Posts byJessica Smith

Two stories about old light bulbs

Source: lightbulb has been illuminating a firehouse in Livermore, CA continuously for more than 100 years. Known as the Centennial Light, the hand-blown carbon filament lightbulb has only been turned off a handful of times. The bulb is now attached to a generator to minimize future power disruptions. To see for yourself, check out this 24-hour live web feed of the bulb.

As unlikely as it may seem, the Centennial light is not the only lightbulb that has been burning for an improbably long time. The Palace Theater lightbulb in Fort Worth, TX, has been burning almost as long. Theories as to why these lightbulbs could last so long include that these bulbs have a particularly perfect vacuum seal, that the lights have been turned on and off minimally and that the bulbs are powered at low wattage.

Nanoparticle distillery

Just in time for the holidays, research out of Naomi Halas‘s group at Rice University shows that nanoparticles can do what we’ve been waiting for all along: distill alcohol. The Halas group is known for making gold nanoshells, consisting of a 60-120nm silica core coated with 10-20nm of gold. The silica core is made colloidally by reacting silica monomers in the presence of a micellar surfactant. Then, the gold shell is applied by reducing gold ions on the surface of the silica.

These nanoparticles have interesting optical properties, including absorbances in the near infrared. The group has used these nanoshells primarily for cancer therapy due to their local heating properties. Luckily, that same surface heating effect can be used to efficiently create steam… and distill alcohol.

Structural color

Researchers in Singapore are pushing the boundaries of printed color. In a recent issue of Nature Nanotechnology, Joel Wang and coworkers report a method of printing diffraction-limited pixels using the structural color of metallic nanostructures. Structural color refers to materials which derive their pigment from the interaction of tiny mico- or nanometer structures with light, rather than the absorption of light that occurs in most organic dyes. The light scattered by silver, for examples, can be different colors depending on the structure (size, shape, aspect ratio) of the metal at the nano-scale. In this recent paper, the idea of structural color is refined to create extremely high resolution printing. Specifically, arrays of nanometer-scale glass posts are coated with silver; the size and spacing of the posts controls the color of each pixel consisting of a 2×2 post subarray. The result is a remarkably reproduced Lena image, a standard test in the imaging community.

Science in Sacramento: Update on Prop 37

In June, I wrote that signatures had been collected for a ballot measure that would mandate the labeling of foods in California that contain genetically modified organisms (GMOs). As expected, residents of California will vote on the measure this November as Proposition 37. In a recent poll, likely CA voters supported the proposition two to one.  You can read the full text of the inititative here.

As noted in my previous post, California tends to set trends for the nation regarding health-related laws.  That means that the eyes of the nation are on this proposition. Mark Bittman, New York Times food columnist, wrote in favor of labeling GMO-containing food, though not everyone agrees with his analysis. Slate magazine presented the argument that GMOs could be good for the environment.

Scientific fraud and non-reproducibility,_October_16,_2007.jpg Science journalist Carl Zimmer recently wrote in Slate about the issue of non-reproducible results in various scientific disciplines. In particular, he cites a famous study of a purportedly cancer-causing gene, SATB1, which could not be reproduced. Zimmer generously rules out intentional fraud as the culprit, instead pointing his finger at the tendency to ignore or diminish negative data for the sake of publication.

Most scientists can probably name a prominent paper that the majority of their subfield agrees isn’t completely true. One of the most shocking things to me when I started laboratory research was when a senior graduate student told me not to use a published protocol because no one could reproduce it. Luckily, advances in my field, noble metal nanoparticles, are unlikely to make it into a the popular media. When papers relating to human health have problematic findings, the results can be disastrous, as in the notorious study linking the MMR vaccine to autism in children.

Sally Ride’s Legacy

Sally Ride, courtesy Ride was the first American woman in space, first entering the Earth’s orbit in 1983. After leaving NASA, she became a professor and dedicated herself to early science education. She continued to be involved in the space program, including after the Challenger and Columbia disasters struck. She died on Monday, July 23rd, 2012 at the age of 61 of pancreatic cancer, leaving behind her partner, Tam Elizabeth O’Shaughnessy.

