Hiding in the brush, the leopard was not seen by the hunters.
this sentence contains a
participle, incorrectly punctuated
participle, correctly punctuated
a dangling participle
gerund, not a participle

The sentence here contains a participle that is correctly punctuated. We have the phrase hiding in the brush which is our participle, and it clearly defines what the leopard was doing. Its is properly punctuated as the comma was necessary before the words, the leopard or else it would become improperly punctuated.

The big bang theory suggests that the universe is constantly expanding and that stars, galaxies and other entities are moving away from each other. if there were a galaxy moving closer to earth then that would contradict the big bang theory since the entities should be moving away from earth and from each other.