Saturday, March 31, 2012

Book Review: Crystal Rain by Tobias S. Buckell

Crystal Rain by Tobias S. Buckell is his 2006 debut novel. I had heard good things about his work, but hadn't yet read him. I finally bought this since it was $2.99 on the Amazon Kindle store, and I love getting bargains like these.

Overall Impression
I have found that when I finish a really long, good book and start a second one, I suffer from 'book fatigue' and it takes me longer to get into and appreciate the following book. Having finished Memories of Ice by Steven Erikson, I felt that this would happen, but fortunately it did not. Either I paced myself with that book (not deliberately- it was good, but I couldn't read as much given my busy schedule) or Crystal Rain succeeds at capturing the reader quickly and effectively. Let's be optimistic and say that Buckell has done his job well.

A cool thing I found was the description of the airship flights. I always imagined them to be nice and smooth like most airplane flights nowadays, but I realize that this is a bogus expectation. Airships must be extremely light and thus any gust of wind will cause them to shake about. Additionally, if you go very high up, you will have trouble breathing as the main 'cabin' is not pressurized. In hindsight, all this makes sense and are just part of the difficulties of high-altitude, open-air airship travel, but it's something I had not thought about that Buckell pointed out.

The plot is very straightforward, which is actually kind of disappointing after reading a massive, twisted, epic fantasy novel. It does move along at a nice pace and you can pick it up very quickly. The simplicity of the plot is refreshing, but only up to a point. Once you finish it, you think to yourself: oh, that's it?
The details are always a mystery of course. For example, you don't know how the Nanagadans are going to repel the Aztecan invasion, until they do, but you do know that the main plot device, the Ma Wi Jung, will save the day. The only potentially interesting plot twist or development is Oaxyctl's last moments, but even those aren't that impressive.

The characters could have been a bit better fleshed out, in my opinion. The story focuses heavily on John deBrun and Oaxyctl, but there are other viewpoint characters as well. John has amnesia and is trying to recover his memories, but it doesn't really feel like he is trying hard. It doesn't seem like a driver for his persona. Instead he focuses on his family, but even then he is able to let go rather quickly. At the end of the book, you have a better idea of his motivations, but even then it feels like something is missing.

Oaxyctl, on the other hand, is a much better developed character. He is Azteca (see Setting), but has crossed over the mountains to join the mongoose-men in fighting the Azteca. However, as is is made very clearly early on, he is actually a spy and he intends to capture/torture/etc John in particular. Circumstances bring them together and they begin to learn from each other. It seems to me that Oaxyctl gets the better deal as he slowly opens up and talks about his wife, his home across the mountains, and his gods. By the end of the story he is conflict: does he follow his god, whom he now knows is false, or does he turn and follow his new friend? Redemption stories like that are immensely interesting when done properly, regardless of whether the 'bad' guys redeem themselves or fail to do so. Oaxyctl's growth through the story is probably the best part of the book. My only regret is that the final execution could have been a little better, more emotional, perhaps.

The rest of the characters are, unfortunately, pretty flat and unchanging. I didn't care about the Prime Minister or the military commander and even John's son, Jerome, is difficult to connect to. Jerome begins to grow when he's in Frenchitown, but he's quickly stunted.
Another minor qualm I had was that there is a strong dialect among nearly all of the people in the story. Word choice and dialect can be used very effectively to set apart a person or group of people, and I like how it was pulled off in The Wheel of Time. Unfortunately, for this book it looks like everyone has the same dialect so you can't use it to distinguish people (with the rare exception like John) and it's fairly heavy. I would have preferred a lighter dialect that is used only sparingly to highlight maybe one or two characters. I suppose that as it is, it doesn't detract from the story, but it does require a little extra effort to parse what people are saying.

Setting / World Building
I find it difficult to think of it as a science fiction story given the very little science we see until the very end. It's like being in the Dream of Peter F. Hamilton's The Dreaming Void. This is sci-fi, though: there are spaceships (and airships), guns, physical enhancements, wormholes, and alien species. But the society there has lived for hundreds of years and (most of) the original people who remember are now dead. Hence, what you have is a population that has grown up and thinks the aliens are gods and the world gets a more magical or fantastical feel. I described it on Goodreads as 'old' sci-fi technology amidst a colonial-type Caribbean world where gods/aliens and religion/technology blend together. It's a very interesting combination and I would have liked to see a bit more of the world (and more airships!).

