The National Parks are a living record of America's past.

Living here in the San Francisco Bay Area I marvel at the diverse culture that sprouts from our surrounding parks and open spaces. In Golden Gate Park alone you can practice fly-fishing, sail a model boat, ride a horse, play golf, kick a soccer ball, tackle rugby, or pitch a horseshoe, bocce or baseball. You can see where the buffalo roam or spin round and round on an antique carousel. Skate, bike, row a boat, play music, dance to the beat of your own drum and stop to smell the roses. Nearby, down at Ocean Beach surfers ride the waves and kids make sand castles. Stroll the promenade at Crissy Field and you’ll see people soaking up the sun on the beach, flying kites, fishing off the pier or windsurfing under the Golden Gate. Go to Fort Funston where you can run your dogs down to the beach or launch your hang glider off the cliff and soar into the sky. I can go on and on but you get the picture. And that’s just here in San Francisco! Add the Peninsula, North, South and East Bay then combine all the city, county, state and federal parks with all the regional open spaces and count your blessings. It’s been said that if you go to any neighborhood in Bay Area, there is a park or a trailhead less than a mile away. These places are calling us outside to play. And in the process they are building our communities, and in many ways defining who we are and who we want to be.

Of all the activities happening in the parks, probably the most important and rewarding is volunteering to help preserve and protect these amazing places. I urge you all to pitch in. Contact your local regional parks and open space district and see what you can do to help. It’s up to all of us to make sure these wonderful places are saved and maintained for everyone in the future.

If you've watched the show, or are reading this blog about the National Parks, the chances are you also know that filmmaker Ken Burns is about to release his next series "The National Parks: America's Best Idea." Through our role in the development and distribution of the series, KQED is collecting viewer stories about their own experiences with these hallowed places. Let us know what these marvelous open spaces mean to you by sharing your story. We’d love to hear about your favorite park, Bay Area or beyond.

Watch the National Parks Special: Bringing the Parks to the People television story online.

Say you consider yourself a top-notch recycler. You buy in bulk as much as possible, compost all your food scraps, can recite the recyclables bin allowable item list from memory. When trash day rolls around, what's in your discounted black mini-can?

According to Sunset Scavenger Spokesman Robert Reed, San Francisco residents should have nothing but "film plastics" (like plastic bags from stores and dry cleaners) and polystyrene, aka Styrofoam.

But the life of a recycling ascetic ain't easy. First of all, it means learning the rules of your particular community, since recycling practices vary depending on where you live. Probably, It means forgoing juice boxes, disposable diapers, complicated, multi-material packaging. It means you've scraped out your cat food cans ("contaminated" recyclables are often tossed). If you're a paper shredder, you've put all the scraps into a paper bag labeled "shredded paper." (Tiny pieces of paper are too hard to collect – sorters usually landfill them.) In short, you've earned a PhD in recycling. (And if you think that's complicated, consider the Japanese.)

Some experts have argued that this is all too much trouble – that instead of aiming for zero waste, we should accept a certain amount of landfilling. Others say that the more citizens recycle, the more efficient the program becomes – hence the movement toward mandatory recycling. One point that nearly everyone seems to agree on is that products on the shelves must be designed to be more easily recyclable than they are today.

Is This Recyclable?

On that note, we interviewed two recycling experts: Mark Murray, director of Californians Against Waste, and Kurt Standen (no relation, amazingly to both of us), general manager of the Sacramento Recycling and Transfer Station. We came armed with six recycling stumpers, including a rubber boot, a juice box, and that much-maligned item of transport, the plastic bag. See what Standen and Murray had to say by clicking on the images below.

Listen to the Getting to Zero Waste radio report online.

The Great Wave off Kanagawa is often mistakenly associated with the Tsunami.

"If a tree falls in a forest and no one is around to hear it, does it make a sound?"

The philosopher George Berkeley posed this philosophical question and a quick internet search found a somewhat scientific answer in an 1894 issue of Scientific American. There they wrote: "Sound is vibration, transmitted to our senses through the mechanism of the ear, and recognized as sound only at our nerve centers. The falling of the tree or any other disturbance will produce vibration of the air. If there be no ears to hear, there will be no sound."

Maybe sometimes vibrations are heard much later, only when the right person is listening.

