Thursday, September 30, 2010

A good week

Its nice to occasionally get good news. As you may recall from a previous post, I had three papers rejected in one weekend in late July. When the editors at Applied Physics Letters refused to send the paper out for review, we submitted it to Optics Communications. Both reviews came in positive. The reviewers' summaries follow.

Reviewer #1: This manuscript describes characterization of the response dynamics of cascaded photomechanical devices based on photosensitive liquid crystal elastomers.  The idea of these cascaded devices is the most interesting aspect of this work.  The authors have built and characterized the time response and fit to a three exponential functions. The authors have identified two possible mechanisms contributing.  The paper is well-written, conclusions well-founded and should be of strong interest in the community.  Publication is recommended.

Reviewer #2: This an excellent study of cascaded optomechanical devices that take advantage of the properties of liquid crystal elastomers. It should essentially be published as is.
We have resubmitted a revised manuscript, which addresses only a couple of minor issues, so we expect the paper to be accepted soon.

In another post, I reproduced a letter that I sent to the Optical Society of America about allowing authors to submit papers in two-column format. I sent a similar email to Applied Physics Letters. Since I hadn't heard back from them, I assumed that they were blowing me off. I just received an email that the journal has actually implemented the change! They write:

Dear Dr. Kuzyk:

Since your e-mail, we have decided to allow 2-column manuscripts to be submitted. We will try it out and see if we receive e-mails from reviewers who do not like the 2-column formatting.

Thank you again for your help with our APL manuscripts.


Ultra-Smart Morphing Materials

Most of today's high-tech marvels are based on the tiny transistor, a device that controls the flow of electrical current. A transistor mediates the flow of one current depending on the properties of a second current. Since the interaction is nonlinear, a transistor can be used to amplify a weak signal, perform logic operations, and be used as a memory element. While a single transistor may be technologically unimpressive with regards to computing power, millions of them working together can perform amazing functionality that some day may meet the criteria of intelligence.

I envision a technology made of Photomechanical Optical Devices (PODs), each with the ability to control the flow of light based on the environment (stress, temperature, chemical agents, etc.), having multiple states for a given set of input parameters (i.e. optical and mechanical multi-stability), and having the ability to change shape based on the inputs. Integrating such devices together would lead to ultra-intelligent morphing materials/systems that would enable technologies that are yet to be invented. I have been dabbling with research in this area for 20 years.

The time is ripe to build the scientific foundations for making a novel new material/system that has the ability to morph in response to stress or light. In contrast to common materials that are made of atoms or molecules, and interact through electric fields, I envision a system made of microscopic units that each communicate with all others using light, imbuing it with enormous processing power and intelligence. Add to each unit the ability to respond to stress and perform actuation, and the system gains the ability to intelligently morph between complex structures. Miniaturization of such systems blurs the line between what is conventionally meant by a system and a material - terms that I use interchangeably.

Such materials would fill a new realm of applications. A series of pictures on a piece of film are projected onto a two-dimensional screen to show motion. A smart material, on the other hand, could be made to morph through a series of shapes leading to true 3-dimensional solid-body animations. For example, automobile designers could use them to continually change the shape of a model to test its aerodynamics or aesthetics; a chair could be made to automatically change shape to accommodate a particular body type; and an exact replica of an individual could be made in real time from information sent from a remote location, in effect recreating an animated three-dimensional solid replica of the sender. And you thought picture phones were great! Other applications would include noise cancellation wallpaper, reconfigurable air craft wings, ultra-stable platforms for precision manufacturing or characterization, and reconfigurable optical filters.

The development of such materials/systems would require extensive research aimed at demonstrating the fundamental building blocks, followed by studies of how a small number of them interact with each other when interconnected with light, and would culminate with the development of fabrication methods that could be used to make a bulk material from a collection of microscopic building blocks. Some aspects of the fundamental physics underlying this idea are in place; that is, photomechanical materials exist, interferometers with such materials can be built into polymer fibers, and a series of gratings can be written into a fiber, which in principle, could be made into a network of interacting units. The challenge lies in demonstrating classes of fundamental units that are naturally integratable, and understanding how to build a system from optimized units that work together to provide the desired function.

