#day7script

Script for Ortho Video v4

 (Long shot of Andrea walking around farmer’s market) Eating foods is one of the great pleasures of life. And to enjoy foods from 

(panning shot of energy bar aisle at Harvest) VO: energy bars

(panning shot of Flour bakery display) VO: to cookies,

(panning shot of Andrea walking in produce aisle) to fruits and vegetables, we rely on one part of our bodies:

 (Andrea picks up and apple from produce aisle) “our teeth.” (Close up on Andrea eating up an apple in quick video)

 (Andrea filmed indoors, medium shot, holding a model tooth in hand) Teeth are the hardest substance in our bodies – harder than our bones, and even harder than iron or steel!

 (Andrea lifts tooth to shoulder height) While we chew, our teeth actually experience forces up to 225 pounds - that’s like having a

(Drawing of mountain goat appears above tooth) mountain goat

jump up and down on our teeth hundreds of times each day…

(Animate mountain goat jumping up and down 3 times)

 (Cut to closeup of Andrea)

so why doesn’t our jaw just crumble under all those forces? (Drawing overlay outlining Andrea’s jaw all cracked and jagged)

 (Show drawing) VO: Between your tooth and your jawbone, there is a specialized piece of tissue called the periodontal ligament, or PDL for short. The PDL can easily absorb the normal forces that a tooth experiences when we chew, say, an apple, cushioning or protecting our jawbone from our teeth.

 (Show b-roll of cells maybe) VO: And inside the PDL, there are all kinds of cells.  One type, called mechanoreceptors, sense forces of movement or pressure applied to the tooth.  If the force is large enough, such as biting into an apple seed, these receptors tell your brain to stop biting down!

(Display model of perfect teeth) Teeth sound like they're perfectly designed already...

(Closeup of Andrea with bubba teeth) VO: But sometimes we really NEED to force them in a certain direction… like with braces. (Cut to Andrea smiling with braces in)

 (Cut to drawing) VO: As the braces slowly force the teeth to move, the PDL is squeezed in one direction and stretched in the other, like a rubber band.

 Here’s where it gets interesting - to make room, the mechanoreceptors in the PDL trigger cells called osteoclasts to come in and dissolve a little bit of the jawbone.

 (Cut to drawing) VO: The mechanoreceptors also trigger another kind of cell called an osteoblast, which builds the jawbone back up, so the PDL cushion can get back into its proper shape, holding the tooth in its new position.

 So if braces use osteoblasts to physically REPOSITION teeth for cosmetic reasons, what if we try to use them to REPLACE things to our bodies.

Dental implants replace teeth that are damaged or missing – to restore chewing function. And MIT engineers are using the properties of osteoblasts and osteoclasts that are already in our bodies to create a chemical coating for these implants. Just like in a mouth with braces, this coating helps create natural bone to help lock the implant in place.

 Cut to image of entire body with skeleton highlighted.

 Voiceover: Your jaw isn’t the only place where these osteoclasts and osteoblasts alter your bone structure.  In fact, this bony remodeling process is happening throughout your body.

So what if we replace things INSIDE our bodies, combining natural cells and tissues with synthetic parts, like a cyborg! 

Sound like something out of science fiction? Well, it’s already happening. And these synthetic implants aren’t just limited to teeth – doctors can replace knees, hips, even spinal discs.

Right now, these implants are designed to have the same functionality as the body parts they are replacing.  But in the future, scientists could make implants that work better than the original body parts.

Then we could become true cyborgs – with implanted parts that fuse with the natural parts of our bodies to make us faster, stronger.

Smarter.

What do snowflakes and cell phones have in common?

  Well, let me start by drawing a snowflake.

  First, I’d draw an equilateral triangle, divide each side into three equal parts, and build another equilateral triangle on top of each side (this “demo” can be done on a blackboard or whiteboard).

  Then take out the middle, and repeat the process, this time with 1, 2, 3, 4 times 3, which is 12 sides. Eventually, the shape will look something like this:

This curve is called in mathematics a Koch Snowflake. If I repeated the process again and again, and looked anywhere, I would see this same pattern: (show)

  Such never-ending patterns that on any scale, on any level of zoom, look roughly the same are called fractals. Computer scientists can program these infinite patterns by repeating an often simple mathematical process over and over.

  In 1990’s, a radio astronomer named Nathan Cohen used the Koch snowflake to revolutionize wireless communications.

  At the time, Cohen was having troubles with his landlord. The man wouldn’t let him put a radio antenna on the roof! So, Cohen decided to make a more compact, fractal radio antenna instead (show wire bent as Koch snowflake) The landlord didn’t notice it.

And it worked better than the ones before!

  Working further, Cohen designed a new version, this time using a fractal called “the Menger Sponge” (build a tangible model of the Sponge, and show it).

  (soapy sponge used as prop; maybe host is in shower?)

The Menger Sponge is not really the sponge you’d be scrubbing your back with, but you can still think of it kind of like that. Imagine both water and soap getting through your sponge’s holes, except the water is Wi Fi and the soap is, say, Bluetooth.

  The fractal’s infinite “sponginess” allows the antenna to operate well at many different frequencies simultaneously. Before Cohen’s invention, antennas had to be "cut" for one necessary frequency. That was the only frequency they could operate at.

  So, without Cohen’s “sponge,” your cell phone would have to look something like a hedgehog to receive different signals, including the radio signal that allows you to hear your friends when they call (illustrate: phone with several antennas glued on and labels).

  Cohen later proved that only fractal shapes could work with such a wide range of frequencies. Today, millions of wireless communication devices, such as laptops and barcode scanners, also use Cohen’s fractal antenna.

  Cohen’s genius invention, however, was not the first application of fractals in the world. Nature has been doing it the whole time, and not just with snowflakes!

  Natural selection favors the most efficient systems and organisms, often of a fractal shape.

  The spiral fractal, for example, is present in seashells, broccoli, and hurricanes.

  So, many natural systems previously thought off-limits to mathematicians can now be explained in terms of fractals. The fractal tree for example, is relatively easy to program, and allows mathematicians to study anything from river systems to blood vessels and lightning bolts.

  Thus, fractals allow us to learn nature’s best practices, and then apply them to solve real world problems. Much like Cohen’s antenna revolutionized telecommunications, other fractal research is changing fields of medicine, weather prediction, and many more. Here at MIT (move camera from host and Charles river to MIT dome right across) and everywhere in the world.