If you’re like most Californians, you’ve probably never heard of the Delta or why it’s important to the state’s economy and wildlife. In three minutes, we’ll explain how the Delta is a key part of California’s water supply and why it’s been the focus of a decades-long water battle.

 Capturing the Night Sky: Past and Present Educator Guide

Which begs the question, how did they do that before cell phones? As the saying goes, behind every good digital astronomy app is an analog photographic plate. Beginning in the mid-19th century, astronomers began utilizing the art of photographic emulsion to capture images of celestial objects. For the first time, astronomers were able to etch their discoveries onto thick glass plates ushering in a new era of data analysis that would help unlock the mysteries of the universe.

But don’t take my word for it. If it’s good enough for Einstein, it’s good enough for me.

Photographic plates helped scientists determine the size, distance and composition of celestial objects such as stars, comets, meteors and planets. Galileo Galilei would be proud. By the early 1990s, the once highly esteemed “analog” plates had fallen out of favor for images captured by new, charged-coupled devices such as digital cameras. Many of the old plates were put on the shelf and stored in basements and barns.

PARI to the rescue: the Pisgah Astronomical Research Institute (PARI) is a non-profit astronomy, research and education facility located in western North Carolina. PARI scientists recognized the archival value in saving the old astro-photographic plates and created the Astronomical Photographic Data Archive, or ADPA, to be housed at PARI’s vast campus.

I recently had the opportunity to visit PARI, poke around their archives and find out why it’s worth saving the old data. What I discovered was that these plates – which a lay-person like me can easily mistake for a dirty windshield {include pic here} – contain a lot data that’s not only historic, but vital to today’s research.

During our visit we spoke with scientists from NASA (link to web extra) as well as the European Space Agency who attribute the success of current and future space missions to data gleamed from APDA.

It turns out there is no expiration date on these invaluable snapshots of the night sky. The plate’s spectral images act as a time-stamp for what the night sky looked like before it was polluted with what one NASA scientists described as “space junk.”

The scientists at PARI compared their collection to the Library of Alexandria. Science Director Michael Castelaz told me, “If that library hadn’t been destroyed, the knowledge that could have been passed on from the philosophers and the Greeks from three millennia ago would just have benefited us greatly. So I think we’re in the same situation.”

Castelaz believes the hidden potential inscribed in the plates have yet to be fully realized. He and his PARI colleagues are stewards of history, preserving the pates for future generations and ensuring that the next Einstein has the resources to turn the world on its axis once again. After all, the proof is in the plates.

^{Mineral springs, fresh air, and a cross-section of South Bay history—not to mention its rocks—are all on display at Alum Rock Park. All photos by Andrew Alden.}

Alum Rock Park occupies the small, steep valley of Penitencia Creek carved into the hills east of San Jose. The city has owned it since 1872, when it became California's first city park. For a generation it was a major regional attraction for its warm mineral springs and the entertainment complex surrounding them, of which only traces remain today.

Today it's a great place to get away from the city's hustle while pretending you're still at the office (except on Mondays, when it's closed). But if you put away the phone and pay attention to your surroundings, Alum Rock Park can show you some of San Jose's deep history and the Bay Area's rocks.

If nothing else, the park provides good views to the west over the Santa Clara Valley from its higher trails. You can choose from a warm south-facing slope and a cool north-facing one, too.

Have a look at the geologic map of the area (from USGS Open-File Map 98-795) below.

Penitencia Creek comes downhill from the right center and exits on the lower left. The park entrance is right at the edge of bedrock (Kbc, conglomerate of the Berryessa Formation), and the uppermost parking area is at the Tcc (Claremont Formation) mark. Hiking trails run along both sides of the creek giving you a good look at all the rock units from the park entrance to the Briones Formation (Tbr) on the right. Let's see some, starting with the conglomerate.

This very coarse grained rock and its related sandstone in the Berryessa Formation are part of the Great Valley Sequence, thick beds of sedimentary rock built up while the Sierra Nevada was intruding all that granite, back around 100 million years ago in Cretaceous time.

Behind the boulder is Eagle Rock, which corresponds to the pinkish blob surrounded by landslides to the right of the "Kbc" label. You can climb up there or stroll through the other outcrop labeled Jbk. The rock itself is well-traveled volcanic material that has been permeated and altered by hot mineralizing fluids. Here's a chunk of it.