On January 26, 1700, at about 9:00 p.m. Pacific Standard Time one of the largest earthquakes ever to strike the Pacific Northwest rumbled across the Cascadia Subduction Zone. This massive earthquake sent a giant 33 foot high tsunami crashing onto shore, inundating the quiet coastline. While there is no written account describing the earthquake, tsunami or consequential damage, the devastation was enormous.

So wait. If there was no written record, how can we know the exact time and date when the tsunami struck? How can we know how big it was or what kind of damage it did? It took some digging and an impressive bit of scientific detective work by geologist Brian Atwater. First scientists discovered an unusual layer of sand in a marsh area that left a clue that a wave had struck, taken sand from offshore and brought it far inland. The scientists were able to date this thin sand deposit to around 1700, plus or minus 25 to 50 years. Then through tree-ring dating they were able to narrow that down to within five or ten years. Further study of tree roots narrowed it down even further to winter, 1700. Then investigators went to Japan and checked for evidence of a tsunami during that time. They looked for one which did not have a known earthquake associated with it. These were known as “orphan tsunami." There, in the records from 1700, was a tsunami the struck Japan, a wave that had the right pattern, right size, and was generated at the same place, the Cascadia Subduction Zone all the way on the other side of the Pacific Ocean. January 26, 1700, 9:00 p.m.

Can it happen again. Yes. Are we listening?

Watch the Scary Tsunamis television story online.

QUEST Producer Chris Bauer rides into the hunt in the back of a pick-up truck.

"Oh, we’ll get letters."

I knew going into this story that we might ruffle some feathers. But one of the things that made this story so intriguing to me is that it would bring up some questions about where people stand on what can be a pretty touchy subject.

So full disclosure – I generally side myself on the side of environmentalists, naturalists and true scientists. I think extremism one way or the other is generally not a good idea. I believe in the overwhelming scientific evidence that global climate change is happening and human behavior is the root cause. I'm pro-open space. I like clean air and water. I support the restoration of native ecosystems. I champion native plants and animals. I am against pollution, invasive species and uncontrolled urban sprawl. Some things we judge for ourselves one side or the other. Such as, I am for native song birds and against feral cats. But some other things don’t tie up into a pretty package. For example, I love natural ecosystems but I am not ready to support clear-cutting the cypress trees in The Presidio. I'm not a hunter. But I eat meat. I may feel some pangs of guilt when I see an animal shot but those feelings are rarely there when I purchase meat at the grocery store. I like my barbecue. That’s me. (If you eat meat too, check out our great Quest radio story on Low-Carbon Diets and get a preview of the letters we’ll receive regarding this story.)

So where do you stand? And what happens if your stances are on opposite sides of the fence? Perhaps you are for clean energy and also happen to care for the native bird populations? See our story "Fatal Attraction: Birds and Wind Turbines."

Sometimes these questions can prompt us to examine what is truly most important to us. This brings me to the invasive pigs. There are people who are adamantly opposed to all hunting or any animal control. I can understand and respect their opinions. But many of those same people also consider themselves pro-environment. So is the thought of shooting a pig so distasteful that you are willing to sacrifice the native flora and fauna? What happens to the indigenous fox, deer, ground squirrel or California quail? Are you willing to give up California's live oaks, wildflowers and other native species that may be directly impacted by this invasive species? You can’t always have it both ways. Anyway…something to chew on.

Oh, and by the way… We'll get letters.

Watch the Hog Wild television story online.

Sketch drawing of the proposed San Francisco-Oakland Bay Bridge (1913) from Overland Monthly, April 1913.

The Bay Bridge will be closed from September 3rd at 8:00 p.m. until the 8th at 5:00 a.m. During these 105 hours, Caltrans will perform an "essential and unprecedented construction feat."

It turns out there was a lot I didn't know about the Bay Bridge. Its official name, for example is not the Bay Bridge. It's "The James 'Sunny Jim' Rolph Bridge," after the California Governor who died in 1934, two years before the bridge opened (The Golden Gate Bridge opened 6 months later). Around 280,000 vehicles traverse the bridge every day—nearly $7 in bridge tolls per second; The Yerba Buena Tunnel that connects the eastern and western segments is the world's largest diameter bore tunnel; Much of the eastern span is supported by old growth Douglas Firs, driven into firm mud.

