The morning light could shine in, but the girl couldn't really see out. Everything outside was only a blur. What made that happen? Do you ever wonder why some objects let light through while others don't? Translucent Materials Sometimes light can shine through materials that aren't really clear. These materials are translucent. A translucent material allows light to pass through, but prevents the light from forming images. The object scatters the light when it enters.
When the light is scattered, the image looses its sharpness. Top of Page. Express your understanding of this principle by filling in the blanks in the following diagrams. See Answer Example A: Green will be transmitted and so the object appears green to an observer. Example B: Both green and blue will be transmitted and so the object appears greenish-blue to an observer. The colors perceived of objects are the results of interactions between the various frequencies of visible light waves and the atoms of the materials that objects are made of.
Many objects contain atoms capable of either selectively absorbing, reflecting or transmitting one or more frequencies of light.
The frequencies of light that become transmitted or reflected to our eyes will contribute to the color that we perceive. Natural philosophers have long pondered the underlying reasons for color in nature. One common historical belief was that colored objects in nature produce small particles perhaps light particles that subsequently reach our eyes. Different objects produce different colored particles, thus contributing to their different appearance.
Is this belief accurate or not? This view presumes that the appearance of an object is independent of the colors of light which illuminate the object.
We observe that the same object appears different colors when viewed under different light. So the secret to an object's appearance is not strictly due to its ability to produce a color. In fact the object's only role in determining its appearance is in its ability to absorb certain wavelengths of light which shine upon it.
What color does a red shirt appear when the room lights are turned off and the room is entirely dark? When the room lights are turned off there is no light , any object present in the room appears black. The color appearance of an object depends upon the light which that objects reflects to the observer's eye. Without any incident light, there can be no reflected light. Such an object appears black - the absence of light. In each case, determine which color s of light are reflected by the paper and what color the paper will appear to an observer.
See Answer Practice A: No light will be reflected; it is all absorbed. Thus, the paper would appear black to an observer. They theoretically show how to induce transparency in otherwise opaque materials using the complex dipole-dipole interactions present in a large number of interacting quantum emitters, such as atoms or molecules. This ability could have several potential applications , such as producing slow light or stopped light, along with applications in the field of attosecond physics.
As the scientists explain, light scattering is very well understood when dealing with individual quantum emitters; that is, single atoms or molecules. But the physics becomes much more complex when dealing with two or more interacting emitters. In this case, the electromagnetic field experienced by an emitter depends not only on the light beam striking its surface, but also on all of the electromagnetic fields radiated by all of its neighbors, which in turn are affected by the emitter in question.
Each quantum emitter can have a dipole, meaning a positive side and a negative side, due to an uneven distribution of electrons within the emitter. In a dense "vapor" of many quantum emitters, strong dipole-dipole couplings can then occur. The collective effects usually result in an enhancement of the light-matter interaction, although a very complicated one. Here, the researchers have theoretically shown that strong dipole-dipole interactions in a dense vapor of quantum emitters can be used to manipulate the spectral properties of the light scattered by the emitters.
In particular, the medium may become transparent at a particular frequency that can be controlled to a certain extent. The scientists explain that, on the most basic level, DIET results from destructive interference between the electromagnetic waves emitted by the quantum emitters. EIT is also based on destructive interference, but it is induced by a laser instead of dipole-dipole interactions. The scientists expect that DIET could have many of the same applications as EIT, which include the generation of slow light or stopped light by interactions with the medium.
Slow light has a variety of optical applications, including information transmission, switches, and high-resolution spectrometers. Also, in the field of attosecond physics, DIET could potentially be used to generate high harmonics in dense atomic or molecular gases. The researchers anticipate that DIET can be experimentally implemented in a few different ways, including in atomic vapor confined in a cell as well as in ultracold dense atomic clouds.
However, both systems still face challenges for demonstrating DIET, which must be addressed in the future. We will publish new results on this topic in Arxiv in the next few weeks. Moreover, DIET offers yet another way to slow the light due to strong anomalous dispersion.
We thus plan to develop the study of slow light with DIET in the near future, with potential applications for information processing. The light does not pass directly through the materials. It changes direction many times and is scattered as it passes through. Therefore, we cannot see clearly through them; objects on the other side of a translucent object appear fuzzy and unclear.
Because translucent objects are semi-transparent, some ultraviolet rays can go through them.
0コメント