Profile

Cover photo
Chris Dolan
Works at Sony Creative Software
Attended University of Wisconsin-Madison
584 followers|239,106 views
AboutPosts

Stream

Chris Dolan

Shared publicly  - 
 
How to fix PCGen out-of-memory errors

On Mac, I frequently get out of memory errors when rendering to PDF. These steps will solve it, but need to be done for each new download of PCGen.

1) Right-click PCGen.app, Show Package Contents
2) In the Contents folder, open Info.plist in any text editor (TextEdit.app)
3) Find the line <key>VMOptions</key>
4) Change the next line to <string>-Xms128m -Xmx1024m -XX:MaxPermSize=256m</string>
5) maybe increase those numbers even more if you've got a sturdy machine and don't mind trading some RAM for better performance.

#pcgen   #outofmemory  
2
1
Chris Dolan's profile photoPaul Grosse's profile photo
 
Heh, amusingly I upgraded to Java 8 on this machine for unrelated reasons tonight, and discovered that MaxPermSize is deprecated and ignored. Looks like a problem that won't bite me again.
Add a comment...

Chris Dolan

Shared publicly  - 
 
Nice. :-)
 
"Why yes, we do offer two-factor authentication!"
6 comments on original post
1
Add a comment...

Chris Dolan

Shared publicly  - 
 
I'm really enormously proud of my brother's work in Maine.

Newspaper reporters are an important check on attempted abuses of power by government and industry leaders. Compared to many parts of the world the US has relatively low corruption, which is a huge economic boon. In my opinion, the decline of American newspapers are a threat to that advantage.

And this: "I wouldn’t say that I was overly concerned about being found in contempt of court and being jailed up to 30 days by Maine’s court rules. But I did arrange for a friend to take care of my dogs just in case." :-)
 
My piece for the New England First Amendment Coalition. #Maine #firstamendment #opengovernment #priorrestraint  
By Scott Dolan At first I was confused when Judge Jeffrey Moskowitz issued his order banning news reporters from reporting anything witnesses said in the …
View original post
1
Add a comment...
 
It is indeed a good article.
 
I have not found a better way of conveying the struggles of becoming a coder than the details in this blog post.

You can make that application work but what's happening beneath the surface? Your code is duct tape and string and, worst of all, you don’t even know which parts are terrible and which are actually just fine. Your periodic flashes of brilliance are countered by noob mistakes and, worse, a creeping suspicion that you still don't have a damn clue what you're doing.

This is a bipolar phase.

#programming #learntocode
What every beginner absolutely needs to know about the journey ahead
5 comments on original post
4
Add a comment...

Chris Dolan

Shared publicly  - 
 
"While light takes thousands of years to travel from the Sun’s core to its surface, the solar interior is relatively transparent to acoustic waves"

That's so cool. What I found most fascinating is that we know more about the characteristics of the core than the middle regions of the Sun.
 
Inner Beauty

The Sun is so intensely bright that it’s difficult to look at (and you shouldn’t try). When observing the Sun with scientific instruments, we often use filters to diminish the light so that we can observe surface features of the Sun in detail, such as sunspots and the churning of granules due to convection near the surface. But how do we study the interior of the Sun?

One way is through neutrinos generated in the Sun’s core. Unlike light, which can take 20,000 to 150,000 years to travel from the Sun’s core to its surface, neutrinos leave the Sun soon after they are produced. We’ve been able to detect solar neutrinos since the 1960s, but these were neutrinos due to secondary reactions in the core. More recently we’ve been able to observe neutrinos from the principle fusion mechanism known as the pp-chain. From these observations we know the rate at which fusion occurs in the Sun, as well as its central pressure, temperature and density.

Between the core and surface things get a bit more tricky. Surrounding the core is a radiative zone, where the heat of the core moves toward the surface mainly through photon radiation. Surrounding that is a convection zone, where stellar material churns in a cycle. Heated by the interior, the material rises toward the surface. It then cools and sinks toward the interior where the process happens all over again. We know of these levels through helioseismology, which is the study of sound waves traveling through the Sun’s interior. While light takes thousands of years to travel from the Sun’s core to its surface, the solar interior is relatively transparent to acoustic waves, which means they can travel through the Sun at the speed of sound.

