FiO/LS 2011 - The Tech

  I took some time off during the Wednesday sessions, as I was having information overload and need some time to recharge my brain for another few rounds of information dump. To chill out, I visited The Tech which is a science museum with an emphasis on technology and interactivity. It was very nicely done, and I had a good time - if I were a kid again you'd have a really tough time getting me out! I was only able to spend a couple of hours in the museum, but there's certainly enough there for a full day.

  One of the first exhibits I encountered on the top floor was this nifty robot arm. You could get your picture taken at a station nearby, and the arm would then draw your portrait.
  Another nearby robot would re-arrange wooden letter blocks until you asked it to spell your name, when it would kindly oblige.

  Around the top floor, they also had some nice exhibits on digital logic and programming microchips (we are in Silicon Valley after all). These consisted of a Mr. Potato Head whose clear head showed off his microchip brain, in a room with lights, fans, thermometers, etc. that you could control. By placing labeled blocks in slots you created a logic chain that would cause Mr. Potato Head to perform some action. For instance, the chain could read "Light is on" "and" "Mr. Potato Head is hot" then "Speak". You then sent these commands to the PIC brain, and he would execute them if the conditions were right. So if the light was on and the fan was off, the temperature would rise, and Mr. Potato Head would start talking.

  They also had nice DNA exhibit, the best part of which was a functioning wet lab. Of course, I had to test it out. I was quite impressed, they had the ingredients (e. coli? and gfp? plasmids) nicely laid out, a how-to video which you followed at your own pace, and included the proper safety procedures; goggles and gloves. They walked you through the entire process of getting the bacteria to uptake the genes by heat-shocking them. Since the bacteria need some time to grow, you incubate overnight and then can check back on them via their on-line interface.

My two bacterial colonies!

A double helix of books

The nerve center.

  Speaking of the online interface, it was well done; the events had barcode scanners that would scan your ticket, and you log in to their website using a number from your ticket. Once online you can check back on the exhibits, and items you may have 'collected'. Admittedly from a review point, I should probably have taken more advantage of this, but at the time I wasn't that interested, so I only scanned the bacteria station above. Those electronic looking racks to the left are the servers.

I think I'm in the monitor at the lower left...

  This was one of the best - it was a remote controlled submarine. They had three in a tank and had them returning video feeds, so you could see things through the sub camera you otherwise would not be able to see. A perfect demonstration of why this tech is used. The pic is an attempted self-portrait, but I was having difficulty keeping the sub stable with one hand.

  Also on the lower level was an awesome demonstration of NASA's Extravehicular Mobility Unit (powered space suit). A chair had several compressed air jets to levitate it, and then a few more for control. Excluding the minor friction I noticed (which may have had something to do with the fact that I'm about a hundred more pounds heavier than their target 7 year old), it was a good demonstration of what the astronauts have to deal with to maneuver in space.

Tracks of flights across the globe.

  The photo on the left is of another exhibit that I quite enjoyed. The globe shows the track of planes as they traverse the globe. It was part of a station that showed how we monitor global weather, of which planes play a part.

  Overall this was a fantastic museum: I was only able to spend a couple of hours here, but one could easily loose a day or two in these very interactive halls.

FiO/LS 2011 - Pictures

The hotel the conference was located at.

The view from our room.

The church across the other way.

The hotel across the way.

The swanky hotel lobby.

Nice nighttime lighting.

The Museum of Art during the day.

Same Museum of Art lit during the night.

The flight back - ahh mountains!

FiO/LS 2011 - Thursday Sessions

  Chronologically, this came right before the flight back. As a consequence, I was only able to attend a few talks in the morning, but they were talks with some good ideas behind them.

