Humor, for engineers only. Most of this has been around for a while, but it is fun to take a break with it.
Write a Computer Science paper in less than a minute
This link allowed you to generate a complete, new, official science-y looking paper, with charts, references, etc, with the push of a button. Site appears to have been archived, but may still work for you.
Some black = white proofs to make your head hurt.
A dirty story. Annotated!
Engineers are pretty smart, right?
Mathematical Triangles Illusion
Every mechanical engineer should know this one
Don't go here unless you have some time. But if you do - GEEK OUT!
From those zany fellows who brought you internet protocol IPv6, the Internet Engineering Task Force.
Timelines for Organic Development of SPICE models
Use of Agile Development Methods in Suspension Bridge Construction
Ask someone who has done Agile development why there is no link for this one.
To expand your mind.
Here is a file you can use to make a paper dragon whose eyes will appear to follow you around the room, if you close one eye. Pretty cool. Print it out, cut it out, tape it up. It's fun.
Cover one eye to see the effect up close, which is very powerful, as shown in this video. Then open both eyes, and move away from the dragon until you see the dragon's eyes follow you around again. This is your stereoscopic vision range. When the dragon is beyond this distance, which is about 10-15 feet for most people, it will again appear to follow you as you move. At that distance, your brain must switch to another method to determine range. See if you can detect the process change.
This is also part of why 3D movies might make you sick. Lemme esplain...
Your brain has three principle ways of estimating an objects distance:
stereoscopic vision, which depends on the different view of each eye. It works up to about 10-15 feet. You can find your range using the dragon above.
Perception of the relative movement of two objects as you change your point of view. Closer things move more than things farther away. Head movement always plays a major part in determining an objects distance from you and other objects. That's why people always move their head side to side when looking at a distant object - they are unconsciously using the change between two views to calculate the distance. Hunting animals do this too, watch for it during the next nature film.
Perception of the relative orientation of "known" reference points on an object. If you "know" it's shape, then you know how it will change as you change your viewing angle. This is how the dragon fools you. It is not the shape of a conventional face, so you make erroneous assumptions about it as you move. Your stereoscopic vision can override this. But if you are too far away, this does not work well enough, and your brain switches to #3.
It is very hard to overcome our belief in what the orientation of the features on a face is. This may even be hard wired in our brains. Here is a nice video on sculptures that use your knowledge of typical object orientations to fool you: Impossible 3D sculptures.
Ok, ok, there is a fourth method. You also use knowledge of the typical size of objects. A car is bigger than a bird, so the car is farther away if they look the same size. But this must be in the absence of other ranging cues, which is very rare in real life.
When you watch a 3D movie, the movie 3D system only uses your binocular vision to create an objects apparent distance. Each eye sees something slightly different, and your brain automatically calculates the relative distance from you of each object.
In actuality, The screen itself is flat, all images are at the same distance. If you move your head slightly, which is a natural reaction when you see something "at a distance", your brain must figure out what to believe. Your binocular vision tells you that the objects are at different distances, while your head movement tells you they are at the same distance. This can break the 3D effect, and really tire your brain out, or make you sick. Just the fact that your binocular vision has suddenly started working at much greater apparent distances than you are used to could be enough to bother you, because of #3 above.
Oh, and 3D movie objects at a distance beyond your binocular visual range is will appear to be at different distances, but flat. I will leave this the explanation of this effect as an exercise for the reader.
Rx: Keep your head still during a 3D movie.
There is another technique available to project 3D images using #2 above, Musion Live Stage telepresence . It projects images on a transparent reflective mesh, which is hung at an angle relative to the stage. It will not fool your stereoscopic vision if you get close. But it projects an object in space, that can move forward and backward, and has relative features like a body or car. You head movement can decipher that the object is actually at a point in space with dimensions, as long as it is beyond your stereoscopic range. So it works for stage shows (greater than 10-15 feet) just fine. It is how the cartoon characters in Gorillaz appeared live on stage, and even interacted with Madonna as she danced around at the Grammies one year.
This is an example of fooling the natural ranging we do by using head movement, but would not fool our stereoscopic vision. This is why some magic tricks can be figured out just by moving within a few feet of them (hey! those aren't really the same size! and this is inside out!). As long as the audience is 15 feet away, stays in their seats, and the performance stays in one spot, the visual cues will totally fool you.
Also - I think (and this is just me) that stereoscopic vision has something to do with fear of heights.
When looking at objects below you, your stereoscopic vision works until about 10-15 ft. I believe that fear of heights is linked to the loss of stereoscopic vision - when you are high enough that it is no longer effective, your ability to judge distances becomes less accurate, and you become wary. Without references, you don't know how high you are. Could be 15 feet. Could be 100. Brain decodes infinity, danger. Just an opinion, no science behind it.