As the methods of helioseismology have gotten more sophisticated, we’ve been able to determine some of the characteristics of the convection flow, and what we’ve found is that it’s much more turbulent than originally supposed. This means that while our surface and deep interior models are pretty good, our mid-range models aren’t. This isn’t particularly surprising, since the complex transition between the radiative and convective regions is notoriously difficult to model.

But what’s amazing is that we can use sound waves to actually test these models. With methods such as neutrino physics and helioseismology, we can really see the complex beauty of the Sun’s interior.

Paper: Laurent Gizona & Aaron C. Bircha. Helioseismology challenges models of solar convection. PNAS, vol. 109, no. 30, 11896–11897 (2012).
The Sun is incredibly bright, so how do we peer beyond its surface to its interior?
21 comments on original post
1
Add a comment...

Chris Dolan

Shared publicly  - 
 
Pretty cool to see how obviously color affects mood.
 
I love how big a difference this makes. Are there any game developer related resources on how learn how to do this (for games/pictures/video)?

http://laughingsquid.com/a-demonstration-of-how-color-grading-affects-films-using-the-independent-feature-the-house-on-pine-street/
Kansas City-based post-production company Grade has created a color reel demonstrating the impact that color grading has on film quality using the 2014 psychological horror film, The House On Pine ...
8 comments on original post
1
Add a comment...

Chris Dolan

Shared publicly  - 
 
That is a fantastic photo! I would love to be on that ice. But maybe not today...
3
Add a comment...
In their circles
856 people
Have them in circles
584 people
Jochen Pielage's profile photo
Pushkar Pahare's profile photo
Aivar Grislis's profile photo
Maruarai Colombel's profile photo
jacksion scott's profile photo
Lorin Klugman's profile photo
Chaomo Li's profile photo
Jim Armstrong's profile photo
Erik Paulson's profile photo

Chris Dolan

Shared publicly  - 
 
"It’s a recurring problem in astronomy, where what’s right in front of you isn’t what you want to observe."

Like clouds, daytime blue sky, lens covers, etc. :-)
 
In the Air Tonight

Yesterday I mentioned the faint glow near the horizon as due to airglow of the atmosphere. It tends to be a very faint effect, even more dim than the zodiacal light, and isn’t often seen with the naked eye. While airglow is beautiful in images, for ground-based astronomers it can be bothersome.

Airglow occurs when atoms and molecules in the upper atmosphere are ionized, either by light from the Sun, or by cosmic rays. There are also chemical reactions that produce light in the atmosphere. All of these effects combine to give the atmosphere a faint but uniform glow day and night. It’s only at night that the effect becomes visible. While the green glow of molecular oxygen tends to be the dominant color, you can also get yellow from sodium, red from atomic oxygen and even a weak blue glow.

Because airglow is spread throughout the sky, it tends to hamper ground-based astronomy. Basically it is a kind of light pollution that never goes away, no matter how isolated your observatory is. One way to overcome the effect of airglow is to limit your telescope’s field of view. If you observe a faint object in a small portion of the sky, the patch of air above your view is likewise small, and the airglow effect is less significant. There are also ways adaptive optics can limit the impact. But as we build ever larger ground-based telescopes to look at ever dimmer objects, airglow could increasingly become a problem.

It’s a recurring problem in astronomy, where what’s right in front of you isn’t what you want to observe.
Airglow is a faint glow of the night sky. It's beautiful, but it's bothersome for astronomers.
8 comments on original post
1
Add a comment...

Chris Dolan

Shared publicly  - 
 
Does the bottom-positioned Mac dock keep switching monitors on you? It drives me nuts. There are many workarounds, but the simplest one is this: "... move your mouse to the center of the screen, and move it all the way down as if you're trying to drive into the bottom of the screen ..."
I have connected on to my MacBook Pro Retina (Model Identifier: MacBookPro10,1) two monitors. A Thunderbolt Display connected to the Thunderbolt port (next to power connector), a HP LCD Monitor w2408h connected to the Thunderbolt port (next to USB) with a DisplayPort to DVI adapter (using ...
1
Steve Yuroff's profile photo
 
If you revert to the pre x.9 behavior of 1 menu bar, this doesn't happen, dock and menu bar stay together. 
Add a comment...

Chris Dolan

Shared publicly  - 
 
My brother-in-law, Joe Hannigan, played a song with Vince Gill last night. Wow! Joe's the major musical talent of the family -- in the past his band opened for Willie Nelson and Charlie Daniels.
2
Add a comment...

