Do you doubt the Love of God? The truth is that God is relentless in His pursuit of you. Though much of our holiness depends upon us, most of it depends upon God. Imagine if someone gave their life for you because they loved you. They were put into a situation where they knew you would lose your life if they did not freely give theirs. Should we fear the truth?
On one hand the truth can get us in trouble. Look, for example, at the Martyrs. They are witnesses to the truth with the shedding of their blood.
Would you like our Daily Reflections emailed to you? My Catholic Life! Click the links below to visit our sign up page. You may unsubscribe at anytime:. Older posts. Series My Catholic Faith! A conventional reflector would be useless as the X-rays would simply pass through the intended reflector. In contrast, when light reflects off of a material with lower refractive index the reflected light is in phase with the incident light.
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This is an important principle in the field of thin-film optics. Specular reflection forms images. Reflection from a flat surface forms a mirror image , which appears to be reversed from left to right because we compare the image we see to what we would see if we were rotated into the position of the image. Specular reflection at a curved surface forms an image which may be magnified or demagnified; curved mirrors have optical power.
Such mirrors may have surfaces that are spherical or parabolic. If the reflecting surface is very smooth, the reflection of light that occurs is called specular or regular reflection. The laws of reflection are as follows:. These three laws can all be derived from the Fresnel equations. In classical electrodynamics , light is considered as an electromagnetic wave, which is described by Maxwell's equations.
Light waves incident on a material induce small oscillations of polarisation in the individual atoms or oscillation of electrons, in metals , causing each particle to radiate a small secondary wave in all directions, like a dipole antenna. All these waves add up to give specular reflection and refraction, according to the Huygens—Fresnel principle. In the case of dielectrics such as glass, the electric field of the light acts on the electrons in the material, and the moving electrons generate fields and become new radiators.
The refracted light in the glass is the combination of the forward radiation of the electrons and the incident light. The reflected light is the combination of the backward radiation of all of the electrons. In metals, electrons with no binding energy are called free electrons.
Light—matter interaction in terms of photons is a topic of quantum electrodynamics , and is described in detail by Richard Feynman in his popular book QED: The Strange Theory of Light and Matter. When light strikes the surface of a non-metallic material it bounces off in all directions due to multiple reflections by the microscopic irregularities inside the material e. Thus, an 'image' is not formed. This is called diffuse reflection.
The exact form of the reflection depends on the structure of the material. One common model for diffuse reflection is Lambertian reflectance , in which the light is reflected with equal luminance in photometry or radiance in radiometry in all directions, as defined by Lambert's cosine law. The light sent to our eyes by most of the objects we see is due to diffuse reflection from their surface, so that this is our primary mechanism of physical observation.
Some surfaces exhibit retroreflection.
The structure of these surfaces is such that light is returned in the direction from which it came. When flying over clouds illuminated by sunlight the region seen around the aircraft's shadow will appear brighter, and a similar effect may be seen from dew on grass. This partial retro-reflection is created by the refractive properties of the curved droplet's surface and reflective properties at the backside of the droplet.
Some animals' retinas act as retroreflectors see tapetum lucidum for more detail , as this effectively improves the animals' night vision. Since the lenses of their eyes modify reciprocally the paths of the incoming and outgoing light the effect is that the eyes act as a strong retroreflector, sometimes seen at night when walking in wildlands with a flashlight.
A simple retroreflector can be made by placing three ordinary mirrors mutually perpendicular to one another a corner reflector. The image produced is the inverse of one produced by a single mirror. A surface can be made partially retroreflective by depositing a layer of tiny refractive spheres on it or by creating small pyramid like structures. In both cases internal reflection causes the light to be reflected back to where it originated. This is used to make traffic signs and automobile license plates reflect light mostly back in the direction from which it came.
In this application perfect retroreflection is not desired, since the light would then be directed back into the headlights of an oncoming car rather than to the driver's eyes. When light reflects off a mirror , one image appears.
Two mirrors placed exactly face to face give the appearance of an infinite number of images along a straight line. The multiple images seen between two mirrors that sit at an angle to each other lie over a circle. A square of four mirrors placed face to face give the appearance of an infinite number of images arranged in a plane. The multiple images seen between four mirrors assembling a pyramid, in which each pair of mirrors sits an angle to each other, lie over a sphere.
If the base of the pyramid is rectangle shaped, the images spread over a section of a torus. Note that these are theoretical ideals, requiring perfect alignment of perfectly smooth, perfectly flat perfect reflectors that absorb none of the light. In practice, these situations can only be approached but not achieved because the effects of any surface imperfections in the reflectors propagate and magnify, absorption gradually extinguishes the image, and any observing equipment biological or technological will interfere.
In this process which is also known as phase conjugation , light bounces exactly back in the direction from which it came due to a nonlinear optical process. Not only the direction of the light is reversed, but the actual wavefronts are reversed as well. A conjugate reflector can be used to remove aberrations from a beam by reflecting it and then passing the reflection through the aberrating optics a second time. Materials that reflect neutrons , for example beryllium , are used in nuclear reactors and nuclear weapons. In the physical and biological sciences, the reflection of neutrons off of atoms within a material is commonly used to determine the material's internal structure.
When a longitudinal sound wave strikes a flat surface, sound is reflected in a coherent manner provided that the dimension of the reflective surface is large compared to the wavelength of the sound. As a result, the overall nature of the reflection varies according to the texture and structure of the surface.