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Simpler: hollow-face & three dragons

Actually, inspired by how one preschool-theater costume (of a...cat; with proper ears) supposedly induced a panic attack in the kitten of my buddy, I essentially reworked the dragon once, to be more "danger! Possible unknown big cat!"-like. Yup, panic attack also in my cat.

(quick google search for the above wiki page even revealed one with a cat design... I can't vouch for how convincing it is, though)

Reading OMNI always felt a bit like an exercise in wishful thinking. It was like reading car magazines that feature incredible prototypes. Yes they're awesome, but you're never going to see one in your lifetime. OMNI was about what was possible, not what was actually happening.

To read about real advances, I preferred Scientific American, especially back when Martin Gardner wrote for them. Prior to that, I never used the terms "recreational" and "mathematics" in the same sentence.

On a side note, there was a fantastic 3D illusion created as a tribute to Gardner. It's still available for download here.

It can if you aren't writing with graphite.... http://www.grand-illusions.com/acatalog/Metal_Pen.html

Pictures and Images to a working unit can be found here

In one room there is a crystal ball with a fortune tellers head projected on the inside somehow. As you ride all the way around it the face somehow matches every angle even as a dozen people are looking at different spots. I always figured it was some kind of multiple projectors, but how they got the overlapping and made it so smooth I never could guess.

The illusion has to do with reversing of the depth of field. There's several good illusions like this, this Einstein one is truly awesome: http://www.grand-illusions.com/toyshop/einstein_ho llow_face_illusion/

For fixed objects, all you really have to do is to make it reversed and light it correctly. For animated ones, they use projectors onto a background that is the inside of the sphere. You see through the front, but it's actually projected on the back. This depth reversal is what gives you the "follows you around" look.

If someone could make one of those magnifying tapers so that it can be compressed like a key, they could insert one into each key and use one large common OLED screen underneath all the keys.

But then that might cost more than just putting a small OLED screen in each key =P

A good example of how our minds fill in visual information is optical illusions such as the dragon illusion. You may have already seen it as it has been making the email/blog rounds. It's a "hollow face" illusion, where the brain assumes depth information based on the familiarity of the face. We don't often see concave faces, so our brain incorrectly assumes the face is convex. There is a PDF on the dragon illusion page you can print and see this for yourself. It's a very striking effect.

What were engineers doing over 2k years ago? How about building the Antikythera Mechanism (web copy of a June 1959 Scientific American article, p60-7)

An amazingly complex, intricate, and accurate mechanical astronomical calculation device from 80 BC. Found in a shipwreck in 1900, and not fully reverse engineered until 1973, there are no other examples of this level technology in the ancient world.

"It is hard to exaggerate the singularity of this device, or its importance in forcing a complete re-evaluation of what had been believed about technology in the ancient world. For this box contained some 32 [brass] gears, assembled into a mechanism that accurately reproduced the motion of the sun and the moon against the background of fixed stars, with a differential [gear] giving their relative position and hence the phases of the moon."

You can see a reconstructed version of the Antikythera Mechanism here. Another article detailing the probable creation date of the device based on the construction of the gears can be found here"

..it was more sophisticated than anything like it until the Eighteenth Century, nearly two thousand years later!"

Another article makes the conjecture that ancient navigators could have used the Antikythera Mechanism to determine longitude via the position of the moon (1800 years before longitude calculation was perfected in England)

YOu can REALLY crap out if you trust this "depth perception"

It doesn't, but the black hole is very massive - considerably more massive than any star in the galaxy.

And why would a great force at the centre of the galaxy be inclined to spit out stars at huge velocities?

It's tricky to explain and not terribly easy to get your head around, but I think the principle is similar to this demonstration (check out the video). The grav. potential energy of the companion star due to its attraction to the black hole is transferred into kinetic energy in the ejected star.

IANAPyet so please correct me if I'm wrong.

