When Anton van Helden talks about whales, it's like a cross between a mother singing her baby to sleep and a die-hard fan talking about the Steelers. His words are full of gentle love -- and passion.

"I love the thought that a 737 aircraft and a blue whale are the same size," the New Zealander said during a recent telephone interview. "It's 100 feet long, it swims around and plays around, and it can look you in the eye."

The words cascade as he describes a mother whale and her baby:

"A baby blue whale suckling on its mother puts on 90 kilos [198 pounds] a day. When the baby weans at 10 to 12 months it has grown from 7 meters [22.9 feet] to 15 meters [49.2 feet]."

Mr. van Helden has parlayed his love and passion for whales into his livelihood. He is collection manager of marine mammals for the Museum of New Zealand Te Papa Tongarewa and curator of that museum's international touring exhibition "Whales/Tohora," which opens Saturday at Carnegie Museum of Natural History and continues through May 2.

The exhibit is designed to be educational and entertaining, interactive and immersive.

The highlight is a 58-foot articulated skeleton of a sperm whale, a skeleton Mr. van Helden worked hard to acquire from the native tribe of Maori people who found it after it beached itself and died.

There are life-sized and scale models of other whales common to the South Pacific; a skull from each of 12 species of beaked whales that swim New Zealand waters; "bits and pieces from the largest whales -- a rib from a fin whale and a baleen from a blue whale"; and ancient and rare treasures such as jewelry, scrimshaw and weaponry carved from whalebone and teeth.

The smallest exhibit is a bullet designed for euthanizing a stranded whale. New Zealand is known around the world for its large number of strandings, which attract both scientists and ordinary people who try to help the whales back into the water.

The exhibition presents graphic imagery of beachings and the varying human responses. Once dependent on a historically bloody whaling industry, New Zealand now is known for its ecotourism and anti-whaling stance.

There are happier, as well as educational, exhibits within a part of the exhibition called the Whale Lab. Probably most popular among them is the life-size replica of the heart of the blue whale, which children can crawl through.

"It's so popular we had to build another for touring," Mr. van Helden said. "We saw it was a popular place for young teenage girls. We wondered why on earth do they like being inside the whale heart? It turned out they were all sitting in there texting people, saying, 'You'll never guess where I am.' "

The Whale Lab also traces the mammal's evolutionary transition from life on land 55 million years ago to life in the sea.

There is a feature called "Search & Destroy" that allows visitors to hunt for a giant squid; it was re-created from data and sounds collected directly from real sperm whales.

There are other whale sounds -- the clicks of toothed whales and the low-pitched sounds of blue whales -- that visitors can dial onto "like an old radio," Mr. van Helden said.

The museum's acquisition of the articulated sperm whale skeleton "got the ball rolling in developing the exhibition" in 2003.

Since the Maori have first rights to stranded whales, the museum had to negotiate for the right to display it.

"The whales belong to [the Maori] in perpetuity," Mr. van Helden said.

This particular whale was among 12 that stranded themselves west of Auckland, New Zealand's largest city. In return for this specimen, Mr. van Helden and his staff recovered and turned over to the tribe the jawbones of all but one of the others. The 12th jawbone was deformed, and it, too, is part of the exhibition.

The details of how the museum staff de-boned this huge creature and cleaned the skeleton are best left to the imagination.

But, Mr. van Helden said, the process of displaying the skeleton "became interesting" when the museum powers-that-be decided the exhibition wasn't going to be just for the museum, but for the world.

The largest element of the touring skeleton is the skull at 18 feet.

So far, so good: The Carnegie will be the third North American venue to stage the exhibition. Whales/Tohora first visited the National Geographic Museum in Washington, D.C., then the Exploration Place in Wichita, Kan.

That's Fascinating, where Mark Roth spotlights the odd and the interesting in everyday life, is featured exclusively in the Opinion section on PG+, a members-only web site from the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.