Final Thoughts
The setting of this story is probably the best aspect of it. Not only is there plenty of sci-fi talk (there's a whole backstory that is alluded to and I don't mention here), but it's also set in a nice tropical climate, like good ol' Puerto Rico. I don't see settings like those often in speculative fiction so that was pretty neat.

The book has some flaws in weak characters and generic plot line, but other than that it's a pretty decent book with very good pacing. Considering that this is a debut novel from 2006 and he has continued writing, Buckell can only have improved.
Perhaps this wasn't the best book to pick in order to get a feel for his style? I have mixed feelings about whether or not to recommend this book. However, Buckell actually provides the entire first third of the book as a free preview. So perhaps your best bet is to check that out and make your own decision from there.

Thursday, March 29, 2012

Iguazu Falls Trip: Paraguay (2/3)

This is the second post of three regarding our trip to Iguazu Falls.
Iguazu falls at the intersection of 3 countries: Brazil, Argentina, and Paraguay. I've already described our brief trip to Argentina. For the second day, we took a brief trip into Paraguay to check it out.

The main attraction to Paraguay is the Itaipu Dam. This is the second largest hydroelectric dam, in size, in the world, second only to the Three Gorges Dam in China. However, the annual energy output of Itaipu is the largest. In 2008, the produced a record 94.7 terrawatt-hours which is comparable to the amount of electricity the entire planet uses in two days.
The Itaipu Dam in Paraguay
The Itaipu Dam is a joint effort between Paraguay and Brazil. There are 20 turbines split evenly between the two nations. Interestingly, Paraguay uses 220V/50 Hz for its electricity while Brazil uses 110V/60Hz.
A broader view of the Itaipu Dam. The foreground shows the discharge channels, which open (but don't generate electricity) if the water level is too high.

Paraguay used to own the territory of Parana, where the Iguazu Falls are located. However, they were landlocked and, according to our tour guide, wanted access to the sea. In 1864, war broke out as Paraguay invaded Brazil and Argentina in order to reach Uruguay. Uruguay was a small nation, easily conquered and with access to the ocean. However, the three nations formed a Triple Alliance and soundly beat Paraguay. Paraguay now no longer controls the falls and lost a lot of territory as a result of the war.
A satellite view (from Google Earth) of Itaipu Dam. The discharge channels are partially open. Up to 40 times the Iguazu Falls rate can pass through these channels.
We were given tons of facts on the dam. The most repeated one being that all the iron and steel used in its production would amount to 380 Eiffel Towers. The one that caused us to be skeptical though, was that the amount of water passing through 2 of its tubes (see photo) is the same as that of the Iguazu Falls. That seemed far too impressive to be true. So like good scientists, we set out to check it with some quick order-of-magnitude calculations.
These 10-meter diameter tubes channel the water to turbines about 50-meters below that generate electricity

We can calculate the velocity water, or anything really, would reach given an initial height of about 100-m with:
mgh = 1/2 mv^2
The mass cancels, and we can ignore the factor of 2. Between friends, g is 10 m/s^2, so we have v^2~1000 or v~30m/s.
The rate of water is just the velocity times the cross-sectional area. We were told the diameter of the tubes were 10-m (internal) so we have a rate of (3*25)*30 ~ 2200 cubic meters/second. This is likely to be off by a factor of a few, but certainly accurate within a factor of 10. In comparison, Iguazu Falls has an average flow rate of about 1800 cubic meters/second so a statement like "the amount of water in the Iguazu Falls falls through two of these tubes each second" is a perfectly believable statement. Considering there are 20 tubes, we can see that the Rio Paraná has 10 times the flow of the Rio Iguazu.
The location of Itaipu Dam with respect to the 3 countries and Iguazu Falls. Red arrows indicate the direction of the water's flow. The Paraná River, which runs south from the dam, divides Paraguay-Brazil and Paraguay-Argentina. The Iguazu River, which flows west and joins the Paraná, divides Argentina-Brazil.

After the brief excursion to the dam, we went shopping. None of us really were up for it, but apparently the rest of the tour group would die if they couldn't shop. At least we got a look at the city, but we were not impressed:
The streets of Ciudad del Este, in Paraguay
We were warned of the blatant corruption of police officers and the streets were so crowded and full of people trying to sell you stuff or run you over with their bikes that we spent most of the time indoors.

