Literally, the half life a radioactive material is the amount of time it takes for 1/2 of that material to break down into it's daughter elements and energy. Think of it like making popcorn. In a pot, imagine 5000 popcorn kernels. The half life of the cooking time, would be the amount of time it took to pop 2500 of the popcorn kernels.
METAMIA is a free database of analogy and metaphor. Anyone can contribute or search. The subject matter can be anything. Science is popular, but poetry is encouraged. The goal is to integrate our fluid muses with the stark literalism of a relational database. Metamia is like a girdle for your muses, a cognitive girdle.