Brownian motion and the Einstein relation

A pollen grain jiggles under molecular bombardment; the mean-square displacement grows linearly with time with D = kT/6 pi eta a.

About this experiment

What you do in the lab

Change the controls and watch the physics behave in real time in 3D. Live readouts and graphs show the numbers behind it, and the Learn tab has the theory, procedure, observations and viva questions. Works on a phone or a laptop, in English and Hindi.

Topics: Brownian motion · diffusion · Einstein relation · random walk

More from this chapter

• Degrees of freedom and equipartition of energy
• Boyle's, Charles' and Gay-Lussac's law with molecules
• Kinetic theory: pressure from molecular collisions
• Maxwell speed distribution
• Mean free path and brownian motion