In The Conscience of the King, we see Kirk take a phaser on overload and drop it in some kind of emergency waste disposal which dumps it off the ship.
Here's a screenshot, I couldn't get one that makes out the words on it.

Nice and convenient.
Other than being used for phasers on overload, can anyone think of a valid use for this? Isn't it a bit like throwing empty beer cans out of your car window? Do people in the future still litter in space?
After watching this scene again, I noticed a few other issues:
1) How did the phaser get put inside the red alert lighting box? The scenes immediately before this show Kirk, Spock and McCoy talking in Kirk's quarters. There is a scene break and then it's Kirk and Spock talking when all of a sudden we hear the hum of the phaser on overload. Since it's inside Kirk's quarters, someone must have placed it there when nobody was around. Then, apparently it must have some type of time delay setting before the overload starts. How did the killer (Karidian's daughter) know exactly when Kirk would be in his quarters in order to set the overload for when he was there?
2) When Kirk and Spock first hear the hum, why do they tear apart Kirk's quarters looking for the phaser? At least Spock's sensitive hearing should have been able to pinpoint the general location of the humming noise.
But...yeah...having that garbage-disposal-out-into-space was really a life saver!
Here's a screenshot, I couldn't get one that makes out the words on it.

Nice and convenient.
Other than being used for phasers on overload, can anyone think of a valid use for this? Isn't it a bit like throwing empty beer cans out of your car window? Do people in the future still litter in space?
After watching this scene again, I noticed a few other issues:
1) How did the phaser get put inside the red alert lighting box? The scenes immediately before this show Kirk, Spock and McCoy talking in Kirk's quarters. There is a scene break and then it's Kirk and Spock talking when all of a sudden we hear the hum of the phaser on overload. Since it's inside Kirk's quarters, someone must have placed it there when nobody was around. Then, apparently it must have some type of time delay setting before the overload starts. How did the killer (Karidian's daughter) know exactly when Kirk would be in his quarters in order to set the overload for when he was there?
2) When Kirk and Spock first hear the hum, why do they tear apart Kirk's quarters looking for the phaser? At least Spock's sensitive hearing should have been able to pinpoint the general location of the humming noise.
But...yeah...having that garbage-disposal-out-into-space was really a life saver!