As construction grows increasingly noticeable, the new eastern section rising out of the bay, more people are wondering: How will it attach? What happens to the old bridge? What's with the retrofit of the western suspension? And what is this unprecedented feat of construction happening over Labor Day weekend?

The construction website, baybridge360, just received a Webby award in the Government category, and is worth a visit. Videos and slide shows are overlaid on a satellite image of the bay and provide answers to these and other engineering questions. There's a bit of Troy McClure style narration, epic synthesizer for the construction scenes, and techno pop for the fast-forward time lapse photography. At one point, the “Governator” dons a pair of terminator sunglasses for a ceremonial blowtorching.

The new site may be sleek, but some of the most interesting information is buried in the old stalwart: baybridgeinfo.org. The western span's retrofitting, completed in 2004, added some 17 million pounds of structural steel, and included new rollers between the roadway and the bridge supports. The new eastern segment (slated for rebuilding since a section collapsed in the 1989 Loma-Prieta earthquake) will include the world's longest Self-Anchored Suspension (SAS) bridge, connected to a pier-supported "Skyway" (elevated roadway over a mile of mudflats), sloping down to the "Oakland Touchdown."

The 2,047-foot asymmetric SAS will be supported by a single steel tower, embedded in rock, rising 525 feet above sea level. While most suspension bridges use a pair of cables, the new SAS employs a single cable, anchored on the east side, wrapped over and around the tower, and down to the west. The Skyway is supported by a set of steel pipes, driven 300 feet into deep bay mud by a massive hydraulic hammer.

Amidst the construction clamor, considerable attention is afforded to local wildlife. Dense columns of air bubbles helped dissipate shockwaves from the hammering to ease construction-related stress on local fish. For the birds, platforms under the new east span provide cormorant nesting habitat, and the crew is building a 500 square-foot island for the pleasure of the snowy egret and ruddy turnstone. And at the Oakland touchdown, a turbidity-controlling curtain was installed to protect eelgrass, which in turn serves as a filter, improving water quality.

So consider all this next time you lament the $4 bridge toll. The original 1936 toll, collected in both directions, works out to over $20 in 2009 dollars. The bridge is scheduled for completion in late 2013.

I admit it, I watch way too much television. Some good television (KQED QUEST for example), but mainly bad television: American Idol, Amazing Race, pretty much anything on the VH1 channel. My brain was turning to mush.

After some cajoling from the wife, I trekked down to the library to check out the science section. I was amazed at the bevy of great pop science books. Most are accessible, quick reads on pretty much every science topic under the sun. However, I'm a social creature, I wanted to discuss science books with peers.

A few quick searches and voila! Science book clubs exist right here in the Bay Area (one of them hosted by myself so I'd have more control on book selection). Lively discussion and science books, it's a good combination.

Down to a Science Book Club

Book: "How We Decide" by Jonah Lehrer

When: Monday, May 25th, 7-9 PM

Where: Books Inc, 601 Van Ness @ Turk, 2 blocks north of SF City Hall

Details: Ever had a experience of option paralysis? Like when you are looking at the 11 different types of Cheerios in the cereal aisle? If you're anything like me, decision making is an "interesting" process. Jonah Lehrer tackles the neurobiology of decision making and points out a few ways you may be able to overcome that paralysis. Watch Jonah discuss decision making at the Commonwealth Club or listen to him discuss Choice on RadioLab.

California Academy of Science Book Clubs

Teens Talk Books: Underwater Explorations

Book: Shark Life: True Stories about Sharks and the Sea by Peter Benchley

When: June 6th, 11:00 am in Education Classroom

Where: California Academy of Sciences

Coming face to face with the jaws of a great white shark.  Chasing leaping orcas near Vancouver.  Swimming with hoards of hammerheads in the Sea of Cortez.  Benchley, the author of Jaws, shares his many underwater adventures with sharks and other marine creatures, while helping the reader learn more about these majestic creatures, how to swim with them safely, and why it is vital for us to protect our oceasn.  Join us for a discussion of Benchley's fascinating read!

Reservations: Free with admission to the museum, but participants should call the Naturalist Center at 415-379-5494 to reserve a space.

Bookworms (Adult Book Group): Why Do Oceans Matter?

Book: Sea Change: A Message of the Oceans by Sylvia Earle

When: June 16th, 6:30 pm in the Naturalist Center

Where: California Academy of Sciences

Details: In recognition of World Ocean Day this month, the group will read and discuss noted marine biologist Sylvia Earle's book which is both a plea for ocean conservation and a very personal story of her own lifelong exploration of life in the deep.

