Bedside Tables - Part III

  Finally decided to get a sander - and boy am I glad I did! We really could have used it for all of our previous projects. After reading up a bit on sanders we opted for getting a 5-inch random orbital sander with the hook and loop sanding pads. [Aside; it never clicked with me that "hook-and-loop" equates to "Velcro", I was worried that I'd be wrestling with the sander threading some crazy loop mechanism through sanding pads!]
  The sander definitely makes sanding easier - I was able to finish off one of the sanding passes in one evening, whereas one pass would take me two evenings before (and I made two passes before this, just if you were wondering what was taking these posts so long). Unfortunately, we noticed that my hand-sanding from before had inadvertently made some light-scratches on the surface. The random-orbital sander, because of the 'randomness' in the vibration does a good job of avoid this. You can go either with or against the grain with the random orbital sander, and as long as you don't push down very hard, or angle so the edges of the sander bite into the wood, you shouldn't leave any scratches and you should have a nice smooth sanded surface at the end.

Brackets attached to the parts, waiting to be put together.

A close-up of the finished product.

  Post Sanding, we stained the wood, placing two coats of our favored "dark cherry" stain that we've used on all our other projects, on all the sides and edges. We finished up with a quick coat of spray polyurethane sealant, although we'll likely go over the finished product with a paint-on polyurethane sealant.
  With everything sanded and sealed, it was time for partial assembly (we still have to cut, sand, and stain the sides and doors). You can see from the photo, that I opted for thin, 2 screw corner brackets, which I first put on the shelves and the top of the legs. I'm a big fan of pilot holes, and there are some on the legs and top waiting for the screws.
  A very small dab of glue accompanied the legs as they were screwed into the top. Once all were in, I inched the shelves between the four legs and screwed them into place. For each shelf, the brackets were first screwed to the shelf. Then I partially screwed in the screws connecting them to the legs, only tightening them down fully once all were in.

The two tables partly assembled!

  Volia! They're assembled and starting to look light nightstands. Now we just need to finish off the sides, which should prove an interesting exercise with the jigsaw - I've yet to perform an cut with the jigsaw blade at an angle. The final steps will be deciding on the door mechanisms and the hardware. Still, it's nice having a picture of what they'll look like when finished. And they seem to be a good height next to the bed (couldn't help taking them up there for a trial).

Bedside Tables Part II

  Here's the physical start to the bedside tables. I've already cut the table legs and the shelves (see the photo to the right). However, I still need to cut the corners off of the shelves to get the desired look. So here's a detailed look at this step.
  Of course, you'll need a few tools, here are mine; a jigsaw and a couple of clamps. I also have a folding table that you can see in the next picture.

  I clamped a guide board to the bench, and am using it to pin the shelf to the bench. I have a couple of shims to help keep everything almost the same height. While cutting, I make sure to put my weight on the guide board, preventing the work piece from moving. At this point, it's still adjustable slightly so I can make sure the saw will cut through at the right points.

  Check that the saw-blade lines up, both where the blade will start and finish cutting the wood. Make sure that the edge of the blade is on the line, and not the center of the blade. Otherwise your cut will be smaller than you want it to be, as the blade will annihilate the wood in it's path, and then a little bit.

  Four cuts later, we have one done! I think they look pretty good, and also reminiscent of something out of the Battlestar remake. Trim the corners to keep the Cylons from assembling the tables.

  Here's a glimpse of what it will look like when finished the inner shelves are a few inches smaller than the top shelf such that the legs are flush with both shelves. When this is finished, it should give it a nice recessed look along the sides and front, while hiding the ugly plywood edges of the sides.

Here are some "pro tips" I've learned while cutting the 24 corners off of the shelves. First the one I knew going in;

Face the edge you want to look nice downward (on the opposite side as the jigsaw).

  The orbital jigsaw blade moves down, forward, and then up, the amount of forward and back is what gives it the orbital name, and most orbital jigsaws allow you to adjust the amount of forward and back motion. For instance, I usually set mine to cut with a light orbital action on plywood because I want a fairly reasonable finish (our plywood is going towards furniture after all), however, you could set it to a larger reciprocal (back and forth) action for rougher, but faster, cutting along plywood.

  I also noticed that the direction of the grain matters. If at all possible, aligning the grain direction with the direction of the jigsaw cut produces a much smoother and nicer cut. It seems when it cuts against the grain, it is more likely to catch and pull up splinters.

  Well, that's the cutting of the main pieces of the bedside tables. Next up will be sanding and staining, followed by putting these pieces together.

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.