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Archive for the ‘Sky and Science’ Category

walk
This animation of a “walking” protein inside a cell is going viral, and I became briefly obsessed with figuring out what’s going on here. Behavior that looks conscious and deliberate can’t, of course, be deliberate or conscious at the subcellular level. It’s just as fascinating, though.

What it is: A kinesin protein hauling a vesicle (pouch that can contain various things the cell needs) along a microtubule.

How are its “feet” moving? Reactions (see video, below.)The protein floats around till one of its feet hits a microtubule, where it binds. Then that foot releases a nucleotide (ADP), which leaves a site on its surface open that gets filled by a different nucleotide (ATP); this triggers the kinesin to wave its other foot forward. The front foot attaches and starts the same cycle; the back foot processes its ATP into ADP, releasing phosphate, and detaches from the tubule, then waves forward and “takes a step,” attaching to the microtubule again.

Why does it look deliberate? The process isn’t as smooth or clean as depicted in some animations like this, which are simplified to show the essential motions. In real life, there’s more jiggling and colliding. In fact, all the floating confusion is one reason why the “two-feet” method works — the kinesin is never completely detached from the microtubule, so it doesn’t float away.

Why is it moving in a particular direction? Microtubules have polarity, and some types of motor proteins will move toward the plus-end or minus-end.

I hat-tip @picpedant, where I first saw this, and recommend this by the artist who created the animation shown above, as well as this discussion of some of the misconceptions surrounding the viral version.

 

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Psychology researcher and author Shawn Achor gave this quite funny TED talk in 2011, with five quick, science-based ways to increase happiness daily that he explains further in the video and in a blog post:

achorstepsedit

Scroll to the bottom of this post for links to most of those research papers and others. Achor talks about why those first two methods work here:

If I put my hand in front of my face and look at it, area 17 in my visual cortex lights up. Now if I close my eyes and think about my hand in front of my face, that same part of my brain actually lights up, area 17 in my visual cortex. Which means my brain actually can’t tell the difference between visualization and experience.

That last bit’s funny, but it might be a stretch; at least some research indicates that Brodmann area 17, the primary visual cortex, responds similarly but not as strongly to an imagined image as to the image itself.

Changes in MRI signal intensity in different parts of the cortex, from Le Bihan, Turner, et al, 1993.

Changes in MRI signal intensity in (top line) visual cortex and (bottom line) non-striate cortex; Le Bihan, Turner, et al., 1993.

Achor says that if he writes for five minutes about some small good occurrence that happened to him that day, “I’m actually doubling the amount of positive experience that I have.” Maybe so; I know that when retelling one of my hi-larious college stories for the 18th time, really what I enjoy is briefly re-living the feelings of fun/embarrassment/panic/legal consequences. And subjects who did written “gratitude exercises” in the 2003 project Achor cites became measurably happier.

So I’m thinking I’ll try the impatient-person version — writing down three good things, things you’re glad about or grateful for, every day — and from time to time if I’m not too shy I may tweet my #3glad things, with a link back here (http://bit.ly/3glad).

Yeah, it sounds like happy fluffy fuzzy bunny foo-foo, but here’s why I think it can work: Newspaper columnists. Once you start to write a newspaper column, the most important thing in your life becomes coming up with three things a week that are interesting enough to fill 13-18 inches of newsprint. These are not so thick on the ground, and your brain rapidly adapts to help you. Everything you see and hear, it starts to consider, “Could I get a column out of that?”

All day, your noggin is considering the fastest ways to get through a task, plotting where you’ll need to go in the grocery store, fretting over a problem even while you’re asleep, and if it knows you have to write down three good things every day, maybe it’ll begin watching for good things all day. And I can see how having that program running in the background might affect your mindset, which is, after all, your interface with the world.

