Category: Technological History


Could Jarn really have made glass?

Sure, if his ability to heat things up with his mind was sufficient to melt the crystals in sand or rock completely. Volcanoes and lightning strikes do it all the time, producing obsidian and fulgurites, both glasses. But he wouldn’t make modern window glass by accident!

Scientifically a glass is an amorphous (non-crystalline) solid. Most are made by melting or dissolving something which may be crystalline to start with and then cooling it so fast that crystals have no chance to form. This can be done, for instance, with sugar. In fact, sugar glass was widely used for breakaway windows in Hollywood special effects. It had to be made up on the spot, as it would absorb water from the air, but if you’ve seen a stuntman thrown through a window, the chances are that window was made of sugar.

When sand is the raw material, silicon dioxide (quartz) is usually the main ingredient. Pure or nearly pure silica sand would give silica glass, which is used when expansion or contraction with temperature would be a problem, or at high temperatures. But it is hard to make, so most modern glass has two “impurities”: soda (Na2O) and lime (CaO). Lots of other things may be added in smaller amounts as well. If Jarn found a sand with these minerals as impurities, he could indeed have produced a crude form of what we would recognize as glass, and given his mental abilities he could have formed it into transparent sheets.

Glass jewelry owned by the author

Modern fused, pressed and flameworked glass jewelry.

Why these particular impurities? Pure silica sand melts at a very high temperature. Mixing it with soda reduces that temperature—but the resulting glass, like sugar glass (though not quite to the same extent!) is water-soluble. Adding lime and a couple of other trace ingredients greatly reduces the solubility and produces greater chemical stability.

Transparency is a property of many large crystals, such as quartz, Most rocks made of silicon dioxide, such as flint or jasper, are not transparent simply because they are made up of many tiny crystals, and light reflects off the crystal boundaries. Glasses, having no crystal boundaries, are often transparent.

Lack of transparency in a glass may be due to bubbles or to the inclusion of elements which color the glass. Many sand grains, for instance, are yellow because of a coating of iron oxide. This would color glass made from yellowish sand, though the color is more green than yellow. Small amounts of various chemicals are in fact used to color glass deliberately.

So Jarn could have made glass by accident and then learned what he had done and how to refine the process from his computer. His fusing of dirt would have been more akin to firing ceramics. But these were not arts he could have taught to anyone else.

Typewriter (Morguefile)When I learned to type, it was on a typewriter. Not a sleek little electric portable, or even a mechanical portable, but a big, clunky machine with keys that had to be pushed hard enough to flip up the letters through a mechanical linkage, and a lever that had to be pushed over when a bell signaled you were approaching the end of a line. And what I hated worst was threading in a new ribbon.

It wasn’t a cartridge, it was a spool of ink-impregnated fabric that you had to thread through a finicky little gadget that held it where the lever with the letter on its end could strike the ribbon and leave a letter on the paper. It was impossible to thread the ribbon without getting ink all over your hands, so I generally used a ribbon as long as possible – until the letters it produced were getting too light to read.

Probably that’s why I try to do the same with cartridge ink and even toner.

No longer.

I’m not sure whether it’s bad design because of not thinking or bad design because the company wants to sell more ink cartridges/toner. In either case it’s bad design as far as customer usability is concerned.

My current inkjet printer is a 3-way HP Photosmart. It serves as a color copier and a scanner as well as a printer. I would have killed for a copier back in the days before Xerox when you layered paper with carbon paper to type, and woe betide you if you made a typo. Especially on the first page of a long document! Likewise a scanner – my first one was a standalone that cost far more than my printer. But having all three together is a great way to save space.

Unfortunately, there’s that design problem I mentioned.

All of my printers, laser or inkjet, now decide for themselves when the toner or ink cartridge is low, often before I even notice any reduction in quality, and simply quit working. Usually they send me a message that they need a new cartridge. Usually this is in the wee hours of the morning when all the stores are closed and when I cannot find the spare ink I’m sure I bought. When it’s a matter of printing something I usually just sigh and put a cartridge on my shopping list. But why on earth does the lack of a black inkjet cartridge keep the combo from scanning? Especially when I need to scan a signed contract and send it off by email, and I promised to do it right away?

It does not help at all that the exact name of the printer, and the size of ink cartridge needed, are hidden inside the machine, and it’s not obvious how to open it.

I finally went to the HP web site, looked for the machine that looked most like mine, and downloaded the instruction book – again. I still can’t find the one I’m sure I downloaded before, but I was able to find the instructions for opening the ink compartment, which (a) confirmed that I’d downloaded the right instruction book and (b) finally allowed me to figure out what kind of replacement cartridge to get.

I still think it’s bad design.

The Perversity of Inanimate Objects 1 4/10/10
Insulin Pumps 5/20/10
Wars With Word 5/28/10
The Perversity of Inanimate Objects 2 6/4/10
Float Chair (fictional) 6/24/10
Tricycles are not Bicycles 8/8/10
Why Temperature Remembered doesn’t match the Record 4/5/11
Does Banking Software Work? 4/21/11
My New Toy – an iPad 2 5/12/11
Before Computers 6/5/11
How do you Eat a Salad? 4/28/12
Battery Woes 5/12/12
Printer Woes 6/14/12
Adult Proof 9/8/12
Digital Cameras 9/29/12
Who Needs a Nightcap? 9/3/13

500+ posts is too many for me to keep track of, and quite a few are “reference” posts, such as the ones on planet building or horse coat color genetics. So I’m putting in a new feature, an index page that links to posts linking to the posts on a given topic. (Sound confusing? Try doing it!)

