Published on May 12, 2017
This juggling ball is normally black,. but if you pick it up, it starts changing colour! The surface of the ball contains a thermochromic pigment, and this reacts to heat. Basically thermochromic materials change colour as the temperature changes.
Mood rings are a fun application of the same idea, and there are practical applications like having a baby’s bottle that changes colour when the contents are cool enough to drink.