Achor says that only 10% of a person’s long-term happiness can be predicted by looking at their circumstances and 90% can be predicted by how their brain “processes the world.” The research he cites breaks that down as 10% circumstances, 50% genetics (your inherited internal “set point” or average happiness level) and “as much as” 40% “intentional activities,” defined as “the wide variety of things that people do and think in their daily lives.” The potential to affect 40% of your happiness makeup ain’t hay. Cheers!

Mmmm, science:

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Hey, Venus

Image

Got lucky with the light out at my folks’ place the other evening.

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This whole talk is great, but at 6:24 you’ll see the holy-schnapps moment: Taking a photo with your fingers.

That’s Pranav Mistry in 2009 explaining how his invention “sees” your gestures through a camera and uses a little LED projector to give you a “screen” to work on.

Because the talk is two years old, we can jump into the future — 2012 — and see what happened next. We’re all using this now, right? Er. Also, no jetpacks.

But give it time. In January 2012, TEDTalks reported Pranav Mistry and his crew had posted the SixthSense code to let anyone who wants to dig in and start building their own devices and apps. Pranav’s website says building a prototype SixthSense device would cost about $350, and links to instructions for building your own.

Companies have been talking about, demonstrating and buying gesture-recognition interfaces for a while now, and Qualcomm has said it expects to ship an ultrasound-based version in late 2012. (Basically, the onboard mike hears your gestures and lets you control your phone without touching your phone. Except, presumably, for the hand you’re holding the phone in… oh never mind.)

If you want to build your own, these are your new friends: This guy has very endearingly cobbled one together using a wood slat and tape, and here’s the status of homebrew 6SD as explained earlier TODAY (I love the Internet) by a member of the SixthSense Workshop group on Facebook:

Here‘s what those drawing, clock and other apps look like. And it looks like other people are thinking about it, but haven’t cooked up their own yet.

We’ve got robots cleaning our houses and the entire world’s information in our pockets and purses. I can wait a couple years to see crowds of tourists in front of the Eiffel Tower snapping photos with their fingers. But it’ll be cool.

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Utterly flabbergasting, this is. (Yoda would agree… no, wait, Yoda probably has one of these in his kitchen.) A recent Economist issue discussed 3-D printing with a cover image of a working violin they said had been created on such a printer. Not the strings and some other parts unsuited to plastic, but the body and most of the rest were printed, then then assembled, their lovely digital editor later told me. [April 2011 update: He recently tweeted this video of the violin being played.]

Yeah. So. Here is a WORKING crescent wrench. Printed in an hour and a half, on a machine that is supposed to cost about $1000. Moving parts. No assembly.

Judging by the YouTube comments, nobody else believes this either — so much so that Snopes, the urban legends folks, tracked it down. And verified it.

See, I have a dream. It’s not a really great dream as such things go. But here it is. For years I’ve wondered about the sheer numbers of duplicate items that must have to be manufactured in order that John Q. Cardriver can go into the auto parts store down the street and choose from six different cupholders. And the number of duplicate stores that have to be built in order for one to be just down the block from Johnny when he needs it.  Of course market forces control all this.  But how many extra cupholders do you have to manufacture so that one — not even one, but a choice of several ones — is waiting for you down the block?  What if nobody ever buys the other five?

OK, that was more of a question than a dream. So here’s the dream: Aside from the utterly incredible effect the Internet is having on the flow of information, surely at some point it must also change manufacturing, and retail buildings. Shopping on the Internet can be so incredibly efficient — you choose what you want, after researching its features, comparing prices and reading dozens of reviews, and then just the one single item you want is shipped to you. If you figure the trucks were going to be driving that route anyway… doesn’t this eventually mean that we will be able to shut down some of the ninety kabillion ugly* urban retail businesses?

Some things, of course not. Fresh groceries. Emergency items (like, say, spark plugs, instead of that frivolous cupholder). Convenience items like aspirin… and we’re always going to want to try on shoes. But already clothing companies are offering free shipping “both ways,” so you can order five items, try ’em on and return three. I know I’m way oversimplifying here… But aren’t we going to be able to do without a “bed and bath” store every two miles?  (And why do we have branch banks at all, much less the four banks per block that are popping up at a furious rate?)

