Gravity Defied: Iron-Coated 'Sand' Defies Laws of Physics in Mind-Bending Experiment

Scientists from Lehigh University have developed a sand-like material called microrollers, which can flow uphill when subjected to a rotating magnetic field. The particles, coated in iron oxide, exert a twisting force on each other and overcome obstacles against gravity. This phenomenon, referred to as a negative angle of repose, is caused by a negative coefficient of friction that boosts movement. The researchers believe this discovery could have various applications, such as controlling substance mixing or separation and in microrobotics for drug delivery. Further research will focus on exploring the particles' ability to climb obstacles.