Light Reflection and Refraction | Science Primer
Reflections and Refractions in Ray Tracing, a simple but thorough discussion of the mathematics behind refraction and reflection. Home /Light Reflection and Refraction a vacuum. The light ray model, on the other hand, can describe interactions between light and matter. angle of reflection (θr) = 60 deg The greater the difference in density between the two media, the greater the refraction. Below is a video overview of the concepts covered. Cite this Video Light travels more slowly in a medium with a high index of refraction and more quickly in a medium with a low index of refraction. and the lens will determine the location of the image according to the thin lens equation.
So that angle right there is going to be the same as that angle right there. That's essentially what we learned the last couple of videos. What we want to cover in this video is when the light actually doesn't just bounce off of a surface but starts going through a different medium.
So in this situation, we will be dealing with refraction. Refraction, you still have the light coming in to the interface between the two surfaces. So let's say--so that's the perpendicular right there, actually let me continue the perpendicular all the way down like that. And let's say we have the incident light ray coming in at some, at some angle theta 1, just like that Light travels the fastest in a vacuum. There's nothing there, no air, no water, no nothing, that's where the light travels the fastest.
And let's say that this medium down here, I don't know, let's say it's water.
Let's say that this is water. This was all water over here. This was all vacuum right up here. So what will happen, and actually, that's kind of an unrealistic-- well, just for the sake of argument, let's say we have water going right up against a vacuum. This isn't something you would normally just see in nature but let's just think about it a little bit.
Normally, the water, since there's no pressure, it would evaporate and all the rest. But for the sake of argument, let's just say that this is a medium where light will travel slower.
What you're going to have is is this ray is actually going to switch direction, it's actually going to bend. Instead of continuing to go in that same direction, it's going to bend a little bit. It's going to go down, in that direction just like that. And this angle right here, theta 2, is the refraction. That's the refraction angle. Or angle of refraction. This is the incident angle, or angle of incidence, and this is the refraction angle.
Once again, against that perpendicular. And before I give you the actual equation of how these two things relate and how they're related to the speed of light in these two media-- and just remember, once again, you're never going to have vacuum against water, the water would evaporate because there's no pressure on it and all of that type of thing.
But just to--before I go into the math of actually how to figure out these angles relative to the velocities of light in the different media I want to give you an intuitive understanding of not why it bends, 'cause I'm not telling you actually how light works this is really more of an observed property and light, as we'll learn, as we do more and more videos about it, can get pretty confusing. Sometimes you want to treat it as a ray, sometimes you want to treat it as a wave, sometimes you want to treat it as a photon.
But when you think about refraction I actually like to think of it as kind of a, as a bit of a vehicle, and to imagine that, let's imagine that I had a car. So let me draw a car. So we're looking at the top of a car. So this is the passenger compartment, and it has four wheels on the car. We're looking at it from above. And let's say it's traveling on a road.
It's traveling on a road. On a road, the tires can get good traction.
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The car can move pretty efficiently, and it's about to reach an interface it's about to reach an interface where the road ends and it will have to travel on mud. It will have to travel on mud. Now on mud, obviously, the tires' traction will not be as good.
The car will not be able to travel as fast. So what's going to happen? Assuming that the car, the steering wheel isn't telling it to turn or anything, the car would just go straight in this direction. But what happens right when--which wheels are going to reach the mud first?
This wheel is going to reach the mud first. There's going to be some point in time where the car is right over here. Where it's right over here. Where these wheels are still on the road, this wheel is in the mud, and that wheel is about to reach the mud. Now in this situation, what would the car do?
What would the car do?Laws of Reflection - #aumsum #kids #education #science #learn
And assuming the engine is revving and the wheels are turning, at the exact same speed the entire time of the simulation. Well all of a sudden, as soon as this wheel hits the medium, it's going to slow down. Angle of incidence exceeds critial angle. The light ray model makes the assumption that light travels in a straight line through transparent media such as air or water.
The model also assumes that light rays behave in a predictable manner when they encounter surfaces such as an interface between different media air and water for example or the surface of an opaque object. This makes it possible to predict the path a light ray will follow as it move from its point of origin to wherever it eventually changes into another form of energy such as heat.
Everyday examples of light encountering surfaces include movement of light from air into the water in a swimming pool, through the glass of a window pane or onto an opaque surface such as a rock or the back of your hand. When a light ray encounters a surface, one or more of the following three things occur, the light ray: Reflects off the surface and travels off in a different direction.
Passes from one medium into the other and continue on a new, straight line path.
Light Reflection and Refraction
Often, more than one of these occur. This causes the pencil to appear higher and the water to appear shallower than it really is.
The depth that the water appears to be when viewed from above is known as the apparent depth. This is an important consideration for spearfishing from the surface because it will make the target fish appear to be in a different place, and the fisher must aim lower to catch the fish. Conversely, an object above the water has a higher apparent height when viewed from below the water.
The opposite correction must be made by an archer fish. But, as the angle of incidence approaches 90o, the apparent depth approaches zero, albeit reflection increases, which limits observation at high angles of incidence. Conversely, the apparent height approaches infinity as the angle of incidence from below increases, but even earlier, as the angle of total internal reflection is approached, albeit the image also fades from view as this limit is approached.
An image of the Golden Gate Bridge is refracted and bent by many differing three-dimensional drops of water. Dispersion[ edit ] Refraction is also responsible for rainbows and for the splitting of white light into a rainbow-spectrum as it passes through a glass prism.
Glass has a higher refractive index than air. When a beam of white light passes from air into a material having an index of refraction that varies with frequency, a phenomenon known as dispersion occurs, in which different coloured components of the white light are refracted at different angles, i.
The different colors correspond to different frequencies.