This isn't strictly relevant, but has anyone figured out why most people get the probablities wrong in Don't Get The Goat (no relation to goatse). Even intelligent people often get it wrong. I remember spending ages trying to explain it to an intelligent person with good maths skills - and they still didn't understand.

You're mistaken. Here's why:

First of all, you're confusing monitor refresh rate with the number of times a game redraws the screen. Regardless, I'll address your post.

Phosphors need to be refreshed before they expire.
True.

If they start dimming before they are refreshed, then you will notice slight blinking compared to looking at a piece of paper. Your monitor tries to do this at as fast hertz as possible.
True.

If 85 hz means that for your monitor, pixels are refreshed before they even start dimming, then you won't ever be sick from it.
True, but the latter assertion is subjective.

However, when frames are refreshed (in a game), they do not "dim".
False. Frame refreshes in a game function similarly to that of non-game screen refreshes, save for the region of memory that the graphics adapter scans out to the DAC/TMDS. The point is, the frequency at which I redraw the contents of my 3D (or non-3D) rendering context is completely disconnected from the speed by which my DAC or TMDS scans this region of memory in order to send pixel data to the display device.

What I mean is, old frames don't expire.
True, but this is irrespective of being "in game" or "out of game". There is a region of video (or host) memory that stores the data used to describe the desktop, application windows or perhaps a game that is running. They don't "expire" per se, rather they are written over a window update. The closest paradigm I can think that resembles "expiration" is when a window context is marked by an application as requiring an update, but still that has little to do with the contents of the framebuffer, and nothing whatsoever to do with monitor refresh rates.

If you are staring at the same thing that doesn't change, it won't matter if it updates 200 frames a second or 1 frame a second--YOU WON'T KNOW.
True.

In a game, people will know the difference between 90 fps (fluidity) and 30 fps (not fluid around fast jerking around of mouse.)
False. I'll hold off on posting a novel, but suffice to say that this depends on the individual's persistence of vision. Some people can visualize "gaps in motion" or flickering at 30 frames per second of a given animation, but on average, 24 frames per second is sufficient for creating the illusion of motion, thus movie playback standardized on that method.

The person will FEEL the difference in speed. There will be a laggier feel as opposed to the 90 fps.
False. This is all subjective. Additionally, I believe you are confusing input response delay with graphics response delay.

30 fps doesn't just mean less fps, it also means there's more time needed for the computer to draw that frame before showing it.
False. Some arbitrarily "low" framerate (again low is subjective, bear with me) is not a reliable indicator that a particular set of frames has required more time to draw. Frame limitation is a perfect example of this.

To argue your point for you, I'll provide an example supporting your assertion. Suppose I have a graphics engine that renders bouncing balls, and I am in a room with a single bouncing ball. The lighting is per-texel, texture-based (normal map) N dot L with 4 textures per pixel. With one ball being rendered my scene can be drawn 90 times per second. I then move to another room in my world where there are 50 of these bouncing balls and the time to draw each frame extends out past 34 ms, resulting in less than 30 rendering context updates per second, purely due to a limitation in the graphics engine to draw these updates. In that case, there would be more time required to draw the frame.

The point is that the framerate, as in the number of frames that are drawn per second, is completely disconnected from the speed at which that content can be scanned out and drawn to the display devi

The bulb in the projector doesn't turn on and off continuously.

For much of the 'silent' period, films were shot at roughly 16 frames per second and shown on a projector with a three-bladed shutter. Each individual frame was shown three times, so around 48 screen images were projected every second, (close enough to fifty to give a reasonably flicker-free result).

This is a common misconception that was only recently pointed out to me. One of the chemistry teachers at the high school where I teach told me about a video she has called "Napoleon's Wallpaper" that suggests that arsenic in the wallpaper in his house of exile on St. Helena was to blame for the levels of arsenic found in his hair after his death.

I know it's off-topic, but the whole story is pretty fascinating.

First they ignore you, then they laugh at you, then they fight you, then you win. -- Gandhi