Observation and Perception

"Who are you going to believe, me or your lying eyes?"
--Groucho Marx

Something Strange

Something a bit strange happened at the beginning of class on 9 September To see what you reported, click here.

  • Idea from the American Bar Association
  • Eyewitness testimony is compelling, emotional evidence in the courtroom, but scientifically it is the WEAKEST form of evidence. Witnesses can be completely sincere, completely sure of what they saw, and completely WRONG!
  • Race and ID
  • How far is it from the south steps of Dallas Hall to the flagpole?
  • What coin held at arm's length will cover the full moon?

Audio Illusions

McGurk Effect video/audio; Wikipedia entry

Top 10 Incredible Sound Illusions

Optical Illusions

Be aware that your brain may misinterpret the input from your senses.

Blind spot

Quick! What is this?

Ugly face illusion

The Lurking Pornographer

Square illusion

Can you believe your eyes? (7 TED talks)

Brain Games: Watch This! Color or greyscale?

Dale Purves' neuroscience lab demonstration of perception



Kurt Wenner Street Painting
3-D Rooms
3-D Outdoors
Dancer - clockwise or counterclockwise?
71 Optical Illusions & Visual Phenomena by Michael Bach
Optical Illusions - from YouTube
Contact Juggling from YouTube
The Break of the Curveball
Charlie Chaplin Optic Illusion
Sea Sickness
The blue and the green - TOTALLY AWESOME!
This Can't Be Happening
50 Amazing Examples of Tilt-Shift Photography - Tilt-shift photography is a creative and unique type of photography in which the camera is manipulated so that a life-sized location or subject looks like a miniature-scale model.
Your Lying Eyes: Can This Be Happening? NPR looks at Kokichi Sugihara's illusions
Lennart Green: Close-up card magic with a twist
Real World MC Escher Waterfall
Real World MC Escher Waterfall Explained

What are you assuming?

One must observe carefully, without jumping to conclusions.

Have your professors ever seen a UFO? You bet! Lots of times!
Have they ever seen a flying saucer piloted by aliens? No.

    Three scientists were on a train, and had just crossed the border into Scotland. A small flock of black sheep were grazing on a hillside.

    The biologist peered out of the window and said "Look! Scottish sheep are black!"

    The chemist said, "No, no. Some Scottish sheep are black."

    The physicist looked irritated. "My friends, there is at least one field, containing at least one sheep, of which at least one side is black some of the time."

Paradigm Shifts

A "paradigm" is a world view or perspective formed from known theories. It is the set of assumptions that you carry along.

The paradigm shifts as new evidence leads to new theories.

Once, the Sun (and everything else) went around the Earth.
Once, it was moral to burn women at the stake because the corn failed.
Once, disease was caused by demons and bad air.
Once, the continents of Earth were fixed in place.
Atoms are only 100 years old.
If humans were meant to fly...


Definition of pareidiolia from the Skeptic's Dictionary:
    A type of illusion or misperception involving a vague or obscure stimulus being perceived as something clear and distinct. For example, in the discolorations of a burnt tortilla one sees the face of Jesus Christ. Or one sees the image of Mother Teresa or Ronald Reagan in a cinnamon bun or a man in the moon.

Check out this image on a grilled cheese sandwich. Here's a marketing opportunity; make the waffle iron plates in the shape of some religious figure instead of Mickey Mouse.

The famous Nun bun.

Lenin on a shower curtain from Philip Plait's Bad Astronomy subpage.

Lots more, from the The The Pareidolia Project.

Penn & Teller on Miracles, Pareidolia, & Wishful Thinking | Yoism

The Face on Mars

    Look at the "face" as first seen in a 1976 Viking orbiter image.


    Now look at a much later image from Mars Global Surveyor and see what the face really is.


    Image recorded during orbits 3253 and 1216 by the High Resolution Stereo Camera (HRSC) on board ESA's Mars Express. Image is based on data gathered over the Cydonia region, with a ground resolution of approximately 13.7 metres per pixel. Cydonia lies at approximately 40.75° North and 350.54° East. When the surface details are just below the resolution capability of the camera (Viking), the proper Sun angle produces shadows in the surface feature that make it look spookily like a face. Mars Global Surveyor, with a camera far superior to Viking, shows the truth.

    Late in 2006, the ESA Mars Express spacecraft orbiting Mars once again explored the "face." Its camera is even better than the one on Mars Global Surveyor, which went silent in late 2006 and is presumed lost. Mars Express resolved even more detail on the feature. Click the link below for the latest image. Does it still look like a face?


It doesn't take much to make the human brain think of a face. ;-)