Gravity has its own force generated by mass and it extends as a weak interaction throughout the known universe. Time slows the further away from a gravitational field time slows down. Stand on the earth and time accelerates stand in the vacuum of space and time slows it is clocked in nano seconds none the less it slows. Motion of an object creates friction and entropy for that object whether it is in vacuum field or not. Look at the tail of a comet or a meteorite they burn up their energy and mass a little at a time.
To role a ball continuously would require you get rid of fiction and you would have discovered perpetual motion but that has not occurred at present time. Time is a dimension; you can have time without any forces, but you cannot have time without any forces. Light is a constant speed nether decreasing or increasing, light speed is about 186,282 miles per second. Hope this helps your understanding of things.
Comets are small, easily broken, erratically shaped bodies composed mostly of a mixture of water ice, dust, and carbon- and silicon-based compounds. They have highly oval orbits that frequently bring them very close to the Sun and then swing them far into space back into the Oort Cloud.
Comets have three distinct parts: a nucleus, a coma, and a tail. The solid core is called the nucleus, which develops a coma with one or more tails when a comet approaches the Sun. The coma is the dirty, nebulous cloud around the nucleus of a comet, and the tail extends from the comet and points away from the Sun due to the pressure of the solar wind. The coma and tails of a comet are brief features, present only when the comet is near the Sun.
A comet has two tails―a dust tail and an ion (gas) tail. The pressure of sunlight and high-speed solar particles (solar wind) can blow the coma dust and gas directly away from the Sun, sometimes forming a long, bright tail. As the comet approaches the sun, solar warming causes the comet to outgas more copiously and brightly. It is estimated that a comet loses between 0.1 and 1 percent of its mass each time it orbits our Sun as a result of the sun's actions.
Image below from setterfield.org