Welcome one and all to a quick discussion on Gravity! I’m going to help you understand why the solar system is mostly flat, why the moon moves around us horizontally, and even why Galaxies are largely flat! You might have thought it was something complicated but indeed it is even more simple than a fancy magic humanoid in the sky!
We live in 3 dimensions as I am sure you are aware, but whenever gravity is shown to us in textbooks and other locations you will find it represented in a 2 dimensional image. Gravity forms a “well” of sorts and all things fall into it.
MS Paint remake of what is often shown for a black hole. An exponentially curved arc into a pit that basically has infinite gravity (effectively). Nothing, even light can escape it.
When I used to see this image I wondered where it all went! If it is a tube then surely things must be getting tubed to somewhere. That’s what tubes do, they wouldn’t be tubes otherwise. Where is all this data getting downloaded? Al Gore please explain this to me!
But no matter how many times I send him letters drenched in perfume with a lipstick kiss on the back, that man just won’t respond! So here I am left to figure it out myself! This is going to be interesting because I’m going to continue using MS Paint for today’s article…so prepare your anus brain!
Up to a certain size in large objects you will find that their shape can be just about anything (in this discussion I’m speaking entirely about inorganic things), but once you hit a certain size a bit larger than asteroids they will start to take on the shape of a sphere. But why, that is the question that used to spring up into my mind. I mean of just about any shape my absolute favorite is a sphere or a circle (depending on the dimensions), they represent something so delightfully beautiful to me.
Gravitation is an odd thing, like peering into a fourth dimension, and you might not believe this but I hope I can convince you a bit. If I can’t then damn it at least I got to use MS Paint for something semi serious! Gravitation does create a well but not in the common 2 dimensional sense, it creates a spherical well. Well how in the sam hell does that work?!
The mass of the object is represented by the dot in the center, the sphere on the outside is the rim of the well. There is another step removed from this that I’ll get to in a few minutes and it is common in film about quantum mechanics or astronomy.
Now you’ll notice in this example I’ve used a perfect circle and its gravitational field is also perfect. This is an interesting example because I’m fairly certain that there are little to no actual examples in the universe of this except for possibly black holes. But even in this case I don’t believe that is true because of the accretion disks that form on a horizon for them. Those accretion disks actually give away how gravitation works and even how it looks.
Likely all objects in the universe are ovoid, this has to do mostly with the fact that these objects are spinning and they are spinning merely because of angular momentum from early impacts and a remarkable lack of friction in space (honestly the fact that space is a vacuum without friction is something I think that is lost on people and why Astronomy can be so hard to stomach sometimes).
This is more accurate in the representation of all massive objects in space. An oval, that is, a sphere that is fat and short as opposed to an object with an equal diameter at all edges [edges? Someone needs more coffee].
So you might ask yourself, what happens to an object that passes by three dimensional ovoid well? The possibilities are fairly few in number, assuming I don’t miss any. You could merely plummet into the object and transfer your mass and energy into it (which can have varying results), you could pass it by without much care other than a shift in your own orbital path, or finally you could end up stuck in its tug and begin orbiting it exclusively.
Imagine if you will you had an ovoid with a little metal ball in it. For whatever reason this ball can actually grip the walls of this ovoid (just for the sake of this example), if you accelerate the ball what is going to happen? Assuming that you’ve done nothing but accelerate it without any sort of direction you will (I expect) slowly see it moving more and more towards the widest edge of the ovoid. Once it is there it will begin rotating around the widest point of this ovoid and will remain there until it no longer has the energy to sustain the motion. That energy being only necessary because of friction in our environment.
This, at least I believe, is why you’ll find all orbiting objects doing so on a rather consistent horizon. That horizon being the plane aligned with the fattest point on the object. Any objects not yet following this path will likely end up doing so eventually. The moon orbits us on a horizontal path, the planets the sun, and the sun the galaxy. Each spinning around that widest point, just as a coin in those plastic wells at the mall will continue along the widest path it can given the energy it has to overcome momentum.
So what is gravity then? I understand that there is this well thingy, but where is that pull coming from? This part I’m sure you’ve all seen. You are looking down at a grid from the top and the massive object is seemingly “condensing” a grid. That condensed space creates a cavitation in space/time and objects that fall into that area move around in that cavitation. If they do not have enough energy to “roll out” of it they will remain there indefinitely.
Any space without dense objects will not be warped, but any space with massive objects will be warped. That warped region becomes a three dimensional pit or well that we cannot easily imagine. Similar to trying to imagine a 4 dimensional square we are left looking at something nearly extra planar without the faculties or precedence to do so.
I’m having a hell of a time finding an image that would show the three dimensional grid as a within structure. In all the examples I’m coming across they show it visually in a without model. The without model treats all objects in the image as motes of dust that float on the surface of a viscous liquid as such:
We aren’t floating on gravitational “water” though, we are deep within it.
Imagine each square in that image as a cube and then imagine them all encompassing in the image. Each object passes through the cubes and their most dense point (their center) pulls cubes towards it. This condensation of space/time is why when you get close to a massive object it begins to pull you harder and you move faster. The literal distance between you and its center becomes shorter and shorter.
In the case of a black hole this crunching of cubes becomes so intense that moving a fraction of a fraction of a millimeter can be the difference between your legs feeling fine and them being separated from your lower torso (and then from their own atoms by powers of 2).
We are not floating on the surface of a beautiful ocean of space and time. We exist within it, think of those cubes as water with you and everything you can see in every direction with every tool for any distance is enclosed in that water. That water is also, for all intents and purposes, everywhere.
I would go further, time to really dig deep into thought experiments! Our universe is one of many, more than likely, and the reason that we are not expanding into anything and likely never will is because this gravitational water that we are floating in goes on in all directions for an infinite distance actually existing outside of our own universe! As our universe expands it “pushes” on this lattice and the entire fabric of the multiverse expands outward from our point.
It is quite possible given this little thought that all the universes of the multiverse are actually pushing against one another and that we are expanding at a faster and faster rate only because we are such a young universe. As we get older we’ll begin pushing against other expanding universes, if we end up at the center of a lot of them expanding they will reduce the rate at which we expand and the universe will slow to a halt and then begin to collapse in upon itself.
That collapse will be just like we see in a star crushing inward till its ultimate extreme where the pressure is far too great to be contained and actually exceeds the pressure from the surrounding universes causing it to once again “explode” or more accurately expand with great force in all directions. This will then push against those other universes which are at this time much less dense and thus less energetic and some or all of them will begin to shift their own expansion or potentially collapse.
You are left with a taffy like multiverse that stretches and contracts all over in response to one another. This obviously leads to the question of what started this stretching and contracting, the greatest error in that question would be to presume that it requires thought. In all our experiences for the entire expanse of human history and from all the data we have ever collected, the entire universe moves in the way it does because it does, if it did not then it would not, there is nothing special about it merely because no matter what it was we would perceive it as exactly that.
It is only special to us because it is the only thing we know, equally any other variation that could lead to sentience would likely outlive its inhabitants and would be the most special thing to them.
Any who, that’s my little foray into gravitation. We live in a giant universe of cubes that are being tugged and pushed in all sorts of ways. This is why you see waves, why orbits all fall on the same planes, and blah blah blah.
Thanks for your time.