So let's talk about size.

So size on this scale is often hard for people to think about.

And so, what we have in the top panel of this graph, is a example of

a nanoparticle called the, single-walled carbon nanotube.

And it has this one dimension, the diameter of the particle is one nanometer

in diameter, so it's very, very small.

And it could be hundreds of nanometers long, but

that one dimension is really makes it kind of special.

And so just to kind of put it in contrast, so if we multiply that carbon nanotube

by 100,000, we get something that's about the size of a human hair and

a human hair is a 100 micrometers in diameter.

If we multiply the human hair by 100,000 we get something that's about the size of

a house about ten meters wide.

So now you kind of see, that's a pretty narrow house maybe that's a row house here

in Baltimore, but now you kind of see the scale of things.

So we're really talking about stuff that's very, very small.

And to place it in perspective for something that's not a long thin fiber,

we have a nanoparticle, the bottom that's cuboid shaped.

It's four micrometers in diameter.

If we multiply that by a million, we get the size of an ant.

If we multiply that by a million,

we get the size of the Indianapolis Motor Speedway.

So, we're talking about things to scale here, it's almost hard to comprehend.

And it's really the advent of modern technology that allows us now

to make things this small, and manipulate properties of matter at this scale.

Now, it's very exciting, because these properties may have us do things with

nanoparticles that can enhance our ability to treat disease, it could enhance our

ability to clean up the environment, it could make bulletproof vests.

But now we have to think about also, are we introducing

unique toxicities with all these unique properties that we're taking advantage of?