冰刀在冰面上滑行的物理机制

       为什么冰面那么滑，冰刀可以在上面尽情飞驰？下面就是标准的答案。其英语原文摘自维基百科，本人作了粗浅的翻译。

Physical mechanics of skating
滑冰的物理机制

A skate can slide over ice because the ice molecules at the surface cannot properly bond with the molecules of the mass of ice beneath and thus are free to move like molecules of liquid water. These molecules remain in a semiliquid state, providing lubrication.

       冰刀能够在冰上滑行，是因为表面上的冰分子不能够与其下面的冰块稳妥结合，从而像液体水分子一样可自由移动。这些分子保持在半液态，起着润滑作用。

It had long been believed that ice is slippery because the pressure of an object in contact with it causes a thin layer to melt. The hypothesis was that the blade of an ice skate, exerting pressure on the ice, melts a thin layer, providing lubrication between the ice and the blade. This explanation, called

"pressure melting", originated in the 19th century. This, however, did not account for skating on ice temperatures lower than −3.5 °C, whereas skaters often skate on lower-temperature ice. In the 20th century, an alternative explanation, called "friction heating", was proposed, whereby friction of the

material was causing the ice layer melting. However, this theory also failed to explain skating at low temperature. In fact, neither explanation explained why ice is slippery when standing still even at below-zero temperatures.

         长期以来人们相信，冰面之所以滑，是因为与之接触的物体压力融化了一薄层（冰）。该假设是这样的，冰刀刃在冰面上施加压力，融化了薄薄一层，在冰和刃之间起到了润滑作用。这种解释，被称为“压力融化”说，起源于十九世纪。不过，这个学说与 −3.5 °C以下的冰面上滑冰对不上号，而滑冰者则经常在更低温度的冰面上滑冰。二十世纪，有个不同解释被提了出来，称之为“摩擦热”说，根据其说，是物质的摩擦在造成冰层的融化。然而，这个理论也无法解释低温下滑冰的情况。事实上，（这两个理论中）哪个都没有解释清为什么甚至在零度以下站立不动时冰面仍很滑。