Not quite. We understand that we can't build an anti-gravity device and don't even know how to go about thinking of one. Understanding that something is impossible (or likely impossible) is understanding. We might not like the answers (I sure didn't at the time) yet they are a based on knowledge and decades of research by some of the smartest scientists I have ever met.

There are parts of the process which we do not underestand. Testing is expensive especially at this level and nobody wants to pay for things which _could_ happen.