Chris Dolan

Shared publicly  - 
 
Fascinating. I never thought about the individual customization needed to counteract hearing loss.
 
Great read on hearing loss and what hearing aids actually do under the hood... Spoiler: no, it's not about volume.
When Alex and I were pitching SoundFocus as an app that helped people with hearing loss, this was often…
View original post
1
Add a comment...

Chris Dolan

Shared publicly  - 
 
Very nice explanation of flora colors. I sort of knew most of this before, but had never put it all together. I liked this consequence the most:

"And since our eyes have evolved to see green at high resolution, not red, Keplerian fields would look very strange to us -- almost uniform in color, with motion hard to see, because our eyes aren't adapted to seeing fine shades of red."
 
As we continue to search for planets beyond our Solar System, we are starting to find worlds that we might actually be able to stand upon. And in honor of this, the folks at JPL have produced some travel posters for these brave new worlds, available as free high-res downloads from their site.

http://planetquest.jpl.nasa.gov/media_categories?category=6

Kepler-186f, the one pictured below, is my favorite because it captures some interesting physics. It orbits a red dwarf about 500 light-years from Earth, and it was the first planet discovered which is potentially suitable (in terms of things like temperature) for life as we know it. But life would be different in some interesting ways.

One of the reasons is that photosynthesis would be a bit different. Plants on Earth are green because their leaves contain chlorophyll, a chemical which absorbs sunlight and turns that energy into excited electrons. Those energetic electrons are then fed into the entire photosynthesis system, and ultimately that energy is stored in the form of sugars and used to sustain the plant's life. The reason chlorophyll is green, though, comes down to three diagrams.

The first is the solar spectrum, that is, the color of light the Sun shines.

http://en.wikipedia.org/wiki/File:Solar_Spectrum.png

The X-axis of this graph shows the wavelength of light, from ultra-violet on the left to infra-red on the right; the Y-axis shows how bright the Sun is in each of those colors. As you can see, the Sun shines fairly evenly in the entire band between about 500 and 700nm, which is exactly the set of colors that the human eye can see. (No coincidence! Our eyes have evolved to see sunlight, not x-rays, because there aren't that many x-rays around to see by) 

There are two graphs here: the yellow curve shows the color of sunlight itself, and the red curve shows the color of the light we see at sea level. The difference is that the atmosphere absorbs some colors of light but not others. For example, the fact that the red curve is way below the yellow curve at the far left is because ozone in the upper atmosphere is very good at absorbing UV light -- the reason why it protects us from skin cancer.

The second diagram is the absorption spectrum of chlorophyll:

http://en.wikipedia.org/wiki/File:Chlorophyll_ab_spectra.png

This graph uses the same X-axis, but the Y-axis shows how effective chlorophyll is at absorbing light of each color. There are two curves because there are actually two different kinds of chlorophyll: the green kind (chlorophyll-A) which is most prevalent, and the red kind (chlorophyll-B) which often stays behind after the green one has left, giving autumn trees their color. The bumps on the left actually aren't very interesting, since the Sun doesn't produce much light in those colors -- they're there because it's hard to design a chemical which doesn't absorb those colors. (For various technical quantum mechanics reasons) The sharp spikes on the right are what makes chlorophyll so important to photosynthesis, and for chlorophyll-A, that spike happens at a wavelength of 680nm, smack in the middle of where sunlight is the brightest. For comparison, sunlight is the brightest at 665nm.

As it turns out, the chlorophyll molecule is fairly flexible and complex, and small modifications to it would likely lead to "pseudo-chlorophyll" molecules with their peaks in different places, which we'll come back to in a moment.

So chlorophyll has evolved (or rather, creatures have evolved to produce this one particular molecule) to very efficiently absorb light of exactly the color that the Sun produces the most of. Why does this make chlorophyll green?

Imagine that you shine sunlight on some chlorophyll. The chlorophyll absorbs the 680nm light; in fact, if you want to be precise about it, you can flip the chlorophyll graph upside-down (that is, replace it with 1-absorption, to instead show how much light it lets through) and multiply it by the sunlight curve, to see what color of sunlight bounces off of it. Light bouncing on chlorophyll would look just like the incident sunlight, but with another gap in it, corresponding to the colors that chlorophyll absorbs away for its own purposes. 

