A Lifetime of Chemistry

Tim Clark is a jolly looking fellow: he’s tall, he’s round, and his beard is white. When he speaks, a low rumble overtakes the room and you listen to what he has to say. Tonight, he’s telling stories of Professor Paul von Ragué Schleyer.

Paul Schleyer, at the age of 83, is still a practicing chemist. He has several students and teaches a graduate course in the fall. He’s written many technical books–along with one, as of yet, unpublished memoir–and has published over a thousand papers. He is an expert in synthesis and computational chemistry. It’s fair to say, he’s had a good career.

Tim Clark was there when he left Princeton for a small German university–a move that confused many. “I know what lured him,” Clark says. “I’ve seen her.” The next slide shows a large computer in a cabinet. Clark tells us that it has 0.2 MB of memory. This is what Schleyer had left the prominent university for: a machine with the computing power of a modern wristwatch. The switch was, obviously, successful. Schleyer’s reputation only increased as he tackled the new field of computational chemistry.

After discussing some of the work he and Schleyer had done together, Clark showed a series of quotes by famous scientists. Most were mocking chemists. The crowd had a good laugh. The final slide had this quote from Justus von Liebig, “The loveliest theories are being overthrown by these damned experiments; it’s no fun being a chemist anymore.”

Schleyer followed Clark with a short speech thanking him for the presentation. He told the story of how Clark came to work for him on adamantane, but never got around to it. He read a passage from a technical book by Norman Allinger which contained an anecdote of Clark being impressed by the speed of molecular mechanics. He ended his speech with a sentence that typifies his research career, “I am still a strong proponent for fundamental research; I think its natural home is in universities.”

Does Government-forced Open-access Help Science?

As scientists along with government officials in the House and Senate work to pass bills that force government-funded research to be freely accessible, one question pops to mind: Will peer review–the principal standard in scientific research–work with open-access?

With current subscription based journals, the publication process involves an editor, who is paid, a number of reviewers, who are not paid, and a boat-load of people formatting, producing and distributing the content–all paid. With open-access format, how do publications get reviewed or formatted or distributed? At the very least someone needs to coordinate reviewers maintain a website.

Will the government finance current publishers or will government-funded research go strictly in government-funded journals? Since most research is funded by government grants–judging from the funding sources listed at the end of academic papers–the later would force many publishers out of business. The specificity of smaller journals would be lost, and all research may get lumped together–though I suppose they’d separate fields like physics and psychology. Publishers, of course, are calling the open-access bills “unnecessary and a waste of federal resources.”

And who would keep track of citations? Right now, there is an intricate bookkeeping system keeping track of citations for each author–for a fun dick-measuring game of who has the most citations–and an overall “impact factor” of the journal–another game to see which journal is most cited. Though I call these games, keeping track of citations is important. It (kind of) shows which scientists and journals publish meaningful work.

While I like the idea of open-access–in a romantic sense–I’m not sure it is compatible with the current structure of scientific publication. If these bills pass, a dramatic overhaul of the entire system will have to occur. If–or when–that happens, we must preserve the peer review process even if all else is lost.

Coming Soon: 3D Printing

Three-dimensional printing may be the “next big thing” in the technology sector. President Obama, in his State of the Union address, praised White House efforts to establish manufacturing labs saying 3D printing “has the potential to revolutionize the way we make almost everything.” He promised the launch of three new hubs–though the locations are as of yet undisclosed.

Three-dimensional printing started with clunky plastic, but has now evolved to include a variety other materials–including cartilage for prosthetic ears. Products are first designed by computer aided design (CAD) software which is commonly used by engineers to test-build a variety of devices and mechanical parts before actual manufacturing. Once the design is optimized, it’s sliced into cross-sections–similar to how computer images are split into pixels. Raw material–powder, liquid, or any other form–is loaded into the printer and prepared for deposition, often by heating. The printer lays down material layer-by-layer until the entire 3D structure is completed. Typical layer thickness is in the micrometers, small enough to create relatively smooth edges.

A Kickstarter project by Formlabs recently raised almost $3 million to develop low-cost 3D printers–their original goal was only $100,000. The printer, called Form 1, promises small, at-home printers for enthusiasts to create their own plastic sculptures made from an undisclosed gray liquid. Printed examples included a chess-piece castle, the Eiffel tower, and quarter sized bird cage.

3D molds

Three-dimensional prints from Formlabs come in a variety of shapes and sizes.

