Brownian Motion: Pollen and Red Ink in Water

AI Thread Summary
Brownian motion can be effectively demonstrated using pollen grains in water, as they exhibit random movement due to collisions with water molecules. In contrast, red ink may not be suitable for this demonstration unless it contains larger pigment particles. The solubility of red ink and its density compared to water raise practical concerns for its use in illustrating Brownian motion. The key concept is that Brownian motion indicates the presence of molecules in a fluid, with larger particles like pollen being observable. Overall, pollen grains are a practical choice for demonstrating this phenomenon in a liquid medium.
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The brownian motion setup using smoke and air particles represents and allow us to conclude that gaseous particles move randomly (in any direction).

Is there a setup using other particles and another fluid instead of smoke and air to represent the movement of liquid particles?

1) Can we use Pollen grains and water? Or Red ink and water?
2) Is the choice of pollen grains practical? For e.g. solubility of red ink/ movement of red ink in water or the density of pollen grains compared water?
 
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Brownian motion is usually taken to indicate that matter consists of molecules. There is one big particle like pollen or a smoke particle that is observed to move randomly in what appears to be an indivisible fluid. The explanation for the random motion is that the indivisible fluid is actually made of molecules.

So pollen grains would work, but ink probably wouldn't (unless it has big grains of pigment).
 
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