From 10 a.m. to 10 p.m., curators will talk and answer questions about what they're up to. So will all manner of archaeo- and anthropologists now at work all over the world. (For the full schedule: www.penn.museum/125.)
Among the highlights is the very cool, recently opened Artifacts Lab, where experts prepare skulls and bones and mummies right in front of you. (The most-often-asked question, according to senior conservator Lynn Grant: "Is that real?")
You into the Sumerians? Etruscans? Romans? Greeks? Mayans? Africa? How about human evolution (now there's a story)? They've got that.
Starting at 1 p.m., you can also see the archives, where archivist Alessandro Pezzati presides over "the untold story behind the story," the notes, letters, maps, photos, and cranky, brilliant stories of the folks who made the museum possible.
It's all part of an effort to redefine the museum and what it does. And what it means to visit.
Siggers, 48, joined the museum as director in July. He belongs to a new generation as good at TV and Twitter as they are at digging and carbon dating.
"Museums everywhere are becoming more interactive," he says. "People get their information differently now. It's not one-way anymore." That's why he sees the museum as "a forum, a meeting place of ideas. A conversation."
Social media and Web-based media are central. Many staff members, including Grant, blog about their daily discoveries at "Beyond the Gallery Walls" on the museum's website.
Handouts tell visitors, "Art belongs to no one. But you can be its mayor." That is, you can use Foursquare to check in at the Sphinx of Ramesses II - or the dazzling headdress of a lady named Puabi, who lived in the Sumerian city of Ur about 2600 B.C. It's a gold-and-trinkets masterpiece weighing about 35 pounds. You'd want people to know you're there.
Siggers has made a career of finding new ways to communicate. He has done that for places such as the National Museum of Science and Industry in the United Kingdom and the Royal Ontario Museum in Toronto. He also has a deep TV resumé - with the CBC, the BBC, and Discovery Channel Canada, as host of the weekly program Hidden Treasures and other shows.
What really woke him up to two-way communications, though, was a stint with an archaeology summer camp for 8-year-olds. "Exceedingly challenging," he says, "and great when you get it right."
He aims to tell the story of a massive collection that began on Dec. 6, 1887, when Penn officials approved an expedition to the site of ancient Nippur, in what is now Iraq. That was more than 400 expeditions and 1 million artifacts ago. And at least that many stories.
Such as the 1955 discovery of the "Midas Mound," a hill in Turkey covering the tomb of a king who probably was the dad of the historical Midas (yes, that Midas) of Phrygia. Rose continues to oversee new work coming out of that project.
How about the tale of Tatiana Proskouriakoff, an immigrant from Russia who, without ever earning an archaeology degree, ended up working at the museum's excavations in Guatemala, studying Mayan inscriptions, and showing they were actually records of dates and dynasties? Her breakthroughs helped later scholars decipher the complex Mayan writing system. (That's how we know the world is supposed to end on what happens to be Siggers' next birthday, Dec. 21. Shiver.)
Or the story of a 55-pound quartz globe from China, stolen from the museum in 1988 - and found three years later in a thrift shop in town?
Rose will be at the open house, talking about the Mediterranean collections at 3:30 p.m. On Wednesday, though, he lectures on "Was There a Trojan War?" as part of the museum's "Great Battles" series. He should know the answer; he has been directing work at Troy for the last 25 years.
One year, on his birthday, while working Roman sites at Troy, diggers found a nifty bust of Hadrian. Four years later - also on his birthday! - they found a head of Augustus. "A gift from the gods," he says.
Rose says that "while technology has changed, the human emotions and character stay very much the same. Love, prejudice, hate, war - those remain, and I hope that's what people bring away from our anniversary celebration."
Archivist Pezzati runs his own museum-of-the-museum, a rapidly exploding collection of records and media related to the museum's many, many works. But it's also "the record of the personalities who drove this museum's history," he says, gesturing to the paintings on the walls.
The portraits include one of Sara Yorke Stevenson, a leading light of Philly society at the turn of the century, an "armchair archaeologist" who was an early (and so far the only female) president of the museum, and evidently, judging from the letters in the archive, an object of admiration of many a dusty shard-hound. And Eckley Brinton Coxe Jr., a scion of the Coxe mining family of Pennsylvania. "One of our patron saints," Pezzati calls him, "a man with a burning passion, especially for ancient Egypt."
Passion dances on the face of a figure from the second-century B.C. sarcophagus of Seianti Hanunia Tlesnasa, a wealthy Etruscan lady. It's in the eyes of Charles Darwin and Rosalind Franklin in the Human Evolution exhibit.
"This museum tells the human story," Siggers says. "It's a place to come to talk about it."
Penn Museum's Open House
What: 125th anniversary open house for the University of Pennsylvania Museum of Archaeology and Anthropology.
When: Thursday from 10 a.m. to 10 p.m.,
Where: 3260 South St.
Information: Free. Special viewing opportunities for Penn Museum members. 215-898-2680, or www.penn.museum/125.
Contact John Timpane at 215-854-4406 or firstname.lastname@example.org, or follow on Twitter, @jtimpane.