2. Why is ice slippery?
Scientists thought that until recently, ice is slippery because the pressure created by stepping on it causes the top layer to melt. However, experiments have shown that this is not the case. So pressure isn’t the reason behind slippery ice.
Currently, the best explanation is that the layer that forms on top of ice is not actually a liquid, but a ‘super solid skin’. This means that the water molecules can stretch without breaking. However, not all scientists agree with this theory.
According to Phys.org, some researchers from Sorbonne University in France were able to demonstrate that the friction on ice generates a really thin layer of water. This water is as viscous as oil and that allows the ice to be slippery.
At temperatures that are below freezing, the watery layer is almost imperceptible for the human eye, because of how thin it is. The same researchers from the lab at the Sorbonne University, determined that the layer of water is thinner than a strand of hair.