An old theory of quantized gravity is gaining new life

The key feature she never names is known as a "UV fixed point".

UV = UltraViolet, which in this context simply stands for "high energy".

Fixed point... for that you need to know that the effective values of coupling "constants" aren't actually constant in quantum field theory; they depend on the interaction energy (i.e. how hard you bang your particles together). So they are called "running" coupling constants. Yes, it's contradictory.

That dependence on interaction energy is described by differential equations (known as the renormalization group flow equations, which may sound impressive but is actually a misnomer), which you can integrate to see how a coupling measured in the lab at low energy will change when your descendants finally get enough funding for a larger accelerator.

One interesting behavior is the coupling going to zero when you increase the energy towards infinity. That happens in QCD: counterintuitively, the harder you bang quarks together, the less they affect each other (via QCD, that is; they also have other kinds of interactions which behave differently). So QCD is called "asymptotically free": in the limit of infinite interaction energy, as far as QCD is concerned, quarks are free particles, completely unaffected by each other's presence.

In asymptotic safety, as opposed to freedom, the coupling does not go to zero as you increase the energy; instead, the rate at which it changes goes to zero, and it does so at some finite value of interaction energy. So, as you crank up the interaction energy toward that value, the coupling constant "runs" slower and slower, and once you get there, it stops "running" altogether. From there on, you can raise the interaction energy all you want, and the coupling constant stays... constant.

And that is a UV fixed point.

So, a small piece of rock that you can hold in your hand, will cause a gravitational ripple in the space surrounding it. This is similar to how the Earth causes a gravitational ripple in the space around it, and it keeps us grounded to the ground. But, the Earth causes a much bigger gravitational ripple, than a small rock.

And we as humans, are grounded to the Earth, as if we are at the bottom of this massive and invisible whirlpool. We cannot see it, but this whirlpool is rotating all around us, and we cannot get out. It is easy for us to move around horizontally, but it is very difficult for us to move vertically. Unless we can move horizontally so fast, that we can reach escape velocity, and then, we orbit the Earth.

That said. What is gravity? Why does mass cause a ripple in the space around it?

I wonder if gravity is just some type of neutral electro-magnetic force. Kind of like the magnetic field lines that you see with the North pole and South pole. But instead of being magnetically charged, it is neutrally charged, and it affects everything around it equally.

Or, instead of being magnetically charged like the North or South pole, it is gravitationally-charged, and the direction points in only one way, into the center of your massive object. And unless you are moving faster than that massive object's escape velocity, then you will always be stuck in that object's gravitational ripple.

If we can truly understand what is gravity, then I wonder if we can create a counter gravity. Like, in your spaceship, if you can create a negative mass above you, then it would cause your spaceship to act buoyant in the planet's atmosphere. And you can use thrusters to move around vertically, as easy as you can move around horizontally.

Or, maybe you can create a temporary blackhole above your spaceship, and instead of your spaceship falling into the gravitational ripple caused by the Earth, then it becomes attracted to the gravitational ripple caused by your blackhole. And this causes your spaceship to rise, and defy the Earth's gravity.

Anyways. I'm not a gravitational physicist. Maybe I should take this idea, and write a novel. There has been much worse Sci-Fi ideas created, like Time Travel, or the ridiculous many-worlds-interpretation theory of quantum mechanics.

That aside, real infinities is a vague concept. What's important is that any theory of gravity has to deal with the fact that the current understanding of classical gravity and quantum field theory make (when you combine them) a theory that has problems at the Planck scale. Those are problems that any theory of quantum gravity or every theory of everything have to deal with.

But it doesn't mean that those potential theories would have any infinities. Such a theory, though, has been very elusive.

With the exception of string theory, which is the leading theory in terms of its success, most theories tend to have fundamental problems. String theory research is certainly not complete, but it's in my opinion currently the best shot we have. Online, and in academia, you can find lots of very opinionated discussions about it, which include aspects of testability, predictivity, etc. which means that some people really dislike string theory and prefer other approaches.