Note: this is a long, rambling entry that swings from naval gazing to some interesting stuff on global energy futures.
There's a gymball in my bedroom: silver, 800mm wide. Having stared at it for a while, I started to wonder - if the sun were that gymball, how big would the Earth be? A few sums later I got 7mm. Some frantic measuring of dried pulses followed, and a chickpea emerged as the perfect - if slightly lumpy - candidate for sitting on the floor next to the gymball. There it sits still, so every night I can stare at it and mutter to myself, 'that's just stupid.' I include a photo of chickpea on gymball. But photos, this description - they don't do it justice. Find a gymball of equal size, get a chickpea: hold it between thumb and forefinger, having made sure to watch a video of the sun first. (Some would argue 'blue marble' better captures the wonder of it; each to their own.)
Incidentally, you can scale to anything you like at this website. At the scale above, chickpea would be 85 metres away from gymball.
I've also been trying to wrap my noggin around our place on Chickpea Earth. This has included an alarming assault on my sense of Earthly security, such as a list of all the ways in which we might never have existed. Some of these were covered in rather sensationalist tone by Tony Robinson's channel 4 series, 'Catastrophe Earth'. This quote sums up the general approach:
85000 years ago, humans were just heading out of Africa; the meteoric rise of our species makes us feel indestructible. Yet we are more vulnerable than we might care to imagine. We live on a thin crust that floats on a sea of pressurised molten rock and we rely on the proximity of a star to keep temperatures optimal for life. Meanwhile our planet moves through space, which is populated by numerous flying objects.