As long as "God" remains in the realm of the supernatural, ie, the unobservable, there will never be scientific proof that he/she/it exists by definition. Science, by definition, is about building and testing hypothesis based on repeatable, observable experimentation. Anyone who expects to find scientific proof for "God" either has a non-traditional view of "God" (ie God is not supernatural) or else has a mistaken view of science.
Yet there are many things that are common now, that 200 years ago would have been CALLED supernatural.
I would say that regarding things in this universe, nothing is supernatural. Some things only appear that way, and will until we find the technology to control them.
It sounds like you're saying you don't believe in a supernatural. Which, as far as I can tell, means that you don't believe in a supernatural God. I think that's a totally respectable belief system.
Look at what God said in Genesis, during the time that the people were building the Tower of Babel: "The LORD said, 'If as one people speaking the same language they have begun to do this, then nothing they plan to do will be impossible for them.'"
Probably reaching right into Heaven is something that people could do if they all joined together and put their minds to it. So, is there really supernatural? Or is it a word that is used to cover a certain form of ignorance that we have?
Lol, I guess by "what God said in Genesis" you're referring to what the J-writer or the P-writer said in Genesis.
Anyway, if youre version of God is a natural phenomenon tied to predictable observation then haven't you taken away his/her/its Godness?
As far as reaching into heaven: Yuri Gagarin is usually the first credited with this (http://en.wikipedia.org/wiki/Yuri_Gagarin).