Posts for Category Science

The crocodile in my bathtub

In which Bill grows a crocodile in his bathtub and contemplates his own mortality
Dec 172014

I just spent two weeks listening to my life passing me by in 20-minute increments marked out by this sound:

Camera in the bathroom pointed into the bathtub That’s the sound of the shutter on the camera set up in the guest bathroom, where it sat for those two weeks with a timer running to take a picture every 20 minutes of the crocodile growing and then shrinking in the bathtub.

Front and back of grow crocodile packagingIt all started a few weeks before that, when I wandered in to a dollar store in search of inspiration for birthday gifts, Christmas gifts, and blog posts. I found a rack of “grow animals”–little plastic animals that expand when you put them in water. I got something similar as a gift once; they were little things made out of sponge or something similar. But the ones I saw in the store were bigger and made of plastic, and what caught my eye was the claim on the package that they grow “up to 600%.” Some of them were fairly small, but one of them was a crocodile that was 11 inches long. The package says to “submerge your creature in a large container full of room temperature water. Make sure there is enough room for your creature to grow.” Six hundred percent of 11 inches is five and a half feet, and I was giggling in the store as I pictured the little animal growing to overflow a bathtub.

So I bought the crocodile and it sat around for a while until I finally had some time to devote to the project. Fortunately I also had a spare bathroom to devote to the project, because I couldn’t think of another container capable of containing my soon-to-be-66-inch-long beast. Since there’s no point in doing a thing unless I can write a blog post about the doing of the thing, I decided I should make a time-lapse movie to document the experiment. And that’s how I found myself, on a fine Sunday evening, rigging up a light stand and tripod in the bathroom.

I put the crocodile in the bathtub, added some water, set the camera to take a picture every 20 minutes, and tried to  go about my business for the next seven days while the crocodile went about its.

Except that the camera shutter is pretty loud, and that bathroom sits right outside my home office and my bedroom. The sound even carries faintly to the lower floor of the house. I have a grandfather clock that chimes every 15 minutes. I’ve had it for 16 years now so I’m used to it and hardly notice it. But that camera. That camera–

It never faded into the background. Two weeks. Whatever I was doing, every 20 minutes there it was, reminding me that another 20 minutes of my life had passed me by. Wrestling with how to word an e-mail message to a customer? Click-click: you’ve just wasted 20 minutes on that. Think you’re making good progress on that knotty technical issue? Click-click. Click-click. Forty minutes and you’re still not finished, so not such great progress after all, is it? Can’t get to sleep tonight? Click-click. Just think of everything you could be doing if you weren’t lying here staring at the ceiling. Click-click. Still awake? Enjoying reading a good book? Click-click. Narrative spell is broken. Think of all the chores you should be doing.

I’ve done some thinking about why it affected me this way, but didn’t come up with anything other than perhaps I was in an existential angsty sort of mood for those two weeks. Maybe it didn’t help that my birthday was mixed in there.

Anyway, aside from taking a surprising toll on my mental state (quoth the camera: nevermore), here’s how it went:

Day 1: The crocodile grew noticeably but not dramatically, changed color, and started to curl backward on itself like you might expect a dead reptile to do.

Day 2: Most of the growth seemed to happen in the tail, which came out of the water and caused the crocodile to tip over from the weight of it. I added more water to the tub to try to keep everything submerged, and, after reviewing pictures from day 1, improved the lighting.

By now it was clear that there was no danger of the thing reaching 600% and bursting out of the bathtub. I never really expected it, but still I was a little disappointed. I also realized that maybe they meant 600% fatter, not 600% longer. I did a Web search to learn more about what I should expect and came upon the Web site of chemist David A. Katz, who explains “the chemistry behind toys, old and new, with hands-on activities,” including an experiment with grow creatures. From this I learned that

The original creature is composed of a plastic called a graft copolymer of hydrolyzed starch-polyacrylonitrile (polyacrylonitrile is commonly known as “Acrilan,” “Orlon,” or “Creslan”). Such materials are called superabsorbants or “super slurpers” and some are capable of absorbing up to 2000 times their weight in distilled water. By combining the starch-polyacrylonitrile with glycerin or ethylene glycol (the active ingredient in anti-freeze), a strong and resilient plastic gel is produced that can absorb up to 400 times its weight in distilled water.

