Posts Tagged ‘science’

Grilled cheese and the science of successive approximation

Thursday, April 17th, 2008

Were you paying attention in those psychology classes?

Do you remember the experiments where a rat was trained to press a lever to get food?

It’s amazing how relevant experiments on rats can be to parenting.

In pursuing my psychology degree, I took a lab where I had to perform that experiment myself. I had a rat of my own, which I named - very appropriately, I thought - Rat (hey, if it’s good enough for George of the Jungle, it’s good enough for me).

The first goal of the experiment was to get the rat to understand that pressing a lever meant getting food. There were other goals once that was accomplished, but let’s focus on that goal for now.

Rat was just not getting it. Either that, or he was just really, really stubborn. I spent many nights in that lab until well after midnight faithfully recording him doing nothing of interest (which eventually translated into a graph that crossed enough pages of graph paper to run the length of our dormitory hallway). Eventually, however, he started to get the picture. When he made a move toward the lever, I dropped him a food pellet. If he moved a little closer, he got another pellet. Brushed against the lever? Another pellet. Touched it intentionally? Another pellet. Pressed it completely? More pellets. This process took a long time - but when it worked, it worked. Eventually, getting him to stop pressing the lever (phase 2 of the experiment) was even harder.

That process of rewarding Rat for each progressive step closer to the goal is called “successive approximation.” At first, he didn’t have to press the lever to get food, he just had to look at the lever. Once he got that, he had to make progress toward the larger goal before he’d get his food. Looking at it was no longer enough. He had to move close to it. Eventually, he’s feeding himself by pressing the lever. This teaching method, it has been proven time and time again, works.

Flash-forward almost 20 years. I don’t think about Rat often. But I did today.

My three-year-old daughter has become a very picky eater. It’s gotten to the point that it’s commonplace for my wife to make two different dinners every night - one for “Little Mommy” and one for the rest of us. Last week we decided that would stop. Little Mommy was going to learn to eat what we gave her.

It didn’t go so well for the first 4 days. We had a complete meltdown just getting the compromised 1/8″ square piece of grilled cheese near her mouth. Much drama ensued at that meal. Food flew; screams were loosed. The next day we were visiting friends and despite some earnest attempts at cajoling on all of our parts, no progress was made by us parents (she succeeded in manipulating us, however, which was a setback). The following day we were back at it, though there was much less drama. Finally, today, at lunch, Rat came to mind.

Oddly, it was grilled cheese again. This time, instead of reducing the size of the task, my wife tried something different. She put some soy-butter, Little Mommy’s favorite - on a small part of the top of the sandwich. While that was promptly licked off, I decided to start eating crackers I knew Little Mommy liked. When she asked for one, I said “Sure. Just lick the sandwich - but not on the soy-butter part.” After some whining, she did it, and I gave her a cracker. The next step was to get her to eat just a bite of the sandwich to get another cracker. She couldn’t have gotten a smaller bite if she used a laser scalpel, but she did take a bite, so she got another cracker.

Now we’re at the breaking point. Lots of accolades went along with that last cracker. She’s all proud of herself. Now we push. “Okay, if you take four bites, you can have another cracker.” She likes counting, too, so we all counted the bites, which - without any prompting - got bigger, and bigger, until bite number 4 was actually too much to have in her mouth at once. But as I gave her the cracker, I knew we had finally prevailed. She herself suggested the next goal would be five bites, which she attacked with gusto. With almost nothing left to the sandwich, and praises all around, she had finally eaten the same lunch as everyone else.

I guarantee that without using that successive approximation of licking, to infinitesimally small bites, to larger bites, we’d still have no progress.

Have we won the war? Nope. We’ll probably be able to get her to eat grilled cheese again with minimal effort, but I’m sure that any other “new” food she tries will take at least some degree of that same process.  But we now have a strategy that works. After 4 days of failure with alternate strategies (yelling, bribing, punishing, & others), I’m thrilled to be making progress.