Here's a brief video of the Itaipu Dam. Not as impressive as my Iguazu Falls video, but here you go:

Tuesday, March 27, 2012

Iguazu Falls Trip: Argentina (1/3)

This is the first of three posts on our recent trip to Iguazu Falls. This trip came about thanks to a Groupon deal several of us purchased. Although park entries weren't included, we knew we would be visiting both sides of the falls and the Parque Das Aves (Day 3). We also took an improvised trip to Paraguay to visit the Itaipu dam (Day 2). Today, I will talk about our arrival and the first day of adventure in which we visit the Argentinian side of the falls.

Our trip there was fairly uneventful, despite the ~hour-long delays that our airline, Pluna, had. This happened yet again on our return trip, but despite what The Way of Kings says, the Destination in this case is far more important than the Journey.
Remember: you can click to see larger versions of these pictures. The panoramic shots are saved separately in this Picasa Album.

You can see the Iguazu Falls while arriving/departing on the flight!

Crossing the border was not problematic at all. I did have to get a visa beforehand to enter Brazil, but no such requirement to cross over to Argentina by land. Our guide took care of all the details while we waited to cross.

Getting ready to enter the park itself.

There are many trails through the park, and plenty of wildlife. Here are some of the animals we encountered:
Coati (tons of them)

But we didn't come here to see wildlife. We came to see the falls. And we saw them:
Garganta del Diablo, as seen from the Argentinian viewpoint

On average, about 1750 cubic meters of water flow down each second, second only to the Niagara Falls. However, the maximum recorded water flow reached 12,800 cubic meters/second, far exceeding the recorded maxima of Niagara or Victoria Falls.
A broader view of the Garganta del Diablo (Devil's Throat)

Victoria Falls in Southern Africa (Zimbabwe/Zambia border) holds the record for the largest curtain of water. Iguazu Falls, on the other hand, has many separate falls that together adds up to the widest waterfall on Earth.
Panoramic shots were made digitally with DoubleTake. Minor errors always show up near the individual image edges, but despite that the program works very well. 

About 3/4 of the waterfalls are on the Argentinian side, but a more panoramic view of them can be seen on the Brazilian side. They actually joke about that: Argentina threatens to put up a big screen to prevent Brazil from seeing the falls, but Brazil dams up the river (which comes from Brazil) to dry them up. So expect even more impressive pictures on my blog post for Day 3.
The lush sub-tropical jungle makes an excellent contrast to all the waterfalls.

The name Iguazu comes from the Guarani language, which used to be the official language of Paraguay. Through circumstances that I'll describe in a future post, Spanish became the official language and Paraguay lost access to the Falls. Iguazu literally means "big water" (y=water, ûasú=big), which in my opinion is a severe understatement.
The island in this shot is San Martin Island, which is sometimes not accessible (like for our trip), depending on the water level.

In addition to walking through several trails and experiencing the falls up close. You can also take a boat ride and get even closer. We were warned that we would get very wet, so we came prepared. The boat actually took us very near two waterfalls so we got soaked twice. I had my camera in a plastic bag, so it was safe, but also result in slightly blurrier photos, like you can see below:

Words alone can't express the grandeur of this place. Even photos have a hard time, and I don't want to flood my website (pun intended) with waterfall pictures. So here is a compilation I made from the videos I took. This includes both sides and captures a fraction of the awesomeness of Iguazu Falls:

Friday, March 23, 2012

Avatar: The Last Airbender

I am currently undergoing an adventure and will report on that later so I'm making use of Blogger's scheduled posts for this. Here's a review I wrote some time ago and updated with new information.

With all the recent hype on Avatar: The Legend of Korra (premiering April 14), I figured I'd write down some thoughts on the original series, why I like it, and what I'm looking forward to on this new series.

This is an american anime that aired many years ago. I refer to it that way since it is very much the same style as other anime you may be familiar with, but was drawn and voiced in the US. I'm a fan of anime, but it took me several years to finally watch the series. I do remember hearing about it when it came out, but it was only with Netflix that I finally got to see it.

There are three main points that make this series shine: the characters, the setting, and the story. If you have read some of my other posts, I keep using this in my reviews to describe the different books I've read. This is one of the few series/books I have watched/read that really stands out in every way. I would also rank them in that order so that characters are the best and story or plot being the weakest aspects of the series. But let's actually start with the setting.

