The window testing facility at Lawrence Berkeley National Lab. (Photo: LBNL)

Windows may not be as sexy as solar panels or electric cars, but they play a major role in energy efficiency. Buildings are responsible for 40% of the country’s energy use, which is why researchers at Lawrence Berkeley National Laboratory are trying to improve windows by making them smarter.

As Berkeley Lab engineer Howdy Goudey demonstrates in his lab, studying windows involves some pretty complex physics.

“So we use an infrared camera to study heat transfer in windows,” he says, pointing to a normal-looking video camera that senses heat instead of visible light. Goudey uses the camera to study how windows lose energy.

For the most part, windows simply aren’t good insulators. They leak heat in the winter when we want a warm house and they let heat in during the summer. Many homes still have single-pane windows, which were the name of the game in the 1940s and 50s when California was booming.

That changed when energy prices sky-rocketed in the 1970s. Double-pane windows became common. And then came double-pane windows with invisible coatings, which are twice as efficient. Today, they make up more than half of windows sold.

Measuring Low-e Windows

Goudey demonstrates how they work by turning on two heat lamps. “You’ve seen them in a diner keeping food warm," he says, putting them behind two identical-looking double-pane windows.

We stand in front of one window, which feels like standing in the sun. “But if you hold your hand to other one, compared to this one, it’s very dramatic,” Goudey says.

An infrared image of two windows during winter conditions, as seen from the inside of a room. The window on the right has a low-e coating while the window on the left doesn't. Warmer temperatures mean a better insulating window. (Image: LBNL)

The second window is cooler because it has a low-emissivity coating, or low-e, as its known. It’s an invisible layer of metal on the glass that acts as an insulator. And it does one more thing.

When sunlight shines directly through a window, it provides both light and heat. Most of us want light coming in, but heat is the last thing we want on a hot summer day. So, the coating on the window blocks the heat from the sun (in the form of infrared light), while letting in the visible light. This is known as solar gain. (Check out this guide for more on what to look for when buying windows.)

“If you have a few windows in a room with direct sun on them, its equivalent to running a little space heater. So it’s significant energy,” says Goudey.

However, on a cold winter day, the extra heat from sun would be helpful. “You’d actually like that solar energy to come in and help heat the space,” he says.

That’s why researchers are working to develop a “smart” or dynamic window that can change based on the weather or temperature.

Using Nanotechnology to Make Windows Smarter

At Berkeley Lab’s Molecular Foundry, Delia Milliron grows tiny nanocrystals that will eventually become a window coating.

“Nanocrystals are very small,” says Milliron. “Way smaller than you can see with your eyes. And so that’s why when we spread them out in a coating on the window, you don’t see anything.”

Milliron’s coating is dynamic. In one setting, it lets in both the light and heat from the sun. But, apply an electric charge of a couple volts and the window blocks the heat from the sun, while still letting light in.

Ideally, these windows would be controlled by your heating and cooling system, which could adjust them based on the weather. Milliron and her team are currently working on the coating itself. Their next step is to build a full-scale prototype. Other companies also have similar kinds of dynamic windows in the works.

Windows as Energy Suppliers

This changes the conversation about windows, says Stephen Selkowitz, head of building technologies at Berkeley Lab. Before, windows were energy losers. Now, windows could actually make buildings more efficient. And that means big cost savings.

“If we add up all the energy and economic impact of windows in the US, it costs building owners about $40 billion a year. And I’d rather have the $40 billion in my pocket than sort of sending it out the window,” says Selkowitz.

Smart windows could start appearing in larger projects like office buildings next year and should be more widely available to homeowners in three to five years. But they could be twice as expensive as today's windows. Selkowitz expects the cost coming down as manufacturing ramps up.

“The biggest expense in replacing windows is often the labor of replacing the window. And if you already decided to put a new window in, the marginal cost of going to a much better window is almost always worth it,” he says.

So, while it may be only a few tech-geeks that spring for smart windows at first, Selkowitz says that leads the way for the rest of us – and for new buildings codes, where technology can have a much broader impact.

On November 2, The World Science Festival, Columbia University and NOVA hosted a screening of What is Space? to coincide with the NOVA: Fabric of the Cosmos series premiere. The screening took place at Columbia's Miller theatre and was immediately followed by a live-streamed webcast, hosted by acclaimed physicist Dr. Brian Greene. The webcast allowed the in-theatre and digital audiences to further explore the program’s rich material in direct conversation with Dr. Greene — the series' host and best-selling author — as well as other featured program participants, including Saul Perlmutter, our local Lawrence Berkeley Lab astrophysicist and winner of the 2011 Nobel Prize in Physics.

What do they use? Mud. Yes, mud.

But not just any mud. For more than 60 years, all the mud used in major league baseball has been harvested from the same secret spot in southern New Jersey.

