Grief’s half-life

I am slowly (glacially?) clearing off shelf space at home, so that some of the books in my office can have a spot. I skim the shelves, looking for books that I can’t imagine reading again (or that I could get from the library should I wish to revisit them). Intermingled with my and Victor’s and the kids’ books are some of Tom’s. Books from college courses, novels. In some ways Tom’s old books were easy to triage. He does not require physical copies of them on this earth, and I have no memories attached to them (we didn’t meet until graduate school). Off they go. 

Tucked into one shelf in the wall of books off the kitchen was a journal I didn’t immediately recognize with a photo of a pair of battered pointe shoes on the cover. I pulled it out and opened it to find letters I had written to Tom after he died. I read two and closed the cover. It seems they are still hot, radioactive, like Marie Curie’s cookbooks.

What, I wonder is grief’s half-life? And how many have elapsed? We say that after 10 half-lives have elapsed the materially is safe to handle(less than 0.1% remains). But even then radioactive events are still occurring, randomly spitting out particles and gamma rays.