Popular Culture Review 29.2
such as the moon , the barycenter is typically inside the more massive object , causing the latter to wobble a bit rather than appear to circle around the other . In the Earth-moon system , the barycenter is located about 2,900 miles from the Earth ’ s core ; and since the Earth has a radius 1,000 miles longer than that , the Earth , indeed , merely wobbles a bit as it moves through space rotating around a point “ inside of it .”
Even when we accept this , we tend to forget how fast the Earth is also orbiting the sun . And how fast the sun is moving in one of the outer spirals of our Milky Way galaxy , orbiting the massive black hole that sits at the center of our galaxy . And how the Milky Way is orbiting a barycenter outside of it along with several other nearby galaxies in what is called The Local Group . And how those galaxies spinning around each other are moving through space , which is , itself , expanding . The motion of our planet , and of our moon , is relative . Depending on which orbit you ’ re talking about , it is taking a different sort of curved , corkscrew , elliptical path . Nothing is still . There are no still points . We , ourselves , are especially not the still center of anything .
And yet , still ....
Orbits are special because they are curved , and because� when we ignore all of these other larger motions in which we are engaged�they seem to return us over and over to the same place , even as that place is changing . It ’ s harder to see the falling this way . As a metaphor , an orbit is rich . And strange . Always allowing occluding , bodies hiding behind each other ; always moving us away and then back . Like truth , always obscuring as much as it uncovers .
On April 12 , 1961 , Yuri Gagarin became the first man in orbit . Alan Shepard became the first man in space who was an
24