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Chris Dolan
Works at Sony Creative Software
Attended University of Wisconsin-Madison
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Chris Dolan

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This is AWESOME! On Earth, air scattering causes a blue sky and red sunset, but on Mars the thin atmosphere means that light scattering by dust matters more than air. "This means Mars can have a dusty red daytime sky, and a blue sunset"
Brian Koberlein originally shared to Our Universe:
 
Two Worlds, One Sun

There’s an image going around of a blue sunset on Mars. Yes, it’s a real image, and yes, the colors are reasonably true to life. It was taken by the Curiosity rover in April. Given that sunsets on Earth are typically red, how does Mars get a blue sunset? It all has to do with the way light scatters in the atmospheres of Earth and Mars.

Earth has a relatively thick atmosphere, so most of the atmospheric scattering occurs when light strikes a molecule of air, known as Rayleigh scattering. Rayleigh scattering occurs when the object a photon scatters off (the air molecule) is much smaller than the wavelength of the photon. The closer the wavelength is to the size of the molecule, the more likely it is to scatter. This means that red wavelengths (which are the longer wavelengths of visible light) don’t scatter with air molecules much, while blue wavelengths (which are shorter) tend to scatter a lot. In fact blue light is almost 10 times more likely to scatter against air molecules than red light. This is why the sky appears blue, since so much of the blue light is scattered.

When the Sun is low in the sky, it’s light has to travel a long path through the atmosphere to reach you. As the light travels through the atmosphere some of the photons are scattered off the air molecules. When the photons scatter off air molecules, they scatter randomly in all directions, so usually when a photon scatters, it scatters away from your line of sight. Since blue photons scatter much more often than red ones, much of the blue light is scattered away. This leaves red photons to reach your eye. Hence the Sun looks red when low in the sky. When the Sun is overhead, the path it takes to reach you is much shorter, so only a bit of the blue light is scattered. So the Sun looks yellow.

Mars has a much thinner atmosphere, so the amount of Rayleigh scattering is much less. But Mars also has a dry, dusty surface, and a weaker surface gravity, so the atmosphere of Mars is often filled with fine dust particles. These particles are more comparable in size to the wavelengths of visible light, so most of the light is scattered by Mie scattering. One of the main differences between Rayleigh and Mie scattering is that Rayleigh scattering tends to occur in all directions, but Mie scattering varies with scattering angle. What this means is that longer wavelengths (reds) tend to scatter more uniformly, while shorter wavelengths (blues) tend to scatter at slight angles. This means that blue light tends to be deflected less than red light. This means Mars can have a dusty red daytime sky, and a blue sunset.

Mie scattering does occur on Earth as well, but since Mie scattering is less efficient than Rayleigh scattering it’s never strong enough to give us a blue sunset. It can (rarely) produce a blue moon. The most widespread incidence of modern history occurred after the eruption of Krakatoa in 1883, which sent so much ash into the atmosphere it produced brilliantly red sunsets and visibly blue moons all across the globe for nearly two years. As a result, the phrase “once in a blue moon” came to mean a rare occurrence.
While Earth can have lovely red sunsets, Mars can have a sunset that is truly blue.
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"5 of the World's Most Dangerous Chemicals" -- this is excellent. I like the narrator's sense of humor.

h/t +JT Smith 
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What a great idea and a useful service: a collection of intentionally misconfigured websites for testing how browsers handle the problems.
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Very interesting article. My only self-employment experience is as a programmer working out of my own home, so a lot of this is novel to me. I especially enjoyed this phrase: "Insurance. It’s the most beige thing in a taupe sea of boring"
 
My latest article on avoiding pitfalls during gig negotiations:

http://goo.gl/3oOueL
As mixers, we relentlessly fill our heads with the arcane and absurdly technical, from frequency responses of various microphones to the intermodulation products of RF signals. We do so to become efficient problem-solvers. On...
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I really don't want to switch to the Nexus 6 (too large) but I'd seriously consider switching from Republic Wireless to Google's new Fi service for two main reasons:

