Aurorarium 2200 yen ($24 USD).
The Aurorarium is an attempt to imitate the northern lights, hence “aurora-rium”. The kit consists of a pre-assembled base plate – with the motor, power switch, and circuit board already built – two small plastic “chips”, the fogged plastic cone sheet, the plastic cone tip, the reflecting tray, and two thin mylar disks. Assembly takes no more than 5-10 minutes, and most of that is for making sure that the cone is taped together right. You can choose whether to put the chips in place or not. There are four sawtooth-like teeth on the bottom of the reflector dish, and as the dish turns, the teeth press against the raised chips, causing the dish to tilt and change the angle of the reflected light a bit. Putting in one chip will make the disk tilt 4 times per rotation, and 2 chips makes it tilt 8 times. Of course, there’s no tilting if you don’t use either chip. Assembly consists of mounting the LED projector arm in the base, putting in the desired chips, making the cone using double-sided tape, putting the reflecting dish on the base, putting the plastic tip on the cone, and then putting the cone in place. The kit also requires 4 AA batteries (not included).
You can mod the kit a couple of ways. First, take one of the mylar disks and draw lightly on it on one side using a pen on a soft surface. It doesn’t take much to affect the surface on the other side. Then put the disk in the reflecting tray, put the cone on, and push the switch. A second mod is to put a little water in the tray. A third is to put plastic crystals in the tray. You can also choose to leave the cone off, which lets the light reach the ceiling and walls. (Naturally, you can also put in a 6V adapter jack.)
There are three small LEDs in the projector head – one each red, blue and green. As the disk rotates (it is really geared down and takes 2-3 minutes to turn once), the LEDs fade in and out, going from red, to blue to green to yellow to white, etc. The actual pattern for the fades is based on the switch. Pushing it once gives it a red-dominated pattern; twice includes purple and yellow colors; 3 times is primarily blue, purple and white; 4 is mostly purple/white; and pushing the button 5 times turns the kit off.
As with all of the other unnumbered mook kits, the mook for the Aurorarium concentrates solely on the properties of light, with an explanation of how prisms and rainbows work; a suggestion to put a flashlight in a liter soda bottle to see a prism effect; photos of auroras; photos of strange effects from the sun, including the green flash and sun dogs; and some pictures of sea life and fireflies that can make their own light. It’s a thin mook, at only 18 pages, but the pictures are nice. Not a lot of alternative suggestions for mods, though. After using up the 2 mylar sheets, you can try using reflective wrapping paper, or aluminum foil.
(The mylar disk really doesn’t look brown like this. It’s silver and highly reflective, which is why it looks so weird here in the photo. The little black arm and cylinder over the base unit is the projector arm and head. The projector head contains the three (red, blue and green) LEDs, which are aimed down at the mylar sheet.)
One thing I need to clear up – the aurorarium is not actually part of the Otona no Kagaku (adult science) series. Instead, it’s part of Kagaku no Tamago (science egg), which are build-it-yourself kits for kids. But, it’s generally included in with the adult kits at bookstores like Kinokuniya. This kit originally came out in 2008, so I’m a little late in reviewing it, comparatively.
Basically, this is a high-tech lava lamp, but without the endlessly changing shapes. The motor is kind of noisy, which can be a distraction. If you leave it on, it’ll turn off by itself after 10 minutes. At $24 USD in Japan, it’s probably not worth buying at the expected import prices of $40-$50. You can easily make your own aurorarium with some colored Christmas light strings and a geared-down 1.5V motor connected to a CD. But, the Gakken kit will probably look better on your bookshelf.