Hi. It's Paul Andersen and this is disciplinary core idea PS4C. It's on information
technologies and instrumentation. And so IT is becoming more and more important in our
lives. And what we're really doing is bending electromagnetic radiation and other waves
to our means. And so an example of this could be the functional MRI. And what this guy is
looking at is really a picture of a brain that's operating. And if it weren't for electromagnetic
radiation and IT we really couldn't do that. And so again to remember what electromagnetic
radiation is, it's everything from radio waves to gamma waves. And the light you see right
now is going to be just a portion of that. So visible light we would say. And so what's
some examples of how we are using this to make our lives better? Telescopes are an example
of bending visible light so we can see what's in the universe. And microscopes allow us
to see what's inside the very small inside our cells. But also know that there's invisible
radiation that's also important. So your phone is picking up radio waves. And it's also transmitting
that radiation through waves as well. And so we use invisible and visible radiation
to make our lives better. So what's some examples of technology? How does an x-ray work? It's
using X rays. And those X rays, as they move through our body move through some of the
soft tissues readily, but the harder tissues like bone, not as well. And sound waves can
be used. So this an ultrasound. And we can look at a picture of a child inside its mother
using the reflection of those sound waves. We can also use that to get a picture of what
our world looks like. And so this is sonar. What they're doing is sending sound waves
down in to the ocean so we can map what the bottom of the ocean looks like as it reflects
back. And then finally we could even send waves out to space. And so this a mirror that
was dropped off by the Apollo XI astronauts. We can shoot laser beams up to the moon. It
can reflect back and we can measure with great precision how far the moon is away from the
earth. So these are all applications of waves. And so how do you teach this? Well in the
lower elementary grades you want to talk about their senses. And so what is vision? Vision
is picking up visible light using our eyes. And what about our ears? Hearing is picking
up vibrations in the air as sound. And our hands can pick up vibrations in matter or
material as well. But they should also understand that we have different senses. And so we have
senses, for example a telephone, is using and picking up waves from a totally different
area and it's transmitting that to the listener. As we move into the upper elementary grades
we want to start talking about lenses and how lenses can bend light. And so as light
hits a lens what happens is it's moving from one medium to another and it's going to be
slightly bent. And so what we get is a change in the angle of that light. And therefore
we can use a series of lenses to magnify distant images or images that are very very close.
And so this is the application of visible light. Also they should understand that electromagnetic
radiation can be used to transmit information. So for example right now you're watching a
screen and that's pixels which are really a bunch of numbers that are being crunched
together to apply my image on your computer screen. And so we can transmit that from computer
to computers using IT. Using information technologies. And we can make it visible to you. As you
move into middle school you want to talk about the electromagnetic spectrum. Make sure students
understand that there's only one slight part of this that we can actually see. That's the
visible portion. And that's light that you can see. But there's also this invisible portion
as well. And so we can use a lot of that invisible portion to send information. And so a simple
telephone is using this electromagnetic radiation to send it through a wire. But a radio would
just be using radio waves to do the same thing. And as we move into the digital age what we're
really doing is taking information and storing it digitally. Storing it in zeros and ones
and then transmitting that information. So the WiFi in your computer is simply radio
waves transmitting digital information and your phone as well. As you move into high
school you want students to understand that we have two ways of transmitting energy from
place to place. That is as a particle and a wave. And what is interesting about electromagnetic
radiation is that it's both. And quantum theory allows us to understand how that occurs at
this quantum state. But students don't have to under the quantum theory to understand
that scientists use that to produce semiconductors. Things like diodes and transistors and microprocessors.
And we use that to make our lives better. We can use it in x-rays. We can use it in
sonograms and mapping the bottom of our planet. And even sending messages to the moon and
back. And so electromagnetic radiation and how we bend it to our will is really really
important. And I hope that was helpful.