I Believe the Hole Thing
CAN This Be True?
The most ordinary things are to philosophy a source of insoluble puzzles.
- Ludwig Boltzman
If you can't figure it out and want the answer, email me at firstname.lastname@example.org. If you have a fast connection, you can find the answer if you go to Brain Games and click on the Quiz "The Hole Thing". When you click the "submit" button in the bottom right-hand corner, the answer page appears with the answer on it. (You might even want to take the other quizzes in the series there...)
A Similar Version
The diagonals of the blue shape and the green shape (and likewise of the red and the orange) in the 5 x 13 figure look like they match up, but they actually don't. There is a narrow gap between them, too narrow to see easily, but when it's added up over the length of the 5 x 13 figure, it amounts to the missing square. The slope of the bottom of the blue shape is 5/2 = 2.5; the slope of the top of the green shape is 8/3 = 2.666....
At x=5, for instance, the blue shape's y=2, but the green shape's y=5x3/8=15/8. The 1/8 difference between 2 and 15/8 is the gap which accounts for the difference. (hide)
The bottom four sites above are all elsewhere in this section if you really like taking tests. In other sections are:
Can You Find 9 People in This Picture?
Source: visionsfineart.com "General's Family" by artist Octavio Ocampo
Source: visionsfineart.com "Forever Always" also by artist Octavio Ocampo
Shades of Grey
"Sixteen equiluminant circles on a luminance staircase. This pattern was created on a CRT display with a computer-controlled instrument. Each rectangular area in the staircase is of a fixed uniform luminance. The luminance of the circles - all of which have the same lumlnance - is the same as the mean luminance of the staircase." [From Contrast Sensitivity]
Source: Science Volume 264 22 April 1994
Fun with Afterimages
Source: the web again
Source: www.thesun.co.uk sent to them by Amit Kakkad
Pink (and Green?) Spots
If your eyes follow the movement of the rotating pink dot, you will only see one colour, pink. If you stare at the black + in the centre, the moving dot turns to green. Now, concentrate on the black + in the centre 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! It's amazing how our brain works - there really is no green dot, and the pink ones really don't disappear. This should be proof enough, we don't always see what we think we see...
I couldn't believe there was no green dot, so I slowed the animation down to one frame per second. Click below to view...
Click to Play
For more articles, tests, film studies and visual amusements click the "Up" button below to take you to the Table of Contents for this Intellectual and Entertaining section.