IM #02: Fused Quartz

So, last week, we talked about normal Quartz, and its surprising properties of piezoelectricity and triboluminescence. We talked about how it had several crystaline forms, including some which were not macrocrystalline, but only microcrystalline (the agate, tiger's eye, etc). However this week we're discussing something that ALSO has the same chemicals, but is not crystalline. At the molecular level, the bits of silicon and oxygen don't form repeating patterns, but instead exist in an amorphous glass arrangement.

Fused Quartz Glass (amorphous SiO2)	Quartz (crystalline SiO2)

This means, in part, that fused quartz (also called fused silica) does not have the piezoelectric or the triboluminescent properties of the crystal quartz. It does, however, have its own set of very interesting properties and uses.

Its three primary properties are its transparency across IR, UV and visible light, its very low thermal expansion coefficient, and its very high softening temperature. Combined with reasonable toughness, these properties make it very useful for many many applications.

The high softening point combined with the infrared (heat-waves) transparency make it a common material for encasing the heating elements in electric heaters. The quartz tubing protects the heating elements from oxidation, and allows infrared radiation out (which can be directed and absorbed by people and objects) while limiting the conduction and convection, which would heat the air instead of the people.

The low thermal expansion coefficient combined with its glass structure make it very useful for telescope mirrors which are less sensitive to thermal stresses. It's generally great for nearly any optical situation where you might use normal glass. The low thermal expansion also means it's been used for pendulums in clocks to prevent them from being as sensitive to time variation from a thermally lengthening pendulum slowing down the clock.

And, one last particularly interesting use of fused quartz is in the Gravity Probe B. Fused quartz was crafted into the smoothest man made sphere known to exist. If it were scaled up to the size of the earth, the highest mountain peak would be about 8 feet! I would highly recommend reading more about the Gravity Probe B experiment, which in May 2011 helped validate previously untested parts of Einstein's General Relativity. The experiment was first suggested in 1960, but only in 2011 was accurate enough technology developed to provide the level of accuracy needed.

Fused quartz is manufactured using laser cutting, grinding, polishing and glassblowing techniques.

IM #01: Quartz

IM = Interesting Material

I'm going to try to do 52 materials this year. Some of these might be longer than others, but I hope all of them are at least somewhat interesting.

The first interesting material post is about quartz. It's a material that most people have heard of, since in the modern world it is actually quite commonly used in quartz watches.

Quartz, chemically, is SiO2, Silicon Dioxide. This same ratio of atoms can be arranged in a variety of slightly different arrangements, the most common of which are α-quartz and β-quartz. They are very slightly different in how the tetrahedrons are arranged, and in general will look the same macroscopically.

However, this clear, six-sided "superman" crystal is fairly rare to see; about the closest that is common is the crystals in geodes, available wherever tourist trinkets are sold.

Chemically pure quartz is clear, but if there are bubbles of gas or liquid, it can be smoky white. If there are other impurities, the color can vary widely. In fact, several "different" gemstones are just different colors of the same mineral, and quartz is no exception.

Citrine,
amethyst,

and rose quartz are all the same underlying material. Even further, Chalcedony, Agate, Onyx, Jasper, Tiger's Eye, and Carnelian are all essentially quartz, with different sets of impurities and a lack of macrocrystaline form.

But the name quartz is probably most famous for being used in clocks, and this is due to one of its unique properties: piezoelectricity. When a voltage is applied to the crystal, it deforms, and when it deforms, it produces a voltage. Because of this, if a piece of quartz is made to "ring" or vibrate at its natural frequency, it produces regular electronic output that can be used to regulate a digital watch. Inside every cheap digital watch is a tiny tuning fork of quartz.

The use of quartz oscillators is a foundational technology to our modern world. Precise timing is at the heart of most of the advances in science, and cheap quartz resonators allowed reliable radios and computer timing circuits to proliferate.

As practical as quartz's piezoelectric property is, there's a much less practical, but far more awesome property that quartz has: triboluminescence. Triboluminescence is the awesome and not particularly well-understood process where mechanical stress produces light directly, not from incandescence due to friction heating. Although several common crystals have this property, the effects are often unnoticed because the light produced is very dim. As noted in the wikipedia article on triboluminescence, some American Indians used the triboluminescence of quartz to make flashing rattles used in nighttime dances. Triboluminescence is also behind the very interesting story of the x-rays from scotch tape in a vacuum story.

So, simple quartz is able to produce both light and electricity by being smashed. How cool is that?

Are you being chased?

The wicked flee when no one is pursuing, but the righteous are bold as a lion.--Proverbs 28:1 NASB  

(By the way, the Proverbs Chapter for the day is a nice handy little way of picking place and a pace for daily reading.) 

I was reading Proverbs 28 today, and this first verse caught my attention in a new way. In what ways do I flee when no one is pursuing?  I don't think I am generally characterized by the "wicked" of proverbs, but if I have been slack in my work or an assignment, do I avoid professors? ---oooh. maybe a little.