The Last Airbender takes place in a fictional universe where certain people, benders, can control one of the four elements- fire, earth, water, wind. The bending is done through physical gestures and is a form of martial arts. Even a casual observer of the series can tell that there are differences in how the various elements are controlled. There is, however, one person alive at any given time that has the ability to learn and control all four elements: the avatar. The avatar is the only person that can master all elements and is born at the instant (or close enough, I suppose) when the last avatar dies. The avatar is born in the different kindoms in a rigid order: fire, air, water, earth, and then repeat; so he/she gets trained initially in the nation he/she started. The cycle has been unbroken for countless years and, at times of great need, the avatar can draw upon the wisdom and experience of all his/her past lives. The avatar is basically a force of nature, whose goal is (supposed to be) to balance the world and bring harmony. During times of peace, this can be easy, but when war breaks out, the avatar is expected to help solve the crisis.

Current and past avatars
The story itself starts with a brief prologue describing the events 100 years ago: the fire nation, about 12 years after the death of the last avatar (of the nation of fire), launches a strike against the other nations and in particular devastates the air nomads as the next avatar will arise from them. Their plan doesn't work completely as the young avatar, not fully realized, manages to encase himself in ice and is thus protected for the next 100 years. When the avatar emerges, he is the last of the airbenders and has a lot to learn to catch up and master all four elements before the next big fire nation attack.

The characters are absolutely amazing. They grow and change throughout the series. The most obvious example being Zuko. His personal story is one of the most compelling aspects of the show. None of the characters are perfect, and we watch them suffer through their flaws, but grow stronger for it. These are the sorts of characters you can identify with and will remember for years and years to come.

Sokka of the water tribe. While he is always somewhat of a comic relief character, he turns out to be a great tactician and swordsman.
Finally, the plot is, though a bit generic, very interesting and moves at a good pace. The avatar has to settle the conflict between the fire nation and the rest of the world, but he has to travel all over to master the elements while at the same time avoiding the bad guys who want to capture him (but not kill, since he would then be reborn among the water tribe). I have my doubts that such a war can really last 100 years, but I try to think of it as more of a Cold War-type scenario. Lots of tension and a few skirmishes every few years. The action increases throughout the series thanks to the upcoming arrival of Sozin's comet, that will greatly strengthen the fire nation's power.

WARNING: As a astronomer, I can tell you that this is completely backwards! Comets are big chunks of ice and rock that orbit the Sun. When they get close to the Sun, the ice sublimates and releases gases and dust out to form tail(s). Because comets are made of ice, they should power water benders, not fire benders. Still, I'm willing to forgive them this as the series itself is quite good and there is no such thing as bending. To be fair: the 'comet' itself appears to gain the tail when it brushes past the atmosphere. That means it is technically a meteor and not a comet...

Comet? I think not.
Another minor gripe I have is that this is intrinsically a kids show and as such is often lighthearted. However, despite this it does deal with some heavier topics like revenge and killing. One potential improvement would have been a darker or more realist setting, which is one reason I got interested in the real life adaptation by M. Night Shyamalan. That, however, was horribly done and not at all what we the fans expected. Still, the lighthearted and humorous nature gives the show a unique flavor when compared to similar series and the important thing is that overall it works. The few scenes where it grows dark or sad are all the more powerful for their scarceness.

As a visual medium, I should probably also comment on the animation and sound. I think both are great, the music in particular is always very appropriate. The animation quality is consistent in all episodes. I've seen animes where the quality varies from episode to episode and this is not the case here.

To finish: I highly recommend this series. I'll probably be checking out the Legend of Korra as well, which picks up the story many years after the original series when Avatar Aang dies (and Avatar Korra is born). Few fantasy series (though Mistborn comes to mind) explore what happens after the hero wins and society changes. From the information we've heard so far, the technology level has increased and looks a bit like an urban fantasy/steampunk type thing. Bending has also become more globalized with a city where people of all nations live.
A lot of people have been excited given the previews, but some of the recent ones haven't seemed that great to me. I'll need to see the whole episode to appreciate these tiny glimpses we've been given. The trailer, though, is great:

Premiering April 14!
One other cool thing: xkcd has a neat comic based on Avatar.
All images (except the last) are screenshots of Avatar: The Last Airbender, copyright Nickelodeon.

Monday, March 19, 2012

Sunspots Group 1429

Just a quick blog post to point you to today's amazing Astronomy Picture of the Day (APOD):
Credit: APOD, Juan Manuel Pérez Rayego

Look very carefully at that sunset picture. Ignore the birds, the tree, and the bands due to the thin clouds in our own atmosphere. On the disk of the Sun itself, you can clearly see some spots. That's not a defective camera lens, those spots are actually on the Sun. The big one there is sunspot group 1429, which you can also see in this other APOD picture:
Credit: APOD, Alan Friedman

Sunspot group 1429 is a particularly large set of sunspots that was quite active a few weeks ago. You may have heard the news of a massive solar flare emanating from this region around March 7th or so. This increase in solar activity happens periodically as the Sun reaches solar maximum.

