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Digital Clock Without Electricity or Moving Parts
NerdMachine writes "Throw away those slide rules and embrace the digital age. The Digital Sundial is a 10 year old invention on display in Sundial Park (Genk, Belgium), Deutsches Museum (Munich Germany), Kölnisches Stadtmuseum (Cologne, Germany), and Martha's Vineyard, USA. You need to pivot it to adjust daylight savings time. If you can't visit one of these, Digital Sundials International can sell you one for US$12,000+, or you can buy a pocket version for under US$100 for that special nerd in your life."
Sigs cause cancer.
$12,000 USD?? That doesn't seem like a very bright idea.
RTFA. From the product info:
Sunlight is cast through two cleverly designed masks in the shape of numbers that show the current time of day
Its a cool idea.
$12,000 USD?? That doesn't seem like a very bright idea.
And if you're not bright enough it won't work when you're inside.... That's deep.
.. they have built-in calculators, can be worn on the wrist, and can run a scaled-down version of Linux.
JMD
When all else fails, feel free to panic.
as in the earth. If the earth didn't rotate, it wouldn't work. Sorry, but there must be a moving part.
No, it doesn't. It consists of two plates with lines, which either transmit or block light depending on the specific location of the sun (the viewer needs to be at a specific position).
The visible lines then align in such a way that you can read off the time in digits. Hence 'digital'.
We "still think digital watches are a pretty neat idea."
Comment removed based on user account deletion
Excellent.
You have two hands and one brain, so always code twice as much as you think!
Sundials don't work, the one I've had in my basement hasn't changed time since I installed it.
Trolling is a art,
...will never learn to read a proper sundial.
A quick hack for this would be to remove the rest of your house.
My appreciation of Douglas Adams is far deeper than yours.
A slashdotter's arch-nemesis.
*runs from the flames*
Although the clock is set to read in 5 or 10 minute intervals, depending on the time of year it could still be up to 16 minutes fast or slow compared to your watch or clock because of the Equation of time. Our sense of time is so conditioned by our dependence on the mechanical/digital that solar time is now percieved to be "wrong".
from the companues website
That's not a digital clock in any sense of the word.
What high school did you graduate from? Obviously they weren't doing their job.
From dictionary.reference.com:
digital
1. Of, relating to, or resembling a digit, especially a finger.
2. Operated or done with the fingers: a digital switch.
3. Having digits.
4. Expressed in numerical form, especially for use by a computer.
5. Computer Science. Of or relating to a device that can read, write, or store information that is represented in numerical form. See Usage Note at virtual.
6. Using or giving a reading in digits: a digital clock.
Please see #6, and then go think about why you don't know the definitions of common words. It also seems that you can't be bothered to look them up.
Are you sure you are 'intelligent' by any sense of that word?
(Sorry, I couldn't resist...)
"Alcohol, Tobacco, Firearms, and Explosives" should be a convenience store, not a government agency.
If it can't be installed in an SUV most Americans won't buy it anyway.
I read an article in an old Scientific American about an especially simple sundial: mount a globe of the Earth outside, orienting it to be exactly parallel to the real Earth. That means pointing the north pole of the globe at the North Star, and rotating it so that your current meridian of longitude runs across the top. This will put your current location exactly at the top of the globe.
The cool thing is that sunlight will now fall on the globe in exactly the way it falls on the Earth (during the day, that is). You can see the day-night terminator and it will be the same as the terminator on the actual Earth. You can see which polar regions are getting 24 hour sunlight or night. You can tell whether it is day or night anywhere on Earth, and even estimate what time it is there.
It sounded pretty cool although I never bothered to try to set one up. You'd need some kind of waterproof globe that wouldn't fade in the sunlight. Probably there are some like this on public display somewhere.
... what kind of battery life does this so-called "Sun" have?
The clock mechanism is powered by a flywheel.
The display is powered by thermonuclear fusion.
Horrors! Have to ban sundials! That "sun" thing is so dangerous when they're working that just a few minutes exposure can give you a radiation burn.
(Bad, bad woodchip mill. Good old outback bill.)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
I can't quite figure out how to use your list of objects to make one of these. The best I can figure out is that it involves taking all the objects except the laser printer and dumping them in the trash. Then you just look at the display on the laser printer and read the time. Am I missing something?
Assuming you wern't just trying to be funny.
The core of each digit of the "digital sundial" is a sandwich composed of:
- A grating with vertical black/clear bars.
- A layer of glass. (Thickness varies depending on how fast the digit should cycle - the thicker the faster.)
- A second grating with a more complex set of bars that I'll describe later.
- A frosted glass "screen" to diffuse the light for viewing from all angles.
The thickness of the bars on the first grating is such that, if the digit goes through N changes, the clear band is significantly less than 1/Nth the width of the clear band plus the dark band. (To get the appearance of the various digits to match, all of the upper gratings have the same light/dark band width ratio, determined by the digit with the most states.)
Stacking the first grating on the glass produces a band of light stripes on the bottom of the glass that slides sideways as the sun moves. The spacing of the bands and the thickness of the glass are such that the bands move by one band-spacing in one cycle-time for the digit. The glass both holds the spacing between the gratings constant and reduces the angle through which the light moves, so the clock produces a readable image for nearly 12 hours, rather than being really dim near sunrise and sunset.
For every light/dark band pair in the upper grating there are N bands in the lower grating. Each band is a stripe through the image of one of the digits, cycling through the N digits. As the sun moves, the bands move across this pattern, sequentially being "stenciled" by a different digit.
The light coming out of the lower grating strikes the frosted glass "screen" and is diffused sideways, so the clock can be read from many angles.
You use the laser printer to make the gratings, by computing their appearance and printing them on overhead-projector foils.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way