Interestingly, the NASB study bible notes (which are heavily based on the NIV Study Bible notes) references David as an example of being bold as a lion.  In particular, they reference 1 Sam. 17:46 where David as a young man challenges Goliath.  It struck me as a curious choice to use David, since for a significant portion of his life he was a fugitive, and toward the end of his reign he fled as an old man in the face of an attempted coup by his son (David Flees Absolom).  However, I realized quickly that in both those cases there WAS someone pursuing.  The wicked have a guilty conscience and imagine their own pursuers, while the righteous have no need to imagine their enemies.

Which will it be? Real hardship and toil in the name of righteousness and God's glory? Or time spent scared of our own conscience, avoiding accountability and living with paranoia?

It is also interesting to think about when it is right for the righteous to flee in the face of a pursuer.  I think that's something for a different time, though.

On the curious connections of Mark Twain.

What do these two things have in common:

• A lake which is the source of the news frenzy-causing bacteria in 2010
• A Castle in the very north of Israel built around 1230?  

The answer: Mark Twain visited them both.
This is particularly remarkable to me as I stumbled upon this little tidbit of knowledge in the same week the bacteria were making the news and I myself visited the castle in Israel.
The news coverage of the bacteria always made sure to mention that Mono Lake was a very harsh environment, and that arsenic was abundant there.  It sounds like the kinda place that would kill you to dip a toe in!  Interestingly, Mark Twain saw the very basic (as opposed to acidic) nature of the lake as a positive aspect of the area.  He writes of how easy it was to do laundry, dragging the dirty clothes in the water for a few minutes to have them come out clean as the best wash lady  could hope to render them.  There's a lot more that he divulges about the wonders (and discomforts) of this strange location in his book "Roughing it," in a chapter titled "The Wonders of Mono Lake."
Not surprisingly, the official site of Mono Lake also works hard to correct the idea of the lake as a toxic dump.  NASA and strange bacteria are no stranger to Mono Lake; it was also in the news back in 2003 for a different crazy bacteria.
While visiting Nimrod's Fortress (really, nothing to do with Nimrod), I heard from one of those little tourist audio stations a quote that Mark Twain had called these the "most well-preserved ruins of its kind."  Actually, the quote is quite varied, as I think most places it appears it has been retranslated to English after being translated to Hebrew originally.  However, here is the quote in full, available here or here:

Two hours later we reached the foot of a tall isolated mountain, which is crowned by the crumbling castle of Banias, the stateliest ruin of that kind on earth, no doubt. It is a thousand feet long and two hundred wide, all of the most symmetrical, and at the same time the most ponderous masonry. The massive towers and bastions are more than thirty feet high, and have been sixty. From the mountain's peak its broken turrets rise above the groves of ancient oaks and olives, and look wonderfully picturesque. It is of such high antiquity that no man knows who built it or when it was built. It is utterly inaccessible, except in one place, where a bridle-path winds upward among the solid rocks to the old portcullis. The horses' hoofs have bored holes in these rocks to the depth of six inches during the hundreds and hundreds of years that the castle was garrisoned. We wandered for three hours among the chambers and crypts and dungeons of the fortress, and trod where the mailed heels of many a knightly Crusader had rang, and where Phenician heroes had walked ages before them.

So, there it is.  Mark Twain certainly got around, and his accounts of his travels are just as colorful and fun-loving as his works of fiction.

Mordecai's first faint

So, this past Friday, I fainted for the first time in my life.

After sleeping in a bit, I decided to go on a bike ride to a place I'd heard about a few times, Nesher Park.  It's a very nice place, with two suspension bridges (made of steel, not grass), and a large cave. There's also a geocache hidden there.

As it happened, Nathanael was gone to his lab, and I wasn't necessarily planning to be back in time for the frisbee game in the afternoon, so I decided to go alone.  I grabbed my bike, phone and water bottle and took off.  Across campus to the gate is all downhill, but once off campus, it was uphill for a few kilometers.  Determined to make it to the top without stopping, I settled in to a low gear and kept cranking.  Reaching the top, I was proud of myself, but noticing that I was less hydrated than I should have been.  I had also skipped breakfast, so I was feeling a little light-headed from the long uphill climb.  After pulling in to the park entrance, I stopped and stood up, straddling my bike, and took a little drink.  Then I went to take another drink, tipping my head back.... The next thing I remember is pleasantly waking up on the ground.

Waking up was by far the nicest part of the whole experience.  I had the exact same feeling as when you sorta drift out of sleep, snuggled deeply in blankets, and refuse to think about what time it might be.  I remember thinking "wow, what a dream I had about riding really fast, and then crashing."  Then I thought "hmm that's funny, I'm lying with my bike between my legs"
Then I thought: "why is my waterbottle over there emptying the last bit of water out of the neck?"
It was about then that I noticed some blood on the pavement by my chin.  After a quick check for oral bleeding (none. hooray!), I evaluated my body, trying to see if there were any injuries.  I determined I had cuts of unknown degree and unknown locations on my face, and my jaw was sore.  Once I decided I was ok to move, I sat for a bit and drank the last water that couldn't get out of the water bottle.  Seeing the last of the water trickle out when I came to is the only time indicator I have for how long I was out; apparently only a few seconds.

