In order to make the athletic shoe to slide faster of a given surface you had to reduce the friction coefficient of the shoe with the surface.
One way to do that is to put some grease of the sole of the shoe, which undoubtedly would reduce the friction coefficient drastically and the shoe would slide more easily.
Also, if you make the sole smoother the shoe the friction coefficient would decrease and, again, the show would slide mor easily.
Answer: yes time is real because though everything is relative to gravity they mean material things while time isn't a material thing making it different from gravity and leaving it as its own entity.
