[LinnieBeth]

To those who claim van der Waals forces are too weak, Diogenesis suggests you examine the energy under the curve of force x distance.

Huh? What's that mean Diogenesis?

[Fudd]

Huh? What's that mean Diogenesis?

It means van der Waal forces are only noticable over rangers of ~100nm and less. If you have two atomically smooth surfaces in contact, you'll get VDW attraction. If you have two bumpy surfaces in contact, VDW will only occur at the asperities (high points). Gecko's foot allows close conformance to surface, getting enough VDW to let gecko climb walls.