So I should have filled the bathtub with distilled water for the best chance at full growth. Also, “Creslan” seems like a good name for my little super-slurping crocodile.

Day 3: Started to uncurl a bit and stretch out.

Day 4: A little bit of excitement overnight, apparently: I found a fly floating in the tub in the morning. I like to think the crocodile made an effort to catch it but then couldn’t be bothered to eat it. So much for super-slurping. I fished it out, but you can see it drifting around a bit in the video.

Day 5: The skin looks like it’s in danger of sloughing off, as if the crocodile is moulting. The tail has developed a crack that looks like what you get when you’re boiling an egg and the shell cracks and egg starts to leak out. Maybe the fly bit a chunk out of it? When I touch it it feels slimy.

Day 6: Continuing to straighten out. And the clicking. The endless, soul-crushing clicking.

Day 7: It doesn’t seem to be growing any more but it is wagging its tail in very, very slow motion, which is very strange and slightly creepy.

Day 8: Like day 7. Time to call this thing and drain the tub.

Here’s how it ended up: grown version on top, and the original inserted into the picture underneath for comparison.

Photo showing original and grown size of crocodile

I’ll spare you from squinting at the ruler and doing the math yourself: it went from about 11½ inches to a bit over 18, making it 163% of its original length. I suppose you could look at it with your eyes squinty and try to convince yourself it bulked up by a factor of six, but this is the 600% I wanted to see:

What the crocodile would look like if it grew to 600%
The instructions say it will shrink back to its original size to be used again and again, so I decided to torture myself with another week of click-click and let it go. By the eighth day it had shrunk down to 14½ inches long but not lost much of its girth. I stopped taking pictures at that point and took down the camera so I could go back to using that bathroom when I didn’t want to walk the 30 feet to the other one. Another two weeks or so have passed now, so it’s been out of the water about three weeks and is back close to its original size, so I went and took another picture. Now I’m a little disappointed I didn’t keep the camera going. When you touch the crocodile, crystals of something flake off all over the place.

Here’s a final comparison of all three stages:

comparison of original, grown, and shrunk versions of crocodile

To cap it all off I spent a few hours learning how to edit movies and made this for my entertainment and maybe yours:

* * *

An addendum for those of you now thinking about rushing out and buying some grow animals as Christmas presents for the kids in your lives: I think you can find better things to spend your $1 on. I don’t know your kid so I could be wrong, but I can’t imagine your kid patiently waiting around for a few days and then being excited by the modest growth. Or even remembering, by that point, how the animal looked to begin with. Watch this video for a demonstration of a parent trying very hard to get his kid excited about one of these animals. The kid is mostly excited that his hand is wet. If you want to make it into a science experiment or time-lapse photography project with your kid, that’s another thing entirely, and you should definitely go for it.


Colds, collops, and meldrops: Bill’s Head snivels

Bill catches a cold and discusses some cold-related words
Oct 032011
Photo by Jen Waller

Though I don’t read a lot of detective fiction, I seem to be drawn to Scandinavian and Icelandic detective fiction, and I’ve been working my way through the Swedish Kurt Wallander series by Henning Mankell.* Last week I started the seventh book in that series, One Step Behind, and within the first two paragraphs read this passage:

…the dampness had nonetheless seeped through his clothing. He felt a sudden flash of anger. He didn’t want to catch a cold. Not now, not in the middle of summer.

Come on: it’s the 21st century (well, it was still the late 20th when the book was written, but still). Don’t we all know that viruses cause colds, not damp weather? In typical Bill fashion I was getting all annoyed at Henning Mankell for propagating an old wives’ tale–I even highlighted the passage and added a cranky annotation (yay, Kindle!)–but then decided to give him the benefit of the doubt and assume that he as the author knows better even if his character does not.
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