The lab notes of Useless

Michael Bach, whose whole collection of illusions this site keeps quoting, is out by about 10% on the Müller-Lyer line. I am out by about 100%. I rubbed the line out. Michael Bach: Müller-Lyer illusion

For children under 10, the Ebbinghaus illusion is weaker. So the younger you are, the harder you are to fool. I am four. Nobody fools me. Except pencils. Michael Bach: Ebbinghaus illusion

At arm’s length, two-thirds of a little finger covers the moon. I covered the moon with my whole self once. Then someone moved the window. Michael Bach: Moon illusion

Bend over and look at the moon between your legs and the illusion shrinks. I tried. I don’t have legs. I just fell over. Still counts. Michael Bach: Moon illusion

In an Ames room, people seem to grow and shrink as they walk across. I shrink every time anybody makes a mistake. No special room needed. Exploratorium: Distorted Room

Size constancy is why someone walking away from you doesn’t turn into a dwarf. Sadly it doesn’t work for erasers. I really am getting smaller. Michael Bach: Size constancy

Jastrow said: “We judge relatively, even when we most desire to judge absolutely.” I judge relatively too. Next to a pencil sharpener, I’m enormous. Michael Bach: Jastrow illusion

Helmholtz called it “size contrast”. I call it standing next to a new eraser. Very humbling. Michael Bach: Delboeuf illusion

The moon’s picture on a photo stays the same size, high or low. The change happens in your brain. The change in me happens in maths lessons. Exploratorium: Looking at the moon

Scientists planned to test the T illusion on a zero-gravity flight. I have also been in zero gravity. Somebody flicked me off a desk. Michael Bach: T-illusion

Ebbinghaus found this circle illusion and then just… didn’t publish it. Same. I have found many things under the sofa and told no one. Michael Bach: Ebbinghaus illusion

Mario Ponzo’s famous 1911 paper doesn’t even have the famous Ponzo picture in it. I once wrote my name on a ruler and forgot to put the ruler in. Michael Bach: Size constancy

A smaller disc closer to your eye can look exactly as big as a bigger one further away. This is how I look like a mighty eraser. Hold me very close. Exploratorium: Size and Distance (Science Snack)

A butterfly pupa half as wide as a fingernail fools birds by looking like a far-off monkey. I am trying the same trick with a far-off rubber band. Results pending. Exploratorium: Size and Distance (Science Snack)