Welcome to Background Noise, where we get totally obsessive about stuff and reveal things you might have missed in your favorite animated entertainment. This entry will take a look at Disney’s Big Hero 6, now available on DVD, Blu-ray, and via iTunes, Disney Movies Anywhere, and other digital services. These are the kinds of observations I’d have hoped for if Disney had included a commentary track in its home video release.

Please note that a lot of the “didja notice?” moments below contain spoilers for the movie. You have been warned.

TONY STARK’S CAMEO (?)

When Hiro first visits Tadashi’s “Nerd Lab,” he sees a bunch of people engaged in experiments. Take a look at the guy in the middle, who’s got a cat hovering in mid-air:

I suspect that’s a cameo by Marvel Comics’ Tony Stark (a.k.a. Iron Man), since he’s got that mustache and goatee, he seems to be standing in front of a large arc reactor, and the cat’s flight vaguely resembles Tony Stark’s first successful test flight in his garage in the first Iron Man movie. The deleted scenes in the home video release’s bonus features reveal that in an alternate opening, the flying cat was originally Aunt Cass’ cat Mochi being used as a test subject by Hiro and Tadashi.

You can also get a closer look at maybe-Tony and his maybe-arc-reactor when Go Go flings her magnetic bike tire into the disposal bin:

WASABI’S IMPRECISE HEX KEY

Considering how obsessive he is about his stuff, it’s a little surprising to see Wasabi losing the hex key that he uses to adjust something in his laser-induced plasma cutter in the lab. He’s using his wrench to adjust his experiment when Hiro almost walks into the thing, but the wrench disappears when he tosses the apple through it and then re-appears so Wasabi can take it out afterwards:

Or it’s just a minor continuity error. Your choice.

THE “CALLAGHAN-CATMULL SPLINE”

When Hiro meets Professor Callaghan, he makes a reference to “the Callaghan-Catmull spline.”

Robert Callaghan was made up for the movie, but the Catmull part of that refers to Dr. Ed Catmull, who made tremendous contributions to the world of computer graphics before he was the president of Pixar and Walt Disney Feature Animation. Also, a “spline” isn’t a robotics term, but refers to math functions used heavily in computer graphics that can calculate smooth curves passing through specified points. There isn’t a Callaghan-Catmull spline, but Ed Catmull was co-author of the Catmull-Rom spline, which dates back to 1974 and is still used today (apparently to “get smooth interpolated motion between key frames”).

CALLAGHAN’S LAWS OF ROBOTICS

Hiro also mentions Callaghan’s Laws of Robotics in that same awe-struck line. This is probably a reference to Isaac Asimov’s Laws of Robotics, which he formally codified in his 1942 short story “Runaround.” The formal definition of Asimov’s Laws are:

A robot may not injure a human being or, through inaction, allow a human being to come to harm. A robot must obey the orders given it by human beings, except where such orders would conflict with the First Law. A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.

Asimov used these rules as a foundation for many of his stories, revolving around the ways the laws interacted with each other to produce strange or unexpected behavior in his intelligent robots. However, while “Callaghan’s Laws” show how important Professor Callaghan is to the world of Big Hero 6, it’s Asimov’s laws that drive a lot of the events later in the movie. Baymax violates the first law once Hiro removes his medical chip. Once Baymax knows what happens when the medical chip is removed, he refuses to let Hiro remove it a second time, showing the second law in action. The way the third law figures into the plot is left as an exercise for the reader.

THE HAMADAS’ PATERNAL GRANDPARENTS

At the beginning of the movie after Aunt Cass and the Hamada boys have returned to their home, Aunt Cass passes by a photo in the hallway of their house. Click the still below to enlarge: it’s the color photo on the left side of the screen of two adults and one younger man.

Later in the movie, when Hiro is trying to hide Baymax upstairs, there’s a similar photo on the wall over his left shoulder (on screen right). This photo is a sepia-toned photo of two adults and one younger man.

This is a composite of both photos side-by-side, with the one that appears earlier in the movie lightened up a bit to make it a little clearer:

I think we’re looking at Tadashi and Hiro’s paternal grandparents. I think the photo on the left is their father as a boy in a photo with his parents. In the photo on the right, the two adults are in exactly the same position (down to the man’s hand on the woman’s shoulder), and you can just make out the same eyeglasses and mustache on the man and hairstyle on the woman. The difference is that they’re clearly older in the second photo, with the woman’s gray hair being the biggest giveaway. However, the boy in the photo seems to be the same age, so I suspect that’s little Tadashi as a child with his grandparents.

The Easter Egg bonus features also point out Mochi dressed in a Stitch costume in the photo on screen-left; one of many Disney references that they show off in that bonus feature.

WHAT’S ON AUNT CASS’ COUNTER?

This isn’t anything important. I just like the jars that Aunt Cass has on her counter, just under her left arm in the shot below.

HOW TO TELL WHEN THE GANG IS IN TROUBLE

One of my favorite scenes in the movie comes about halfway through, when the super-team-to-be has to make an escape from Yokai and the microbots in what I assume is Wasabi’s tiny car. Once Go Go shoves Wasabi aside and takes the wheel, you’ll notice that her face almost never changes from her intensely focused scowl.

If you’re watching closely enough, you get the briefest hint that they’re in real trouble when her stoic expression changes, registering surprise followed by panic right before they drive off the pier.

All 4 of Tadashi’s college friends get some great reaction shots during the movie. Keep an eye on the ones in the background.

RAMEN SURPRISE

When Baymax gets upgraded and takes Hiro on their first flight through the city, the pair shoot past a small street ramen cart (and yes, that’s what the sign says in katakana), where a police officer is just sitting down for a snack.

As Baymax shoots by, his pressure wave blows the hat off the officer, revealing the world-weary duty sergeant who they met earlier in the movie (“A man in a Kabuki mask attacked you with an army of miniature flying robots…”). Considering that Disney’s latest CGI crowd systems can supposedly generate over 600,000 unique characters, they didn’t just recycle that character model because they didn’t have the resources.

“I’M NEVER RIDING THE BUS AGAIN”

One last amusing bit. Once their flight is over, watch what Baymax does when he and Hiro are sitting on top of the electrical windmill balloon.

There’s no reason for him to start twitching his legs the way Hiro is, and he only does it because he sees Hiro do it. It’s just a throwaway tic that they added into the scene to show how Hiro is rubbing off on him, just as Baymax adopts Hiro’s “Sick!” as a positive adjective as well as Hiro’s phrase, “It is just an expression.”