# Why have scientists accepted that Brownian motion is caused by collisions with water molecules?

Colloid (sol) particles have a diameter between 1 and 1000 nanometers, approximately. If a sol particle, 275 nm in diameter, were compared to a water molecule, 0.275 nm in diameter, it would be 275 / 0.275 = 1000 times the diameter of a water molecule. Since volume is a cubic function of diameter, the sol particle would be 1,000,000,000,000 (one trillion) times the sol particle's volume and therefore, one trillion times its mass (Patterns in Fluid Flow Paradoxes., 1980; pp. 73-74 and Simple Harmonics, 2015: pp. 16-17, by G. Hamilton).

Sir Isaac Newton would roll over in his grave if he heard that modern scientists accept that which defies his principles relating to momentum exchange physics.

Furthermore, Brownian motion has been related to thermodynamics. Motion created in fluids by heat results in convection currents with gently curved paths, not abrupt sharp zigzag changes in direction.

• Don't read Newton. Read Einstein (1905). His paper and thesis treated this very model and that's what explained the drunken walk of pollen grains and colloidal suspensions alike in experiments that followed. Many 'apparent' paradoxes in physics - either missing or wrong information. Commented Jun 29, 2017 at 20:00
• -1 for your pretentious way of asking a question. Before assuming that all scientists are stupid, please consider the possibility that there's something that you may have misunderstood.
– pela
Commented Jul 3, 2017 at 11:20

What makes you think that you can assume that the density of a colloid particle is comparable to that of a water molecule? In other words, why do you think that the density of bulk water is the same as the density of a water molecule? Why not actually compute the mass of such a particle and compare it to the measured mass of a water molecule; you get a very different mass ratio (circa $10^9$ rather than $10^{12}$).
Then take into account the speed of water molecules (hundreds of meters per second) and the speeds for the colloid particles that can be observed in a optical microscopic (circa $\mathrm{\mu m/s}$); that makes the ratio of speeds on order of $10^8$.