Ninety-seven years ago on this day, August 2, my father was born in the little town of Cave Spring, Ga. Cave Spring is about eight miles as the crow flies from where I now live with Leah. The house where he grew up in Rome would be about the same distance by crow, if it still existed. The house where I grew up would be about a mile closer to us than that house, if it still existed. The house where my father spent the last years of his life is three or four miles further out. A new family is in that house now.

At this point, my father’s life exists only in memory or imagination. The memories seem real, but distant. They’re like postcards from the past. I can remember my father coming to my bed to say goodnight when I was a little boy. He would kneel and lean over me silently for a few moments. It was only many years later that I realized he was praying. I remember standing with him and my brother on the railroad tracks, throwing stones into a little pond. I remember him standing in the driveway when I pulled in from Huntsville, and I remember the scratchy, day-old stubble on his cheek as he hugged me. I remember hiking on the Appalachian Trail with him and my brother. I remember him lying in the hospital bed on the last night of his life, worrying that he wouldn’t be able to help me build the house where Leah and I live.

There are a lot of things I will never know about his life. I can’t ask someone at the Post Office about what happened when he worked there, because he retired 40 years ago. Lots of people have started and finished their postal service careers since he retired. Some of the men who served in his Army reserve unit are still around, but not many at this point; he retired from the reserves even before he retired from the Post Office.

It’s a little jarring when I think that he died over 14 years ago. For a long time after he died I would catch myself thinking that I was going to show him some little thing I had done while working on the house. These days I just feel cheated when I find something he would have been interested in.

I’ve written before about how I feel like both of my parents’ lives are receding into the past, out of my reach, and soon enough out of the memories of any living person. That’s a shame, but it’s the fate shared by billions of us who don’t rate a footnote in the history books.

There’s some small comfort in science fiction. Even reputable physicists don’t reject the possibility of time travel as physically impossible. Leah asks me what in the laws of physics says that time travel is possible. I reply, “Nothing, at least as far as I know.” But that’s the point, at least as I understand it. Nothing in the laws of physics says time travel is possible, but nothing says it isn’t. So if time travel is possible, that means that the past still exists.

I believe that I am cut off entirely from that past, even if it does still exist somewhere. I will never see my father again, but I can at least imagine that somewhere he’s still throwing stones in a pond, hiking the Appalachian Trail, and doing everything else he ever did.