Brownian motion is caused by the impact of fluid molecules or atoms in rapid and random motion from heat on small particles suspended in the fluid. Brownian motion, which tends to disperse particles as widely as possible, is the major force in diffusion. Brownian motion occurs in small suspended particles, regardless of any overall movement or current in the suspending fluid.Continue Reading
Brownian motion was first noticed and described by botanist Robert Brown in 1827 while observing the movement of pollen grains in still air. His initial thoughts were that the movements were caused by some self-powered movement of the plant sperm, but later experiments showed that the motion occurred with dead and even inorganic particles. Robert Brown never came up with a satisfactory explanation for the motion.
The current explanation was first offered 50 years later with the kinetic theory of heat, which stated that heat was actually the random vibration of the atoms and molecules that composed a substance. These random movements within a fluid hit suspended particles rapidly and randomly, producing motion. This theory was initially resisted, as it seemed to violate the tendency of energy to degrade, with friction always converting motion into heat. Nonetheless, experiments confirmed that this is, in fact, the mechanism of Brownian motion.Learn more about Particle Physics
According to the kinetic molecular theory, particles in a gaseous state, whether in the form of molecules or atomic gases, are in constant, straight-line motion, occasionally bouncing off each other in perfectly elastic collisions which change their direction without slowing them down. It depends on a number of assumptions, such as the idea that the particles are very small compared to the space between them.Full Answer >
A sensor is a device that can read and measure input, such as heat, motion, pressure and moisture, from its physical environment and output the results as readable data. Transducers, such as antennas, stereo speakers and thermostats, convert one kind of energy to another. Some devices have both sensors and transducers.Full Answer >
Smoke is defined as a colloid, which is any substance consisting of particles substantially larger than atoms or ordinary molecules. However, these are too small to be visible to the unaided eye. It is a suspension of solid and or liquid particles in the air.Full Answer >
Heat conduction is the transfer of internal energy (microscopic kinetic and potential energy) from a region of higher temperature to one of lower temperature by the interaction of particles like atoms, molecules, ions or electrons in the intervening space. Conduction can only take place within an object or material or between two objects that are in direct or indirect contact with each other.Full Answer >