Reservations: Free.  Reserve a space by calling 415-379-5494.

This Week In Science Online Book Club – Hosted by TWIS.org

An Ocean of Air: Why the Wind Blows and Other Mysteries of the Atmosphere

Details: Most of the time we hardly notice that we're moving through air. But when a storm system whips it into a whirling mass that grows into a tornado or a hurricane, then the air around us makes headlines. Science consultant Walker (Snowball Earth) presents a lively history of scientists' and adventurers' exploration of this important and complex contributor to life on Earth, from Galileo's early attempts to show that it has weight to the explorations by 20th-century scientists Oliver Heaviside and Edward Appleton of the ionosphere, which acts as a giant mirror bouncing radio waves from one side of the globe to another. Walker provides readers with easy-to-follow discussions of the science behind the discovery that carbon dioxide levels are rising exponentially.

"2008 was one of the hottest years on record."The conventional wisdom is that a warming planet means more wildfires–and in many cases the conventional wisdom is right. But globally it's a more complex question.

Just last week, Max Moritz and his team at UC Berkeley's Center for Fire Research & Outreach published a study that shows widely varied fire response to climate changes around the world. Post-doctoral fellow Meg Krawchuk was the lead data cruncher in the effort, with contributions from researchers at Texas Tech University.

What they found were suggestions of rapid changes in fire regimes, and not all in the same direction. Some places (like most of California) will likely see a spike in the fire hazard, while other regions (like the Pacific Northwest) could see a retreat of wildfire frequency and intensity:

"In contrast to any expectation that global warming should necessarily result in more fire, we find that regional increases in fire probabilities may be counter-balanced by decreases at other locations, due to the interplay of temperature and precipitation variables. Despite this net balance, our models predict substantial invasion and retreat of fire across large portions of the globe."

Moritz has been stumping for new approaches to fire-climate analysis. He says rather than treat fire strictly as the product of other climate change variables, we should think of it also as a climate driver.

Map shows areas of potential fire advance (orange) and retreat (blue) by 2010-2039 (medium-high emissions scenario)

You can use the player below to hear an excerpt from my interview with Moritz, in which he explains the new perspective that he thinks his team's study brings to the fire-climate connection.

Audio clip: Adobe Flash Player (version 9 or above) is required to play this audio clip. Download the latest version here. You also need to have JavaScript enabled in your browser.

"Opossums are marsupials, just like kangaroos."I think opossums get a bum rap. People think just because they look kind of funny, walk kind of funny, have beady eyes and sharp teeth, and can emit the most foul-smelling scent you've ever had the misfortune of coming across, that they are kind of "icky."

But they are just trying to make a living like everybody else. They need those teeth to crush bone – which means that they are good for clearing out those unwanted rodents in your neighborhood. (No, they are not rodents themselves; opossums are marsupials… that’s right, just like kangaroos!). Their eyes… well, they just look that way and they're not particularly useful, however these critters have an excellent sense of smell and hearing to make up for it. As for that smell that they emit, they only do that when they're fighting for their lives. Believe me, if you could spew a foul stench when some unsavory character is harassing you, you'd do it! And let me take this moment to clear up a very common misconception: no, opossums cannot hang by their tails, though they can use them to balance themselves and gather bedding materials for their nests.

The truth is, if you ever get the chance to know one like we did, you'll see they are really sweet creatures. Most of the times that they find themselves in direct conflict with humans, it’s the human's fault. Their habitats are shrinking due to our development plans, which forces them to live closer and closer to us. If you leave your pet food outside… well, who doesn't take a free snack when it's offered up? And the poor creatures only live for two to four years, so please folks, give the opossums a break!

Watch the Cool Critters: Opossums television story online.

Animals generally receive diets that are rich and varied.

Few images will stay as indelibly with me as the sight of a 500 pound grizzly bear devouring a horse bone while standing waist high in water. I should add to that the sight of a geriatric koala slurping his eucalyptus meal. In the aquatic realm, there's something ineffably captivating about watching an anemone's candy-pink arms wrap around its lunch of grain-sized krill.

