You could hear the capital letters.
“Told you so,” said Emma Gowers. And she stood up, tugged her short dress down as close to her dimpled knees as it would go, and swept out.
If McAndrew’s words were designed to impress me, they failed.
“Mac,” I said. “With me, three invariants and a dollar will get you a cup of coffee.”
“You’re a barbarian, Jeanie,” he said amiably. “I’m just using the term that Kugel used: a new invariant of nature. Would it help if I rephrased that, and said that he claims to have found an important new conservation law?”
It did help, because I have been around McAndrew for a long time. But it didn’t help much.
“New, how?” I asked. “I mean, I know that energy is conserved, and momentum is conserved—”
“In a closed system.”
“In a closed system, fine. But how can there be a new conservation law?”
“Well, that’s where things get interesting. Now and again, physicists realize that certain things that they used to think of as independent are actually different aspects of the same thing. For example, a few hundred years ago, heat and motion and light used to be thought of as quite separate entities. But then, after lots of work by people like Rumford and Joule and Kelvin, scientists realized that those separate things were all forms of energy. And though different types of energy can be converted, one to another, they decided that the total could never be changed. That was the principle of conservation of energy.
“Starting with the work of chemists like Lavoisier, people also observed that mass is conserved, too, in every form of physical and chemical reaction. So you had conservation of energy, and you had conservation of mass. But the big breakthrough came in 1905, when Einstein showed that mass and energy are equivalent, and that their total is the thing that is conserved, rather than either one. And he also showed that it didn’t matter which reference frame you use for the measurements. The energy-momentum four-vector is invariant. That single principle helped to unify the whole field of physics.
“The same thing happened with angular momentum. For a while it looked as though it wasn’t conserved in nuclear reactions. But then workers in quantum theory found that an internal angular momentum had to be added to the picture for many particles — spin — and after that angular momentum became a fully conserved quantity. That, too, was a terrific generalizing idea. Did you know that in 1931 Pauli deduced the existence of a new particle, the neutrino, just because the principles of conservation of energy and of angular momentum required that it exist?”
“I did know that, Mac” — once — “and you haven’t answered my question. I realize very well that there are conservation principles. But how can there possibly be a new one?”
“I can give you two possible answers to that. The first is that the physical laws of the universe, as we already know them, admit some conserved quantity that we simply haven’t recognized yet.”
“Isn’t that unlikely?”
“You might think so, after all the time and effort we’ve put into searching for that sort of invariance principle, for the past hundred and fifty years, with nothing to show for it. But there’s another possible answer, one that at first doesn’t sound much more likely. It could be that Ernesto Kugel’s lab has discovered a new fundamental form of physical law.”
McAndrew was starting to make sense to me, which should have been a tipoff right there that something was about to go wrong. Usually, the longer that we talk, the more confused I become.
“You mean, a new force? Something like discovering gravity for the first time?”
“That will do nicely. We happen to have been aware of gravity for as long as humans existed, and we’ve had theories of it for over five hundred years. We’ve known the electromagnetic force for three centuries, and the strong and weak forces that govern nuclear interactions for just a couple. But gravity is actually a very weak force, something we only feel because very large bodies are involved. Suppose that we had evolved as tiny creatures, no bigger than fleas, in the middle of an energetic plasma? Then gravity wouldn’t have much immediate effect on our lives. We’d have learned about electromagnetism early, but we might still not know about gravity.”
I was finally getting the head-swirling buzz that usually accompanied a McAndrew explanation. “But we didn’t evolve smaller than fleas, in the middle of a plasma.”
“No. But different environments make it easy to detect different forces.”
“But less than a year ago you were telling me that the place to look for new laws of nature is out in deep space where we’ve never been, out where the sun and planets don’t interfere with observations.”
“I did say that. But suppose I’m wrong. Wouldn’t that be exciting, Jeanie? A new law of nature, sitting there under our noses all this time, and detectable down on the surface of Earth.”
And there you had it. Most people hate to learn that they are wrong. Not McAndrew. When he’s proved wrong, he’s ecstatic. It means he’s learned something new, and that’s his main reason for existence.
But I still hated the idea that he’d be going to Earth. “This Ernesto Kugel. If he’s in the Energy Department, that means he works for Anna Griss.”
“So?”
“Do you know him?”
“Not personally. But I know his work, very well. Ernesto Kugel built the Geotron.”
Capital letters again. I resisted the urge to be distracted by that. “Is he the sort of person you believe might make a fundamental new discovery?”
“Oh, no.”
“Well…”
“Not him. He’s an engineer — and a first-rate one — but he’s no physicist. Someone in his lab would have done the work. Someone I don’t know. Kugel would probably put his own name on the report just to make people pay attention.”
“But surely you don’t think that some total unknown would have come up with a big scientific breakthrough?”
“Jeanie, the big breakthroughs always come from some total unknown. And genius can pop up anywhere. Kugel got lucky.”
“Maybe. But Kugel works for Anna Griss, and she hates your guts. Don’t you remember what you did to her?”
“Ah, away with you.” He ran his fingers through his thinning hair. “Jeanie, I’m sure that’s all long forgotten. The invitation to visit Kugel’s lab was approved by Anna. She signed off on it.”
“Did she?” I said. “Well, of course that makes everything fine, doesn’t it?”
I should have known better. Irony is totally wasted on McAndrew.
He beamed at me. “I knew you’d see it my way when you had the facts, Jeanie. How soon can we leave?”
I think my inner voices are pretty good when it comes to warning of trouble. The problem is, I don’t always listen to them.
This time I allowed another event to occupy my mind when I ought to have been worrying about McAndrew’s visit to Earth. In my own defense, I must say that the intrusion came from outside. When the linked spheres of the Assembly were halfway to Earth, with Mac and me cozy in the Control Section, I received a message from Hermann Jaynsie at the United Space Federation Headquarters.
It was long and wordy, because Hermann is long and wordy, but I can boil it down. It said, in essence, “What the devil did you do, Captain Roker, on your last cargo haul from the Jovian system to Earth? We thought we had a deal with them for four billion tons of vegetable foodstuffs, grown in our Europan ocean farms. Now Earth is telling us they don’t want to take delivery of any more shipments.”
The lightspeed round-trip travel time to USF Headquarters was seven minutes, so I couldn’t exactly chitchat back and forth. But I did send him a pretty long reply, which again can be boiled down to, “Damned if I know, Hermann. They seemed happy enough with what I dropped off last time.”