The large outcrop along the creek gives the park its name. An early visitor mistook the whitish crust on these rocks as alum, which would have been a nice find at the time. It's actually sulfate minerals, but the name stuck.

Farther upstream, just past the visitor center, is where the mineral spring zone begins. On the geologic map, it corresponds to the exposure of Claremont Formation (Tcc), a belt of ribbon chert of Miocene age (about 10 million years) familiar in the East Bay Hills. Here the chert is dark with organic matter and its beds are upturned almost to vertical. That combination of chemistry and structure has given rise to warm upwellings of chemically interesting groundwater.

There are more than 20 different springs here, each with a nice stone housing. The ones I dipped my fingers into were bathtub-warm, and the water is sulfur-scented. A hundred years ago Alum Rock Park was a big health spa, with a rail line direct from downtown. That was when the stonework was done. You can see where seepage has built up cones of minerals on the lower wall. All of the springs issue from the Claremont chert—here's a closeup of the chert and the mineral crust.

After all that excitement you may want to continue upstream, into the structurally overlying and younger Briones Formation. This set of rocks is coarser grained than the Claremont, deposited nearer to shore. The other way to look at it is that the shoreline grew closer to this spot as geologic time progressed. This is a well-scrubbed outcrop in the stream bed that shows its bedding.

Parts of the Briones are so full of fossils that the rock is best described as shell hash. You'll see this same stone at Lime Ridge in Walnut Creek and other places in the East Bay.

This whole belt of rocks lies in the zone where the Hayward fault merges with the Calaveras fault. On the map above, the Calaveras runs down the right edge of the Briones Formation, between the Calaveras and Anderson Reservoirs. The Hayward fault formally ends a few miles northwest, but the many smaller faults marked as heavy lines are of the same ilk and reflect the same tectonics. Friction along the faults may account for the warmth of the springs, just one more way that the deep Earth affects us in our region.

You can also check out QUEST's Alum Rock Science Hike for more info.

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Although it may not be obvious at first glance, the bay side of San Francisco is largely artificial. The huge increase in population associated with the California Gold Rush of the mid 1800s resulted in San Francisco becoming the major port on the west coast. In some cases, people seeking riches in the Sierra Nevada headed off to the mountains and simply abandoned their ships in San Francisco. Some of these ships ended up being used as landfill and, year after year, the shoreline along the northern and eastern sides of the city was modified.

The area where Market Street meets the Embarcadero was among the earliest areas to be extended into the bay, but landfill — a combination of sediment dredged from the bay with rubble — continued to be used to create new "land" for decades to come.

The map below* shows this modification quite nicely. Original creeks and streams are in blue, marshes in aqua-green, and modern landfill in pink.

What I like about this map is how the pink landfill areas highlight the old shoreline. Note where the original creeks and marshlands met the bay. What is now a relatively straight shoreline was once very irregular with several natural embayments. Mission Bay was once an actual bay. I find it fascinating to picture the city in this way — the way it was a little over a century ago.

The areas that are now landfill are important to consider not just as interesting history, but also in the context of earthquake hazards. Last week I discussed Bay Area seismic hazard preparedness and an important component of getting ready is to learn about how different types of land respond to the shaking.

The map above** was produced by the USGS and shows the liquefaction hazard — red is very high hazard, orange is high, yellow moderate, green low, and no color is very low. Liquefaction is essentially when loose sediment behaves like a fluid when shaken, which can result is serious damage to buildings and houses.

Note the correspondence between the red areas on the liquefaction hazard map with the map showing where landfill and old marshes are. While it may seem like solid ground when you are walking or driving on the street it's important to remember that the fill underneath is quite loose compared to actual bedrock.

~

* This great map, and many more, can be found at the website for the Oakland Museum of California: http://museumca.org

** See the entire zoomable map, learn more about liquefaction hazard, and how the USGS made this map here.

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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.

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This 1928 home in Albemarle County, Virginia recently
underwent a renovation through the EarthCraft Virginia
existing homes renovation program. After the renovation,
electricity use dropped by 24% and energy costs dropped
by 42%.

Home Energy Magazine is celebrating its 25th anniversary with a special May/June issue. We're taking the opportunity to look back at the past several decades of energy policy in America, and look ahead to what may come. Here's a sneak preview of some of what we're thinking.

