Karl Raimund Popper - was a philosopher who's work included considerable contributions to the philosophy of 
science and the scientific method. The contribution he is most known for is the doctrine of falsifiability.
28-July-1902  to  17-September-1994
 
The doctrine of falsifiability states (simplified) that in order for a theory to be a scientific theory, it must be able to be falsified by some experimental observation.
As you might guess, this upsets a lot of very well established, and well-known, agendas and structures.