  The first one was on adaptive optics in microscopy. Instead of using a wave-front sensor to measure aberrations in their beam of light, they were using the signal generated (the brightness of their image) as their metric for correction. This only worked because it was a nonlinear microscope, so their signal gets much stronger when more light is concentrated at the focus, as opposed to a linear microscope, where the signal would be equally strong regardless of where the light was smeared to. It's a neat idea, but I'm not sure that rate of adjustment necessarily justifies the image enhancement in my case. They have to use 2n-1 images to correct for aberrations in n modes; for correction of the first 3 main optics induced errors, this would be 5 images. So while this would probably be okay for a microscope that can do an image in a half-second, it's not particularly applicable to my 30 minute scan times. While ideally I would only have to do this correction once for each optical system, I'm taking down and re-assembling frequently enough that an investment in the required spatial light modulator doesn't justify itself in my mind.

  The second was a case of 1 + 2 = cool. Take: 1) What do astronomers want? Larger telescopes of course! 2) What do solar power stations do during the night? Not much of course! But if we put these two together, we could make a giant telescope from a solar concentrator. The design issues are still being worked out, primarily because the solar concentrator they're looking at does not have parabolic (curved) mirrors to concentrate the light. So each plane reflects light onto the generator (now detector), and they have to have an intriguingly redundant array of sensors that needs to not only piece together how an image is supposed to be formed, but also correct for the non-smoothness of the panes (hence why this appeared in the wave-front aberration session). This would be easier if the mirrors were curved, because then they would have a focus, and with that they could form an image at a detector.

  Anyway, I understand that this was somewhat brief, but if you ever want more details or clarifications, feel free to leave a note in the comments below.

Fiao/LS 2011 - Travelling back

<p>I'll likely be writing on the plane, but I am also just as likely to not have wireless, so the next substantial post will have to wait until I'm back home. Of the two talks I was able to snag this morning, they were both good, so I'm looking forward to sharing those ideas when I get back.</p>

FiO/LS 2011 - Wednesday Sessions

    Today was quite the whirlwind, after getting breakfast in the morning, I went off to a room that I hadn't been to before. Unfortunately, I thought it was somewhere else, so I ended up circling the conference center and coming back to the room right above the coffee shop. And this was after I had my morning coffee... sigh...

    Anyway, there were a few gems of talks today. The first was a talk by Mark Foster on his work doing time lensing - essentially using an all fiber setup to shift the pattern in the spectrum of light into the time domain, and the time domain into the spectral domain. This is cool stuff because in telecom they have well developed methods for handling one type of signal but not the other, so by having an all fiber way of switching between the two makes it easy to modify either signal. This could lead to faster bandwidth with only minimal overhead. It turns out that you can use a similar method to do extra-precise analog to digital conversion by using a pulsed laser (which has very small timing jitter of about 5 fs, that's 5*10^-15 s) to do the sampling, then stretch the samples out a bit so that an electronic ADC can pick it up (these have timing jitter of about 100 fs). So you pick up a factor of 10-100 accuracy by this method.

    The rest of the morning wasn't particularly my field, so I didn't get a lot out of it. Consequently I went off to The Tech Museum to have some fun, but also decompress and get my brain ready for more talks. I had a really good time there, and to do it justice, I think I'll make a separate post (with pictures).

    By the time the afternoon rolled around, a few more talks popped up on my radar. First up was a talk by Eric Van Stryland's group on their work in seeding supercontinuum (SC) generation. I mentioned this briefly before, but the idea is that if you go through special optical fibers or, in this case, a krypton gas cell you can turn a short laser pulse of a few frequencies (about 100 nm bandwidth) into a longer pulse of many more frequencies (usually spanning the visible, from 400 nm (deep purple) to 800 nm (red) and even longer wavelengths). Since supercontinuum generation is the result from a plethora of nonlinear processes, you have to have very intense light to do it. Usually there is also a sharp turn on, from having no SC to having the SC by tuning the laser power very slightly. By seeding the supercontinuum, a process where you add a bit of light - his group used a pulse with 40,000 times less energy - to get the process started. Not only did they find it works, but it increases the amount of light you get out by a factor of 4 or so. They don't completely understand it yet, but this is a fantastic result, because having a bright light source that is continuously variable over such a broad range of spectrum really opens to door to many experiments, and is something I may be working on in the future.