One last thing I want to point out is the scale of these sunspots. If you look at the first image you'll see a few smallish spots near the center. Each of those is larger than the planet Earth. The Sun is big, and yet it is an average star that's just one of a hundred billion or so stars in our own Galaxy.

Sunday, March 18, 2012

Book Review: Memories of Ice by Steven Erikson

Memories of Ice is Book 3 of the Malazan Book of the Fallen. Naturally, you should probably check out Book 1 (Gardens of the Moon) and Book 2 (Deadhouse Gates) before this one. It feels like the series diverged in book 2/3 with the story following some characters in book 2 and simultaneously following the other characters in book 3. However, the stories are very well contained so it doesn't feel like the similarly split Feast for Crows/A Dance with Dragons by George R.R. Martin.

Saturday, March 17, 2012

Chilean Sunset: 3/16/2012

Now THIS is a sunset:

I stayed late at Cerro Calan last Friday and managed to capture this shot (among others) of the setting Sun. We are facing west here and you can see the Sun setting behind a distant mountain. I'll admit to not realizing there was a mountain there- the smoggy haze is usually sufficient to obscure such distant objects (about 24mi/39km away).

The city of Santiago is technically in the picture, but since it's dark most doesn't show up. However, to the left of the sunset you may notice a very tall building infront of a pair of hills. That building is the Gran Torre Costanera, which is the tallest building in South America. The hills behind is Cerro San Cristobal, which is home to the largest public park in Santiago (Parque Metropolitano).

Update: Lironah of Iron Wolf Games tweaked the image with Photoshop to get this:
Though some of the subtlety in the sky colors and distant mountains is lost, it's now far easier to see the city. I should mention that this photo was taken with an iPhone 3GS camera so it's quite impressive that so much detail is captured in a low-light situation.

Wednesday, March 14, 2012

WISE All-Sky Data Release

Today marks the full data release from the Wide-field Infrared Survey Explorer (WISE)! From their website:
NASA's Wide-field Infrared Survey Explorer (WISE; Wright et al. 2010) mapped the sky at 3.4, 4.6, 12, and 22 μm in 2010 with an angular resolution of 6.1" 6.4" 6.5" & 12.0" in the four bands. WISE achieved 5σ point source sensitivities better than 0.08, 0.11, 1 and 6 mJy in unconfused regions on the ecliptic in the four bands. Sensitivity improves toward the ecliptic poles due to denser coverage and lower zodiacal background.
The sky, in Galactic coordinates, according to WISE. The blue band across the image is the Milky Way Galaxy, the yellowish, diffuse band is the ecliptic- the plane of our solar system. The blue-white bands perpendicular to the ecliptic are artifacts as a result of residual Moon glow when the observations were taken.

For the non-astronomers reading this: WISE is a satellite that has mapped the sky at infrared wavelengths. Light from these wavelengths is invisible to the naked eye, but we perceive it as heat. All objects glow with light and the wavelength of peak emission depends on its temperature. For humans, with a typical temperature of 37 Celsius (98.6 Fahrenheit), the peak wavelength happens to be about 10 microns (μm). You can see that WISE probes wavelengths similar to this, so in principle it can observe objects as warm/cool as humans, though in practice these must be much physically larger in order to be detected.

There's actually a type of very cool objects out there known as brown dwarfs. Physically, these are objects that are not massive enough to have hydrogen fusion in their cores, which is the defining characteristic of a star. These brown dwarfs can range in mass from about 13 to 80 times the mass of Jupiter and are not much larger than Jupiter in size. The temperature for the coolest brown dwarfs discovered to date reaches 300 Kelvin (K). The Kelvin temperature scale is like Celsius, except shifted by 273 degrees, so this corresponds to 27 Celsius or 80 Fahrenheit.
Here are the relevant WISE temperature limits for brown dwarfs:
With WISE we will be able to see 450-K brown dwarfs out to a distance of 75 light-years (ly), 300-K brown dwarfs out to 20 ly, and 150-K brown dwarfs out to 10 ly.
That's really cool (pun intended)! 

