It’s the Doppler effect, people!
Moving to the music
Did you hear a chromatic passing tone? Because something led me to you!
Cool link.
Is there something inherent in major vs minor that makes them feel happy or sad to humans? Or is it the contexts they’re used in that make one associate them one way or the other?
Context, and cultural association. There’s plenty of pieces which work the other way - this is hardly happy, nor will this have many people in tears.
The minor chord does make it sound a little tense and creepy, though.
Besides, the saddest key of all isn’t A Minor, it’s D Minor. 
I don’t hear it that way at all - a good example of subjective analysis which can’t tell us anything about the fundamental characteristics of major or minor sounds.
It’s a little bit Cafe, it’s a little bit MPSIMS. I’m going to move this to Cafe because I think they might be able to answer gigi’s question.
If I’m understanding the article right, this would require three different sources for each note of the triad, right? Otherwise, with one source playing a chord, it would only be shifted in pitch, not perceived tonality. Am I missing something? If not, why is this news?