Question

How is it possible to skate on ice without leaving any trail behind

Answer 1

How is it possible to skate on ice without leaving any trail behind

Answer 2

No, you will always leave behind a trail, it might be faint but its there.

You see for a skater to glide across the ice, the skater/blade must over come the static (standing) coefficient of friction. This static coefficient of friction and moving coefficient of fiction (which is always less then static friction) generate energy or heat, this heat generated instantly melts the ice as a skater travels. But because the ice and the refrigeration unit under ice, after a skater passes on, the section on which they just skated on, refreezes!