With this data release, the full WISE catalog is available to everyone. Here's a map of the WISE coverage in Equatorial coordinates (right ascension and declination, different from the figure above):
The colors indicate how often an area has been observed. The more a particular area is observed, the fainter the objects that can be detected. As you can see from the figure, most of it is green indicating WISE observed most of the sky at least 12 times. UCLA's own Ned Wright is the principle investigator (the lead scientist responsible for the project) of the WISE mission so I'm sure everyone back there must be super excited.

In addition to the brown dwarfs already mentioned, WISE has also discovered plenty of asteroids and has studied distant dusty galaxies. These wavelengths are also useful when studying warm disks around nearby stars.

Here's a video with Amy Mainzer from JPL summarizing what WISE can do:

What else WISE can find will be up to the many astronomers that will soon be diving into the WISE data release. Given that useful science is still being carried out with the Two Micron All Sky Survey (2MASS) long after its completion (2001), we can anticipate that WISE data will play a key role in the astronomical research for the next few decades.

UPDATE: Here's a link to a very nice WISE mosaic of the sky. Similar to the first figure I have, but cleaner and it identifies some of the more famous regions in the sky.
And here's a nice Flash applet that allows you to zoom in through the WISE data.

Saturday, March 10, 2012

ESO Conference: Observing Planetary Systems II

I spent 4 days this past week attending the European Southern Observatory (ESO) conference "Observing Planetary Systems II". This post is a brief summary of what went on and my thoughts during the conference.

The conference was fairly small- about 100 people or so. Compare that to the American Astronomical Society (AAS) meetings where you can have easily more than 1,000 astronomers show up. This makes finding people much easier and you interact with the same folks continuously. An additional difference is that things are much more focused: all the talks and poster were on planet, planet formation, observations (AO, infrared, sub-mm), models, disks, and all topics in between. That's a cool set of topics and everyone seems to be working on the same thing so you get some useful discussions.

There was also a small poster session. Because of so few posters, though, by day 2 one has really seen them all. Still, I tried to hang out near mine and approach people who seemed to be reading it. I'm always shy about doing so, but I try not to let that stop me. It helps that the astronomers here were cool folk and are interested in this type of research. My poster was about debris disks in binary systems. The main goal is to advance our understanding on planet formation and evolution in binary star systems.

Day 1
Some good talks, most notably the invited talks. These were longer and more big-picture type talks. As a big-picture type person I totally appreciate these overview presentations. The break-up of topics was well done. The first day focused on disks and the first few million years of planet formation, and indeed all the topics dealt with these topics.

We also got to see (again, after AAS) the Fomalhaut ALMA data. I was told by the speaker this should be submitted later this week so we may see the data soon. I'll try to write a brief post on those results when they come out.

I'm never been a big coffee person, but on conferences like these I do consume quite a bit. You really need it to stay alert after hearing 4 back-to-back talks or after 8 talks or after 14, though by then you should probably just go home as 14 was the number of talks for the first day.

Day 2
Met some more cool people and saw some nice talks, especially about efforts in the direct imaging of exoplanets, which was the main topic of the day (along with planet models). I had crafted an origami-style business card holder the prior night (thanks to this video) so I could put my brand new business cards by my poster. I got a chance to describe my research to a few more people today too.

By the end of the day I had information overload. At a larger conference I wouldn't feel too bad about skipping out on a few talks and just resting, but I wanted to hit all the talks. That's the problem with such a focused conference: everything ties together and, if you like seeing the big-picture as I do, then you want to see it all.

My poster! Pretty much recycled from AAS. The QR code points to a page on my professional website describing the research in a bit more detail along with providing links to the poster, the paper, and my other research.

Day 3
Same as the prior days in terms of talks (some good, some so-so) and meeting people. A lot of talks about our solar system; Dave Jewitt (UCLA) gave a really interesting talk on ice in the solar system. I learned a lot. Like Hilke Schlichting (also UCLA), he took the time to work out some math on the board. Is that a UCLA thing? I did my graduate studies there and took a class called Order of Magnitude Astrophysics (OoMA), which involved going up to the board and solving astronomy-related questions on the fly. This was very much like that. Both times worked very well, in my opinion.

After lunch, we switched out from the solar system and ices and into planetary atmospheres. This isn't my field of expertise and I'd already heard some of the topics back in the US among my UCLA colleagues.

Day 4
I missed the first half of the day since I was running some errands. This is related to something really cool I'll be doing at the end of the month so expect some awesome pictures then. This meant, though, that I missed the talks on biomarkers (signatures of life on other worlds), which should have been interesting. Coincidentally, one of the talks was, and I kid you not, by John Carter on Mars. I did a double take when reading the schedule given the fact that the movie was coming out that day here in Chile and it concerns a man of the same name (John Carter) and Mars. I honestly hope he had some good jokes or humor regarding the connection between them in his talk.

