Tag Archives: Perspective

Spot the Difference

A little while ago, I wrote a blog post concerning autostereograms, more commonly referred to as Magic Eye images. These are images that, at first sight, seem to possess nothing but a random-seeming pattern. However, looked at in a certain way, a three-dimensional image can actually be made visible. Below is an example of a such an image (taken from Wikipedia):

Autostereogram of a shark

In my previous post about these stereograms, I pointed out that the best way to understand what is going on is to look at a two-image stereogram (see below). Here, the left eye looks at the left image while the right eye looks at the right image, and the brain is tricked into triangulating a distance because the two images are almost the same. The only difference is that part of the image has been displaced horizontally, which makes that part appear like it is at a different depth. This is explained at the bottom of this page, and an example is shown below:

Random Dot Stereogram

Boring old square

In this post, however, I would like to point out that this visual technique can be used to solve a different kind of puzzle. When I was in middle school, one of the most popular games to play was called Photo-Hunt, essentially a spot-the-difference puzzle. You probably know what I’m referring to, but here is an example just in case you don’t:

The bizarre thing about these images is that if you look at them like you would a Magic Eye image, the differences between the two images essentially “pop out” (or rather they flicker noticeably). Because each of your eyes is looking at each image separately, your brain is tricked into thinking there is a single image at a certain depth. Therefore, the differences reveal themselves, because while the parts of the image that are identical are viewed with a particular depth of view, the differences don’t have the same effect. Your eyes cannot triangulate the differences, and they appear to flicker. I wish I had learned this trick in middle school, when this game was all the rage.

While this may all seem a little silly, I noticed recently while zoning out during a rather dry seminar, that I could notice very minute defects in TEM images using this technique. Here is an example of an image of a bubble raft (there are some really cool videos of bubble rafts online — see here for instance), where the defects immediately emerge when viewed stereoscopically (i.e. like a Magic-Eye):

TEMBubbleRaft

Bubble raft image taken from here

I won’t tell you where the defects are, but just to let you know that there are three quite major ones, which are the ones I’m referring to in the image. They’re quite obvious even if not viewed stereoscopically.

Because so many concepts in solid state physics depend on crystal symmetries and periodicity, I can foresee entertaining myself during many more dry seminars in the future, be it a seminar with tons of TEM images or a wealth of diffraction data. I have even started viewing my own data this way to see if anything immediately jumps out, without any luck so far, but I suspect it is only a matter of time before I see something useful.

Book Review – The Gene

Following the March Meeting, I took a vacation for a couple weeks, returning home to Bangkok, Thailand. During my holiday, I was able to get a hold of and read Siddhartha Mukherjee’s new book entitled The Gene: An Intimate History.

I have to preface any commentary by saying that prior to reading the book, my knowledge of biology embarrassingly languished at the middle-school level. With that confession aside, The Gene was probably one of the best (and for me, most enlightening) popular science books I have ever read. This is definitely aided by Mukherjee’s fluid and beautiful writing style from which scientists in all fields can learn a few lessons about scientific communication. The Gene is also touched with a humanity that is not usually associated with the popular science genre, which is usually rather dry in recounting scientific and intellectual endeavors. This humanity is the book’s most powerful feature.

Since there are many glowing reviews of the book published elsewhere, I will just list here a few nuggets I took away from The Gene, which hopefully will serve to entice rather than spoil the book for you:

  • Mukherjee compares the gene to an atom or a bit, evolution’s “indivisible” particle. Obviously, the gene is physically divisible in the sense that it is made of atoms, but what he means here is that the lower levels can be abstracted away and the gene is the relevant level at which geneticists work.
    • It is worth thinking of what the parallel carriers of information are in condensed matter problems — my hunch is that most condensed matter physicists would contend that these are the quasiparticles in the relevant phase of matter.
  • Gregor Mendel, whose work nowadays is recognized as giving birth to the entire field of genetics, was not recognized for his work while he was alive. It took another 40-50 years for scientists to rediscover his experiments and to see that he had localized, in those pea plants, the indivisible gene. One gets the feeling that his work was not celebrated while he was alive because his work was far ahead of its time.
  • The history of genetics is harrowing and ugly. While the second World War was probably the pinnacle of obscene crimes committed in the name of genetics, humans seem unable to shake off ideas associated with eugenics even into the modern day.
  • Through a large part of its history, the field of genetics has had to deal with a range of ethical questions. There is no sign of this trend abating in light of the recent discovery of CRISPR/Cas-9 technology. If you’re interested in learning more about this, RadioLab has a pretty good podcast about it.
  • Schrodinger’s book What is Life? has inspired so much follow-up work that it is hard to overestimate the influence it has had on a generation of physicists that transitioned to studying biology in the middle of the twentieth century, including both Watson and Crick.

