#Jiggle, jiggle…
What, you don't own several seismographs tuned to various frequencies? 🙂
A few ideas come to mind: waht was the outdoor wind speed when it started to
rock? Is there a floor above this room? Do you know how the walls were
fastened to the concrete slab? (Over time, wood might shrink or bolts might
loosen.) How cold was it outside? Can you move the trophy to another place,
return it, and the effect continues? Can you rock the trophy by hand at
various rates to reproduce the effect?
I've always maintained that people who see ghosts believed in ghosts before
they ever saw a ghost.
On the other hand, I've witnessed a few events in my life that tested my
beliefs. I attribute them to either thermal or vibrational effects. One, I
was sitting in a booth at a bar. My beer bottle was in front of me on the
table. I put both hands down on the seat and scooted to the right and my beer
bottle followed me, moving about six-eight inches down the table. I had
witnesses, and we weren't drunk. 🙂 Another, an ordinary drinking glass was
sitting on the counter in another room suddenly exploded, shattering into tiny
1/2 inch pieces, perhaps an hour after it had been washed. Another, a bowl of
chili jumped about two inches off the table when I set it down and sat in front
of it. In this case, it was one of those layered, Thermos-like bowls, so there
was plenty of potential for thermal stress and rapid release.