Habits of seeing

What do you see when you look at the Moon?

Our astronomer was up before dawn on an errand a few days ago, and noticed the nearly-full Moon in the western sky.  He has seen the Moon before, of course.  Not only setting but rising, high in the sky, and from the Southern Hemisphere (where lots of things look upside-down to a northerner).  But for some reason this was the first time he made out the Rabbit in the Moon.  Then, with a little trying, he could see the Lady in the Moon.  The familiar Man in the Moon (which he’d always seen before) was absent.

What you see depends on how you look, as we’ve noted before.  But it also depends on what you expect to see.  That’s no new idea, though it’s a much stronger effect than we normally realize.  The great astronomer Sir William Herschel noted that, once he discovered something with a big telescope it was easily visible in a much smaller one; even if he had used the smaller one to examine the same object carefully before, without result.

Herschel’s observation is not quite the same thing as “confirmation bias,” where we are disposed to see (and believe) things that fit in with our picture of the world, discarding information that conflicts.  However, they both come from relying on habits to guide our eyes.  And they both can lead us astray.  Some nineteenth-century astronomers made out new features in Saturn, for example, with their new larger telescopes, and found they could be seen in the smaller ones used during the previous century.  They concluded that the features themselves were new, and that the planet was changing over a few decades.  Well, the planet is changing, but not on that scale over such short times; they had failed to keep in mind Herschel’s observation.  And (more practically) we all filter the news we hear, pouncing on what reinforces our beliefs and discarding what conflicts.  The first instance led to some confusion among astronomers for a period of time; the second has enormous bad effects on society.

So why do we look by habit?  Well, it would be intolerable to have to construct our visual world from scratch moment by moment.  It takes years for babies to sort the avalanche of data from their eyes into identifiable objects, people, situations.  And we simply do not have the time: driving down a road we have to have the visual picture already sorted out, in order to react quickly to things that don’t fit.  Discarding habits can be difficult and dangerous.

But so can retaining them.  We urge you to take advantage of any Rabbit-in-the-Moon moments you come across.  Rather than succumbing to bewilderment when things are unfamiliar, or forcing your eyes to find the familiar Man, see what new ideas there are to be found.  And it may not be necessary to get up before dawn to find your own Lady or Rabbit.