Blind spots, illusions, and impossible objects make it hard to believe your eyes!

It is impossible for this box to exist! The longer I am in here the crazier I feel. Our brains do not always see what is actually there! This is because of the way our brain perceives and processes information. Check out some of these illusions and Dr. Smith and I will even help you build some impossible objects yourself!

we use our senses to see, hear, and become aware of our surroundings. But our brains can be fooled. Try this. Hang a weight on an end of a string and swing the weight like a pendulum. For the strongest effect swing the pendulum only lightly and keep looking straight ahead. Do not have your eyes follow the pendulum. The pendulum should look like it is traveling a straight path back and forth. Now dim the view through only ONE of your eyes. Dr. SMith is using a pair of sunglasses with one of the shades removed. Be sure to keep looking straight ahead and you will now see the path of the pendulum become circular!
Here are some different classifications of optical illusions:

when we fixate on a pattern, it momentarily remains on our retinas as an after-image. Some theorize that small, involuntary eye movements cause this ghost image to overlap with the image we are fixating on and the result is a vibrating image…
This is a hering illusion. the two red parallel lines appear to be bent even though they are perfectly straight!
This is a hermann grid illusion. the small grayish dots at the intersections are actually not there! Our brain puts them there. The phantom dots disappear though if you look directly at them.
This is a Kanizsa triangle. We perceive a white triangle where nothing is drawn!
A Mueller Lyer illusion is one where inverted arrowheads make a line appear longer when it really isn’t!
This is a Munker White illusion. In this image A and B are actually the same color! Can you believe it? I couldn’t so I took a piece of paper and cut a hole in it and covered up everything else and compared the two colors. They are the same!
Do you have any lego’s? If so, go get’em because Dr. SMith is going to build a penrose triangle which is an impossible object and he is going to use lego’s. First you will need a 10 stud and an 8 stud Lego, four two stud Lego’s and some tape and some sort of weight so your penrose triangle will not fall over when completed. …..When you look at the Lego structure from just the right view your brain sees an impossible object, a Penrose triangle! The first thing you have to do is draw a large equilateral triangle ; Next draw small equilateral triangles at each corner; Now join these equilateral triangles with lines that are parallel to the first triangle you drew; Do you see the innermost triangle? the last set of lines you need to draw are three lines parallel to this innermost triangle. Now we are all done drawing lines, we just need to start erasing. The first thing Dr. Smit is erasing are the small outside triangles, then he erased the lines necessary to create the final image to figure out which lines these are just compare your drawing to the final image! To make the illusory effect stronger, Dr. Smith is now going over all the lines with a marker. He is now going use a scissors to cut out the center triangle and the outside border to create his “Verrastro Impossible triangle!”
A mobius strip has only one side. let’s make some mobius strips and do some experiments with them. The results are surprising because we are not used to working with single sided objects!

Dr. Smith is first going to cut two ¼ strips from a single piece of paper. He is then going to tape them together to make one long strip. Next he is going to tape the two ends of the strip together but first place a single twist in the paper before taping. The resulting object is a Mobius Strip!
In our first experiment, lets draw a single line down the entire Mobius strip. Where do you think you will end up? We end up right where we started!

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