Someone say yes. someone say no. Could anyone explain easily in scientific way?
Maybe this quote be perfect for beginning discussion.
this has somewhat fazed me as well... the original bitcoin didn't have segwit and didn't have larger blocks, so, the bitcoin running now, which has segwit, and the forked one - bitcoin cash, whose blocksize was increased, are both modifications of the original.
so that means the original bitcoin is gone (?) 
Maybe this quote be perfect for beginning discussion.
Yes because it is (BTC Cash)a divergence from the current bitcoin so would mean it is an alternative version of bitcoin so altcoin it is, regardless if more people support it and it becomes the leader it is still an altcoin, in my eyes anyway.
this has somewhat fazed me as well... the original bitcoin didn't have segwit and didn't have larger blocks, so, the bitcoin running now, which has segwit, and the forked one - bitcoin cash, whose blocksize was increased, are both modifications of the original.
so that means the original bitcoin is gone (?) From my point of view, Bitcoin SegWit is not the original bitcoin. Satoshi Nakamoto dreamt bitcoin in other way, so that means the original bitcoin is the digital currency which is in the mind of its creator.
As they've said, Satoshi Nakamoto don't like SegWit so we can say that the original Bitcoin is gone. And, the BCH now is the digital coin Satoshi Nakamoto is dreaming but it is an altcoin so we cant say that it is the original one.