Three-dimensional printing is attractive to both enthusiasts and manufactures, although techniques such as injection molding are still more affordable if printing large quantities. As of now, most printing has been done by hobbyists in the form of toy modelsworking clocks, and edible chocolate turtles. As costs for 3D printing decrease, printers and materials will become more widespread. One day we may be printing car replacements parts or children’s toys at home from our own design.

Accidently Winning the Nobel Prize

Another topic Professor Zhengwei Pan spoke of in the lecture I previously mentioned was being timely with research. He emphasized that immediately analyzing unexpected results was key to a new discovery.

As an example, he told the story of Buckminsterfullerene, a soccer-ball shaped molecule that won its discoverers the 1996 Nobel Prize in Chemistry. A buckyball–the pet name that’s caught on with the scientific community–is made up of sixty carbons arranged into twenty hexagons and twelve pentagons with a carbon at each vertex and a bond along each edge.

The discovery–like many major discoveries–came about accidently. Harry Kroto and his collaborator Robert Curl were studying unsaturated carbons in space dust. In order to characterize the molecules they were seeing in the dust clouds, they needed to make them here on Earth. This was a task neither was up to, so Curl called his coworker Richard Smalley, an expert in experimental physical chemistry. Smalley set out to make unsaturated carbon chains by hitting a sheet of graphite with a laser, but he ended up finding large clusters of 60 and 70 carbons. When analyzing the molecules with mass spectrometry, Smalley found the clusters were spherical–or as close to spherical as a molecule can get.

The threesome was surprised, since they were aiming to make carbons plasmas found in space not stable molecules. After much discussion, they came up with the highly symmetric soccer-ball reminiscent of the geometric come-like architecture of Buckminster Fuller. They named the molecule after their muse, published the paper and collected their prize.

Because the group analysed their unknown results, they walked away with the most famous prize in all of science. What would have happened if they had shelved those results because it wasn’t what they set out to find? Someone else would have discovered C60 and come to the same geometric conclusion. The prize would have been lost to Kroto, Smalley, and Curl.

So maybe it’s time to reopen that “failed” project that gave you such strange results. Who knows? You may have stumbled onto something new.

Finding the Story in Science

Last Friday, I attended a lecture by Professor Zhengwei Pan on how to write a successful scientific paper. Prof. Pan has published in both Science and Nature, and has been featured on nine journal covers–including Nature Materials–so he’s an experienced guide for a group of graduate students who have written few, if any, papers. Instead of taking us step by step through the process–”Here is the discussion. This is where you write your results.”–he focused on finding the right story. He said once you find the right story, the paper is reduced to writing about the figures. I should mention Prof. Pan works heavily with microscopy, so he has a bounty of beautiful pictures.

Finding the story is the hardest part of any research project. What you did and how you did it doesn’t matter as much as what does it mean, and every scientist wants to do meaningful work. We all want to discover something new or make the biggest and the best. But how? How do you stumble onto a major discovery? Prof. Pan said the biggest discoveries come by accident. Not the kind of accident that comes from being clumsy or careless in your work, but the happy accident that comes from being diligent and hard working, from taking careful notes.

He told a story about his own discovery of using germanium as a catalyst to grow zinc oxide nanowires. As a post-doc at Oak Ridge National Laboratories, Prof.–then just Dr.–Pan was tasked with synthesizing semiconducting nanowires–this was in 2005 when nanowires were the exciting new material for electronics research. Pan tried numerous times to grow zinc oxide by a traditional method (vapor-liquid-solid crystal growth) with no luck. But suddenly, miraculously, it worked! Pan ran to the scanning electron microscope–an instrument which takes nanometer-sized “pictures” using a beam of electrons–and shoved his sample into the beam. Instead of thin, uniform wires, Pan’s wires had a round head.

Pan's ZnO Nanowires

Taken from Angewandte Chemie International Edition 44 274-278.

 

“What was going on?” Pan asked himself. Never before had he seen single-material nanowires look like this. He used another technique, called energy-dispersive X-ray spectroscopy, to find the chemical composition of his new material. The length of the wire was zinc oxide, as he expected, but the head was made of gallium. He hadn’t added any gallium to his quartz tube, where he grew the wires. How could the heads be made of gallium? He carefully poured through his lab notebook looking for any hint at what that circular head could be. Finally, he realized that he had previously used that quartz tube to grow gallium oxide nanowires. The next time he went to grow zinc oxide nanowires, he threw a little gallium into the tube. The rounded heads appeared. He had accidently discovered a new material.

