Reflections in a Mirror

I’m feeling lazy today and not at all like working on a post. But since I’m shooting for 899 by year’s end, and have 16 15 to go, I’m returning to an idea I had long ago but never really pursued. The idea, called Wednesday Wow, is writing posts (on Wednesdays, obviously) about things that really wowed me.

The truth is, lots of things do. For all my cynicism and misanthropy, life and people still fascinate and enthrall me. The various mysteries of physics and consciousness are engaging on their own, but life — for all its ups and downs — is one hell of a ride. (And, of course, I’ve been both blessed and lucky.)

Anyway, here are some wow things and a nice Christmas tune…

Has it ever bothered you that, when you look in a mirror, things are reversed left-and-right, but not reversed up-and-down?

You’d sort of think, especially if you’ve worked with lenses, cameras, or telescopes, that: If a mirror reverses or inverts things, why does it only affect left and right but not up and down?

The answer is that mirrors don’t reverse or invert things; they reflect things, and that isn’t the same thing.

Here’s a recent minutephysics video that explains it really well:

This made me go “Wow!” because it’s the best explanation of this I’ve seen.

In a weird way, a mirror shows you what you look like from behind. Except your front surface has been mapped to your back along the visual axis.

(This becomes more apparent if the lighting keeps your surface dark against a light background. Now you see a silhouette of yourself as seen from behind.)

Anyway, really good video from a really good channel.

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A guy I knew long ago once said something to the effect that:

“If it goes really fast or really high; explodes or catches fire; or makes a very loud noise; it’s cool.”

I think there’s a lot of truth to that, and it explains, at least in part, the popularity of: NASCAR, rockets, guns, and fireworks, to name a few.

Here’s a video about sonic booms that’s been in my Wow! playlist a while:

One thing that’s nice about this video is that it’s not just the cool images — it explains what’s going on! (And seeing the pattern the rocket makes is very cool!)

As an aside, faster-than-sound travel, paired with faster-than-light travel, have long been part of a comparison I use to differentiate “engineering” problems from problems that would require new physics to solve.

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As promised, because it’s the season, here’s a nice Christmas tune.

It’s Yo-Yo Ma on cello and Alison Krauss on vocal. The song is an old Irish song, The Wexford Carol.

Wow! Is that beautiful or what?

May it bring you a few moments of peace in turbulent times.

Stay wowed, my friends!

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