Because chlorophyll's absorption peak is so sharp, you can basically imagine this as light with the 680nm part of it removed. What color is 680nm? It's a bright red. And that brings us to the third diagram, namely how the human eye sees color:

http://en.wikipedia.org/wiki/Color_vision#mediaviewer/File:Cone-fundamentals-with-srgb-spectrum.svg

Color vision works by having three kinds of "cone" receptor in the eye: one which sees red, one green, and one blue. (These are called L, M, and S in the diagram for obscure reasons) This diagram has the same X-axis again, and now the Y-axis shows how sensitive each cone type is to each color. So for example, if you shine pure 680nm light onto an eye, that stimulates the red cone some, and the blue and green cones not at all, which the eye reads as "red." If you shone 580nm (yellow) light instead, that would stimulate both the red and green cones a lot, but the blue cone not at all, which our brain interprets as "oh, that must be yellow."

(Incidentally, that's also why color-combination tricks work. If you shine both red and green light on a point, it looks yellow to your eye. If you look at the monitor you're reading right now with a magnifying glass, you'll see that each pixel is actually three little pixels -- one red, one green, and one blue -- and that a yellow pixel has red and green lit but not blue, taking advantage of the same illusion to show you all the colors)

So back to plants. Sunlight on its own tends to stimulate your red and green cones a lot, but not much blue. (Take a look at the steep drop-off on the left of the sunlight diagram, and how that overlaps with what the blue cone sees) That's why the Sun normally looks yellow. But sunlight bouncing off chlorophyll -- i.e., what you see when you stare at a plant -- is missing a bunch of its red light, so it only stimulates green. And that's why plants look green.

(Incidentally, when you look at the eye-sensitivity chart, you might notice that the red and green cones are right next to each other, but the blue cone is off by its lonesome. This isn't a coincidence: many species only have red and blue. The green cone only shows up in some species, and because it's just like red but a little off, small differences in color in the range that they both hit therefore look very different to us. That gives us tremendously high frequency sensitivity in the greens: 490nm and 500nm light look really different, while 650 and 660nm are nearly indistinguishable. That's really useful when you need to recognize different kinds of plant!)

So back to Kepler 186f: its star is a red dwarf, which is smaller, dimmer, and redder than our own sun. We could repeat the entire calculation above using its color of starlight, and what you discover in this case is that efficient Keplerian chlorophyll would be absorbing light off in the infra-red. Doing the same subtraction of reflected light, we find that Keplerian chlorophyll under Keplerian skies would look deep red to our eyes.

And since our eyes have evolved to see green at high resolution, not red, Keplerian fields would look very strange to us -- almost uniform in color, with motion hard to see, because our eyes aren't adapted to seeing fine shades of red.

You can actually do this calculation for any kind of star, and you'll find that the color of "local chlorophyll" will range from red (for red dwarfs), through green (for stars like our own), out to yellow (for slightly blue stars). It never gets beyond that, because stars beyond "slightly blue" have a very short lifespan, and would never be around for long enough to develop their own native flora anyway.

So when you're going out traveling among the stars, expect a fairly wild color show.

If you want to play with what different wavelengths of light look like, this site has a simple slider:
http://academo.org/demos/wavelength-to-colour-relationship/

To read more about color vision, start at:
http://en.wikipedia.org/wiki/Color_vision

And for photosynthesis, start at:
http://en.wikipedia.org/wiki/Photosynthesis

Incidentally, the planet's name simply means that it's the sixth (f) planet out from the 186th star studied by the Kepler planetary survey.
56 comments on original post
2
Add a comment...
People
In their circles
856 people
Have them in circles
584 people
Jochen Pielage's profile photo
Pushkar Pahare's profile photo
Aivar Grislis's profile photo
Maruarai Colombel's profile photo
jacksion scott's profile photo
Lorin Klugman's profile photo
Chaomo Li's profile photo
Jim Armstrong's profile photo
Erik Paulson's profile photo
Education
  • University of Wisconsin-Madison
    Astronomy, PhD, 1994 - 2000
  • Cornell University
    Astronomy, 1990 - 1994
  • Derryfield School
    1986 - 1990
Story
Bragging rights
I was the #1 Google result for "constellations" for about 12 years (ended 2013); Toughest bicycle ride: 125 miles + 11,000 ft climbing
Work
Occupation
Programmer, software architect
Employment
  • Sony Creative Software
    Staff Software Engineer, 2012 - present
  • Avid Technology
    Sr Principal Software Engineer, 2007 - 2012
  • Clotho Advanced Media
    Sr Software Developer, 2001 - 2007