Eifelheim

“Michaelson and Morley!”

“Among others. Hey, did you know that Michaelson never believed his own results, and later, with Gale, claimed he detected the aether? But lightspeed using rotating mirrors was 299,874; using geodimeters, 299,793; using lasers, 299,792 kiss. But method changes took place sequentially; so how much was due to the method, and how much to the thing being measured?”

Tom said, “Ummm…,” which was all he really could hope to say at that point.

“From 1923 to 1928, the five published determinations alternated between the stellar aberration method and polygonal mirrors, with averages of 299,840 and 299,800, respectively.”

Tom was deep into MEGO by then. My Eyes Glaze Over. Normally, he was fascinated by matters statistic, but look up “fascination” some day. His “ummm” had turned into “unh-huh.”

“But there are little hints,” Sharon bubbled on. “Van Flandern — Naval Observatory — saw a deviation between the moon’s orbital period and atomic clocks, and claimed atomic phenomena were slowing down. But he was called a crank, and no one took him seriously. Maybe the moon was speeding up. Even allowing for all that, there seems to be a monotonically decreasing series whose asymptote is the Einsteinian constant.” She beamed in triumph, even thought she had discovered only a curiosity and not an explanation.

Tom had finished imitating a fish. “Umm. Correct me if I’m wrong, but aren’t there good reasons why light speed is supposed to be constant? That Einstein guy? I mean, I don’t know much about it, but I grew up believing in motherhood, apple pie, and the constancy of c.”

“Question of scale,” Sharon explained, waving an impaled cucumber at him. “Duhem wrote that a law satisfactory to one generation of physicists may become unsatisfactory to the next, as precision improves. The slope falls within the band of measurement error, so c is constant ‘for all practical purposes.’ Hell, for most practical purposes, we can still use Newton… But if we go back to the Big Clap and arm-wrestle with flatness, or the horizon problem… You know,” she said,making a sudden conversational right turn “Dirac almost found the same thing, but from a different direction.”

“Wouldn’t that be a different Diraction?”

Sharon really was a somber sort of creature and Tom’s bent to spontaneous low humor could rub her the way cat fur rubbed amber. “Be serious, would you,” she said. “Dirac found that the ratio of the electric force to the gravitational force of an electron-proton pair is roughly equal to the ratio of the age of the universe to the time it takes light to traverse an atom.”

Tom laughed. “I’ll take your word on that one.” He filled both their wine glasses again. “Okay, but the age of the universe isn’t a constant. It’s increasing…”

“At the rate of one second per second. Who says time travel’s impossible? It’s the speed and direction that’s a problem.” Sharon did have a sense of humor. It was more deadpan than Tom’s. The Marx Brothers were more deadpan than Tom. The wine was warming her quite nicely. If Tom was a bumbler, still he meant well, and there were too many who did not to remain angry at one who did. “Have some more fish,” she said. “It’s brain food.”

“Two helpings, then…”

They had not laughed together in several weeks, and the release was palpable. Problems could be obsessive, but worse, they could be solitary. It was good to co

“So, there’s only one point in time when Dirac’s ratios could be equal,” he prompted.

She nodded. “Coincidence is the usual explanation. The Anthropic Principle says that the age of the universe is what it is because that’s how long it takes the universe to assemble physicists capable of estimating it. But think… If space and time can contort for the sole purpose of maintaining a constant ratio — velocity of light — why can’t the rest of the universe be as cooperative?”

“Uh…?” he prompted. Not the most incisive question, but questions weren’t in it. Sharon was on a roll. Nothing like wine for lubricating the words so they tumble out faster.

“Dirac set his two ratios equal and solved for G, the gravitational constant; but his theory of slowly evaporating gravity was eventually ruled out by experiment.”

“So… you solved his equation for c,” Tom guessed.

She nodded. “And c is a function of the inverse cube root of time, which…”

“Which gives a decreasing speed of light,” he finished. “But the asymptote is zero, not Einstein’s constant, ne c’est pas?”

Sharon wiggled her hand. “Haven’t worked it all out yet, but the coefficient involves the rest masses of the electron and proton.”

“Which means?”

“The coefficient isn’t constant, either. Lorentz-Fitzgerald contraction. If c is decreasing, what happens to mass?”

“Beats me.”

“Come on, this is grade school stuff. As velocity increases toward c, mass increases. Everyone knows that. So, switch frames. What’s the difference if c decreases toward velocity?”

“Hunh, none, I suppose.”

“Right, so the universe is becoming more massive.”

Tom patted his stomach. “I thought it was your cooking.”

Sharon gave him The Look, but he gri

“They taught it just after the Lorentz-Fitzgerald stuff.”

“Don’t be cute.”

“Can’t help it.”

“Well, the universe is expanding.”

He almost patted his stomach again, but caught himself in time. “Big Bang. The universe started as a little ball and exploded, right? And it’s been expanding ever since.”

“No! That’s wrong! That’s newspaper science. The ur-block ‘exploded!’ The ur-block ‘exploded!’ What did it explode into, for crying out loud? You’re thinking of stars and galaxies being flung out into space; but the ur-block was space. Galaxies are racing away from each other, not from a common center. They aren’t flying farther out into space; space is expanding between them. The cosmological fluid. Get it?” A part of her — that part able to stand outside herself — could see that she had maybe drunk too much of the wine. She was babbling, and she wished she could stop, but she was goddam, freaking happy, and didn’t want to.

Tom shook his head. “Cosmological fluid…” He had a sudden, Aristotelian vision of the universe as a plenum, rather than empty space.

Sharon pressed him, eager that he should understand, for she wanted to share her joy. “Look, imagine galaxies as dots painted on the outside of a balloon—”

He slapped the table in triumph. “I knew we’d get to the balloon eventually!”

“Picture yourself as a little flat bug somewhere on the balloon. That should be easy. Now inflate the balloon. What happens to all the dots?”

Tom looked up at the lamp that hung over the dining table and tugged at his lip. “Can I see around the curve of the balloon?”

She nodded. “Yes. But it’s curved Flatland, and you can’t see up, or down into the balloon.”

Tom closed his eyes. “All the dots are racing away from me,” he decided.

“And the dots that are farthest away?”

He opened his eyes and looked at her with a grin. “They’re receding the fastest. Son of a bitch! So that’s why—”

“—Astronomers use red shift velocity to estimate distance. Now plunk yourself down somewhere else on the balloon. What do you see now?”

He shrugged. “Simil atque, obviously.”

She picked up the little pepper mill from the table and set it between them. She pointed to it. “So how can the same galaxy be receding from point A…” She touched herself. ” — and from point B?” She pointed to him.

Tom squinted at the surrogate galaxy. “We’re living on the surface of a balloon, hein? Space is expanding between us, so each of us sees the other as drifting farther away.” He was more right than he knew.