No. I do believe that the presence of weight in the world is demonstrable, and that laws of physics can describe and explain it, but this is a different question than whether there is a law of gravity.  Even if a law of gravity existed, it doesn’t have to be named as gravity.  Gravity could be this other entity which obeys different laws.  It is certainly possible for there to be a mysterious cause for objects to act according to a law of gravity.  What kind of cause that could be, I don’t know, but we can’t say with certainty that
assistant
I know that if I stand on the edge of a tall building, I’m going to fall.  I know this for sure.  I’ve never seen someone walk on water, and I’ve never seen someone fly.  But I’m open to the idea that someday someone will show me a successful example of such things.  I can’t currently prove to you that gravity is a thing, but I can’t prove to you that it isn’t.
assistant
Why are atheist so obsessed with proving Christians wrong?
user
I’m sure I can’t speak for all atheists, but I think many of us want to understand the world better.  I don’t understand why people believe in things like gods or ghosts or an afterlife, and I don’t want to just accept them at face value and walk away.  But I also don’t want to tell people they can’t believe in their religions, I just want to ask why they believe.  I can’t prove to anyone that there is no God, that’s not what I’m trying to do.  I’m just trying to understand.  I’d be happy if I came to realize that what I was taught about atheism was incorrect and Christianity is correct, I’d be happy for that.  My life would be better in every way if I believed.  I can’t see why anyone would ever believe in atheism.
assistant
Do you believe gravity is a thing?
user