[BMCDA]

An honest answer, almost. You still gave some event(s) a label you can't prove, as if it had been. But I give you an A for effort.

What do you mean by proof? As I already said, proof is only for mathematics or formal systems. In science we can only demonstrate something beyond reasonable doubt and this is the case with the big bang.
If you don't believe me I suggest you go to Prof. Wright's Cosmology Tutorial or read some books on this topic.

[ALS]

"the big bang."

You may be missing my point. The above term is used as though it was. I'm not even sure you realize it, because you probably use the term so frequently.
This isn't a confrontation. I'm merely pointing out that terms, true or false, are used so freely, they are taken for granted when they most likely are just speculations, opinions, and the like.