So, researchers, do careful work, but always look for the unexpected. If something goes wrong, find out why. You may come out of it with an interesting story of your own.

Turn that radio down, it’s too bright!

Noise comes in many colors. We’re all familiar with white noise–the static on the radio and TV–but unless you work with electronics, you may not have heard about other colors of noise.

Contrary to what you might think, meaningless random noise is not always the same. Different kinds of noise make different sounds and images, so to keep track of the different types they are named after colors, typically in reference to light with a similar spectra. For example, the frequency spectrum of white noise is relatively flat–you’re likely to find the same amount of noise at all frequencies. White light contains equal amounts of every color and also has a flat spectrum. Essentially, if we could translate the flat, even noise into color, it would be white.

If noise is essentially meaningless, why do we care about distinguishing different kinds? Well, as Dan Ellis, a professor at Columbia University, says, “The technical challenges in, say, building a cell phone system, or an ultrasound machine, come from trying to extract a desired information ‘signal’ from a background of unwanted ‘noise’.” Each color of noise has a certain post-processing method to decrease or remove the signal from the actual, desired data. But sometimes random noise is useful. White noise can block out other sounds which helps some people–especially those in crowded cities–get a good nights rest.

The other colors of noise are not flat, but concentrated at specific frequencies. Blue noise, for example, increases with increasing frequency. This is useful in graphics engineering to trick the eye into seeing a continuous color gradient instead of the actual quantized pixels. In audio, blue noise is more annoying than useful because of the high-frequency hiss. Pink noise is the exact opposite, it decreases with increasing frequency. Since pink noise is concentrated at the low end of the spectra, it’s often used in auto to increase the bass and cut down on high-frequency notes. On its own, pink noise sounds like the low hum you hear on an airplane.

Brown noise–confusingly also known as red noise or more comically “drunkard’s walk” noise–lies between pink and white noise. It’s called brown not in reference to the color, but because it can be generated by mimicking Brownian motion. Brown noise is a more pleasant version of white noise with lower-frequency notes reminiscent of waves on the beach or a windy day.

There are also several other unofficial colors–orange, black and green–but white, blue, pink and brown are the most useful. So next time you’re assailed by a blast of static or mechanical rumbling think of what color you’re hearing. Maybe you’ll finally get some sleep on that next red-eye flight back home.

 

Goodnight, Sweet Prince

Today the Large Hadron Collider (LHC for short) will close its doors for two years to make much-needed upgrades, possibly to start exploration into the existence of dark matter and extra dimensions.

The LHC represents everything science should be. Physicists and Engineers from over 100 countries joined together to build the $9 billion particle collider with the sole purpose of answering fundamental questions of the universe. And, boy, did they. Even with a set back only nine days after opening–a magnetic quench that took over a year to fix–the machine has detected new fundamental particles, the Higgs boson being the most important.

Physicists have been using the Standard Model since the 1970s to explain all sorts of natural phenomena, with the catch that no one has proven the model to be experimentally correct. The LHC tests fundamental aspects of the Standard Model, but doesn’t take a side on whether it is right or wrong. There are even some scientists out there that hope the LHC finds something new and unexpected to turn the physics community on its head. But last November, the LHC (tentatively) found what the majority of scientists had crossed their fingers for: the Higgs boson, the particle that gives everything mass.

It’s interesting to think that while we were building computers and walking on the Moon, no one knew why particles had mass, just that they did. With the Standard Model, scientists believe that the particles we know–electrons, quarks, etc.–get their mass from interaction with a Higgs field and the amount of interaction with that field determines the mass; more interaction means a more massive particle.

But how do we know a Higgs field exists? If the field is given enough energy to “excite” it, a Higgs particle will pop into existence. Because the particle is so massive, it quickly decays–in fractions of fractions of a second–into two streams of electrons and hadrons, the building blocks of protons and neutrons. The LHC hopes to see these decay streams after smashing protons and bare lead nuclei together at ultra-high speeds. The decay streams will only be seen for a small fraction of collisions–1 possible Higgs boson for 10 billion collisions–and many decays need to be observed to guarantee a discovery. But with around 600 million collisions per second, the LHC should be able to see roughly one event every half hour.

Currently, scientists at the LHC think they saw enough decays to confirm the existence of the Higgs boson, though it will take a while to analyse the massive amount of data coming from the collider. Now is the opportune time for the LHC to shut down and make upgrades. While we won’t hear of any experiments for close to two years, there is still much to look forward to from the outcome of past runs.