While I could go on and on with this list, I’ll stop ruining the book for you. I would just like to say that at the end of the book I got the feeling that humans are still just starting to scratch the surface of understanding what’s going on in a cell. There is much more to learn, and that’s an exciting feeling in any field of science.

Aside: In case you missed March Meeting, the APS has posted the lectures from the Kavli Symposium on YouTube, which includes lectures from Duncan Haldane and Michael Kosterlitz among others.

Do you ever get the feeling that…

…when you look at science today that things seem blown way out of proportion?

I get the feeling that many press releases make a big deal out of experiments/theoretical work that are not groundbreaking, are not going to cause an upheaval in anyone’s way of thinking and frankly, are humdrum science (not to diminish the importance of humdrum science!).

In all honesty, really great scientific works are rare and sometimes it takes a long time to recognize the importance of a great leap in understanding. There are many examples of this, but here’s one: Gregor Mendel, who I would refer to as the discoverer of the gene, died before his work was recognized as truly path-breaking, which took about 50 years.

A lot of good science happens all the time, but let’s not kid ourselves — the science is not as revolutionary as a lot of press releases make it seem. Of course, most professional scientists are aware of this, but to the young graduate student and to the public at large, press releases can easily be mistaken for groundbreaking science and often are. How many times have you come across someone from outside of science excited about an article they read online that you know is either extremely speculative or actually pretty mundane? It is hard to respond to reactions like this because you don’t want to dampen someone’s excitement about a subject you care about!

I don’t know what is driving all of this — the media, funding agencies, university rankings or some other metric, but to be perfectly honest, I find much of the coverage on sites like Phys.Org ugly, cynical and detrimental.

While it can be argued that this media coverage does serve some important purpose, it seems to me that this drive to “sell one’s work” may have the adverse effect of exacerbating impostor syndrome (especially among younger colleagues), which is already rampant in physics departments as well as in other academic fields (i.e. you feel like because you need to “sell your work”, and because it gets blown way out of proportion, that you have manipulated people into thinking your work is more important than you really know it to be).

If you just went about your business, trying to do science you think is worthy (without the citation-counting and the excessive media coverage), my guess is science (and more importantly scientists!) would probably be healthier.

I know this viewpoint is pretty one-dimensional and lacks some nuance, so I would like to encourage comments and especially opposing opinions.

Discovery vs. Q&A Experiments

When one looks through the history of condensed matter experiment, it is strange to see how many times discoveries were made in a serendipitous fashion (see here for instance). I would argue that most groundbreaking findings were unanticipated. The discoveries of superconductivity by Onnes, the Meissner effect, superfluidity in He-4, cuprate (and high temperature) superconductivity, the quantum Hall effect and the fractional quantum Hall effect were all unforeseen by the very experimentalists that were conducting the experiments! Theorists also did not anticipate these results. Of course, a whole slew of phases and effects were theoretically predicted and then experimentally observed as well, such as Bose-Einstein condensation, the Kosterlitz-Thouless transition, superfluidity in He-3 and the discovery of topological insulators, not to diminish the role of prediction.

For the condensed matter experimentalist, though, this presents a rather strange paradigm.  Naively (and I would say that the general public by and large shares this view), science is perceived as working within a question and answer framework. You pose a concrete question, and then conduct and experiment to try to answer said question. In condensed matter physics, this often not the case, or at least only loosely the case. There are of course experiments that have been conducted to answer concrete questions — and when they are conducted, they usually end up being beautiful experiments (see here for example). But these kinds of experiments can only be conducted when a field reaches a point where concrete questions can be formulated. For exploratory studies, the questions are often not even clear. I would, therefore, consider these kinds of Q&A experiments to be the exception to the rule rather than the norm.

More often then not, discoveries are made by exploring uncharted territory, entering a space others have not explored before, and tempting fate. Questions are often not concrete but posed in the form, “What if I do this…?”. I know that this makes condensed matter physics sound like it lacks organization, clarity and structure. But this is not totally untrue. Most progress in the history of science did not proceed in a straight line like textbooks make it seem. When weird particles were popping up all over the place in particle physics in the 1930s and 40s, it was hard to see any organizing principles. Experimentalists were discovering new particles at a rate with which theory could not keep up. Only after a large number of particles had been discovered did Gell-Mann come up with his “Eightfold Way”, which ultimately led to the Standard Model.

This is all to say that scientific progress is tortuous, thought processes of scientists are highly nonlinear, and there is a lot of intuition required in deciding what problems to solve or what space is worth exploring. In condensed matter experiment, it is therefore important to keep pushing boundaries of what has been done before, explore, and do something unique in hope of finding something new!

