[PeteB570]

Would it not be the same for the laser?

You fire a three second laser pulse and you have that 3 second length of laser beam continuing thru space until it hits something? Granted after a few light years it may be dissipated?

[Laserman]

Due to diffraction the beam will spread out over long distances. Within relatively short astronomical distances the intensity will be below eye safe levels.

[Pontiac]

True but a laser pulse would get out of the neighborhood a lot faster.