The real announcement is that they studying gravity waves using a device intended to electromagnetically reduce the weight of a suspended object. IN the process they discovered a strange mold that normally takes 1 year to grow a layer had completely covered their apparatus overnight. They built a larger machine and crawled inside of it with a tank of oxygen and found themselves at next thursday. Thus they can't actually make the announcement until time catches up with them. They could go back in time to announce it now but then their current selves might got to the same meeting and this might change the time line destroying the future Thursday. So they have to wait till time catches up to them. Fortunately Aaron started a failsafe before he left so no worries.
1. gravity waves
2. time travel