Exposure to a wide variety of observations and methods is required to choose what boundaries to push and where to spend one’s time exploring. This is what makes diversity and avoiding “herd thinking” important to the scientific endeavor. Exploratory science without concrete questions makes some (especially younger graduate students) feel uncomfortable, since there is always the fear of finding nothing! This means that condensed matter physics, despite its tremendous progress over the last few decades, where certain general organizing principles have been identified, is still somewhat of a “wild west” in terms of science. But it is precisely this lack of structure that makes it particularly exciting — there are still plenty of rocks that need overturning, and it’s hard to foresee what is going to be found underneath them.

In experimental science, questions are important to formulate — but the adventure towards the answer usually ends up being more important than the answer itself.

Disorganized Reflections

Recently, this blog has been concentrating on topics that have lacked a personal touch. A couple months ago, I started a postdoc position and it has gotten me thinking about a few questions related to my situation and some that are more general. I thought it would be a good time to share some of my thoughts and experiences. Here is just a list of some miscellaneous questions and introspections.

  1. In a new role, doing new work, people often make mistakes while getting accustomed to their new surroundings. Since starting at my new position, I’ve been lucky enough to have patient colleagues who have forgiven my rather embarrassing blunders and guided me through uncharted territory. It’s sometimes deflating admitting your (usually) daft errors, but it’s a part of the learning process (at least it is for me).
  2. There are a lot of reasons why people are drawn to doing science. One of them is perpetually doing something new, scary and challenging. I hope that, at least for me, science never gets monotonous and there is consistently some “fear” of the unknown at work.
  3. In general, I am wary of working too much. It is important to take time to exercise and take care of one’s mental and emotional health. One of the things I have noticed is that sometimes the most driven and most intelligent graduate students suffered from burnout due to their intense work schedules at the beginning of graduate school.
  4. Along with the previous point, I am also wary of spending too much time in the lab because it is important to have  time to reflect. It is necessary to think about what you’ve done, what can be done tomorrow and conjure up experiments that one can possibly try, even if they may be lofty. It’s not a bad idea to set aside a little time each day or week to think about these kinds of things.
  5. It is necessary to be resilient, not take things personally and know your limits. I know that I am not going to be the greatest physicist of my generation or anything like that, but what keeps me going is the hope that I can make a small contribution to the literature that some physicists and other scientists will appreciate. Maybe they might even say “Huh, that’s pretty cool” with some raised eyebrows.
  6. Is physics my “passion”? I would say that I really like it, but I could have just as easily studied a host of other topics (such as literature, philosophy, economics, etc.), and I’m sure I would have enjoyed them just as much. I’ve always been more of a generalist in contrast to being focused on physics since I was a kid or teenager. There are too many interesting things out there in the world to feel satiated just studying condensed matter physics. This is sometimes a drawback and sometimes an asset (i.e. I am sometimes less technically competent than my lab-mates, but I can probably write with less trouble).
  7. For me, reading widely is valuable, but I need to be careful that it does not impede or become a substitute for active thought.
  8. Overall, science can be intimidating and it can feel unrewarding. This can be particularly true if you measure your success using a publication rate or some so-called “objective” measure. I would venture to say that a much better measure of success is whether you have grown during graduate school or during a postdoc by being able to think more independently, by picking up some valuable skills (both hard and soft) and have brought a  multi-year project into fruition.

Please feel free to share thoughts from your own experiences! I am always eager to learn about people whose experiences and attitudes differ from mine.

A few nuggets on the internet this week:

  1. For football/soccer fans:
    http://www.espnfc.us/blog/the-toe-poke/65/post/3036987/bayern-munichs-thomas-muller-has-ingenious-way-of-dodging-journalists

  2. Barack Obama’s piece in Science Magazine:
    http://tinyurl.com/jmeoyz5

  3. An interesting read on the history of physics education reform (Thanks to Rodrigo Soto-Garrido for sharing this with me):
    http://aapt.scitation.org/doi/full/10.1119/1.4967888

  4. I wonder if an experimentalist can get this to work:
    http://www.bbc.com/news/uk-england-bristol-38573364

Consistency in the Hierarchy

When writing on this blog, I try to share nuggets here and there of phenomena, experiments, sociological observations and other peoples’ opinions I find illuminating. Unfortunately, this format can leave readers wanting when it comes to some sort of coherent message. Precisely because of this, I would like to revisit a few blog posts I’ve written in the past and highlight the common vein running through them.

Condensed matter physicists of the last couple generations have grown up ingrained with the idea that “More is Different”, a concept first coherently put forth by P. W. Anderson and carried further by others. Most discussions of these ideas tend to concentrate on the notion that there is a hierarchy of disciplines where each discipline is not logically dependent on the one beneath it. For instance, in solid state physics, we do not need to start out at the level of quarks and build up from there to obtain many properties of matter. More profoundly, one can observe phenomena which distinctly arise in the context of condensed matter physics, such as superconductivity, the quantum Hall effect and ferromagnetism that one wouldn’t necessarily predict by just studying particle physics.

