The Origin of Nanoscopic Grooving on
Vesicle Walls in Submarine Basaltic Glass:
Implications for Nanotechnology
Figure 4
Interpretation of branching nanogrooves as viscous fingering trees. (a) Drawing traced from a photograph [12] of a very unstable viscous finger of air injected into silicon oil, within a linear Hele-Shaw cell of 10 cm width and 0.25 mm thickness. (b) Drawing traced from a composite image of four photographs [13] of viscous fingers at four different stages of growth, formed by air injected into silicon oil within a sector-shaped Hele-Shaw cell of angle . (c) Drawing traced from a computer generated image [14] showing multiple growth stages of simulated viscous fingers that were produced using an algorithm related to diffusion-limited aggregation. (d) Drawing traced from a close-up view from Figure 1(c) showing 100 nm incremental growth of viscous fingers (numbers), and additional 10 nm incremental growth for all tip-splitting (side-branching) and spreading events, assuming that all viscous fingering trees started to grow simultaneously at constant rates. Examining this growth model in forward motion: finger A undergoes a tip-splitting (side-branching) event at around 650 nm, as does finger B at around 750 nm. The new side-branch produced by finger B stops growing and spreads out into a terminal bulb at around 1050 nm of growth, because finger A has already passed through the region that it is approaching, effectively shielding it from further growth. At 1300 nm, finger A undergoes a final tip-splitting event, after which the main finger in addition to the new side-branch both stop growing and spread into terminal bulbs as they are shielded from further growth by the sulfide spherule.
