Earth & climate · the experiment
Fill the jet's first drop
A bubble bursts at the surface of algae-laden water, a jet shoots up, its first drop flies off. Load the water with algae and find the moment the drop is full.
1 · Load the water with algae
Beginner
What concentrates the algae in the jet's first drop?
Chlamydomonas, radius 4 µm. Raise the concentration and find the one where the first drop's enrichment starts to fall.
2 · Saturate the drop
Past the turning point, the drop is full: the enrichment is 1.7 × 10⁻⁴/(r³ C), where r is the cell radius and C their concentration in the water.
Intermediate
At ten times the turning-point concentration, what is the enrichment?
3 · Switch to Ostreopsis
Ostreopsis, the toxic alga of the Basque beaches, has a radius of about 18 µm, four and a half times that of Chlamydomonas.
Expert
From what concentration does its first drop start to saturate?
Check it: with Ostreopsis, find the concentration where the enrichment starts to fall.
4 · Double the concentration
The drop is full: we are past the turning point.
Expert
If you double the concentration again, the number of cells in the first drop…
Drop filled
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