Burros are braying, roosters are crowing, and rufous hummingbirds are fighting over sugar water in the feeder. This pre-fall weather the last few days has been perfect for sitting with my wife on the back porch till dark and enjoying the sights and sounds of life in Magdalena. But wait, for some mysterious reason the Sun seems to be doing something different and recently there has been less and less daylight and our back porch time is getting shorter.

The autumnal equinox – which has nothing to do with horses or oxen – happens at 7:54 p.m. this Saturday and I can’t say I object, especially after the past few months of 90-plus degree afternoons.

If you didn’t sleep through science class, you know that fall comes when the tilt of Earth makes the southern hemisphere be closer to the Sun, and where we live…well, farther away, and we’ll chill out for a while.

Supposedly right around the equinox, we’ll have the same hours of day and night. I say supposedly because it depends on where you are. And the curvature of the earth.

I once heard it explained this way. On the equinox the center of the Sun is above the horizon for 12 hours. However, sunrise is defined as when the upper edge of the Sun’s face becomes visible over the horizon, and ends when the entire Sun has set. So, daylight would be longer than 12 hours.

But hang on – recalling Dave Thomas’ demonstrations showing that Earth is round – in the morning, the Sun is actually visible while it’s still below the horizon, because the atmosphere refracts the Sun’s rays and bends them in an arc over the horizon. That’s right. You can actually see the Sun before its top edge reaches the horizon. This causes daylight to be longer than 12 hours as well.

But then again, perception is reality. Or is it, reality is perception? I guess it depends on where you are standing.

My brain is starting to hurt.

Fun Fact: Fall foliage isn’t due to current weather conditions like you’d think. In reality leaves change color because of fewer daylight hours and the photosynthesis thing.

Fun fact, part 2: Migrating birds know when to migrate by the southward movement of the sun.

I’m wondering if the hummingbirds migrate south. I can imagine swarms of those testy rufouses (rufousi?) buzzing headlong down to Mexico or someplace in search of new nectar to fight over. In our little corner of New Mexico autumn is quite different from those scenes we see of falling leaves where there’s deciduous trees galore. We have none of that nonsense of spending an entire Saturday raking leaves up into a huge pile which kids and dogs love to jump into and spread them out all over again. ‘Course now one can just get out the leaf blower and send them scattering into the street to let somebody else deal with them.

Personally, there’s something very comforting about things like the equinoxes and solstices. If nothing else, they’re reliable and if you don’t like them there’s not a thing on earth – no pun intended – you can do about them. That regularity, the changing of the seasons, is another reassurance that everything is right in the world and things can go on as planned.

Aside from the arrival of autumn, we’re coming up on Banned Books Week, starting Sunday. It’s sponsored by the American Library Association and other organizations that support intellectual freedom and free speech. It turns out that every year somebody, somewhere, gets het up about one book or another. The reasons are varied, but one thing’s true; the minute you ban it, like say, a Harry Potter book, a million kids will want to read it.

I’m thinking maybe parents should be the gatekeepers of reading material for their kids. Growing up at our house, I can’t remember any reading material that was verboten, except maybe the Playboy my big brother kept hidden under his mattress. Naturally, mothers have a sixth sense about these things, and when she confronted him he swore he was only reading the articles, paying no attention to the sideways picture in the middle. After that, he must’ve found a new hiding place that even I couldn’t find.

Anyway, I found a few books that were banned for not-so-obvious reasons.

• Tarzan by Edgar Rice Burroughs. Because Tarzan and Jane weren’t married before they started playing house – um, treehouse – together.

• Merriam-Webster Dictionary. Because the Anchorage School Board didn’t like the definition of the word “bed.”

• Little Red Riding Hood. Because the illustration on the cover depicted the basket she carried as including what looked like a bottle of wine.

And the winner is: Hansel and Gretel; challenged by two self-proclaimed witches who said it gave witches a bad name.