I cleaned my wounds with some tissues and borrowed water from a big birthday party that was happening in one of the gazebos in the park, and then went on to look around the trails and find the geocache.  I was a little concerned that I would scare some people since I didn't know how scary my cuts looked, until I realized I could take a picture of myself with my phone as a 'mirror' of sorts.  In this way, I discovered one of the benefits of a beard: it not only hid the worst cut, but since my beard is dark, you couldn't tell by looking at it that part of it was wet with blood, instead of just sweat.

While I was hiking in the park, two dogs started to follow me around.  It seemed like they were abandoned or runaways, since they were very friendly, and both had collars (with no tags or id).  However, one of them was very thin and thirsty, and I was sad since I don't know of any shelters that I could take them to.


The bike ride home went great, and I got back just as the frisbee game was ending.

A few days later, everything is healing nicely, and I'm trying to make sure that I keep good tabs on my hydration level.

Gap's recycle your blues Oct 6-20

If you're in touch with the latest in things running around the internet, you probably heard about the Gap logo crisis. Basically, Gap changed their logo on their website, people hated it, Gap tried to spin it positive by encouraging submissions, and in the end they said, never mind we'll keep the old one and didn't quite admit to making a mistake.

However, as much as I myself really, really, really don't care about Gap's logo, and have never purchased anything from Gap (I do nearly all of my clothes shopping second-hand), I wish that this other action by Gap would get more press: Gap's donation program Another, more thorough description

Basically, if you bring old, worn-out denim (of any brand) to Gap, you'll get a 30% off on a pair of new jeans.  The donated jeans get turned into housing insulation through Bonded Logic and distributed to various housing projects.  The last time they did this promotion, some of the insulation went to Katrina rebuilding projects.

Now, obviously, a lot of perfectly good jeans will be going to the Gap instead of to a Salvation Army store, or Goodwill or other options that provide clothes for those with lower income.  However, I think that the idea of a store that addresses end-of-product-life issues WITH AN INCENTIVE is a wonderful idea.  RadioShack long ago had a battery recycling program for people who brought batteries in to be replaced.  This was great, but was never really well-known, and if a person was buying a new cordless phone instead of just a new battery, they would almost never recycle their battery from the former phone.  There was no reason to go to the trouble of hauling a dead battery with them that they were never going to use.

Anyway, I think that the only negative here is Gap's potentially less-than-great treatment of overseas labor.  Which, as far as Gap itself goes, I don't know too much about.

One of my (many) chess sets

A lot of people collect things-- stamps, coins, baseball cards, cars, debts, stocks, socks... you name it, most likely someone, somewhere collects it. I made a decision a long time ago that I would collect chess sets.

Now, I also like building and making things (part of the reason I am an engineer...). So, obviously, it was inevitable that I would make at least one chess set. Browsing the internet, I'd come across a few different "nuts and bolts" chess sets, but they all seemed like they compromised in some way. Usually, there were a few pieces that seemed like quite a stretch interpretively. Or maybe a piece seemed stretched literally; there's a normal sort of height pattern for pieces in relation to one another, and a lot of the hardware piece sets didn't do a good job of following that.

So I set out to make my own, better "nuts and bolts" chess set. As with any good design project, I started out by defining the requirements:

• The chess pieces will conform to standard chess piece height conventions (more on this at the bottom)
• The chess pieces will conform to key chess piece features (it should be obvious what each piece is)
• The chess pieces will be made of unaltered hardware (with the allowable exception of cutting all-thread to length)
• The chess pieces will be disassembly-friendly.
• The chess pieces will use no glues, welding, or solder.
• The two sides will be differentiable without using paint.

The results are below in the picture and slide show.

From hardware set

Turn on the comments for the slide show to see some of the details of making each piece. A list of the parts used is available here.

For the interested: My rant on chess sets

There is a certain order to chess sets which dramatically helps with recognizing pieces and gives a sort of creative framework which I find very appealing. I'm much, much less inclined to play/purchase a set which breaks these 'norms.'

I think one of the most salient features of a good chess set is that the pieces conform to a given height scheme: the pawns should be short and about half the height of the king/queen. The rooks (castles) should be the second shortest. The knights and bishops can be approximately the same height, but if one is taller, it should be the bishop. The king and queen should be approximately the same height, with possibly a top point of a king's crown taller than the queen.

A classic indicator of the king is a cross topping his crown. (I'm particularly proud of the fact that my hardware kings are phillips head screws, and thereby are topped with a cross.... sneaky...).  A classic indicator of the queen is a many-pointed crown.  The only piece which is never radially symmetric is the knight; most of the time the others will be radially symmetric. In the case that a set is actually representing people with faces, this radial symmetry can be neglected in favor of more sculptured people.

 If you want to see the other chess sets in my collection (minus a few recent ones) you can see them here.

From chess pictures