The afternoon session focused on some of the future instruments and surveys coming online that will help find planets. The talks were a bit diverse and I think this was mostly just the overflow of those talks that didn't quite fit anywhere else. Still, there were some interesting talks.

The conference room while at a coffee break.

Final Thoughts
Overall, the conference was good. I enjoyed most the review talks, especially those about topics only tangentially related to what I do. I learned a lot of interesting facts and concepts in these. The individual topic talks were sometimes good, but it depended a lot on the speaker. A few speakers were clearly enthusiastic whereas others just looked tired. The talks will eventually be posted on the conference website in case you want to check them out.

While there weren't a lot of brand new results, there were still many interesting facts/concepts that I either didn't know or didn't appreciate before. Here are a few that stood out:

  • The inward migration of Neptune is believed to have stirred up the planetesimal population in the Kuiper belt preventing the run-away growth phase and causing collisions to be destructive. This prevented any other large planets from forming out there. 
  • Angular differential imaging (ADI), a technique used to search for faint planets around nearby stars, can significantly affect extended structures, such as disks. Potential effects include producing warps, overly bright disk midplanes, or cavities in the disk.
  • A giant planet survey with the Gemini NICI imager suggests that less than 10% of solar type stars have giant planets of more than 4 times Jupiter's mass at separations larger than 10 AU.
  • Single power law models for planet characteristics among radial velocity detected planets cannot be extended to the directly imaged planets. Our understanding is still incomplete and/or these two techniques probe different populations of planets.
  • The Kozai mechanism, in which a 3rd object in a system (say a distant secondary star or planet) causes the eccentricity and inclination of the 2nd object (say a planet around the primary star) to oscillate, also works in the case of an inclined planet crossing a disk. Dynamical friction will dampen the inclination oscillations, though the disk can dissipate before it is fully damped.
  • The ~1m/s limit on radial velocity planet searches is driven by intrinsic stellar phenomena. Data analysis techniques, such as binning the data, can be used to get higher precisions.
  • There's both crystalline ice (like the type on your freezer) and amorphous ice, where the molecules are randomly arranged. Amorphous ice can very quickly, and explosively if it has trapped gases, convert to crystalline ice if it has enough energy or it gets warm enough. At 100 Kelvin (-173 Celsius, -280 Fahrenheit), the transformation takes only a millisecond.
  • At any given time, there are 1-2 1-meter size 'mini-Moons' sharing the Earth's orbit for a period of a few months. Much larger mini-Moons, say 100-meters, only share the orbit once every 100,000 years. These larger objects would be visible to the naked eye. Note that these mini-Moons are not truly bound to the Earth and are just passing through.

 The best quote from the conference:
Planets are more exciting than galaxies.
  - Dave Jewitt

Wednesday, March 7, 2012

Chilean Sunrise: 3/7/2012

I've been getting up early each day in order to get to the ESO conference on time (more on that on a future post). I get up before the Sun, so here's a shot at today's sunrise (7:15 AM):

And a bit later (7:49 AM):

The Sun still hadn't peeked above the Andes by the time I wrote this so I'm missing the best part, but I have to go...

Saturday, March 3, 2012

How to Make 3D Images with GIMP

Recent years have seen an increase in 3D movies wherein you use special glasses to see a film with an added perception of depth. It turns out you can easily do the same with a basic camera, free software, and some careful planning. When using red/blue glasses (or any two opposite colors, really) these are known as anaglyphs. I've been creating these since 2009 and have uploaded some to my Picasa albums. In this post, I will describe how I generate these.

Step 1: Take the Pictures
You need at least 2 pictures for this to work. The important thing to realize is that human eyes are separated by a few centimeters. If you want to duplicate this effect, you need to take two photos and move between each one. If you want a more pronounced effect, you can shift more than a few centimeters, but I wouldn't recommend shifting by more than a foot (30 cm). 
An alternative is to have two cameras attached together and going off at the same time. The advantage there is that by taking simultaneous images you don't have to worry about any moving objects, rotating the field of view, or capturing a slightly different angle. Unfortunately, you do need two cameras and a more complicated setup.

