A laser beam is emitted on earth (event $A$ ), bounces off a mirror placed on the moon by Apollo astronauts (event $B$ ), and then returns to a detector on earth (event $C$ ). The detector is $12 \mathrm{~ns}$ of distance from the laser.
-(c) Events $A$ and $C$ are definitely causally connected.

Question

Quizplus · Accepted Answer

Events $A$ (emission of the laser beam) and $C$ (detection of the laser beam) are causally connected because the detection of the laser beam (event $C$) is a direct consequence of its emission (event $A$). The fact that the laser beam was emitted is the cause of its detection upon return, establishing a clear cause-and-effect relationship between these two events.

A Laser Beam Is Emitted on Earth (Event AAA ), Bounces Off a Mirror Placed on the Moon by Bounces

A Laser Beam Is Emitted on Earth (Event $A$ ), Bounces Off a Mirror Placed on the Moon by Bounces