Quadratic Gravity is Possible

Quanta magazine has article on quadratic gravity.

I mentioned this before as an obvious alternative way to quantize gravity.

People have been saying for a long time that string theory is the only hope for quantizing gravity. It is completely false. For example, Brian Greene says in a new video:

0:00 String theory is the most potent and powerful approach that we have discovered as a species for blending general relativity and quantum mechanics.

He goes on to say that string theory is still viable as long as researchers want to work on it, and that is how science works.