* Most buildings are ugly because functional is cheap, and attractive design is expensive. So you don’t get good-looking buildings until the point at which it becomes profitable to have your building look good. The term for “architecture” that just kind of happens is vernacular architecture, although it appears to me they’d rather use that term for pretty things like Saltillo tile and mashrabiya screens, as opposed to the gravel-on-tar-paper roof of your local Stop-N-Rob.

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Sun glints off a lake of methane on Titan

NASA image used with permission.

Sunlight reflects off a methane lake on Titan, Saturn’s largest moon. Holy wow. The lake is called Kraken Mare, and it’s in Titan’s northern hemisphere, which began to come back into daylight in August after 15 years of night. (This pic was taken July 8 by the Cassini spacecraft.) All this according to NASA’s release today. Haze on Titan scatters most light in the visible spectrum, so this is an infrared photo. And Titan is very cold. So Kraken Beach Cabanas aren’t going to be a resort spot for a while.

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Yesterday’s NYT had a very interesting story about biologists discovering evidence that humans are naturally helpful to each other — very young humans, before our parents presumably whap it into us.  Of course if we didn’t cooperate to some degree we’d have croaked long ago… and if we weren’t kind of warlike, we wouldn’t have survived either.

It all puts me in mind of a “game theory” strategy that I once read was the most useful: Begin by cooperating, but as soon as your opponent does not cooperate, retaliate. This applies to a lot of areas, obviously, but grew out of a very specific problem used in philosophy and now played out by computers in programming tournaments: the prisoner’s dilemma.

Basically, in its various versions, the dilemma is this: You and another person are in a situation where you each must choose to cooperate or to betray each other. You don’t know what the other will do. If you both cooperate, you get a great reward; if you both betray, neither gets a reward. If one cooperates and one betrays… the betrayer gets half the reward.

Any pair of siblings, roommates or lovers will recognize the scenario. When one does all the taking and one does all the giving, misery ensues – though only for the giver. The taker does just fine. Mutually assured destruction comes to mind also: We hoped the Russians loved their children too.

Douglas Hofstadter, in whose “Metamagical Themas” I first read about the dilemma, introduced me to the idea that the game is different if you know you’re only going to play once, versus expecting to have to continue to deal with the same opponent in future. If you only play once, you are better off betraying. But if you both expect to deal with each other again, the game changes.

Hofstadter described the first programming tournament on these lines, and says it was won by an incredibly simple program called Tit For Tat, which simply did whatever the opponent did right back to it. If its opponent always cooperated, then so did Tit For Tat. If its opponent defected (betrayed), Tit For Tat retaliated – once (whereas some programs strategically would keep defecting every time once “trust” was broken). But if Tit For Tat’s opponent cooperated again, it would cooperate again.

Hofstadter writes, “(Tournament architect Robert) Axelrod’s technical term for a program for a strategy that never defects before its opponent does is nice. … Note that ‘nice’ does not mean that a strategy never defects! Tit For Tat defects when provoked, but that is still considered being ‘nice.’ ”

The chapter goes on to explain how Axelrod defined several characteristics of Tit For Tat’s success. TFT was “nice,” but also “provocable” — that is, it would retaliate if provoked; it wasn’t always nice — and “forgiving.” Some strategies that did even better added a fourth: “clarity,” a kind of ability to analyze when the opponent’s behavior wasn’t making any sense. When that happened, they switched to pure defense.

Axelrod, and after him, Hofstadter, are careful to warn against drawing any too broad conclusions.  I note the New York Times article says the researcher claims that “inductive parenting,” defined as explaining to kids why they logically stand to gain from cooperating, is best. (Good luck with that.) He doesn’t mention that a well-timed retaliation, followed by forgiveness – and backed up by the wisdom to realize when you’re mired in a losing game – can be really useful too.

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