Jim Bintliff, the third-generation owner of Lena Blackburne Baseball Rubbing Mud, gets it from the banks of a tributary of the Delaware River.
Legend has it rubbing down new baseballs started after a wild pitch killed a batter in the 1920s. Bintliff said players and umpires tried tobacco juice and infield dirt to remove the factory sheen. What ended up working best was mud drawn from near the favorite fishing spot of a friend of Bintliff’s grandfather.
What makes his mud so special?

"It's the texture," said Bintliff, who described it as a mixture of cold cream and chocolate pudding. "If it's too gritty, it can damage the leather on the ball. It can scratch it."

Bintliff runs the mud through a series of screens before packaging it, aging it (like fine wine, he says), and shipping it.

Baseball is a sport of tradition and superstition, and many chalk up the sport’s fidelity to this particular mud to just that.

“To do it is a good idea,” said Robert Adair, a former Yale professor who wrote The Physics of Baseball. “To use this particular mud and everything is (one of the) charming traditions that connect us to our grandparents.”

But Adair acknowledges that there is some science behind Bintliff’s main selling point – his product’s smooth texture.

"Let's say you scuff or scar the ball on one side, that can produce asymmetric forces on the ball," Adair said.

If the ball is really scratched up, the air going over the marred side would have a different pattern than air going over the smooth side and the ball would curve toward the roughed-up side, Adair said. "If you threw the ball just any old way, you wouldn't get much of an effect, because the scarred spot would rotate,” he said.

If a sneaky pitcher is good, though, he throws the ball so the scarring is always on the same side. Adair estimated serious scratches could make the ball veer six inches one way or the other.

The mud’s origin in a tidal tributary rather than the larger Delaware River, then, is key.

"(In) the main-stem Delaware, a lot of the bottom sediment is coarser grain material," said David Velinksy, a marine biogeochemist with the Academy of Natural Sciences in Philadelphia.

Fine-grain sediments stay suspended in the rushing water of major rivers. In slower-moving tributaries, they have a chance to settle out, Velinksy said.

Of course, Jim Bintliff adds a secret ingredient to the mud after harvesting, so it’s not just Mother Nature who is responsible for the magic mud.

To see additional video from QUEST Philadelphia for this story, see: Baseball's dirty little secret.

These glass capillaries contain liquid solutions of silver nanoprisms synthesized by artist Kate Nichols. Image courtesy of Kate Nichols.

Originally inspired by the work of Northern Renaissance painters, one could also describe artist Kate Nichols as a “Renaissance” artist herself. Nichols applies a wide variety of skills and media to her creations, most recently with her pieces that incorporate her experimentation with nanotechnology.

Nichols was fascinated with the rich, bright hues of the Morpho butterfly, and sought to replicate those vivid colors in her work. Through research, she learned that the butterfly wings' brilliant blue color arose through structural color, and that nanotechnology could help her obtain this vibrant palette.

After writing an e-mail to scientist Paul Alivisatos and expressing her interest in nanotechnology, he enthusiastically supported her endeavors (Alivisatos is also a photographer) and Nichols became the first artist-in-residence at the Paul Alivisatos Group at Lawrence Berkeley National Laboratory.

Working in the laboratory setting didn't come naturally to her as she had no background or formal training in science.

"I spent the first part of my experience in the laboratory reading scientific papers that would describe specific procedures. And I would get so frustrated that I couldn't achieve the same results. It takes a lot of practice to be able to be up and running in a material science chemistry lab," says Nichols.

But over time and through the guidance of her colleagues, Nichols learned to synthesize nanosilver particles to create the beautiful colors she uses in her work.

Learn more about Nichols and her work in Color By Nano: The Art of Kate Nichols.

QUEST on KQED Public Media.

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Lawrence Berkeley Lab's TEAM 0.5 is capable of resolving individual carbon atoms in the honeycomb crystal structure of graphene. See QUEST's video The World's Most Powerful Microscope for more information. Image source: Nano Letters

Fifty years later, a new field of nanotechnology has exploded. At the cutting edge, researchers are successfully manufacturing everything from corporate logos to radios that are all small enough to be stacked end-to-end perhaps a million items long across the proverbial head of a pin. The advent of personal computers and smart phones has brought the power of such miniaturization into sharp focus for the general public. In a very real sense, we have all become bottom feeders. Below is a brief progress report on the state of the field.

Microscopes: The old adage “seeing is believing” was not lost on Feynman back in the late fifties. He noted that many of the most fundamental questions in biology could be readily solved if we only had the ability to see the molecules directly. Today, new inventions such as the scanning tunneling microscope (STM), the atomic force microscope (AFM), and the transmission electron microscope (TEM) have all achieved resolution at the scale where individual atoms can actually be seen and manipulated.

Miniature Motors: Perhaps the speech’s most imaginative scenario, due to Feynman’s friend (and graduate student) Albert Hibbs, was the concept of being able to “swallow the surgeon.” Feynman imagined that we might some day be able to construct robots capable of repairing or investigating the inner reaches of an ailing patient’s body. Mixing engineering and biology like this can run quickly into thorny ethical questions. Nevertheless, interesting progress has been made. Researchers in Alex Zettl’s group at UC Berkeley have recently constructed a nano motor, for example.

