# Merging Gravity with the other forces

I don't see the incompatibility of QM with GR.......
Don't take it personal, but what you wrote there shows that you have no idea what you are talking about. $R$ is not a radius, and Einstein equation is not an algebraic equation, it's tensorial so you can't just simply divide by $g_{\mu\nu}$.

Don't take it personal, but what you wrote there shows that you have no idea what you are talking about. $R$ is not a radius, and Einstein equation is not an algebraic equation, it's tensorial so you can't just simply divide by $g_{\mu\nu}$.
Then what is that R?

Scalar curvature. You should know that if you try to manipulate this equation.

but isn't scalar curvature just the two principal radii? where are the principal radii of the surface. For example, the scalar curvature of the 2-sphere of radius r is equal to 2/r2.

Not in four dimensions. General definition is $R=R^\mu_{\phantom{\mu}\mu}$. You should really study some textbook on very basics before you try to learn about quantum gravity.

Not in four dimensions. General definition is $R=R^\mu_{\phantom{\mu}\mu}$. You should really study some textbook on very basics before you try to learn about quantum gravity.
The parameter r is a geometrical invariant of the hyperbolic space, and the sectional curvature is K = −1/r2. The scalar curvature is thus S = −n(n − 1)/r2. Explain this to me, from what I understand it is just a radius.

from what I understand it is just a radius.
Then your understanding is flawed. As I said before $R=R^\mu_{\phantom{\mu}\mu}$, that is $R$ is a trace of Ricci tensor. Please get some textbook on general relativity and learn everything properly, not from random articles on the internet.

• Matter Times
Why is this a "hot thread"? It is basically someone quoting from Wikipedia who demands an answer to something he is not capable of handling.

Why is this a "hot thread"? It is basically someone quoting from Wikipedia who demands an answer to something he is not capable of handling.
No, I am perfectly able to handle the information, it is just me and weirdoguy have differing opinions about this.

Okay :)