Of the many websites I peruse to keep myself informed of what goes on in the world, there's one I go to that's pretty good about keeping up-to-date on rocketry, astrophysics, energy sources, basic physics research, and so on. It's called Space Daily. Most of the time I check it, I just scan the headlines and say, "Meh...." But occasionally there's an article that catches my fancy.
Today there were two. And since on this blog I get to bloviate about whatever tickles my fancy at the moment, you're going to be bloviated to.
The first article describes a new crew-escape system that is being developed for use with the new generation of manned space vehicles the US is designing. Now, this particular crew-escape system is part of the launch gantry. The idea is, if something goes wrong on the launch pad, they need to get the crew away from the rocket (which is basically a huge bomb) and into a nearby hardened bunker as fast as they can. The best solution that anyone has come up with involves a set of purpose-designed tracks that start at the top of the gantry, head straight down until they reach ground level 380 feet below; then they gently level out, and continue for a while until stopping in front of the bunker. There would be a couple of connected train cars designed to run on these tracks. Upon being given the order to evacuate the rocket, the astronauts would leave the capsule, step into these cars, and....
And if you've been thinking that this whole thing sounds a lot like a roller coaster, give yourself a kewpie doll. That is exactly what it is. In fact, NASA is consulting with various firms that design and build roller coasters for advice about how to put this thing together. Of course, the NASA stuffed shirt guy says "It's obviously not a thrill ride..." but I suspect he'd find it pretty thrilling if he had to ride it. I know I'd love to give it a try!
(Yeah, that'll happen just after I win my Ig Nobel Prize.)
And then there's the other article, entitled Physicists Tackle Knotty Puzzle. This one attempts to answer the age-old questions: why is it that every time you try to coil up some rope, or twine, or string, or electrical cord, or Christmas Lights, it always gets tangled up into a mess of knots? How many knots does it form? How bad do the knots get? And why?
I've been wondering about this a lot as I've been working on the Backyard Thingy this summer, as I've been stretching lots of lines to help guide my forms for concrete and to put down barriers to hold the pavers in place. I find that I usually can't re-use any of the lines. I mean, when I'm done with a guide line, I gently remove it from its stakes, pull out the knots, and carefully coil it up--but the moment I try to uncoil it to use it again, it tries to imagine it's a bird's nest. I usually throw it away after wasting ten minutes trying to undo it, while thinking to myself: "Meh... String is cheap."
Of course, reading the article reminded me of a chapter in one of the greatest Victorian-Era novels ever written, entitled Three Men in a Boat (To Say Nothing of the Dog). In the book, three friends (all hypochondriacs) take a trip in a boat up the river Thames, with all intentions of roughing it, to try to improve their health. In one chapter, it talks about all the joys of towing boats by hand, and describes in detail what happens to the tow-cables:
(The entire book is available online through Project Gutenberg, here. This excerpt is from Chapter IX, which in my opinion is the funniest in the book.)
There is something very strange and unaccountable about a tow-line. You roll it up with as much patience and care as you would take to fold up a new pair of trousers, and five minutes afterwards, when you pick it up, it is one ghastly, soul-revolting tangle.
I do not wish to be insulting, but I firmly believe that if you took an average tow-line, and stretched it out straight across the middle of a field, and then turned your back on it for thirty seconds, that, when you looked round again, you would find that it had got itself altogether in a heap in the middle of the field, and had twisted itself up, and tied itself into knots, and lost its two ends, and become all loops; and it would take you a good half-hour, sitting down there on the grass and swearing all the while, to disentangle it again.
That is my opinion of tow-lines in general. Of course, there may be honourable exceptions; I do not say that there are not. There may be tow-lines that are a credit to their profession - conscientious, respectable tow-lines - tow-lines that do not imagine they are crochet-work, and try to knit themselves up into antimacassars the instant they are left to themselves. I say there MAY be such tow-lines; I sincerely hope there are. But I have not met with them.
This tow-line I had taken in myself just before we had got to the lock. I would not let Harris touch it, because he is careless. I had looped it round slowly and cautiously, and tied it up in the middle, and folded it in two, and laid it down gently at the bottom of the boat. Harris had lifted it up scientifically, and had put it into George's hand. George had taken it firmly, and held it away from him, and had begun to unravel it as if he were taking the swaddling clothes off a new-born infant; and, before he had unwound a dozen yards, the thing was more like a badly-made door-mat than anything else.
It is always the same, and the same sort of thing always goes on in connection with it. The man on the bank, who is trying to disentangle it, thinks all the fault lies with the man who rolled it up; and when a man up the river thinks a thing, he says it.
"What have you been trying to do with it, make a fishing-net of it? You've made a nice mess you have; why couldn't you wind it up properly, you silly dummy?" he grunts from time to time as he struggles wildly with it, and lays it out flat on the tow-path, and runs round and round it, trying to find the end.
On the other hand, the man who wound it up thinks the whole cause of the muddle rests with the man who is trying to unwind it.
"It was all right when you took it!" he exclaims indignantly. "Why don't you think what you are doing? You go about things in such a slap-dash style. You'd get a scaffolding pole entangled you would!"
And they feel so angry with one another that they would like to hang each other with the thing.
Ten minutes go by, and the first man gives a yell and goes mad, and dances on the rope, and tries to pull it straight by seizing hold of the first piece that comes to his hand and hauling at it. Of course, this only gets it into a tighter tangle than ever. Then the second man climbs out of the boat and comes to help him, and they get in each other's way, and hinder one another. They both get hold of the same bit of line, and pull at it in opposite directions, and wonder where it is caught. In the end, they do get it clear, and then turn round and find that the boat has drifted off, and is making straight for the weir.
At any rate, physicists are now starting to get a handle on this phenomenon. Behold the march of progress.
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