Odd Little Items From Hither And Yon
If you go back in time and shoot your grandparents before they had children, I think you and your parents would simply disappear. You never existed and all memory of you would vanish. Life would just swallow you up and circumstances would take a different path. You and your parents were just never here.
If a tree falls in the forest and nobody is there, does it make a noise? No; not at all. Noise is simply air waves that hit an eardrum. You could have a bomb go off and if nobody (people, animals, etc.) were around, it would remain simply a wave of air at various frequencies. Drop somebody in and you get sound.
The Titanic operated on, was powered by, fatally damaged by, sank because of, people drowned in, a combination of hydrogen and oxygen at different temperatures.
The first igloo was built tomorrow. So to speak. When I went to the Arctic, the natives said there is no such thing and the first one they saw was in a Hollywood movie, whereupon they laughed themselves silly.
Church organs were built for parishes that could not afford to hire musicians with real instruments and were considered “second best.”