I know more than one person who was inspired to become a scientist because of Sally Ride. Speaking to them, they rarely pointed to the barriers she broke, but rather, the integrity she demonstrated throughout her life. In addition to her work on science education, her work with NASA exemplified conscientious leadership. Her support for Roger Boisjoly, the whistleblower who predicted the Challenger disaster, must have come at a price.

Science in Sacramento: Steps toward a ban on genetically engineered food in California

This post is part of a series called “Science in Sacramento” which examines how science effects California state policy and vice-versa.

Source: in May, supporters of a proposed California ballot measure to label foods containing genetically modified food celebrated. They had surpassed their goal, turning in over 900,000 signatures to put a measure before voters in November. Given the topic’s contentious past, and because the number of signatures is double the amount required, California residents are very likely to be hearing quite a bit about genetically modified organisms (GMOs) until Election Day.

Some countries in Asia and Europe require labeling of any product containing genetically modified food, but similar progress has not been made in the United States. California would be the first state to begin the practice. Similar ballot measures in Connecticut recently and years ago in Oregon have proven unsuccessful. Because California health and environmental laws, like the ban on smoking, tend to set trends for the nation, opponents of genetically modified food from all over the US are hoping the law is passed in November.

Nanotechnology with caution, not fear

I’m always wary of popular science articles about my field of research: nanotechnology. For some reason (probably related to yet-to-be-invented nanorobots), the word nanotechnology strikes fear into the hearts of many. I felt I had reason to be optimistic, though, when a friend sent me a blog post about nanotechnology from the New York Times. The author, Diane Ackerman, consulted none other than Carl Sagan for her first book; I hoped she might be reporting on nanotechnology with the same perspective and insight.

Unfortunately, that did not turn out to be the case. I really enjoy Ackerman’s style (I have a fondness for literature in general and Walt Whitman specifically.) She could have used his poetry in explaining a nanoscience concept in a way that appeals to lovers of literature or science. Instead, she resorts to fear-mongering and misrepresentation of the fundamental science of these new technologies.

Robo-graders like long words, not so big on intellectual coherence

When I glanced at the title of a recent New York Times piece on automated essay grading, “Facing a Robo-Grader? Just Keep Obfuscating Mellifluously,” I assumed it was just another fluffy popular science article. Surely no serious organization would use a computer program to grade essays. Not long into the article, however, I discovered that the “robo-grader,” named the E-rater, was developed not by university scientists but by the Educational Testing Service — the organization that administers the GRE and the TOEFL, among other exams.

For now, E-rater only grades essays that are also read by a human grader. Though the grades given by humans and E-rater have been remarkably similar, Les Perelman, an MIT professor, has his reservations about the software. After a month of testing, he has determined that E-rater favors long paragraphs and sentences, connecting words like “moreover,” and words with many syllables. Most troubling is that the E-rater can’t determine the truth or intellectual coherence of statements in the essay, used to hilarious effect in an example essay  by Perelman.

What is the difference between pepper spray and tear gas?

Pepper spray is back in the news in California. Students at Santa Monica College were pepper sprayed by the police during their ultimately successful protest of higher fees for the most popular classes. Other high profile clashes with the police have included the tear gassing of Occupy Oakland protesters earlier in the year and the notorious misuse of pepper spray by a University of California police officer against students at UC Davis.

Every time one of these incidents hits the news, the scientist in me wonders what the difference is between pepper spray and tear gas. My own experiences with tear gas in protests in Oakland shed little light on the distinction.

Science fair advice from a judge’s perspective

This Wednesday, I was a judge for the San Francisco Bay Area Science Fair. Seventh through twelfth grade students submitted original research projects in field including physical science, biological science, environmental science and behavioral science.

I didn’t know what to expect when I showed up in the morning to get my judging assignment. I had no idea what the quality of the projects would be like or how far from my field of expertise I would be assigned. I was just excited to be around young people who weren’t as frustrated with science as the grad students and post-docs that I interact with every day.

