Just yesterday I had a CO2 valve close on me during an experiment while I was away for a moment. It takes effort to turn the valve so it couldn't have just shaken closed or something. The valve was in the corner of the room and was blocked off by boxes, so nobody could have accidentally bumped it. And, besides, nobody was in the room anyways. Before the experiment I made damn sure that the CO2 valve was open, and even looking through the computer records (which records the CO2) says that the CO2 valve was open until I walked away.

I still have no idea how the valve could have closed on its own. Now, I'm not saying it's a ghost, but I am saying that I cannot think of a single non-paranormal explanation. I've clearly angered the science gods and I would do well to sacrifice some more cells to the science gods to appease them