Alan Meier, Senior Executive Editor, and Steve Greenberg, Technical Editor, among others, lived through the first energy crisis precipitated by the Arab oil embargo in 1973 and its aftermath. They remember the sudden interest in energy efficiency and renewable energy; the proliferation of solar water heaters on the roofs of homes that broke down quickly, had no one trained to fix them, and have become rusted monuments to the best of intentions gone wrong; the sudden and short lived gain in the average car’s fuel efficiency. They also recall some major successes: the huge and lasting increase in appliance efficiency, especially refrigerators; the success of the Energy Star program; and California’s progressive Title 24 building standards.

Alan, in a yet-to-be-published editorial, has been musing on what will happen after the billions of dollars from the American Recovery and Reinvestment Act (ARRA) have been spent on building and retrofitting more efficient and sustainable buildings. Will it be the same three steps forward, two steps back pattern that we’ve seen before? Not so, according to Alan, if we:

Steve came up with some powerful images to stimulate our thinking about the future of energy efficiency:

We've been on a ramp with a rather gradual (and usually upward, with notable exceptions) slope. Suddenly the ramp gets so steep it looks like a wall. If we make it to the new, much higher level, what does the terrain look like? Do we go off a cliff, completing a boom and bust cycle the likes of which we've never seen? Or is there a reasonable ramp down to a sustainable level?

I lived through the lines for gasoline, though I couldn’t yet drive. I've observed the resulting interest in miles per gallon instead of horsepower; the return to a horsepower-mentality; and the recent switch back to a concern about miles per gallon. My family had a great experience with our new-fangled heat pump in the early 70s. My Dad, an engineer and all-around handy man, first got me interested in how houses and cars work during that time. I guess I vote for a steep, but not impossible ramp up in efficiency, followed by a less intense, slow and gradual climb that continues for a long time, with sudden jumps due to new, undreamed of (or only just dreamed of) technology. The pressure will come from high energy prices and people starting to feel the real effects of global warming and unhealthy air. I don't think these things will change anytime soon.

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Dr. Daniel Hale Williams (1856 – 1931)
Physician
Williams was born in Pennsylvania. He helped support his family after his father died when he was nine. At first, he worked as a shoemaker’s apprentice. Then as a teenager, he learned to cut hair and became a barber. While working as a barber, he met Dr. Henry Palmer, who later became the Surgeon General of Wisconsin. Dr. Palmer took Daniel on as a medical apprentice; and helped him gain acceptance to medical school. Dr. Daniel Hale Williams graduated with his medical degree in 1883. Disillusioned with the second-class care for African Americans, he founded the Provident Hospital in Chicago in 1891, the first African American-owned hospital in the United States. He made history at Provident Hospital by performing the first successful open heart surgery in 1893. His patient James Cornish, injured from a knife wound, fully recovered and lived for another twenty years.

Percy L. Julian (1899 – 1975)
Chemist
Alabama-born Julian held a bachelor's degree from DePauw University. He was unable to procure a chemistry Ph.D. from Harvard University because of discrimination, and left after receiving a master's degree. He later received a Ph.D. from the University of Vienna in 1931. He became a pioneer in the chemical synthesis of medicinal drugs from plants. He gained over 130 chemical patents in his lifetime. The most notable patent was for the production of cortisone. For his contributions to medicine, he became the fist African American chemist inducted in the National Academy of Sciences.

Elijah McCoy (1844 – 1929)
Inventor
The son of escaped slaves from Kentucky, McCoy was born in Canada and educated in Scotland. Settling in Detroit, Michigan, he invented a lubricator for steam engines. It was patented in 1872. Lubricators were a boon for railroads. Trains could run faster with less need to stop for lubrication and maintenance, thus improving profit lines. McCoy improved on the lubricator design over his lifetime as well as amassing over 50 other patents. Lacking the revenue to manufacture his own lubricators, he sold the patents to employers until 1920 when he was able to open Elijah McCoy Manufacturing Company. It is still disputed today if the phrase “The real McCoy” was derived to compare McCoy lubricators to generic and inferior copies.

Cat Aboudara is the Special Projects Manager at California Academy of Sciences and works in the public programs division. The Academy is a wonderful fit for her because of her curiosity about the natural world and her experience in working with native California wildlife.

latitude: 37.7734, longitude: -122.454