With the 400th anniversary of Galileo’s use of the telescope upon us (along with the 400th anniversary of the use of the telescope by other, less well known individuals such as Thomas Harriot, as mentioned in my previous post), here’s a rarely commented upon point about the way in which the telescope transformed our view of the cosmos.
It’s taken from my book, Where Are We, What Are We, Why Are We?.
One of the most remarkable, though little remarked upon, aspects of the story of Galileo (and the other telescope users) is that the things that they saw through their instruments – the sight of which changed forever the way we see the universe – are things that are just beyond the range of unaided human vision. If our eyes were capable of seeing with only a smidgen more detail we’d be able to see the craters on the Moon and the satellites of Jupiter just by looking at them (The Jovian satellites are of a brightness where they are actually teetering on the edge of visibility to the naked eye, although the glare from the planet itself contributes to making seeing them well-nigh impossible). I would speculate that a hawk, with its hunter’s eye, or even more so an owl, with its excellent night vision, can see the craters on the Moon and possibly the satellites of Jupiter (if they can get around the glare problem) quite easily just by glancing casually at them. But they know not the implications of what they see.
Think how different the history of our awareness of our place in the universe may have been if we’d only had very slightly better eyesight.