Click For Photo: https://i.dailymail.co.uk/1s/2019/05/24/14/13912524-0-image-a-58_1558705045591.jpgClick For Video: https://videos.dailymail.co.uk/video/mol/2019/05/24/6893640199746506159/1024x576_MP4_6893640199746506159.mp4
Towers of stacked tennis balls built in gravity-defying shapes have been created by a physicist without the use of tape, glue or any other adhesive - just friction.
Professor Andria Rogava of Tbilisi, Georgia, built the towers in his office, finding that friction and balancing forces alone can keep the bizarre structures upright.
Tower - Balls
He has even succeeded in creating a thin, nine-story tower made up of just 25 balls — and could go higher still.
Professor Rogava described himself as a 'keen tennis player' and told Physics World: 'In my office, I have about 20 used tennis balls and so decided to try building some tennis-ball "pyramids".'
Pyramid - Base - Balls - Layer - Ball
Initially, he created a four-level pyramid with a triangular-shaped base, with ten balls in the bottom layer, six in the next, then three and finally one ball at the apex.
'When I carefully removed the three corner balls from the bottom layer plus the upper-most ball, I ended up a with a beautiful, symmetric structure of 16 balls with three hexagonal and three triangular sides,' Professor Rogava explained.
Balls - Layer - Remain - Equilibrium
Despite appearing precarious, the over-hanging balls in the second-to-bottom layer remain in equilibrium.
'These exposed balls are held in place because the balls directly above press down on them and into the two adjacent balls of the bottom layer, producing a pair of reaction forces to balance their weight,' Professor Rogava explains.
Torques - Friction - Balls - Equilibrium
'The torques are balanced too, with enough friction between the felt-covered balls to guarantee equilibrium,' he added.
The fact that this structure could support itself left the physicist 'intrigued' as to what else he could build.
Four-layer - Pyramid - Corner - Balls
Next, he recreated the original four-layer, 20-ball pyramid and removed all the three corner balls in the...
Wake Up To Breaking News!