Monday, May 4, 2009

My Research Explained: Electromagnetic Radiation (Light)

Light is a combination of electricity and magnetism. Without one you cannot have the other and without both there would be no light. There is a component of light that is electrical and another component that is magnetic. It just so happens that both components oscillate and they are perpendicular to each other. This setup allows for some very interesting manipulation of light. One such manipulation is the Optical Trap. I will talk about that more next time, but for now I will just discuss a couple of useful tidbits that will become the basis for what I will describe next time.

Light also has properties of waves and particles. It behaves like a wave, it has amplitude, period, and frequency, and that is what gives us the spectrum of light (colors, radio waves, microwaves, etc). The fact that it is a wave also allows us to study some interesting phenomena like diffraction. Light is also a particle called a photon. When a photon interacts with something that is the mechanism that allows us to see. A photon will strike an object (say your hand), the object will absorb and emit the photon, and then it will be absorbed by our eye which our brain interprets. We see colors when a photon is emitted as a specific frequency.

Why is it important to know that light is both electric and magnetic? Well that will come in due time, but for now know that we can use materials known as dielectrics (which are insulators). These materials can interact with an electric field to produce some useful results. Basically every atom is made of positive and negative charge. Manipulating an electric field around an atom will change the way the charge (both positive and negative) is positioned. For instance, say you have a positive charge with a negative charge completely surrounding it. If you apply some sort of electric field, the charge distribution may change so that the negative charge gets pulled to one side, maybe creating a dipole.

There are lots more interesting things that can happen with light as a result of its properties, but for now this is a good precursor to what I will explain when I discuss Optical Tweezers.

1 comment:

Dad said...

Hey Professor, awesome job explaining the properties of light. Very clear and concise. i have also heard light referred to as a wavicle (pronounced wave - i- cle (i know you already know that)). i found it extremely interesting...

i still need those optical tweezers for that splinter i have... :):):)

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