My vision of the fundamental building block is a waveguide-based feedback device, such as an interferometer, that is made in thin films or fibers, containing a nonlinear-optical and photomechanical material -- thus simultaneously having the ability to manipulate light, sense stress, and apply anisotropic stress to its surroundings. These PODs would simultaneously respond to optical and mechanical stimulus to yield mechanical/optical multistability, logic, stress/temperature sensing, optical/mechanical memory, positioning, and more. A network of PODs, interconnected by light signals along an integrated waveguide device would be scalable to a an ultra-smart material/system with functionality that goes well beyond present materials/systems paradigms. In contrast to a neural network, in which each neuron is connected to a small number of neighbors, a linear array of PODS along an optical fiber would interact with all others, processing information, reacting to stress and responding by selectively passing light and stressing the surroundings.

The development of this new technology may impact many future applications that have not yet been invented. Conversely, the novel materials concept may motivate new ideas for applications that have yet to be invented. I have submitted this idea to the National Science Foundation as part of a solicitation that seeks suggestions for new programs in areas that have the potential for transforming socienty. If NSF chooses not start a major program in ultra-smart morphing materials, I am hoping that this kind of research will someday be supported - even if I am not around to participate.

Wednesday, September 22, 2010

Tavel and Context

The flip side of getting research funding is the requirement to attend yearly meetings to update the funding agencies on progress made in meeting milestones. I am sitting in my hotel room in Washington DC this morning getting ready for my presentation. I arrived last night at about midnight and I head back to the airport after I give my talk in the early afternoon.

I am reminded of the many quick work trips that I take to all kinds of neat places. But usually, all that I see is my hotel room, the conference room, and the road between the hotel and the airport. Each geographic location offers unique vistas and local culture (or lack thereof). But, in addressing the deepest questions, to me, sightseeing and travel provide only the most shallow returns.

An itinerary that highlights places that spawned ideas that changed civilization would be much more interesting to me. It would be awe-inspiring to see the simple objects used by Cavendish to do his famous experiments or to view Galileo's crude telescope in the natural setting of the Italian countryside, where his observations yielded insights into the true nature of the universe, overturning centuries of dogma and ignorance.

I would like to revisit the meeting room of the first continental congress, where the new paradigm of self governance took root and changed the world. Having recently read the biographies on James Madison, Thomas Jefferson, and John Adams, a visit to the birthplace of their great ideas would now be more meaningful to me.

While the site of the ruins in Rome were deeply moving based on the human ingenuity and appreciation for beauty that they exemplify, I found that the experience would have been more fulfilling had there been a broader intellectual context. Similarly, the Vatican and Notre Dame Cathedral in Paris are magnificent, and the fact that all those people labored for so many years to express their faith may be admirable, but I found the structures to be akin to beautiful facades harboring emptiness.

Events and places are meaningful to me only when there is an intellectual context. Contrast the zombie feeding coins into a slot machine for hours on end with the experience of understanding a deep idea for the first time. When I first took Quantum Field Theory, I recall the thrill of seeing the connection between fields and particles and how so many laws of physics arise from a variational approach (i.e. nature acts in a way that minimizes or optimizes a quantity). When struggling with my attempts to understand the fundamental limits of the nonlinear susceptibility, I recall the final stretch of my frenzied derivations with fondness: a beautifully-simple equation crystallized into its final elegant from out of a huge mess of mathematics. In that moment, I understood something new to the world for the first time.

Learning is characterized by long periods of drudgery, punctuated with the occasional elation of understanding. Similarly, humanity evolves through long cycles of stasis that are interrupted with abrupt paradigm shifts, which change the course of civilization. If I am forced to travel, my preference is to visit those places that produced singular moments that led to revolutions in thought.

Sunday, September 12, 2010

The Insider - honesty and integrity

My life has been in a state of frenzy for the last couple of weeks, with commitments that far exceed my available time. As usual, the quality of my productivity suffers, as one can tell from the paucity of posts and the deterioration in the quality of my writing. Last night, I made a conscious decision to relax by watching The Insider, a movie that got me thinking about many topics that I will touch on today.

This 1999 film chronicles the whistle-blower Jeffrey Wigand, a former VP of research at the tobacco giant Brown & Williamson. Dr. Wigand was fired for being vocal to his management about his concerns related to the presence of carcinogens in cigarettes. His severance package was contingent on him honoring a confidentially agreement. Such agreements protect intellectual property, but Brown & Williamson used it to prevent Wigand from disclosing shady corporate practices.

