The Draco Tavern - Larry Niven [45]
“Using those as meters to measure the universe, we get a rate of expansion that suggests around thirty percent of the mass that’s needed to close the universe, or ten percent, or seventy percent, depending on who needs a grant. ”
“So you look for more mass.”
“Right! We look in places obscure and weird. We postulate mass we can’t see, dark matter, in all sizes from neutrinos to intergalactic dust, to near infinities of brown dwarf stars, to hypothetical massive particles left over from the Big Bang itself. I wasn’t a front-runner in all this, but I kept track. And I got old, and we had too many solutions and none of them made a lot of sense. Aliens came down in Siberia, hordes of them, and they know. So what was the point?
“Then ‘Helmuthdip’ popped up on my screen. And for a while he was making sense, and then he got into the Casimir effect.”
“What brought you here?”
“And then he started insisting that I use my influence on the pilots of an interstellar liner! That would have brought me here anyway, but what influence? If he comes from a place where astrophysicists have more power than fucking politicians, it’s for damn sure he’s from interstellar space! But I have to tell you about the Casimir effect.”
“Do you really?”
“Actually,” he said, “no. Let’s leave it that there’s energy in the vacuum. Fantastic levels. Space isn’t really empty, it’s a froth of virtual particles appearing and annihilating each other faster than any hypothetical instrument can detect them, and that’s where the energy is. It’s been demonstrated mathematically that if the vacuum in free space was empty of energy, you’d have minus energy near a black hole.
“The Casimir effect is an experiment that measures vacuum energy. You machine two plates very flat, and you move them very close together. They pull at each other—”
“Gravity?”
“No.”
“Oh.”
“It’s done with virtual particles. Virtual particles flash into existence and annihilate each other everywhere in space. But you put these plates so close together that the wavelength between the two plates is too small. There’s no room for virtual particles to pop up between them. The pressure on the outsides pushes the plates together, and that’s the Casimir effect.”
“Strong?”
“Tiny. ‘Helmuthdip’ has been trying to tell me—Is that entity waving at you? The half-mechanical, ah, person?”
The Terminator Beaver was on his feet and coming around the bar. I said, “Terminator Beaver, meet Roger Teng-Hui, also known as ‘chinaRoger.’ Teng, meet ‘Helmuthdip,’ aka Terminator Beaver. I believe you have much to discuss.”
They sat at the bar with their computers in front of them, sometimes activating displays to supplement the Chirpsithra translators. They both kept slipping into jargon, then remembered that they were talking to the bartender too. Sometimes it takes a third party to get two people talking the same language.
“The Chirpsithra won’t discuss what powers their star-to-star liners,” the Terminator Beaver said. “Our landers are various and we build them ourselves, but the liners have apparent infinite power and not enough fuel storage.”
“Antimatter?” Teng asked.
“Antimatter they keep for attitude jets, with dross from refined sewage as reaction mass. Our landers use antimatter. Spies have identified a system aboard Scrilbree Zesh for making antimatter! Where do they get the energy? Many species wish to solve the puzzle. Sometimes we cooperate. We know that the liner’s mass varies during a voyage, losing and gaining again.”
“The energy of the vacuum is thinly spread,” Teng said.
“By some measurements,” the Beaver agreed. “Some theories render it huge. The Casimir effect may measure only the least of what is available.”
I saw fit to cut in. “Near-infinite energy in the vacuum,” I said, “and near-infinite energy in these huge Chirpsithra ships. That isn’t all of your argument, is it? Because they don’t have to be related.”
They both tried to interrupt. The Beaver’s translator cried, “No, no, no! What