Then I was correct about you. You walked straight into Skippydom. In which case bacteria did not exist in physical reality in 1500AD and there is DEFINITELY no such thing as aliens living on the other side of the galaxy.
I've never claimed to have positive evidence of such an entity. However you just claimed to have falsified a non-falsifiable concept. In which case I'd like to hear about the scientific test you performed, presumably by making use of the scientific method, which enabled you to falsify the concept.
Bacteria did in fact exist then , microscopes did not.
No I'm not in skippydom or anything but physical reality . As to aliens that is another subject altogether. There could be aliens , but is there aliens that have the possibility of interacting with Earth?
Bacteria existed before all other lifeforms , that is known.
The ability see them did not , but our ability to see now has gotten to the sub atomic. You are in fact going into the "what if".
There were physical signs of bacteria in 1500.
There is no physical sign of your premise.
Bacteria existed in 1500 if you drank harmful bacteria infested water you got sick. It had a physical aspect that was testable and identifiable.
You present something that is not identifiable or can not even show me any physical effect of it. That means it *really doesn't exist in reality.
Alien life is testable , we can eventually go find out if it is there. We may have even found indications in the physical reality that it exists. Even if inconclusive at this point it is testable.
We also are testing this right now on mars.
Now present me a physical aspect of your premise that has some physical indication that is testable. Otherwise you are into pure conjecture and fantasy.