Witnessing the feeding scenes firsthand, I marveled at the bewilderingly diverse array of mammals, reptiles, amphibians, birds and insects that are fed every day at zoos and aquariums worldwide. Fortunately, to facilitate the feedings and developments of diets, today there are tools like Zootrition, a software program developed by the St. Louis Zoo that allows for the nutritional evaluation and comparison of various diets. Then there's ZuPreem, a manufacturer of ready-made meals for exotic animals. A perusal of their web site reveals such tasty items as "Primate O's" (naturally preserved with vitamins C and E), canned monitor food (boasting nutrient levels comparable to "a mouse in a can"), bags of dry omnivore diet for the hungry bear or boar.

The upshot of this is that animals at facilities accredited by the Association of Zoos and Aquariums generally receive diets that are rich and varied, frequently monitored for the effect they have on the animals to whom they’re served. Not surprisingly, many animals at zoos and aquariums live longer in captivity than they would in the wild, not only because of the high level of care they get in captivity but also because they are safe from predation in the wild.

Jacquelyn Jencek, Chief of Veterinary Services at the San Francisco Zoo, shared with me an amazing story of how they greatly expanded the longevity of koalas with an intervention that has been emulated at other zoos throughout the nation. Most koalas in the wild don’t live past thirteen years of age, when their teeth have been ground down from years of eating coarse eucalyptus leaves and they no longer have enough dental surface to break down the leaves and extract their nutrients. Thus, even if they attempt to eat the leaves, they can still die of malnutrition. So the SF Zoo decided to help the koalas by breaking down dried eucalyptus leaves with a coffee grinder and mixing the powder with water and supplements, turning it into a solution that could be fed by vial to geriatric koalas at the zoo. The zoo first tried administering the eucalyptus solution to Clarry, who lived to be nearly 20 years old, and is now giving it to Clarry's son, Leo, and a few other koalas whose longevity attests to its success. According to Dr. Jencek, "they love the taste of it", and it's clearly good for them.

The story affirms for me the bond of trust that exists between the animals and the zoo and aquarium personnel who take care of them, and how there’s nothing cookie-cutter about feeding the animals and creating their diets.

Watch the Animal Chefs television story online.

At Sonoma County State Beach, just south of the mouth of the Russian River, stand two seastack rock pillars surrounded by large boulders. The prominent blue schist rocks form something like an amphitheater above the coastal cliffs.

There is something about these rocks that draws you in. Maybe it's the way they jut out of the ground? Or perhaps it's the "Stonehenge" way they form an enclosed circle? Or maybe it's just a nice place to get out of the wind? Whatever it is, they seem to pull you towards them. And once you are there, they almost call out to be touched. The rocks, long known as the "Sunset Boulders", have attracted rock climbers for years. I've climbed these rocks before. But like so many other people, I had no idea I was touching history.

During the Pleistocene, 10 to 20,000 years ago, this place was very different than it is today, inhabited by massive mega-fauna; bigger elephants, lions, bears and wolves, than we see today. While those big animals went extinct thousands of years ago, they left their mark on this place.

Looking around these rocks it is easy for me to imagine the herds of Columbian Mammoths lumbering from the nearby wallow to rub against the boulders. I can picture huge herds of camel and horse grazing nearby. Yes, those animals evolved here in North America and then crossed into Asia where they thrived and survived. Weaving my way between the boulders, I can imagine how the predators could have used these rocks as an ambush site. I envision a huge saber-tooth cat slinking between the craggy rocks, looking to pounce on an unwary bison. I can see the prides of American Lion, similar but much larger than African Lions, basking on the tabletop boulders after a big kill. I can also picture the ultimate predator making their campsite here when that first hunting party foraged deeper inland. Yes, humans were here too. And I'm sure the same pull these rocks have today existed back then.

This seems like a sacred place to me. Sacred to history. So when you visit these rocks think about those who came before you. Think about the mammoth and the bison and the camel and the horse. Think about the lions, tigers, bears and wolves. And think about those first people. Tread lightly and respect this wonderful place. With care, these rocks will be here long after we all become part of history.

Special thanks to the San Diego Natural History Museum for contributing artwork and HD video to our story. Also, to see more artistic representations of Pleistocene mega fauna, by the artists who contributed to our segment, see:

Laura Cunningham's artwork

Artwork of Joseph Venus

William Stout's wonderful murals

Watch the Ice Age Bay Area television story online.