1) Republic's wi-fi calling is completely unencrypted over the WAN, where Google has promised theirs will be encrypted
2) Republic's wi-fi calling has horrible audio latency, almost unusable. Google's Voice and Hangouts services have typically had excellent latency (event though Republic's parent company provides the Google Voice infrastructure!) so I'm hopeful that Google will get this right.

and three smaller reasons:
1) for my typical data usage, Fi will be slightly cheaper ($30 vs. $40). But that's crushed by the more expensive phone ($650 vs. $300)
2) transparent failover between Sprint and T-Mobile (instead of just Sprint)
3) coverage outside of the continental US

But Fi has one big limitation:
1) Republic allows roaming to other CDMA networks (US Cellular, Verizon, etc). This makes a big difference in rural Wisconsin
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I just signed up for an invite... Alice is on Ting, which I love for the billing and customer service, but having the Sprint coverage map only is not awesome.  I hadn't realized the Nexus 6 is a $649 phone... thats a pretty hefty up-front fee.
400ms latency makes phone conversations quite awkward.  My other VoIP pain point is the echos I commonly hear- having my own words of a fraction of a second earlier routed back to my ear makes it hard to form my next sentence.
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"GDB will be the weapon we fight with if we accidentally build Skynet."
Ha!!
Judgement Day. GDB will be the weapon we fight with if we accidentally build Skynet. Posted by gbenson on Friday, April 17th, 2015, at 20:07, and filed under GDB. Follow any responses to this entry with the RSS 2.0 feed. You can post a comment, or trackback from your site.
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Chris Dolan

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Wow, I remember when OCR software was really expensive back in the 90s.
 
Using hidden Markov models, +Google Drive now supports OCR in over 200 languages and more than 25 writing systems.
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Interesting idea: consider how long ago a domain was registered in whether to trust it. I'd love a browser plugin that would warn me if I tried to navigate to a domain that was less than 4 weeks old.
 
in for a dime, in for a dollar.
Short trial period would help detect malicious use of domain names, Internet expert says.
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Best comment: "Imagine what smartphones will be like in 10 years..."

Cue the Monstro. :-)  http://teamcoco.com/video/conan-highlight-New-Apple-Ad-The-iPad-Mini-Has-Company
 
Evolution of the mobile phone

h/t @itredux
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I had somehow missed the Monstro ad... Quite funny.
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This is really funny. And effective: now I think I want to attend Gamehole Con.

(background: Ed Greenwood is a BIG name from the early days of Dungeons & Dragons, so his endorsement of this local role-playing game convention is pretty meaningful)
 
You never miss a Gamehole. Ever. From now on. No matter what. 
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As an fyi...Ed has formed The Greenwood Group. A group of authors that he'll be collaborating with on future projects. They have made the decision to bring their group to Gamehole as their central, annual, meeting place! So yeah, Ed's a fan.
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This is mostly silly, but a little bit awesome. I love the idea that 0xF5 is pronounced "fleventy five"
 
0xDDDDDDD
> dee bitey dickety-dee halfy dickety-dee bitey dickety-dee


Kid: Here it is: Bit… soup. It's like alphabet soup, BUT… it's ones and zeros instead of letters. Bachman: {silence} Kid: 'Cause it's binary? You know, binary's just ones and zeroes. Bachman: Yeah, I know what binary is. Jesus Christ, I memorized the hexadecimal times tables when I was fourteen ...
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Last week, I attended the NAB SuperMeet for the first time. It was a pretty cool event, filled with very enthusiastic fans. But now comes the onslaught of vendor emails... Not so bad I guess -- not truly spam -- but a little tedious to unsubscribe to all of them.
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Chris's Collections
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In their circles
856 people
Have them in circles
601 people
Kristin Darden's profile photo
Pete Prodoehl's profile photo
Dave Taht's profile photo
Rui Cui's profile photo
Dennis Adams's profile photo
Turbo Diesel's profile photo
Nick Anthony's profile photo
Christen white's profile photo
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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