Let's consider you have one camera only, like I do. You take image 1, then you shift by about 10-20 cm or so to the right and, facing the same direction, take image 2. Ideally you will not have any moving objects (cars, birds, etc) in your frames. If you do, these will ruin the desired effect. Try not to rotate the camera in any way when shifting, just face the same direction. The two images will look very similar, but there will be minor perspective changes. It is these changes that will provide the illusion of depth.

Here are two such frames I've taken. I've placed them side by side for two reasons. One is so you can compare them. The other is that by displaying these images side by side and crossing your eyes you can see a 3D image and can check that everything is fine. It takes a bit of practice to learn how much to cross your eyes. You basically want to see 3 images, the one at the center will be the combination of both of them and will have the added depth perspective. Remember that you can click these images to see them larger.

The images above were taken with a SONY DSC-S500 6MP camera so as to demonstrate that you don't really need a fancy camera for this. I've used the iPhone camera to make good anaglyphs as well. I usually (like in this case) reduce the raw image size to 1024x768 so as to make them easier to process.

Step 2: Load up the images on GIMP
GIMP is a free and powerful image processing tool. The basic tasks to produce an anaglyph are fairly simple, so any decent image processing program should be able to work. So feel free to use Photoshop or similar programs if you have them.

You can either open up the image directly in GIMP or open the program blank and copy-paste the image onto the frame. Dealing with large images can take up a lot of processing power. It's up to you how big you want your images, but as this technique does have it's faults I try not to go beyond 1024 pixels in one dimension. If you have a good camera, a steady hand, and a beautiful shot, then go ahead and use the largest you can handle!

You want to load up the two images in separate layers. In GIMP, this is accomplished easily. When you paste the frame, click on the new layer icon on the Layers Dialog window and it will automatically create a new layer with the image you just pasted. Or even easier: just go to Edit -> Paste As -> New Layer.

Step 3: Make Some Color Layers
Set a new foreground color to FF0000; this is red. Make a new layer and select the Fill Type to be the foreground color. You will have a uniform red layer. Set the layer mode to Screen, duplicate this layer, then do Color -> Invert. That will basically produce another layer with color 0000FF, which is cyan. You could have created the second layer the same way as the first layer, though. The important thing is that both layers must have mode=Screen activated (you can do set on the Layers Dialog window).

Step 4: Merging Layers
Move the layers so that you have them in this order: Cyan, Image 2, Red, Image 1. Image 1 is the left-hand image I have above and Image 2 is the right-hand image. It is very important to get this right otherwise you will need to flip your red/blue glasses backwards (your left eye should see the red image). Activate only the Cyan and Image 2 layers (ie, hide the other two). I do this by clicking the eye symbols on the Layers Dialog window. Merge those two layers (Image -> Merge Visible Layers) and set the mode to Multiply. Now activate all layers and look at the result:

That works, but I personally don't like it. The shift is a little bit too large, especially for the center feature. This brings us to the last step.

Step 5: Tweak to Perfect
With the cyan-merged frame selected, use the Move tool to tweak the image until getting a desirable result. You may also find that you need to apply a small rotation. I personally like distant objects to be neutral (ie, no red/cyan on their edges). However, that may cause some of the foreground material to be too far shifted. You want to hit a balance such that things don't appear too close or your eyes will have trouble seeing details. Here I aim for such a balance and crop out some of the edges:

This is the version I'm happy with and so I save it as a PNG or any other format I prefer.

Images taken July 2011 at Joshua Tree National Park in California. More such anaglyphs I've created can be found in my Picasa albums.

Remember that there is some eye strain when crossing your eyes and when looking at these artificial 3D images, so don't spend too much time looking/creating them or you'll end up with a headache.

Common pitfalls to avoid:
  • The two images are slightly rotated. This can be fixed in GIMP, but is a bit more involved.
  • Different light levels in the images. Again this can be fixed, but ideally you want similar light levels on both raw images.
  • Intense red/blue colors. Most red/cyan glasses aren't perfect and if you have some bright colors this can mess up the intended effect. For example, a red rose will not end up very nice as an anaglyph.
  • Moving objects. Sometimes a bird in the background appears in only one frame, or the wind shifted a flag, or you have a shot of the sea. If it has motion, it's going to be tricky to arrange with this simple setup. You may have to use some dual-camera setup.

A few anaglyphs I've made are displayed below for your viewing pleasure, more can be found here:
The Kitt Peak National Observatory (KPNO)
The Shane 3-m telescope at Lick Observatory
Camptosaurus at the Museum of Natural History in Los Angeles
The Cerro Tololo International Observatory (CTIO) in Chile
A panda at the San Diego Zoo