As it turned out, though, I didn’t get to interact with the students at all! I was so disappointed. I was to select the recipient of a special award in materials science while all of the students were gone for the morning. This plan minimized the possibility that I would be charmed into giving the award for a less worthy project. But it also meant that I didn’t get the chance to dispence my wisdom to any aspiring scientists, so I will offer it up in this space.

Sneak preview of BERC’s Electronics Waste Roundtable: an interview with Zoey Herm

Ever wondered what you’re supposed to do with your old electronics once you stop using them? Ever considered how the often toxic materials in your old laptops and cellphone can best be managed? If you’re interested in learning more about electronics waste recycling, head over to the Berkeley Energy and Resources Collaborative (BERC) sponsored Electronic Waste Roundtable this Friday, February 17th at 2:30 in Banatao Auditorium, Sutardja Dai Hall. Speakers will include employees of market-drivers in the field, like Dell, and members of policy-oriented organizations, like Electronics TakeBack Coalition.

Last week, I had the chance to talk to Zoey Herm, Berkeley grad student and organizer of this forum, about electronics waste.

Why did you choose to organize a roundtable on electronics waste?

This is a very pressing issue globally in terms of human health and the environment. Specifically the topic was of interest to the Berkeley Energy and Resources Collaborative because there’s a huge vacuum in the market for solutions to this problem. There are a lot of market incentives to work on this problem, which can be pushed by regulations, but also exist on their own. There’s a lot of valuable materials – plastics and metals – in electronics waste which can be recovered for profit.

A solved puzzle

If you pick up a Sudoku puzzle with your morning coffee, you may want to count the number of clues before you begin. An Irish mathematician has recently proven that Sudoku puzzles with 16 clues or less do not have unique solutions. Sudoku fans and mathematicians have long suspected that designing a puzzle with 16 clues was impossible. Using a supercomputing facility, Gary McGuire was able to prove it. Unfortunately, if you’re struggling with a more forgiving puzzle, you have no one to blame but yourself.

Radiolab and the philosophical origins of scientific inquiry

I love Radiolab. I’ve listened to pretty much every episode of this innovative science radio show, so I was thrilled to attend Radiolab: Live In the Dark at Zellerbach Hall last Friday. The live version of the radio show was put on as part of the 2011 Bay Area Science Festival (you can read more of BSR’s coverage of the festival here).

The funny thing about Radiolab is that many of its listeners don’t realize they’re being treated to rich science radio programing. In a way, they aren’t; the show doesn’t follow the usual script of explaining recent research breakthroughs in simplified terms, and the live act was true to the show’s unconventional style. Two of the three segments, a discussion of the experience of blindness and a few stories from an astronaut, were only tangentially connected to specific scientific discoveries. The third, an explanation of the eyeball’s evolution, was closer to standard popular science fare, but shared with the other two segments a profundity that surpasses the glorified press releases that often pass for popular science.

I thought the third segment, hosted by Jad Abumrad and Robert Krulwich, was particularly fascinating — as well as visually sumptuous in a live setting — simply because, well, I’m a big science dweeb. But my friends — historians, artists, librarians, and waiters who previously knew very little about the science of the eye — loved the segment for very different reasons. For them, the intrigue came from the way that Jad and Robert connected a series of scientific discoveries back to a fundamental idea: the validity of evolution itself. Their experience reminded me that science makes important contributions to greater understanding of “existence, knowledge, values, reason, mind, and language.” As a graduate student, it is easy to lose sight of the big picture, but Radiolab made the connection obvious again.

Science in Sacramento: A ban on BPA for babies

You don’t have to live in Berkeley for very long to know that BPA is decidedly uncool around here.  BPA – short for Bisphenol A, a hardening agent in plastics – is part of the reason metal or glass water bottles long ago replaced plastic as the hip hydration accessory for many Berkeleyans. Now, the California State Assembly – perhaps a little slow to get with the program – has introduced a bill which would ban BPA from all baby products.