At the time, tobacco industry executives were fully aware of the presence of certain carcinogens in cigarettes, but the industry was reluctant to remove them because of their effect on a cigarette's flavor. In testimony before congress, the CEOs of the seven largest tobacco companies claimed that they did not believe that nicotine was an addictive drug. Internally, however, these same executives specifically instructed the the scientists to develop means to enhance the addictive effects of nicotine. In his testimony, Wigand made it clear that it was common knowledge in the industry that "a cigarette is a scientifically designed drug delivery device that is intentionally engineered to deliver nicotine to the brain in seconds."

It took a great deal of courage for Dr. Wigand to expose the facts. To discredit him, the tobacco companies orchestrated a smear campaign attacking his integrity. Other tactics included death threats as well as financial blackmail. Before testifying in a suit filed in Mississippi against the tobacco industry, his tobacco-friendly home state of Kentucky issued a gag order preventing him from testifying. He risked incarceration when returning to Kentucky by ignoring the order. This ordeal cost him his marriage.

It was clear that the tobacco companies' behavior was despicable. Motivated by profit, they formulated methods to optimize the delivery of nicotine to addict users into a life-threatening habit. This brings to mind allegations that the oil companies are using similar tactics to discredit global warming research.

The stakes of global climate change are much higher. If the oil companies are discrediting serious research in public forums for the deliberate purpose of gaining political advantage at the expense of the environment, then the decision makers should be held legally culpable for their actions.

The Insider left me with a great respect for professional journalists, who are doggedly determined to expose the truth. I am concerned that this type of professionalism is being lost as news organizations pander to readers and viewers who are more interested in entertainment than information - consumers who would rather have support for their ideology rather than the truth.

Journalistic market pressures have resulted in news outlets that cater to ideology. Fox News is a glowing example of ideology taken to the extreme. John Stewart of the Daily Show does a great job of exposing the gross lies championed by Fox. Fox News takes video clips out of context, make statements without evidence and uses repetition to give the sensation of truth, and fires up viewers into misplaced anger. This irresponsible behavior borders on the criminal.

Some cases in point:

1. Repeating over and over again that President Obama was foreign born even when his birth certificate was available to the public.

2. Glenn Beck asking why the other networks did not show the videos of Israeli servicemen being beaten as they boarded the Turkish flotillas. (John Stewart showed date-stamped videos of several other networks that were showing the videos at the same time or prior to Fox.)

3. According to, "Saudi Prince Al-Waleed bin Talal -- the second-largest shareholder of Fox News’ parent company News Corp. -- has deep funding ties to Imam Feisal Abdul Rauf, the “principal planner” of the Islamic community center in lower Manhattan." It is interesting that Fox News associates Imam Feisal Abdul Rauf with terrorist groups, but fails to mention his ties with their #2 stockholder. Ironically, following the logic presented on Fox News, Fox News is directly contributing to terrorists.

4. Fox News showed a short video clip of President Obama stating that he was enacting the biggest tax increase ever on everyone. John Stewart played the full clip which stated that if the Bush tax cuts were allowed to expire, this would result in the largest tax increase ever on everyone. Obama was justifying his decision not to allow the tax cuts to expire.

The list goes on.

In conclusion, corporations and the news media should be held to the highest standards of honesty and integrity, which are the pillars of truth. Executives of companies who lie to increase profit at the expense of humanity should be held legally liable as should members of the media who intentionally distort the truth to increase ratings. If we as a nation make the wrong decisions, let them be made solely on the basis of the facts.

Saturday, September 4, 2010

Are multiverses real?

An article in the Wall Street Journal by Hawking and Mlodinow on Why God Did Not Create the Universe begins with:

"According to Viking mythology, eclipses occur when two wolves, Skoll and Hati, catch the sun or moon. At the onset of an eclipse people would make lots of noise, hoping to scare the wolves away. After some time, people must have noticed that the eclipses ended regardless of whether they ran around banging on pots.

