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Thx for the replies guys, Explained it.

To avoid confusion, I understand what gravitational waves are and I am convinced that they were detected. I am not questioning the detection of gravity waves. LIGO did detect gravity waves as they passed through earth. What I want to know is how did they know that it was the collision of two black holes that caused those gravity waves to form. I mean after all there are other ginormous objects in space whose collisions can also cause gravity waves, two neutron stars colliding into each other. So how do they know that the waves that LIGO found, where from 2 Black Holes colliding together and nothing else.

That made a lot of sense. Thx

We know things in free fall are weightless. We know in a way that the Moon is in free-fall around the Earth. Only since the moon is travelling sideways at the same rate at which the earth is bending away from it, it never hits ground. However it is still free-fall. 1) So is the moon weightless? If it is, then if there are (say) astronauts on the moon, then they too are in freefall along with the moon. So would those astronauts weigh anything? If we extend it then the Earth is effectively also in freefall around the sun in the same way that moon is around earth, then is Earth weightless too? If not why not? 2) If the earth is weightless, as its in freefall, then humans or for that matter anything on earth, a stone, a remote, a table, etc. is also in freefall around the sun along with the earth? So when in freefall, why do humans, remote, stone etc. have weight?