe began to expand faster, not slower. That started maybe 4 billion years ago. We can see it. We don't know anything that can speed up the expansion of the universe, but something clearly is. We call that, dark energy, until we have a better name.

Of interest, the expansion of the universe is not just stuff moving apart, like usual. When physicists and astronomers say the universe is expanding because of something they call dark energy, they literally mean, space itself - the actual distances in space - are getting bigger. If objects like stars and planets could stay still, we could come back tomorrow and find that there's a bit more distance between them than there was today - even though they didn't move in space at all. Because all distances are increasing, it isnt like there is some central point they are moving away from. You could be anywhere, and everything would look like it's further away tomorrow than today. But its only really visible on huge scales, like the distances between clusters of galaxies. Yes, this is hard to get your head round!!

So back to your question/s...

What's the connection between centrifugal/centripetal forces and gravitational forces? Is anything "created" there?

Absolutely zero point zero and no, unless you are asking a basic physics question - and basic physics questions about centripetal force tend to be things like cars going round a corner or buckets being whirled on a string.

What's the connection between centrifugal force/centripetal force/gravity balance, and dark energy?

Absolutely zero point zero, at least at the level you're asking, and as far as we know. Centrifugal/centripetal forces are very basic mechanics, gravity and whatever dark energy turns out to be, are apparently 2 parts of the fundamental structure of this universe. If there is any more intimate connection between gravity and dark energy than that, we don't know it. (But if such a connection exists, then centrifugal force, centripetal force, "null resonance" or some kind of "balance" between them and gravity, are almost absolutely surely, not it.)

The rest of your question is - apologies - physics word salad, and doesn't seem to mean much.