What is John McDonnell's background and why has he joined this science forum?

[John McDonnell]

Hello. My name is John McDonnell. I'm now retired and a free thinker with interests in physics and related sciences. I've joined this forum to learn, share ideas, and hopefully contribute.

 

[Greg Bernhardt]

Welcome to PF John. What are you retired from? Do remember we are a mainstream science education community. Please see our guidelines
https://www.physicsforums.com/threads/physics-forums-global-guidelines.414380/