Perpetually ascending staircase.

How can the man go up all the steps and come back to the same place over and over?
(Thanks, Escher...)

                 


                   Did that Escher drawing inspire this one?





        The red squares are the same color
        in the upper part and in the lower parts of the "X"

            The diagonal lines are parallel.


   



   There are no gray spots at the corners of the squares.

               

         The rows of black and white squares are all parallel.

      




                    Impossible Triangle and Impossible circle.

   

                    Parallel lines at sunrise.
   
            

   Impossible cube. (Welder's nightmare.)

         

   The center circles are both the same size.





   The Vertical lines are both the same length.






           Ambiguous Cubes

         

      There are only white circles at the intersections

      

            All the bumps are identical
       The one in the lower middle is upside-down,
       The image to the right is rotating.

              



                Wavy Squares? No!
   The background of concentric circles makes the
   squares appear distorted.





                              Rotating Wheels
       The circles appear to rotate when you move your
       head closer and further away from the screen while
       looking at the dot in the center.

         

      

                  Which way is this dancer spinning?

                   Clockwise or counterclockwise?

                     

    If you strare at it hard enough you can make her reverse direction.
    This is not a joke, you can really see her spin in both directions.



                       Two Words in One Painting

      

                        Warped Square?
         There are no curved lines in this figure.

            

 

    How many columns here?        A simpler drawing of the columns.

                

          Rotating Dot

            If your eyes follow the movement of the rotating pink dot, you will only see one color, pink.
            Stare at the black + in the center, the moving dot turns to green.

            Now, concentrate on the black + in the center of the picture. After a short period of time,
            all the pink dots will slowly disappear, and you will only see a green dot rotating if you're lucky!
            There really is no green dot, and the pink ones really don't disappear.  © 2005 M Bach & JL Hinton

               

    This cube can't decide which way it is oriented.