These indexing posts start today (see below) and will appear occasionally until the reference posts are all indexed. After that I’ll just be updating the index posts, which will be accessible from the Index tab above.

With 550 posts as of today, I’ve started to have problems remembering what I’ve already put on here. This is particularly a problem with posting existing content such as poems, short pieces from the Summer Arts Festival, or science explanations originally written for the Alaska Science Forum. I can’t remember which books or DVDs I’ve posted reviews on. It also is starting to be a problem when I want to link to a previous post and can’t remember when it was put up or what the title was. And there are posts on this blog that have permanent information, like the series on planet building and the one on horse color genetics, or the book and DVD reviews. I want to make it easier for my readers as well as myself to find things.

I made a start some time ago by adding an index page, which can be accessed from the menu at the top of any page. Right now, the only links are to index pages on my author site. This takes you out of the site and sometimes back in, which is rather clumsy. The index list is also incomplete.

I’m going to start posting an occasional entry which is strictly an index of past posts on a particular topic. These posts will be linked from the index page, and will link forward to the individual blog posts. As it takes a while to find all the posts that belong together, this will be a slow process—probably extending over the next few months. The first in this series, on DVD reviews, is already queued for January 3. Others will follow, most on Thursdays.

I probably won’t be indexing every post. Some, like those early posts which were simply glossary entries for my books, are on the author site and really belong there. Others, like the regular Monday updates on North Pole weather starting in November 2010, can be found easily enough just by using the calendar on the site. But I hope that by the time I have finished this, older posts of interest will be easier to find.

Fireworks displayTrue or false: The Chinese invented gunpowder a thousand years before it was known in the West, but being a peaceable people, they used it for many centuries only for fireworks.

This is one of those trick questions that is neither true nor false. The real story seems to be that the Chinese did indeed have fireworks at the time of the Roman emperors, that they did invent gunpowder, and that the use of gunpowder in war started sometime around the tenth century. Nevertheless, gunpowder was used as a weapon in China from the time of its discovery. The unstated — and false — assumption is that fireworks require gunpowder.

Early Chinese fireworks consisted of colored and perfumed smokes and noisemakers often called firecrackers. These early firecrackers were simply sections of bamboo thrown onto a fire. The bamboo sections would explode as the air and moisture inside the closed sections heated and expanded. The bamboo crackers may have been used initially to frighten more primitive tribes away from campfires, while smoke was used for fumigation and as a signal in warfare, so even these fireworks were not entirely peaceful.

Fireworks displayThe first evidence for gunpowder is in about the 9th century, and consists of a Taoist warning against mixing saltpeter, sulphur, arsenic compounds, and honey (which supplied carbon), on the grounds that burnt hands, faces, and houses had resulted from the experiment. By the beginning of the 10th century, however, there is mention of the use of “fire-drug”, the term later used for gunpowder, in war.

The early gunpowders were low in saltpeter and burned rather than exploding. They seem to have been well established in incendiary bombs, poison smoke bombs, and fire arrows — not exactly peaceful uses — by the eleventh century. At about the same time, a new and noisier kind of firecracker appeared, probably similar to modern firecrackers. Fireworks on frames were known by the 12th century, and may have involved gunpowder.

Fireworks displayOne kind of fireworks, definitely known by 1264, may have been the first step toward the rocket. This was the “ground-rat”, probably a bamboo tube filled with gunpowder and with a small hole in one end. When lit, it rushed violently around on the ground. (A dud firecracker will sometimes behave in the same way.) The exact date has survived because of an incident in which a ground-rat chased the Emperor’s mother at a fireworks display. Luckily for the officials in charge of the display, the Empress-Mother, though frightened at the time, had a sense of humor and was able to laugh about the incident by the next day.

At some point in the next century, ground-rats of this type were used in warfare. They would certainly have been quite as upsetting to horses as they were to the Empress-Mother, and in addition the military ground-rats were fitted with hooks to catch on clothing.

Fireeworks displayA ground-rat bouncing around on rough ground would at times take flight for a short distance, and some alert designer of weapons came up with the idea of fastening a ground-rat to an arrow. The result was the first rocket, an arrow that could be fired without a bow. The fireworks designers promptly stole the idea back from the military, removing the arrowhead and adding a gunpowder bomb, whether plain or packed with material that would produce colored lights. Modern flights to the moon and planets are based on exactly the same principle, though the details are more complex.

By the middle of the 13th century Dominican and Franciscan friars were traveling to the Mongol court at Karakorum. One of these friars may have sent a package of firecrackers to Roger Bacon, whose writings indicate a knowledge of firecrackers as children’s toys, an awareness of the ingredients of the gunpowder within them, and a realization of the military potential of larger versions. The Chinese, however, had at that time already been using cast-iron bombs filled with high-nitrate gunpowder for a century or more.

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