    Then there were two talks on biology and biological optics. I'm going to save the one by Nicholas Roberts on polarized vision in animals for a later post - this was the research on Mantis Shrimp being able to see circularly polarized light, but there's so much more than just that. Instead I'd like to focus on Hui Cao's work on mimicking nature's optics... and then doing better! You may have heard that butterflies have a wing scale pattern that has very fine microstructure, acting like a diffraction grating and giving them their wing iridescence. Well, it turns out that some birds, and for some colors, have a similar effect that colors their wings. However, while the butterfly wing will seem to change colors as you change viewing angle, this does not happen for the birds. This is a result of having local structure but no large scale structure in the bird wing. By making similar structures, they were able to re-create the effect in the lab. But if that were all it would hardly be entertaining. They went a step further, and placed what are known as quantum dots into their structures, these are small metallic spheres that emit different colors based on how big they are. When they hit this structure with light, it would preferentially amplify a certain frequency - they had created a laser! Hopefully the birds don't figure this one out.

FiO/LS 2011 - Tuesday Sessions

    Wow! Today was absolutely packed and quite exciting. First off I just invented my "Most Amusing Talk" award so I could give it to John Dudley, whose talk (slides available here) was very entertaining. He started off with a case of how he was wrong, then moved into a recount of how he was observing super continuum generation (where you get white light from almost single color laser light using special optical fibers) as a solution to the nonlinear wave equation and couldn't get it published anywhere (Science, Nature, and on down the food chain), but eventually got it into Applied Optics. Now these types of results make the cover of Nature Photonics! He suggested they start the journal "Nature Reinterpretations" which got a good chuckle from the audience.
    This was mixed with a recount of how the first nuclear weapon design (gun type) was not actually tested, but the engineers who were building it had a good idea it would work, so while the physicists were busy testing their bomb (implosion type), the engineers just dropped theirs! I really have no idea how this fit in, but interesting trivia anyway. Another good quote; "Fluid dynamicists were divided into engineers who observed things that could not be explained and mathematicians who explained things that could not be observed …" (Sir James Lighthill). I can think of some other fields, where this is true.
    Finally, he ended by showing just why science is exciting - the solutions they were seeing in their nonlinear optics experiments should have been possible in water (where the equations the optics people used were first developed). Despite searching, no-one had been able to produce the effect in water until the optics folks showed the way. And now we have rogue wave type solitons in water;

    The best part of the day, however, was going by the '"Mission: Optical" Student Chapter Competition'. The goal was to build a project for under $25 (US) that demonstrated an optics principle. So many good and fun ideas - I'll definitely be stealing many of these! My favorites were a balloon stretched across the end of a tin can, the other end was cut off so you could speak into it. A laser pointer was then attached pointing at a mirror (or CD) that was glued to the balloon. When you spoke into it, the balloon drum would vibrate, and the reflected spot would trace out a pattern on the wall. A great way of 'visualizing sound', and much easier, more direct and more robust than having motors drive mirrors to deflect the laser beam. Another group used legos, LED's, CD's and some ingenuity to build a 3D stroboscopic viewer. It almost worked. But it was enough of an ingenious idea, that I'd really like to give them credit for it.
    Other groups used just a bucket of water, sugar and milk to demonstrate as many different optical principles as they could: Reflection and refraction, the later of which changes with the addition of sugar to the water, total internal reflection in the bucket and the addition of milk for scattering. And another had a great setup that really made it easy for students to get into the scientific principle (just don't tell the kids that). They had kids split into groups and try different ways to heat water. Yet another demonstration of just why I think these conferences are awesome - I never would have thought of some of these ideas on my own, but now I can use them to teach others about optics.

