A Guide to Understanding Optics
Do you know how our vision works? How about magnifying glasses or lenses?
Well, they all operate around optics.
By understanding optics, you’ll better understand the world around you. And, you’ll get a nice looking some of the physics that secretly lies around us each and every day.
If you’re not sure how to understand optics or you need an optics guide, you’ve come to the right place.
Just keep reading. We’re going to discuss everything you need to know.
What Is Optics?
Optics is a brand of physics that studies electromagnetic radiation and how it reacts with the matter around it. This branch of physics also looks at the instruments that we can use to gather information about these ligue 1 en direct.
Even more, optics involves studying our sight.
To put it simply, optics is the study of light. And, we rely on optics every single day to see things around us.
But, it also operates in our devices like digital cameras, wireless mouses, and even discs. Optics enables all of these things to work.
By studying optics, scientists can learn more about the world around us. They can study the special properties of light and use them for good. Experts use principles found within the study of life to explore the universe around us, monitor our environment, and solve crimes.
Light behaves differently under certain conditions. So, by using this knowledge, scientists can create helpful technologies.
The Reflection of Light
If an object doesn’t emit light itself, light has to reflect off of it in order for us to see it. Makes sense, right? We can’t see in the dark.
But, light reflection is a lot more complicated than you may think. You turn on your lamp and see things around you. Meanwhile, there are light rays bouncing around.
In particular, light reflection requires two rays of light. There is one incoming ray of light and one outgoing ray of light.
Some people refer to the incoming ray as the ray of incidence. And, they refer to the outgoing ray as the ray of reflection.
The law of reflection requires that the incoming ray and the outgoing ray are identical in angle but opposite in placement.
The means that the outgoing ray has to bounce off the object at 30 degrees if the incoming ray hits the object at 30 degrees. Of course, because the light bounces off of the object, you can imagine this as a V-shape, assuming that the angles are greater than zero degrees.
If the incoming ray of light hits the object at zero degrees, the outgoing ray must come off of the object at zero degrees. Therefore, this light ray forms a straight line.
In these scenarios, we are referring to opaque objects through which light cannot pass. If you start considering objects that are see-through or semi-see-through, the calculations become a little bit more complicated.
Some special coatings are anti-reflective. To learn more about these, click here.
The Refraction of Light
Light can also pass through other mediums such as liquids and gases. When we turn on a light, it has to pass through the air to get to the objects around it. And, it may gleam off of the cup of water that you have sitting on the kitchen counter.
Light refracts when it travels into a substance with a different refractive index. You may also hear some experts refer to the refractive index as the optical density of an object.
The refractive index refers to how light travels through a substance. Water has a different refractive index than air. And, different kinds of liquids and gases have their own refractive indexes.
Because of the difference in refractive indexes, you may see the light bend as it goes from one substance to another. You may notice this happening when you look underwater in the swimming pool.
The light changes direction as it goes from one substance to another because it changes its speed while it’s traveling through that substance.
The amount that the light bends depends on two main factors:
- The change in speed
- The angle of the incoming/incident ray
In order for the light to change angles, the incoming ray has to enter at an angle greater than zero degrees.
If the incoming angle enters a substance with a higher refractive index, the light ray slows down. This bends the light ray towards the normal line. This is an imaginary line that is drawn perpendicular (90 degrees) to the surface.
If the incoming angle enters a substance with a lower refractive index, the light ray speeds up. This bends the light ray away from the normal line.
How We See With Light
The eye is a one-lens system for looking at visible light. Light passes through the cornea then through the iris. This brings the light into the anterior chamber with its aqueous humor, through the lens, into the vitreous humor, and then into the retina.
The aqueous humor and vitreous humor are both water-based fluids within our eyes. The iris is what limits the amount of light that enters the eye. And, the lens is a tough membrane that has many long cells.
You’re able to see objects closer or farther away based on the ciliary muscles. These change shape which causes the focal length (power) of the lens to change.
Our eyesight changes as we get older because the cells within the lens multiply. But, the membrane that surrounds the lens doesn’t allow the cells to escape outside of the lens.
As the density of cells within the lens increases, the index of refraction of the lens changes. This means that it’s harder for the ciliary muscles to control the focal length of the lens.
Learning More About Optics
Learning about optics helps us to learn more about the world around us. It’s fun to know a little bit about the light rays that are bouncing everywhere. And, it explains some of the phenomena that you may experience in your everyday life.
To learn more about optics and other fun subjects, check out the rest of our blog. It’s always great to learn a little more about the world around us.
