2 answers
Oh là là, I think I have an idea
If the vase doesn't move too much, what could be doable is to pre-break it, glue it back with a very weak glue (just so it doesn’t fall into pieces), inflate a balloon inside, and at the right moment, trigger a mechanism that would pop the balloon with a needle. The force of the explosion would cause the vase to shatter again.
If I find something better, I will post again, but as a first response, this is the best I can come up with for now, and it’s just hypothetical.
Good luck
If the vase doesn't move too much, what could be doable is to pre-break it, glue it back with a very weak glue (just so it doesn’t fall into pieces), inflate a balloon inside, and at the right moment, trigger a mechanism that would pop the balloon with a needle. The force of the explosion would cause the vase to shatter again.
If I find something better, I will post again, but as a first response, this is the best I can come up with for now, and it’s just hypothetical.
Good luck
Otherwise, there might be a sudden change in temperature (like going from -10°C to 30°C), but that would be quite complicated.
Otherwise, there might (again a hypothesis) be the possibility of placing the vase on a hot plate with a little water inside and sealing the vase, and at some point, the pressure should cause the vase to burst. This solution is more likely to work but is harder to control.
Otherwise, if you want to go big, get a block of alkali metal (lithium, sodium, anything in the hydrogen column of the periodic table) that is pure, fill the vase with water, and just before the time, drop the alkali metal in and get away to admire from a distance :D (I know, not safe, but impressive)
Otherwise, there might (again a hypothesis) be the possibility of placing the vase on a hot plate with a little water inside and sealing the vase, and at some point, the pressure should cause the vase to burst. This solution is more likely to work but is harder to control.
Otherwise, if you want to go big, get a block of alkali metal (lithium, sodium, anything in the hydrogen column of the periodic table) that is pure, fill the vase with water, and just before the time, drop the alkali metal in and get away to admire from a distance :D (I know, not safe, but impressive)