What if(on my theories)

What if my presenting my old and new theories on the internet for all to
read and study makes them very hard to steal?  Like I just posted my
Pulse fusion Theory,and a professor at Harvard comes up with the same
idea and is up for a Nobel prize using my theory.  Does he have to share
the Nobel with me since I put it out first.?      If not can I sue him?
I do have a theory for every thing   bert