Meaningfulness v meaninglessness; theism vs atheism;

[Zen Badger]

False, lets say someone believes that there is no gravity and that they floating everywhere, this would not disprove gravity.

Well you go right ahead and stop believing in gravity, let me know how you go.
That is my point, gravity is not subject to belief, disbelief, peoples opinions or disapproval.
It just IS, and will continue to be no matter how much you might want to think otherwise. On the other hand morality is very subject to peoples beliefs and opinions( and prejudices,and hatreds, and fears for that matter)

All you have done is shown that people have made mistakes with morality because it is a hard subject.

They are mistaken because they have arrived at a different set of values that yours? How arrogantly christian that attitude is.

And if you look hard enough you will see that morals are more similar than they appear at first glance. For example, people in India cremate, Christians bury, but the morals behind this is respect your dead.

Really? and what about cannibalism, quite common in several societies(some quite advanced) which was often considered a mark of respect to your fallen enemy.

Or Slavery? in the OT god sets down quite specific rules for how to treat slaves yet what christian country today permits slavery?

Even the morality set down in your bible has changed, or are you willing to go down to your local MacDonalds next Sunday morning and stone the staff to death for working on the Sabbath?

Also, some issues of morality are largely subjective.

No, they are ALL subjective, and you have yet to show otherwise.