Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
One ragweed plant can release as many as one billion grains of pollen!
51
One 75-watt bulb gives more light than three 25-watt bulbs.
57
Approximately 70 percent of the earth is covered by water. Only 1 percent of this water is drinkable.
65
A ball of glass will bounce higher than a ball made of rubber.
73
A 'jiffy' is an actual unit of time for 1/100th of a second!
66
Dr.Jonas Salk, the man who came up with the cure for polio, didn’t patent the drug. This made the drug more affordable to the general public, and he lost out an an estimated $7 billion dollars for himself.
41
Iron weighs more after it rusts.
16