Is there a difference between a theory and observational science of actually observing a chemistry experiment in live-time, in real-life, in-person, as it happens, in the flesh, not hypothetically, not theoretically, but simple observations LIVE, you know what I mean? How often do people contrast historical science with observational science?

I would say the two are constantly feeding into each other, so for instance, if I might come up with a theory that 10,000 years ago, when an ancient tribe performed a particular dance, it rained.

Then you come along and make lots of current observations about rainfall, after a while you report that you cannot find any modern incidences of a dance-rain connection.

What's more you report that you have discovered that precipitation has a lot to do with rain, and so therefore my theory breaks down. There might still be some people that agree with me, however your theory gains much more traction because it is backed up by observational evidence.

In the real world this happens all the time, so for instance Albert Einstein gave us the mathematics for discovering gravitational waves, however it took decades of observation and advances in technology before we could prove it beyond a shadow of a doubt.

So we are constantly comparing historical science with current observational science.

Cg