Facts are verifiable peices of information.
This is what science is all about. However, when a scientist puts his hands up and declares a area of research as FACT he has in affect ended his research. He has become closed minded and cannot interpret information in an unbiased fashion. You can observe gravity but real evolution has never been observed. We understand gravity and the forces of the planets, sun and moons well enough to put satellites in orbit for years at a time along with interplanetary travel.