"Ignorance of nature's ways led people in ancient times to postulate many myths in an effort to make sense of their world. But eventually, people turned to philosophy, that is, to the use of reason—with a good dose of intuition—to decipher their universe. Today we use reason, mathematics and experimental test—in other words, modern science. "

and ends with

"Our universe seems to be one of many, each with different laws. That multiverse idea is not a notion invented to account for the miracle of fine tuning. It is a consequence predicted by many theories in modern cosmology. If it is true it reduces the strong anthropic principle to the weak one, putting the fine tunings of physical law on the same footing as the environmental factors, for it means that our cosmic habitat—now the entire observable universe—is just one of many.

"Each universe has many possible histories and many possible states. Only a very few would allow creatures like us to exist. Although we are puny and insignificant on the scale of the cosmos, this makes us in a sense the lords of creation."

This article and the hundreds of the comments it elicited brings up a point that I have wanted to discus for some time, and that is the idea of multiverses. The multiverse is a collection of universes that are predicted by certain cosmological theories. Many physicists object to the notion that the existence of the other universes are undetectable, therefore, they would argue that "believing" in a multiverse is akin to accepting God.

This objection is similar to objections that have been waged against other new ideas in science that are now commonplace. For example, Ernst Mach objected to the idea that atoms were "real" even though chemists had indirect evidence a century earlier. His gripe was based on his conviction that if something were real, it could be seen directly. Ludwig Boltzmann, Mach's contemporary, struggled for years to get physicists to accept atoms, a critical ingredient of Boltzmann's thermodynamic theories. As the stalwarts died out, and theories based on atoms were experimentally verified from every possible angle, the new generation of physicists of the early 1900s accepted atoms as real.

These arguments hinge on the question of what is meant by "real." Mach's criteria was that one had to be able to see reality "directly" using, for example, a microscope. Ironically, Galileo's contemporaries did not believe that his views of the heavens were real because the telescope purportedly distorted reality. He proved that the telescope depicted far-away objects in true fidelity by comparing what was observed in his telescope to direct visual observation of terrestrial objects. Today, we have been to the moon and confirmed Galileo's observations of craters and other features.

A more modern view of what is real might be defined by its consequences. Though one cannot see an electron, its existence has astronomically many testable consequences that have been confirmed. Every time we use a computer, watch TV, or drive a car, the existence of the electron is confirmed and reconfirmed.

Einstein never believed in quantum mechanics because of its inherent probabilistic interpretation. He felt that someday, an underlying theory with hidden variables would be found that would make quantum mechanics fully deterministic. In the 1960s, Bell showed very elegantly that hidden variable theories were inconsistent with observations. It would have been interesting to have gotten Einstein's impressions of Bell's work, had Einstein lived a few more years.

A deeper issue with quantum mechanics is the central role of the wavefunction, which cannot be directly measured. Only the consequences of the wavefunction are observable. Once again, because quantum mechanics makes so many accurate predictions in the realm of atoms, molecules, nuclei, and force fields, we accept that wavefunctions exist, not as an object that we can directly sense, but as proxy for some unmeasurable structure of reality.

Getting back to the multiverse, if a cosmological model of the universe predicts the existence of multiverses AND simultaneously predicts everything that we observe in our own universe, then accepting the existence of a multiverse is qualitatively no different than accepting much of what is standard physics of today. The key is that the theory must predict what is observed as well as making new testable predictions. The postulate of the existence of God, on the other hand, does not make any quantitative predictions that can be tested.

Are multiverses equivalent to theology? I would say not. Science seeks answers through hypothesis and experiment. Theology, according to is "the field of study and analysis that treats of god and of God's attributes and relations to the universe; study of divine things or religious truth; divinity." Theology presupposes the existence of God while science accepts a theory only when it is consistent with measurements. If an experiment falsifies a hypothesis, it is discarded. Theologians, on the other hand, take without proof the existence of God.

While many people are driven by the inspirations they get from their belief in God, I find more inspiring the wonderful marvels of the human intellect, which can conceive of things that are well beyond the reach of our senses. In a way, our minds provide an added sense that transcends the mundane, and allows us to question the very nature of our universe and our existence using the scientific method as an impartial guide. Are atoms, electrons, wavefunctions, and the fabric of space-time real? That depends on how one defines real. The fact that observations are consistent with theories that use such constructs are an indication of an underlying truth. That fact alone makes the whole scientific endeavor so satisfying and exciting.