Parallax Quotes
![These [binary stars] may serve another very important end.... Several stars of the first magnitude have been observed or suspected to have a proper motion; hence we may surmise that our sun, with all its planets and comets, may also have a motion towards some particular point of the heavens.... If this surmise should have any foundation, it will show itself in a series of some years in a kind of systematical parallax, or change due to the motion of the whole solar system. (William Herschel)](https://cdn.quotesdtb.com/img/quotes_images_webp/70/william-herschel-binary-change-445770.webp)
For common purposes we may without sensible error suppose the earth's motion equable and neglect the corrections, and then the rule for the parallax of right ascension will be this:
Sine lat. : rad. : : cotang. A : cotang. C, or rad : sine lat. : : tang. A : tang. C; then long. star \mp C = long. of λ.
Cosine C : cosine A : : semi transverse axis : z.
And cosine decl. cosine (ʘ - λ) :: z : x = parallax of right ascension.
James Bradley
Friedrich Bessel... achieved a breakthrough. Please hold your thumb at arm's length and alternate closing your left and right eyes a few times. ...[Y]our thumb appears to jump left and right by a certain angle relative to the background... [M]ove your thumb closer... and you'll see this jump angle growing. Astronomers call this jump angle parallax... [W]e can... compare telescopic photographs taken six months apart, when Earth is on opposite sides of the Sun. ...Bessel noticed ...61 Cygni ...moved a tiny angle, revealing its distance to be almost a million times that to the Sun... Now that Bessel knew the distance he used... [the] inverse-square law to figure out how luminous it was... in the same ballpark as the Sun... Giordano Bruno had been right after all!
Max Tegmark
