A rainy day and business is slow. Vinnie and I are playing cards in my office. He lays down a queen of hearts and gets a distant look in his eye. “I wonder where she is now. Or when.”

That ‘or when’ phrase told me who he’s thinking about — Anne, with her white satin attire and molten‑silver voice. “I’m always wondering about that, Vinnie, but it’s hard to apply the word ‘now’ to a time‑traveler. She’s visited so many time periods. When you say ‘now’ you’re covering a lot of separated moments from our perspective, even if there’s only one continuous series from hers.”

“Good point, Sy. I still have trouble believing she’s real and not some figment of your imagination. Yeah, Eddie and Cathleen and Susan and me, we’ve all met her. But like Cal said the other day, it looks like she breaks some pretty fundamental rules. Conservation of Energy, for one.”

“How do you figure that?”

“Stands to reason. Einstein says mass is energy, right?”

“Mm-hm.”

“Anne has mass, right?”

“Mm-hm.”

“So the Universe is moving along, one second per second as usual, with however much total energy it’s got. Suddenly Anne appears when there wasn’t an Anne before. That’s a burst of energy that wasn’t in the Universe up to then. Later on, when she feels like it, she pops out to some other time or Universe and her mass‑energy disappears. Where’s the Conservation?”

“I can think of two possibilities. First, maybe Anne is a virtual particle. According to Heisenberg’s Uncertainty Principle, virtual particles are always popping into and out of existence even in empty space. In this application, ‘uncertainty’ is the difference between ‘there’ and ‘not there.‘ How long a virtual particle lasts depends on how much energy it packs — sneaky little ones can hang around for a while, big ones generally check out quickly. Stephen Hawking said that black holes evaporate by eating the anti‑particle partners of virtual particle pairs created at the Event Horizon.”

“Put numbers to that.”

<poking at Old Reliable’s keypad> “Let’s see… I have no idea how much she weighs, say it’s about 50 kilograms. For an object with that mass, the minimum expected lifetime would be about 10^‑53 second. Anne’s lifetime is enormously longer than that, thank goodness, so we can probably rule out the virtual particle option. On the other hand, maybe Anne somehow keeps a separate set of books. Maybe she conserves her own personal mass‑energy which doesn’t count in whatever Universe she’s visiting. As a physicist I’m not willing to guess how she’d do that.”

“I like the second one. Makes sense, sorta. But Cal came up with another difficulty, though.”

“Which is?”

“Chains of cause and effect. You’ve said keeping the links in the right order was a big part of Einstein’s Relativity theory.”

“That’s true. Any observer should see a distant cause precede its effect no matter the observer’s speed relative to the event locations. That imperative means that the Universe has Lorentz symmetry which is the basis for Special Relativity. That’s a fundamental.”

“Right. So what blocks time‑traveling Anne from looping back to cause or uncause something? Killing off Hitler while he was still painting houses, for instance, or getting Columbus to schedule his trip a little later into hurricane season. Anyone else in the Universe would see Anne’s effect happening before she went back to do that.”

<ff_fshwww^POP!!> A molten‑silver voice behind me. “Easy answer, Vinnie. And no, I’m not in Sy’s imagination, see?”

“Whoa! Talk about timing. Hi, Anne. You look way too good for Sy’s imagination. What’s your easy answer?”

“Pure self-interest. Ever read Heinlein’s story, By His Bootstraps? My timeline is so twisted back and forth I don’t have any idea where I started from. Sometimes I meet myself and I don’t know whether I’m coming or going. We never know what to say to each other. If I were to change anything, anywhere or anywhen, it’d probably get in the way of my being me. My strict rule is, ‘Always an observer, never a participant.‘ It’s worked so far.”

~ Rich Olcott

• Thanks to Alex for getting me started on this topic.