This achievement can be obtained at the beginning of chapter 24 but, you have to play all the way through chapter 23. NOTE: You cannot just load from chapter 24 to get this achievement the Vending Machine will not work correctly.
Directly after completing Chapter 23 as you walkthrough the door a vending machine will be on your left. Simply hit the button on the Vending machine it will close the sliding doors and spawn something inside. You want to do it until a cat spawns in the room behind you. Every time you open the door it has a chance of spawning the Schrodinger's cat. I was able to get it with two button pushes but it might take you longer. Keeping going until the achievement pops.