The thing is, 100-200 years ago we didn't know jack shit about anything. No knowledge about relativity, no knowledge about atoms, no electricity, no computers. Heck, we couldn't even fly.
You're showing your ignorance more than your knowledge. Atoms, electricity, computers and even flying are much, much older than a century or two. A book like
ANCIENT INVENTIONS or a documentary series like
ANCIENT DISCOVERIES can be real eye-openers. Highly recommended. Your local library may have both on hand.
The history of science is also littered with broken pronouncements of what is impossible, or certain. Many famous people have been credited with saying "Keep an open mind, but not so open that your brain falls out." One should be just as wary of the converse, that logic/science is a way to go wrong with confidence.