Why, you may ask, does BPA have such a bad rap? Besides its role as a hardening agent in plastics, BPA mimics estrogen, the hormone responsible for female sex characteristics and metabolism control. This is bad news bears for little babies and older folks alike. In rodents, exposure to BPA has been shown to cause problematic symptoms such as obesity and mammary gland development. Most humans display a constant low level of BPA in their bodies, and while experts disagree about how dangerous such an amount of BPA might be for adults, scientists are increasingly agreeing that BPA is bad for infants. Because many baby bottles contain BPA, levels of BPA in infants’ bodies can spike with each feeding; some data shows that BPA is correlated to obesity, diabetes, and ADHD later in life.

Science in Sacramento: Researchers and gold miners

This post begins a series called “Science in Sacramento”, which will examine how science effects state policy and vice-versa.

Governor Jerry Brown’s recent line-item veto might have big consequences for… gold miners. Yes, gold miners. Though many California residents likely think of gold mining as an industry of the past, gold mines and other gold extraction endeavors continue to operate throughout California.

Modern miners rarely use gold pans or shovels, but rather a technique called suction dredging. After gravel from a river bed is loosened and pulled through a hose, the heavy gold is separated from the unwanted material by centrifugation. While efficient in collecting gold from riverbeds, the process has been shown to disrupt certain aquatic environments.

Peter Moyle, a professor at UC Davis, has studied the Klamath River and demonstrated that suction dredging irreversibly alters the life-cycle of Chinook salmon that spawn there. Moyle’s scientific research interests require him to observe fish in their native habitat; he initially realized suction dredging is a problem because he couldn’t see fish in rivers due to the sediment clouding the water. As a result of this and other research, a moratorium was placed on suction dredging for gold mining in California in 2009 until a comprehensive study could be conducted by the Department of Fish and Gaming.

Are we there yet?

I recently went to see (or, I suppose, hear) a new sound exhibit at the Contemporary Jewish Museum in San Francisco called “Are We There Yet?”, which will be on display until July. This exhibit is, in a word, cool. I walked into an architecturally beautiful room and heard different voices reading questions, sometimes overlapping and sometimes complementing each other. Just as cool as the aesthetic experience, though, is the visual tracking system that UC Berkeley engineers developed to give every participant a unique experience. The combination of cutting edge sound equipment with cleverly engineered computer tracking allows the voices to seemingly follow a viewer throughout the room.

The questioning voices of the exhibit are intended to invoke the practice of questioning within the Jewish faith. The engineers who designed the technical scaffolding to achieve this vision also started with a question. “How do you accurately tell the difference between the sun’s reflection on the floor and a person’s bright white shirt, if you’re a computer?” asks UC Berkeley Electrical Engineering graduate student Andrew Godbehere.

A fresh look at green chemistry

“Problems cannot be solved at the level of awareness that created them.” – Albert Einstein

I had never heard the above Einstein quote until I attended “Green Chemistry: Collaborative Approaches & New Solutions”, a conference hosted by the Berkeley Center for Green Chemistry on March 24th, 2011. To my surprise, two separate speakers included this quote in their presentation; by the end of the conference, I understood why. Making materials that are both safe and inexpensive is one of the main challenges in the field of chemistry today. After listening to all of the speakers, I’m convinced that chemists can only overcome this challenge if we consider it an opportunity to think about chemistry in a new way.

The field of green chemistry grew from an awareness among chemists of the environmental and human health effects of many chemicals. Green chemists endeavor to design molecules with toxicology in mind, ultimately replacing hazardous materials that must be contained with materials that are designed to safe. Two of the founders of green chemistry, Dr. Paul Anastas and Dr. John Warner, spoke at the conference about their twelve principles for chemists who are dedicated to creating less hazardous materials. These principles include using safer solvents in synthesis and designing molecules that will degrade into harmless components. Warner refuted the idea that “green chemistry is a set of handcuffs that slows productivity,” citing examples from his own company (Beyond Benign) of chemicals which are both profitable and harmless, such as a green hair dye.