WASHINGTON, DC - MAY 20: Connie Willis, author of “Blackout” and “All Clear” won the Best Novel Nebula. (Marvin Joseph/WASHINGTON POST)

Before Rachel Swirsky won the Nebula award for best novella Saturday, she went to an authors’ reception and learned some tips from veterans of the science fiction awards circuit.

“Apparently the Hugo makes a great paper-towel holder,” Swirsky says. “And if you put a sock over the World Fantasy Award,” it looks like a profile of Jacques Cousteau. But what to do with a Nebula — a heavy glass block — no one knew. And so Swirsky, a first-time author whose novella, “The Lady Who Plucked Red Flowers Beneath the Queen’s Window,” recounts the weary adventures of a resurrected magician, made a vow in her acceptance speech at the Washington Hilton:

“I will figure out” what to do with a Nebula.

The Nebulas are the Screen Actors Guild of the sci-fi world, a prestigious, peer-selected award voted on by the members of the Science Fiction and Fantasy Writers of America. They are the centerpiece of the SFWA’s annual three-day conference, held this past weekend in Washington.

Swirsky took the novella prize; Eric James Stone took best novelette; Kij Johnson’s “Ponies,” an allegory about female bullying, tied for best short story with a piece by Harlan Ellison.

Mark Levy had his books signed by his favorite authors attending the 2011 Nebula Awards. The Science Fiction Writers of America are holding their annual conference and a book signing event. (Marvin Joseph/WASHINGTON POST)

The winner in the main-event novel category was Connie Willis, a celebrated favorite — and former teacher of Swirsky’s — whose two-part “Blackout” and “All Clear” chronicles a group of Oxford historians who become stranded amid World War II when their time-travel assignment goes awry.

“It took me eight years to finish,” Willis said after the ceremony. “Around the five-year mark, people did start to point out that it was actually taking longer than World War II.”

One of the geekier pleasures of living in Washington is wandering past any large Hilton or Marriott, or the Mount Vernon Square Metro stop, and playing “Guess That Convention.” Are the participants wearing wool or hemp? Carrying tote bags (librarians) or plastic binders (engineers) or gourmet snacks (pharmacists)? How many of the men have ponytails? What is the costume situation? What strange and bizarre subgroup has landed in Washington, and what cultural practices have they brought with them?

The SFWA gathering is no outlandish Comic-Con. There are no roaming Spock ears, no “Battlestar Galactica” tribute get-ups. This is a writerly conference for writerly people wanting to improve their craft. Joe Haldeman is here, and Paolo Bacigalupi, and a bunch of other people whose names prompt squealing in this crowd. Inside the Hilton’s lower level, a couple hundred happy-looking attendees wearing a preponderance of planet-themed neckties shuffle from session to session.

In “Using Science in Science Fiction,” a panel of astrophysicists and engineers from NASA takes questions from writers who are searching for their next great plot in NASA’s latest great discoveries.

“Has anyone considered,” one participant asks the panel, “what calculation would be needed to measure the infrared heat exhaust from a Dyson sphere?”

Andrew Steele, a NASA astro­biologist, tells the group that no sci-fi alien can compete with the weirdness on planet Earth. What about the Cymothoa exigua, Steele suggests — a parasitic crustacean that crawls into the mouth of a fish, eats its tongue, then slowly becomes its tongue?

Everyone writes down “Cymothoa exigua.”

Or what about the fungus that burrows itself into the brains of various ant species, causing them to behave in self-destructive ways? “The ant completely loses fear,” Steele explains, “then feels the need to crawl to the highest thing it can find, clamp to a leaf and die.”

Everyone writes down “zombie ants.”

In “Warfare for Writers,” a military historian teaches a classroom of novelists how not to embarrass themselves when sketching out fictional battle scenes. “To be a war, it must involve enough people to have military units,” Timons Esaias tells his class. “Are you describing war, or just armed folks fighting?” Do the writers know what kind of fighting they are talking about? A raid? A siege or an outpost battle? A war of annihilation? Credibility is key. Accuracy is everything. After the three-hour seminar, people cluster around Esaias asking follow-up questions.

“Can a laser cut through a mirror?” one guy wants to know. And if so, is there some sort of electromagnetic pulse that could defract the laser? And also, do these rules apply when the war is happening in space?

“There’s a movement afoot called the mundanes,” says Tom Doyle, a short-story writer based in Washington who’s attending SFWA. It’s a newer movement. The mundanes believe that science fiction rules should obey science fact rules. The mundanes will have none of your teleporting, none of your intelligent species traveling to Earth and enslaving the population with mind control. Says Doyle, with a hint of both admiration and exhaustion, “They don’t even do faster than light.”

Poor science fiction writers. They are still so often banished to that unfortunate realm of “genre fiction,” despite the genre-transcending brilliance of “Dune” or “Ender’s Game” or anything by Ursula Le Guin. People always expect them to be speaking in Klingon or carrying a lightsaber or worshiping an idol shaped like Joss Whedon. People roll their eyes at the complicated rules that fantasy writers construct for their universes, at the fact that it genuinely matters to them whether fairy dust would be a cure for dragon’s blood, or whether a soldier that had been possessed by a demon would obey the same rules of warfare that a regular human might.

What these people do not understand is that sci-fi writers are not creating books but creating whole worlds, and that these worlds are the building blocks for their readers’ imagination and discovery.

After the Saturday awards ceremony, the winners from every category gather for pictures in the ballroom.

Someone asks Connie Willis — who has won seven previous Nebu­las in various categories — whether she has any advice for Swirsky’s quest to find an alternative use for the award.

“If you got enough of them, you could use them like Legos,” says Willis doubtfully, weighing her solid, rectangular trophy in her hands. “But you would really need an awful lot.”