Information Storage: Using order-of-magnitude arguments, Feynman argued that the Encyclopedia Britannica could be squeezed into a pin’s area if the text were reduced by a factor of 25,000. He offered a $1,000 prize to the first person capable of printing one page of any book at this scale. Tom Newman, a graduate student at Stanford, first accomplished this in 1986 with an impressive reprinting of the first page of Dickens’ classic A Tale of Two Cities. Today, you can buy the book in its entirety for only 1.9 megabytes. For a high-end smart phone with 30 gigabytes of memory, you could perhaps hold 15,000 books within the palm of your hand. Not bad.

Then again, at the extreme limit, Feynman also reasoned that you ought to be able to squeeze the text of every book that has ever been written (now more than 32 million titles according the Library of Congress) within the confines of a single speck of dust. We still have a long way to go.

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The Sloan Telescope used to conduct BOSS

One of those is BOSS, the Baryon Oscillation Spectroscopic Survey, is a new project to create a 3-D map of over 2 million galaxies and quasars representing the best data ever obtained on the large-scale structure of the universe. Baryon oscillations began as pressure waves through the hot plasma of the early universe. Those waves left an imprint on the matter that makes up the universe, including the dark matter. The survey will essentially act as a ruler, in order to measure how the universe has been expanding.

Next Monday, you’ll be able to meet David Schlegel, the principal investigator of BOSS. He’ll be part of a panel of Lawrence Berkeley Laboratory scientists discussing their search for dark energy. As a primer, check out QUEST’s story on Dark Energy from last year. The piece features astrophysicist Saul Perlmutter, who will also be speaking at the event.

See QUEST's Video on Dark Energy below:

QUEST on KQED Public Media.

Dark Secrets: What Science Tells Us About the Hidden Universe

Where: Berkeley Repertory Theater, 2025 Addison Street, Berkeley

When: Monday, October 26th 7-830 PM

Cost: FREE

Details: No mystery is bigger than dark energy — the elusive force that makes up three-quarters of the Universe and is causing it to expand at an accelerating rate. KTVU Channel 2 health and science editor John Fowler will moderate a panel of Lawrence Berkeley National Laboratory scientists who use phenomena such as exploding stars and gravitational lenses to explore the dark cosmos.

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A scanning electron microscope image of an invisibility cloak recently fabricated by Valentine et al. at UC Berkeley. The inset at lower right shows a close-up of the triangular cloak and the corresponding bump that the experiment worked to conceal. Reprinted by permission from Macmillan Publishers Ltd: Nature Materials 8, 568 – 571, copyright 2009.

While invisibility has been largely the stuff of fiction and allegory, that may only be true a short while longer. Two papers published by groups at UC Berkeley and Cornell have recently demonstrated that objects can now be rendered invisible at wavelengths nearly (but still not quite!) short enough to fool human eyes. The technique has come to be known as optical cloaking.

How does it work? Essentially, cloaking makes an object appear invisible by wrapping the object in a metamaterial designed to bend light. Such bending is common in everyday life, seen for example when you look though a glass of water. The genius of a metamaterial is that it has been carefully crafted to bend light exactly to where it would have gone in the absence of the cloaked object. As a result, both object and cloak are rendered invisible.

In 2006, the first physical version of this concept was demonstrated at Duke in the form of a microwave invisibility cloak. It was not without limitations. Imagine a magic rug that, when wrapped around a standing person, makes the person invisible to only one color, and unfortunately not even a color you can see with bare eyes. You would need something like a radar detector to see how invisible they were. Nevertheless, it was stunning demonstration of the cloaking principle.

The push since this first demonstration has been to extend the properties of this to ever shorter wavelengths, and the Berkeley and Cornell groups (respectively headed by Xiang Zhang and Michal Lipson) have succeeded in doing that with a newly designed "carpet cloak." The new design works quite literally by sweeping an object under a rug. An irregular bump on an otherwise flat conductor is covered with the carpet cloak. Then, when light bounces off both cloak and conductor, the cloak rearranges rays of light to make it appear as if the entire surface were flat.

The cloaks of both groups are at best capable of concealing an object no bigger than a speck of dust, but they make up for it in other areas. The demonstrated cloaks may now hide objects from wavelengths as short as 1,400-1,800 nm. (The microwave cloak above is optimal at about 3.5 cm.) Cut that number down to 700 nm and you truly begin to render objects invisible to human eyes.

The prospect of such technology dazzles the imagination. Could we use such a cloak to hide spy planes? Ugly buildings? UFO landing sites? Jason Valentine, the lead author of the Berkeley group, said that more realistically the new technology could be used to refine defects in expensive electronics. However, because of the mathematical parallels between metamaterials and general relativity, some have even proposed that the new technology be used to test deep space theories related to things such as a black hole's event horizon.

Maybe Alien vs. Harry Potter isn't quite such an awful movie idea after all.

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