FiO/LS 2011 - Personal Experiences

    Today, I gave my first Real Conference Talk. For those of you from a non-science background, a conference talk is essentially a 12 minute window (25 minutes if you're a big-shot) during which you present your cutting edge research to others in your field. You then have 3 (5 for the bigwigs) minutes for questions. Why is this important? Because this is one of those rare times that Ideas get generated. Most of the time you're working in the lab, trying to solve the problem of why your image is out of focus, or unevenly lit, or why you have chirp and where did it come from anyway...? But at a conference the point is to present your research, listen to others talk about their research, look for cool ideas that you could do in your lab, and figure out a way you could do it better, or in a way no-one else could. It's a period of pure thinking and flexing your intellectual muscle. At least that's how I view conferences.

    I lied though, this actually isn't my first first Real Conference Talk. I gave a talk at the 10th International Conference on Non-linear Dynamics. That was back in high-school, and while I took the data and came up with the analysis, the talk was actually handed to me as we were driving to the conference. This talk is still special though, because it's my third year in graduate school, and yet my first conference talk. My research for the last year has not gone quite as well as I planned, but it went, and I have solid (if perhaps somewhat simplistic) data and a solid model to back it up with.

    So I gave a good talk. I know this because I practiced it before hand, tried it out on several members of my group (sometimes multiple times, thank you by the way), thought about the graphical layout of my slides (really this is important, the last thing you want is someone thinking 'oh, great' and pulling out the conference proceedings because he can't read your title from the front row (true story from today)), I thought about the content on the slides and tried to ask myself what was a) wrong with it, b) confusing about it, c) what it could lead to and imply, and d) what does it mean anyway? And then I thought of how to answer those questions.

    I've taught recitation sections and lab sections by now, so I know the look on people's faces when they don't understand something and as I was giving my talk I was seeing (mostly) the opposite of that. I know my message made it through and not just the people in my group complemented me afterwards. So I know it was a good talk.

    Yet I feel as though I just got handed a C. Why? Because despite all the thinking I did beforehand I flubbed the first question. Okay, so I get seriously nervous giving talks, and while my leg no-longer twitches like it used to (although I did do a lap around the conference center afterwards, during the coffee break, thankfully), my heart rate and blood pressure skyrocket whenever I give talks, especially for the question and answer sessions - I can't help it. Back to the story - despite all my thinking about my slides and going over questions and reasoning in my head, when I get that first question I stall. Wait, what? He just said something that I thought I knew how it worked, but apparently I don't, how does it apply here? Does it really apply here, can he clarify, oh yeah sure, go on a tangent... wait... that didn't actually help OR answer the question... stumble... um... anyway.....

    I knew I was going to get this question too. How did I know I was going to get it you ask? Well I just put up a picture the size of the projector screen with a fairly obvious imaging artifact* tiled all over it, duh someone was going to spot it.

    So I had seen this artifact the first time I displayed the image, but at the time I thought, 'hey cool, this is a pretty awesome image!' Then about a couple of days later I thought it could be a mis-alignment of my imaging system (which was mis-aligned, the blasted thing can't stay on straight) which could be causing a preferential direction to emerge. Despite having these two rational arguments I stopped dead in my tracks and flopped like a fish out of water for a minute or so until someone saved me and got in another question.

    So, it was a good talk. It might not have been a Great Talk, but I have a few more years to work on that one. Yeah, I flubbed one question, but I answered the others reasonably well, and the question got some others thinking, and they gave me some great experiments to try, so I really learned a new experimental method from it. Plus it pointed out a hole in my knowledge, I assumed I knew what a certain method was, but apparently not, so I'm now inspired (shamed?) into going back and reading over the methods of my field so I don't get caught off-balance again. I may have hated it, but I'll likely be a better scientist for it. And that's what conferences really are for - making better science.



* It might not be an artifact, I don't think it is, and I realized while I'm out here that I can do a quick experimental check for this when I get back, but for the point of the story it doesn't matter, artifact describes what it looks like.