It can be physically abused, without risking damage to a potentially expensive electronic device... for myself, namely in the waiting area for patients at my office.

Sure, lots of people just play around/read on their smartphones these days, but for those who are not, I'd rather have a bunch of magazines which they can flip through if they're looking for something different to read, rather than providing an electronic device for them to do the same.

Also preferable for active, destructive, kids. :P

Granted, the alien species there weren't terribly memorable in any way... the series was built more around the lower-tech methods of the human resistance, which I did find to be an interesting concept.

I remember once I extracted the MIDI files from TIE Fighter (ahh good ol' days poking around things with a hex editor). The music for the menus/etc. were some 30-odd regular length pieces (minute or two long)

The actual in-flight music, on the other hand, was something like 60 or so (I don't remember exactly how many, maybe more?) pieces, about 5-15 seconds long each, which the game would stitch together with some sort of logic (afterall, only certain phrases will sound right following other phrases of the music) to provide the background music while playing, which would of course attempt to match the action which was happening at the time in-game.

The effect was quite neat, but something like this requires a lot more work on the part of the composers and everyone else working on the game to make sure that the action and the music match up properly as well.

I'm pretty sure there was some element of randomness to it as well, since I remember flying around after having completed a mission, listening to the music which played indicating you were done, and listening for a good 20 minutes or so trying to figure out where it was looping or such, and not finding it. While there was a certain sequence in that one phrase of the music would follow another, it seemed like it would randomly pick what to play next at times.

I really miss stuff like that...

Ahh... good ol' GUS. I think I've still got a GUS ACE in an old system somewhere...

A pain to configure at times... though being able to swap samples on a per-game basis was fun... a rather decent sample set (still use a few of them to this day)... and the sound output was very clean too (SB16 *shudder* sooooooooo noisy)

Then everything became prerecorded...

RIP dynamic music imuse style...

Most white fillings placed these days are a composite, the resin part typically being something such as Bis-GMA, the 'MA' being 'methacrylate', the chemistry behind it being acrylic chemistry which allows for the polymerization of the individual molecules together. Look up 'acryl' or 'acrylic acid'... same basic end group, but the properties of whatever you end up with vary greatly with what you attach to it.

The light activation itself is not of the Bis-GMA though, but a separate photoinitiator, commonly camphorquinone, which absorbs in the blue range... knocks an electron off, creates free radical, free-radical polymerization of the Bis-GMA, etc., the usual story with acrylic-types. (Fun fact: camphorquinone is a very yellow molecule [since it absorbs blue!], which makes for all sorts of fun for the composite manufacturers trying to get the shades right for filling materials). Once upon a time, UV photoinitators were used, but due to safety concerns everything's gone to blue light these days for filling and sealants. UV photoinitiators are still used in many other different areas though... the last time I had a chip in my windshield repaired, it was with a UV-cured acrylic.

This wound treatment though, is using Rose Bengal, which is typically used as a dye, but as with many coloured molecules, absorption of that frequency of light which characterizes them knocks that electron off, creating a free radical... which in turn can react with other substances. In this case it is collagen molecules.

So, to compare with acrylic chemistry... it's sort of an analogous process, where Rose Bengal is the photoinitiator, and the collagen in the body is like the acrylic!

The nature of the reactions, despite 'application of energy', is quite different; the energy involved is also on vastly different scales.

Cauterization involves application of heat, burning the tissues (killing the tissues) and denaturating the proteins (completely wrecking their structure), causing them to precipitate out of solution and clump together, plugging things up (plugging up bleeding blood vessels, and also causing blood to clot around the plugs, being a side effect of it). Lots of heat energy, sufficient to burn flesh. Usually done with a fair bit more precision these days of course.

This technique, on the other hand, is quite similar to one which I use from time to time for disinfection of periodontal pockets around teeth... application of a dye (in my case, toluidine blue) which binds to the bacteria, and then activation of the dye with the appropriate frequency of light which is matched to the absorption spectrum of the dye (sorry, not at the office so can't look up the specs), generating free radicals which react with bacterial components and ultimately killing the bacteria. The energy involved is literally that of the photon of the proper wavelength which knocks the electron out of the dye when the dye absorbs it... multiplied many times of course. Without the matched dye to absorb the light though, the light won't be doing a heck of a lot of useful work... sure it'll be absorbed by other molecules, which does heat them up somewhat, but nowhere near the level of heat used in cauterization.

In this situation, the dye is Rose Bengal, which likely has an affinity for collagen. Activation of the dye causes the collagen molecules to form bonds with one another, cross-linking them. Essentially, it turns the existing collagen where it is applied into the 'glue' to hold the wound together. No destruction of living tissue as cautery would (whether tissues die from other factors with the injury, such as insufficient blood supply, are a different story), and also much less of a mess of various byproducts left behind afterwards as well.

Disclaimer: I am a dentist...

Is this such a good idea? The mouth is a rather harsh environment... moist, corrosive environment; very very abundant in bacteria (which just love to grow onto anything foreign we place in there); and subject to some very strong forces (hundred or two pounds of pressure of conscious biting force, can be many times more unconscious [eg. sleeping]).

Less invasive I suppose, but it'll have its own issues.

I think the main issue here is that when you're developing a type system, you generally want the types to classify objects into certain categories that tell you things about them. So if I define some kind of a reference type, what I am saying is that an object of that type is a kind of a pointer to something.

So now, if I allow null references, then my reference type is really saying that "objects of this type are pointers to either something or nothing". That's all well and fine, but it makes the type less precise, in that it conveys less information about the object it is categorizing.

As it turns out, this lack of information is quite important because one of the most common things you have to check when you're given a possibly-null reference is whether or not it is null. You need to insert "if (ptr == NULL)" all over the place. Thus reference types which allow null references ultimately give me less expressive power.

Most of the time null references are created because either an error condition must be reported (e.g. malloc fails), or it is unclear at some point in time whether or not an object exists. Error conditions can be better signalled using exception handling. As for cases where you're not sure if the object exists or not, then one possibility is to use an option type like in Standard ML:

datatype 'a option = SOME of 'a | NONE

This is a polymorphic type that says that either the object exists or it doesn't, and you can find out what the situation is by using a "case" statement on the datatype constructors:

case foo of
    SOME(x) ==> ... [do something with x] ...
| NONE ==> ... [the object doesn't exist] ...

Thus by combining a reference type without nulls with an option type, you can create "reference option" types, which have all the flexibility of "with-null" reference types.

But the cool thing is, you only ever need to check the "null-ness" of the object only once; once you do the check, you're handed a reference object which is guaranteed to be non-null. Thus you can easily partition your code into parts that will do the non-null check and those that assume all references handed to it are valid.

This is why a good type system can make programming so much cleaner and easier :)

Being able to produce pretty pictures is always fun. I learnt programming by spending all my time drawing bouncing balls that changed colour in 320x200 VGA. Of course nowadays kids can use a lot more powerful graphics libraries like the aforementioned SDL, which can let them make a lot cooler stuff.

If he gets the hang of it, you could even teach him how to write a raytracer. That would also be good for his math, and be a nice project where more advanced programming techniques (e.g. data structures, recursion) and more advanced math (calculus, 3D geometry) have practical uses.

AFAIK, Sparkle is just a rebranding of a FSP power supply. There's a few other names they sell under, but thats the only one I can think of offhand.

grade of annoyingness/painfulness is directly linked to frequency/dBa spl and varies greatly depending on the frequency spectrum though. but yeah, it's all covered :)