Wow. September already. Where’s the rewind button? The 2nd of September finds a very thin crescent Moon joining Jupiter and Venus low in the west. You have 35 minutes after sunset to spot the group, so don’t dawdle. Hopefully it won’t cloud over like it did for the Venus - Jupiter conjunction last week. Not quite as challenging, in the south west, Mars continues to move eastward between Saturn (above) and Antares (below). Not the stuff of legend, but what’s not fully appreciated is that the star and those planets would not be there were it not for Gravity. A few weeks ago at a yard party, a retired friend (we’ll call him Brian, ‘cause that’s his name) was having a bit of a struggle getting out of a low-slung lawn chair. “Jeez”, Brian wheezed, “gravity seems to be getting stronger every year”. Normally, I would have chuckled, had it not suddenly occurred to me that I was beginning to experience the same effect (I’m also having difficulty reading fine print, but I’m not sure of the connection yet). Gravitation is a mysterious phenomenon responsible for making objects ‘gravitate toward’ each other: stars, planets, galaxies, and apparently Brian and his lawn chair. Everything in the universe is attracted to everything else. Some things bump into other things, but if they miss, they will eventually go into orbit around each other. The Moon orbits us, we orbit the Sun, the Sun orbits the centre of the Milky Way Galaxy, and the Milky Way, with its local group of galaxies, orbits the Laniakea Cluster which orbits the Virgo Supercluster which orbits the Great Attractor which... and so on. Galileo started it all by dropping canon balls from the Leaning Tower of Pisa. Much later, an apple falling on his noggin gave Sir Isaac Newton the Universal Law of Gravitation, which explained things just fine until Albert Einstein proposed his General Theory of Relativity, surprisingly without a single blow to the head.
Now we’re all confused again. I majored in physics when I started university because I thought I wanted to know this stuff. What I learned was... no, I don’t. I care less why we have gravity; I just want to enjoy its effects. Well, maybe except for the lawn chair part. “So”, I said to Brian (well, I didn’t, but should have), “maybe gravity is getting stronger, but without it, we wouldn’t have stuff like planets and stars to look at, and then where would we be? And what would I write about?” So, pull up a lawn chair and enjoy the skies, secure in the knowledge that the same mysterious force that holds the stars and planets in their courses also holds you firmly in your seat, apparently a little firmer with each passing year.
