Now that we know that light is a wave, let’s explore a bit what this means…
What do waves look like?
One of the most important attributes of light is the wavelength. That’s the distance between two crests.
Our laser here has a wavelength of 532nm (that’s nanometers, which is 1 billionth of a meter, 0.000000001 m).
Our eyes can see light in the range of 400nm (violet) to 700nm (red). That range is called the “visible light”.
Remember the rainbow?
What about light outside the “visible light”?
How can we measure the wavelength of a light?
Different lights will create a different pattern and we can measure the resulting light pattern to calculate the wavelength!
We can even use diffraction to measure really small objects, such as the diameter of your hair and that’s exactly what we’ll do in the next lecture 🙂