While I have no objection to these claims (and actually agree with them quite strongly), it seems to me that one rather (almost trivial) fact is infrequently mentioned when these concepts are discussed. That is the role of consistency.

While it is true that one does not necessarily require the lower level theory to describe the theories at the higher level, these theories do need to be consistent with each other. This is why, after the publication of BCS theory, there were a slew of theoretical papers that tried to come to terms with various aspects of the theory (such as the approximation of particle number non-conservation and features associated with gauge invariance (pdf!)).

This requirement of consistency is what makes concepts like the Bohr-van Leeuwen theorem and Gibbs paradox so important. They bridge two levels of the “More is Different” hierarchy, exposing inconsistencies between the higher level theory (classical mechanics) and the lower level (the micro realm).

In the case of the Bohr-van Leeuwen theorem, it shows that classical mechanics, when applied to the microscopic scale, is not consistent with the observation of ferromagnetism. In the Gibbs paradox case, classical mechanics, when not taking into consideration particle indistinguishability (a quantum mechanical concept), is inconsistent with the idea the entropy must remain the same when dividing a gas tank into two equal partitions.

Today, we have the issue that ideas from the micro realm (quantum mechanics) appear to be inconsistent with our ideas on the macroscopic scale. This is why matter interference experiments are still carried out in the present time. It is imperative to know why it is possible for a C60 molecule (or a 10,000 amu molecule) to be described with a single wavefunction in a Schrodinger-like scheme, whereas this seems implausible for, say, a cat. There does again appear to be some inconsistency here, though there are some (but no consensus) frameworks, like decoherence, to get around this. I also can’t help but mention that non-locality, à la Bell, also seems totally at odds with one’s intuition on the macro-scale.

What I want to stress is that the inconsistency theorems (or paradoxes) contained seeds of some of the most important theoretical advances in physics. This is itself not a radical concept, but it often gets neglected when a generation grows up with a deep-rooted “More is Different” scientific outlook. We sometimes forget to look for concepts that bridge disparate levels of the hierarchy and subsequently look for inconsistencies between them.

The Struggle

Haruki Murakami, the world-renowned Japanese novelist, has garnered a large following because one can easily relate to his protagonists. I have been reading his novels for around ten years now, and recently picked up his unique memoir What I Talk About When I Talk About Running. It is a quirky book, at once about his marathon and ultra-marathon running endeavors, his writing struggles, and how the two are interwoven.

To me, the most inspirational part of this book lies in how through mundaneness and mediocrity springs a rather unique exceptionalism. Murakami is an outstanding writer, but his talents have a limit, and he is honest about this. Most of the book is about struggling, with running and with writing. When I reflect on the book, the image I have in my mind is of a  truck wheel, bearing huge weight, going around and around, yet somehow trudging forward.

Here is a passage from the book I particularly enjoyed, which is applicable in many contexts:

…writers who aren’t blessed with much talent — those who barely make the grade — need to build up their strength at their own expense. They have to train themselves to improve their focus, to increase their endurance. To a certain extent, they’re forced to make these qualities stand in for talent. And while they’re getting by on these, they may actually discover real, hidden talent within them. They’re sweating, digging out a hole at their feet with a shovel, when they run across a deep, secret water vein. It’s a lucky thing, but what made this good fortune possible was all the training they did that gave them the strength to keep on digging. I imagine that late-blooming writers have all gone through a similar process.

Naturally, there are people in the world (only a handful, for sure) blessed with enormous talent that, from beginning to end, doesn’t fade, and whose works are always of the highest quality. These fortunate few have a water vein that never dries up, no matter how much they tap into it. For literature, this is something to be thankful for. It’s hard to imagine the history of literature without such figures as Shakespeare, Balzac and Dickens. But the giants are, in the end, giants — exceptional, legendary figures. The remaining majority of writers who can’t reach such heights (including me, of course) have to supplement what’s missing from their store of talent through whatever means they can. Otherwise it’s impossible for them to keep on writing novels of any value. The methods and directions a writer takes in order to supplement himself becomes part of that writer’s individuality, what makes him special.

Most of what I know about writing I’ve learned through running everyday. These are practical, physical lessons. How much can I push myself? How much rest is appropriate — and how much is too much? How far can I take something and still keep it decent and consistent? When does it become narrow-minded and inflexible? How much should I be aware of the world outside, and how much should I  focus on my inner world? To what extent should I be confident in my abilities, and when should I start doubting myself? I know that if I hadn’t become a long-distance runner when I became a novelist, my work would have been vastly different. How different? Hard to say, but something would have definitely been different.

The book ends with what Murakami hopes his tombstone will read:

Haruki Murakami

1949-20**

Writer (and Runner)

At Least He Never Walked