Tuesday, December 16, 2008

Sublimation


Sublimation, as I am sure you all recall from high school chemistry, is a thing that involves skipping a stage in evaporation.

The word also has a psychological meaning, which we won't go into, save to say it usually involves turning a desire that might be frowned up into one that is more socially acceptable. Say, if for instance, you like to beat the snot out of people, so doing on the street might get you arrested. But if you join a boxing gym or a martial arts class, the law figures you and the rest of the gang thumping each other deserve each other.

Mmm, meanwhile, back at the definition ...

When sun shines on snow, but the temperature isn't warm enough for the snow to melt and then evaporate, the snow will eventually sublime, i.e. go from the solid to the gaseous form of water without the liquid phase. So the snow gradually recedes, albeit somewhat slower than evaporation. Different densities do so at different rates, so that footprint you left out on the driveway yesterday, being compressed and denser, might be sitting there all by itself today.

Thus, snow is more active than it appears on a bright-sunny-but-cold day, and that there are changes that make it more dangerous to traverse, especially on a sidewalk that has been packed down by many passersby. That means that if you are walking your dogs and they decide to give a tug just as you step on one of these sublimating patches, you might find yourself skiing without the benefits of skis.

To deal with such things, there are little rubber things with cleats that you can strap to your shoes. These go by various names, but probably the most popular ones are YakTrax. We have some cheaper knock-offs that don't have as many cleats, but even so, they are hip-savers.

You might consider getting some of these if you have to be out and about in the snow. Less than twenty bucks, and cheap considering what having a busted wrist or hip would set you back.
You can get them in a lot of places, but here, at Amazon.com is convenient.

7 comments:

Dave Huss said...

Steve,
You are the Bomb,,,
My wife is a real challenge to find cool little neat things for. Cool idea.
Dave

steve-vh said...

My wife ran 6 miles with them yesterday on the snow. Sometimes even the cleats won't work if they haven't plowed (or plowed it down to ice).

Drew said...

This is also an example of why many of us believe that learning to fall well from any vector or position is one of the most important "self-defense" skills one can acquire. Learning to fall, and to be relaxed enough to manipulate my fall in-flight, literally saved my neck on icy chicago steps a few years back.

Steve Perry said...

Yep. Going to the ground requires practice. I've hit icy patches a couple times and ended up sailing. Been lucky so far. An icy sidewalk is not a nice padded mat, but better to know ways to get down than not.

In my case, having two small but strong dogs on a leash give a tug at exactly the right moment when they see a squirrel is another risk factor. One thing to navigate the slick walk on your own; another while trying to ski behind White Fang and Cujo ...

Steve Perry said...

Snowing again, and the prediction is more of that, maybe some freezing rain, then more snow. Temps below freezing for at least the next several days.

Gonna have to step lighter walking the dogs -- yesterday, I was putting my feet down a little harder than usual, to be sure to get good traction. Amazing how that stresses the feet even after a few blocks.

Tiel Aisha Ansari said...

Went for a walk yesterday morning and managed to hit a stretch of sidewalk that had apparently been flooded, then frozen, then gotten a light dusting of snow over it.

Cool thing was, when I fell, I managed to land in a decent Iron Cross position. Which I didn't actually realize until after I'd gotten up and brushed myself off.

Steve Perry said...

Nice that all that groundwork is good for something ...

Looking at cold again today and they are talking about six inches more snow tomorrow, with maybe some freezing rain thrown in a bit later.

I'm sure it's Bush fault.