[AntiGuv]

That's very interesting. I wasn't aware of that! I can see why that would've presented quite a dilemma.

[PatrickHenry]

I think (RA will correct me if I'm wrong) that the lack of any visible parallax shifts wasn't something that could be dealt with until the development of photography, which made possible very detailed records of star positions. The photos could be compared, when taken six months apart, to finally detect the minute apparent movement of the very few stars that are close enough to exhibit a parallax shift. Then, knowing the size of earth's orbit, and with a little high-school trig, their distances could finally be determined. I think that was one of mankind's greatest intellectual accomplishments. With better telescopes, I think there are now hundreds of such stars.