Algodoo

Yup, you got it! No magic at all!!!!

That's a bird?????

Yes, I plan on making more over the next few days (if I can squeeze some free time between my X-ray repair jobs!).

Much more realistic than other Slinkys on Algobox. Very nice job!

Thanks Faytree! No, I did not invent this illusion. I find illusions on the web and make Algodoo scenes with them. Some are easy to make and some are quite difficult.

If the thumbnail picture shows black and yellow squares instead of black and white, it's because the first time I uploaded this scene, the right square was yellow. But I realized that I can get a much stronger effect by making the right square white, and so I changed it. After editing and uploading the scene, I noticed that the thumbnail from the original scene was still being displayed on Algobox.

faytree - Yes, I see that the thumbnail is now correct. It must take a while for the thumbnail to update after editing a scene.

s_noonan - Both of our equations give the absolute value of the sine function, but yours is more efficient because it doesn't use exponential functions. I didn't think to use the "+ 1.0" for getting rid of negative values, but I will in the future! Thanks!

That's easy! I won't give the answer here, just a hint: The red arrow points the way!

I have a hard time believing that an 8 year old child created this scene. But if he is that good, then I agree with electronicboy that he should have his own algobox account. But if faytree did most of the design and work on making this scene, then the 8 year old brother should wait until he is older and can do the basic steps of designing, creating, testing, and uploading scenes to Algobox.

Just my humble opinion.

Is this supposed to do something?

Much too laggy. Maybe all that water is the cause?

PacSine - You are entitled to your opinion, and you gave it. Thanks.

Okay. I guess I was confused by the red and green houses. I couldn't figure out what they were there for. And your instruction: "Enter on green" was confusing too. It would have made more sense if you would have said: "Press the Enter key when you see the lights turn green". I still don't know why you have those red and green houses (or whatever they are), but at least now I know how to start the race! Thanks. It's pretty cool!

Thanks, s_noonan! Yes, I believe that it works because our brain makes assumptions about what it sees. Rather than seeing two distinct paths (one square and the other circular) we assume that the balls are bouncing off of each other, causing irregular motions. The motions become resolved when we are allowed to see the actual paths with tracers.

Nice effect. Simple, yet elegant!

I can drag the puppets with the black circles (not silver), but I do not understand the part about making movies. Please explain more about how to use those three selections to make movies.

After a few seconds I feel like I'm flying through the galaxy in a spaceship. AWESOME!

I never heard of Bessel and airy points before. Interesting. But the beam on the right does not follow with your explanation. That is, the end faces are not perfectly vertical when the scene is started. Am I misunderstanding this?

What do you mean by "height of red ball"? It appears that the laser is measuring a vertical displacement of the top of the ball rather than the height of the ball off of some reference point. Please explain.

I tried your experiment, and now I see your point. Thanks!

That's pretty gross, Steve!

Nice job!

What is BSOD?

You and faytree must be brothers.

K and S ---- Yes, I realize they are not "perfectly" the same size. Part of the problem was because I'm not very skilled at cutting out textures, and the other problem was, I needed to get the exact height to width ratio of the box. It had to match the original dimensions of the background of the picture. If it was not exactly the same, then the mona lisa image would not have the exact same dimensions as the original.

S -- Thanks for all your suggestions! They are very good, and I appreciate them, but I'm not going to bother making any changes. The scene is "good enough" as it stands, and if not too picky about being "perfect", it does demonstrate very well how your brain can be fooled by perspective. Be my guest if you would like to improve it!

Thanks again, guys.

Um, sorry s_noonan, but my scene is much more impressive BECAUSE of the fact that my two pictures look totally different until you merge them together (that's the point of the illusion!). Your two pictures look almost identical whether they are separated or moved together. Your Thyme script was nicely done, though.

EDIT - I feel kinda dumb because I didn't get the joke until a few minutes later.

Not bad! I think it would look awesome if you were to make the body and head solid, and gave it a texture so that it looks like a real dinosaur.

OH DARN! Thanks for letting me know because the scene of course works like it's supposed to on my computer. I'll fix it. THANKS!!!

s_noonan -- Please check it out again and see if all 13 animation frames were saved. THANKS!