"You have no proof the flood didn't happen"
Russell's Teapot, bitch. We're not the ones saying a 'Flood' happened. Also, records from ancient China - dated and proven to be genuine & from their time - made absolutely no mention of a cataclysmic civilisation-destroying 'Flood', due to the fact that such records were written before, after, and especially during said supposed 'Flood' happened, according to your 'True' Bible.
Now, either said ancient Chinese records or the Bible are false. Which is it, considering even your 'True' Bible is inadmissable as evidence in a court of law.
"Where do you think the rainbow came from?"
From a certain pegasus pony? I dunno, you tell me. [/Doug Piranha-levels of sarcasm]
"There is no scientific explanation"
Sunlight refracted & split into it's component colours - via the Prismatic Effect - through tiny droplets of water suspended in the air soon after a rain shower. I learned that at primary school, so if you didn't know that...!
"How is it impossible to flood the entire world?..."
(*Switches to hyper-Doug Piranha snark mode*)
Oh, I dunno, you tell me, seeing as you lot supposedly have all the answers. And 1 Thessalonians 5:21 (KJV) says you must 'Prove all things', therefore I'm waiting for that exact, precise, detailed explanation, with equations, formulae, diagrams etc. And NO 'Apologetics' nor 'Interpretation' allowed, even if your 'Word of God' doesn't happent to have that exact, precise, scientific info verbatim. You can't make it up as you go along.
No evidencee, no Floodee.