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Who’s that wall-crawler?!

Wednesday, August 29th, 2007

SCI-FI to SCI-FACT: A Working “Spider Man” Suit - Slice of Scifi

A “Spider-man” suit that enables its wearer to scale vertical walls like the comic and movie superhero could one day be a reality, according to a study. Natural technology used by spiders and geckos could help a human climb the side of a building or hang upside down from a roof, the analysis suggests. The findings are published in the Journal of Physics: Condensed Matter.

Both spiders and geckos possess tiny “hairs” that allow them to stick to surfaces. Some studies suggest that geckos can hold hundreds of times their own body weight. In 2002, US research suggested this adhesion in geckos was due to very weak intermolecular forces. These are produced by billions of hair-like structures of different sizes that are arranged in a hierarchical structure on each gecko foot.

That is too cool. I gotta have one. Click the link above for more details.

If I had something like this I could avoid buying that extension ladder I need!

‘Cause I’m sure this suit would cost less than an extension ladder…

Now we just need someone to start working on artificial “webs” and a web-shooter.

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Look out for the edge!? What edge?

Thursday, July 26th, 2007

Newsflash: Time May Not Exist | Physics & Math | DISCOVER Magazine

Every once in a while I read articles like this to remind myself that there is a lot that can’t be explained in this world, and much of what we experience isn’t as concrete as we like to think. Here’s a good quote from the article:

…the thing we experience as time might emerge from a more fundamental, timeless reality. As Rovelli describes it, “Time may be an approximate concept that emerges at large scales—a bit like the concept of ‘surface of the water,’ which makes sense macroscopically but which loses a precise sense at the level of the atoms.”

That is one of the best analogies I’ve seen. I can actually picture a camera zooming in on a drop of water, magnifying the “edge,” moving through an increasingly foggy reality until we see no distinction between the water and the surrounding air: just distances between atoms, indistinguishable from each other. This is why physics is so cool. Forget about the “time doesn’t exist” idea…. there’s no such thing as an edge! And we walk around like we understand reality….

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Plasma Converter - the ultimate waste disposal

Saturday, February 17th, 2007

Slice of Scifi - Science Fiction TV & Movie News, Interviews & more » SCI-FI to SCI-FACT: Plasma Converter

Sometimes I wonder where all the really good inventions are. Breakthroughs like the telephone, or light bulbs. Things that could change the world. This may just be one of them.

This device, dubbed the Plasma Converter, uses plasma to rip waste apart at the molecular level. The benefits of this are extensive. Landfills? Who needs ‘em? Looking for a clean, reproducable source of ethanol or natural gas? Here you go. It even helps people in the bathroom tile manufacturing business! :)

The by-products are an obsidian-like glass used as a raw material for numerous applications, including bathroom tiles and high-strength asphalt, and a synthesis gas, or “syngas”—a mixture of primarily hydrogen and carbon monoxide that can be converted into a variety of marketable fuels, including ethanol, natural gas and hydrogen. The only type of waste that it cannot break down is nuclear waste since the radiation is already in its natural atomic state.

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We are insignificant

Tuesday, February 6th, 2007

Slice of Scifi - Science Fiction TV & Movie News, Interviews & more » There’s No Place Like Home

Photo showing Earth (in the box) from Saturn, taken by the Cassini-Huygens spacecraft.

Photo of Earth from Saturn

Cassini–Huygens is a joint NASA/ESA/ASI unmanned space mission intended to study Saturn and its moons.

For more information on the mission and craft, visit NASA’s Official Cassini-Huygens website.

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A cure for Type I diabetes?

Saturday, December 16th, 2006

Diabetes breakthrough

Before you get too excited, let me say this: from my read of the article, it’s a long time before humans could benefit, and even when they can, you’ll probably have to catch it within a certain amount of time.

In a discovery that has stunned even those behind it, scientists at a Toronto hospital say they have proof the body’s nervous system helps trigger diabetes, opening the door to a potential near-cure of the disease that affects millions of Canadians.

Diabetic mice became healthy virtually overnight after researchers injected a substance to counteract the effect of malfunctioning pain neurons in the pancreas.

The link to the nervous system is the breakthrough idea. Until this point, the auto-immune system was seen as the problem. But recently the researchers in the article tried a nerve inhibitor that actually removed the disease from infected mice.

In diabetes, the inflammation (and eventually death) of pancreatic islet cells, which produce the insulin we all need to convert sugar to energy, is the root of the problem. The researchers concentrated on the nerves surrounding these cells, and told them to stop firing “emergency” messages to the nervous system. In the mice, this caused the islet cells to recover and begin functioning normally again. In other words, they were cured.

(Note: obviously the islet cells have to be inflamed, not dead, for this to work. That’s why I said at the beginning that you’d have to catch the disease within a certain period of time.)

Obviously if this holds true for humans as well, this is an incredibly huge development, not just for Type I, but for Type II diabetes as well:

They also discovered that their treatments curbed the insulin resistance that is the hallmark of Type 2 diabetes, and that insulin resistance is a major factor in Type 1 diabetes, suggesting the two illnesses are quite similar.

While this study concentrates solely on Diabetes Type I (or Juvenile Onset Diabetes), other diseases not previously linked to the nervous system may benefit from this research as well:

They also conclude … that nerves likely play a role in other chronic inflammatory conditions, such as asthma and Crohn’s disease.

This is potentially the biggest medical breakthrough since curing polio. Here’s hoping the research proves to be true and transferable to humans!

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Impairment while driving on phone > drunk driving

Wednesday, August 16th, 2006

I talked about this one before, but I had to mention that I just watched a Mythbusters episode on the Discovery Channel that confirmed that impairment is at least as bad, if not worse, while driving and talking on a cell phone, as while driving drunk.

The participants/testers drove a driving course three times. Once with no distractions, once on the phone while answering questions they had to think about, and once with a blood alcohol level of approximately 0.07 (i.e., just below the legal limit).

They each passed the course on the non-impaired trial, failed more than half of the course on the cell phone, and failed about half the course while drunk. In other words, they did slightly worse while on the cell phone than they did while drunk.

Now… how many of you will stop talking on the cell phone in the car? Those of you with your hands raised: I applaud your intentions. I also don’t believe you for a second. But maybe you’ll spend less time on the phone, and that’s good.

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Hydrogen Technology - New unlimited energy source?

Thursday, May 11th, 2006

Hydrogen Technology Applications

Whoa. You’d think if this was really viable they’d be talking about it all over the news. Well, I’m going in with skepticism, but holy cow, it sure sounds cool.

(Interesting site design, too.)

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Huygens probe lands on Titan - movies

Thursday, May 11th, 2006

NASA - Titan Descent Data Movie with Bells and Whistles - Movie

Okay, this is by far the best movie I’ve seen of a probe landing. Really puts the events in perspective. Very cool.

Another version of the landing
This one is also very cool. Same landing, focused only on the pictures and narrated by a guy who obviously did voiceover work for every planetarium I’ve ever visited.

Here is an article that includes links to these same movies, as well as much other information.

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Sodium: A real blast at pool parties

Tuesday, April 18th, 2006

Sodium Party

This site is great! Science with a kick. I love it.

Sodium metal reacts rather badly with water. That makes for some great videos!

The site has the same kind of crazy fascination with chemistry that my friend had as we were growing up. He even made nitroglycerin once (and he’s now a pharmacist… scary).

From the main Sodium page:

As with any reactive element, sodium’s character is changed completely when it’s incorporated into a chemical compound. Let sodium, a reactive metal, and chlorine, a poisonous, choking gas, react with each other (which they do with a violent explosion) and the result is common table salt, NaCl, blowing out all over the place. Isn’t the world a wonderful place to live?

Suddenly I’m getting the urge to play with those home chemistry sets again…

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