What objects absorb light? What substances both absorb and repel light?

Whatever color the object reflects, it absorbs other light.

Summary. Pro, fluorescent, Chinese words. Also known as "fluorescence", it refers to a photoluminescent cold luminescence phenomenon.

When a normal temperature substance is irradiated by a certain wavelength of incident light (usually ultraviolet or X-ray), it enters the excited state after absorbing the light energy, and immediately de-excitation and emits an outgoing light longer than the wavelength of the incident light (usually in the visible light band); As soon as many fluorescent substances stop being incident with light, the luminescence disappears immediately. The outgoing light with this quality is called fluorescence. In addition, there are some substances that can still emit light for a long time after the incident light is removed, and this phenomenon is called afterglow.

In ordinary life, people usually refer to all kinds of faint light as fluorescence in a broad sense, without carefully investigating and distinguishing their luminescence principles. It also refers to cold light with a low temperature (not SE temperature).

Hello dear, glad to answer for you! Fluorescent substances can both absorb and repel light.

Pro, fluorescent, Chinese words. Also known as "fluorescence", it refers to a photoluminescent cold luminescence phenomenon. When a normal temperature substance is irradiated by a certain wavelength of incident light (usually ultraviolet or X-ray), it enters the excited state after absorbing the light energy, and immediately de-excitation and emits an outgoing light (usually the wavelength is in the visible band) than the wavelength of the incoming light; As soon as many fluorescent substances stop being incident with light, the luminescence disappears immediately.

The outgoing light with this quality is called fluorescence. In addition, there are some substances that can still emit light for a long time after the incident light is removed, and this phenomenon is called afterglow. In ordinary life, people usually refer to all kinds of faint light as fluorescence in a broad sense, without carefully investigating and distinguishing their luminescence principles.

It also refers to the temperature (not SE temperature) of the cold light of the low hall.

Thank you first, and then ask: Does glass have the function of absorbing light or transmitting light? What is the reflectivity of a flat silver mirror? What are the permeability and irregularity rate, reflected light rate, and slow light absorption rate of glass?

Pro, the transparent glass infiltrates Zen to absorb all the se-light, the reflectivity of the plane cross-silver mirror spine shouting such as 80% left cherry blossom right, the reflectivity of the glass + absorption rate + light transmittance = 100%. On average, the light transmittance of daylighting glass is slightly more than 80%.

White. The most reflective objects are highly reflective scenes, such as white or light-colored scenes; Scenes with low reflectivity are weak in reflectivity; Black objects do not reflect light.

The strong reflectivity is the scenery with high reflectivity, such as the reflection rate of white snow is 98%; The weak reflectivity is the low reflectivity of the scene, such as the reflectivity of carbon black is 2%; In general, there are not as many objects with high reflectivity as there are objects with low reflectivity in the photographable subject, and the average reflectivity is about that, so it is "neutral gray".

Experts know through experiments that the reflectivity of white and yellow people is about 18%, as a manifestation of the "people-oriented" photography principle, the stipulation of camera metering is to define the reflectivity of 18% as the so-called "standard gray" slightly higher than the "neutral gray". The camera metering system treats the reflectivity of all the different substances in the metering area as a standard gray with a reflectivity of 18%.

Regardless of whether it is sunny or cloudy, the metering point displayed on the computer screen** and the 18% gray board** will have the same brightness visually. According to the results of the experiments, which may not be precise enough, this luminance value is expressed in color scales (i.e., 148) and gray levels (i.e., 58%); Histograms of levels on camera and Photoshop, with an intermediate level value of 128 and a gray level of 50%, with little difference.

Answer: Choose.

Analysis: Matter will selectively absorb light, because the vibrational frequency of the molecules that make up the substance is certain, and only when the frequency of light is equal to the vibration frequency of the molecules of this substance, such as the frequency of the opening of the molecule, can the light be absorbed by the substance to the maximum extent.

There are several possibilities. The fundamental property to be considered is conservation of energy. Photons have energy.

If photons are absorbed by a material, the energy is deposited in that material. Take an atom, for example, whose electron cloud surrounds a positively charged nucleus. According to the rules of quantum mechanics, electrons can exist in discrete energy states.

If a photon is close to an atom that has an electron that may exist at a higher energy level, where the energy gap is very close to the energy of the photon, then the photon has the potential to be absorbed. In addition to the energy difference between energy levels, this probability is determined by a number of factors. The electron cloud needs to be twisted in such a way that it can be coupled with the electromagnetic field of the photons.

This is known as the transition moment, and if the transition moment is dipolemic, the absorption probability is the highest. transition dipole moment). In this case, photons and atoms are coupled, and a lot of things are possible.

A transition dipole can scatter photons as a radiating dipole. This is known as Rayleigh scattering, and scattered photons essentially retain many of the properties of incident photons. The coupled system does not absorb photons (which is most likely), and the photons continue to carry some slight phase shifts as memories of the interaction.

The atom completes the transition, in which case the photon is destroyed and the atom is in an excited state or a higher energy state. This is called a quantum transition, and you can't say much about it, except that the photons are destroyed and the atoms are in an excited state. Of course, the opposite process is possible, and the atom can emit photons as it makes a transition back to a lower energy state.

This is called spontaneous radiation.

Finally, atoms can continue to store energy through other interactions with their surroundings, from which energy can be stored in a long-lived excited state, or transferred to other nearby atoms and molecules through any number of interactions, such as Foster coupling, etc. This is a dissipative channel typically associated with large or open systems.

In conclusion, the interaction of light with matter is quite complex, and there are many possible outcomes beyond the absorption of photons.

I don't think the photon will change because it doesn't have a specific form, so we can't see it even after absorbing it.

Photons make transitions. Because light is also a kind of energy, it causes photons to change the energy level they are in, causing photon transitions.

Photons are absorbed by the surface cells of this substance and converted into energy.

In fact, whether the light is transmitted or not is determined by our eyes, in fact, light is a kind of electromagnetic wave, and electromagnetic wave is a transverse wave, and the propagation of the wave has a certain vibration frequency, I don't know if you have learned mechanical vibration.

For example, glass, we all know that glass is transparent to light, but not all light is transparent, and infrared rays will not pass through. In other words, whether the light can pass through or not depends on whether the vibrational frequency of the light can just let the crystals of the object be arranged.

The propagation of light is s-shaped, you can imagine it.

There are many things that are opaque, but when the structure is changed, it transmits light, such as graphite and diamonds.

About this "absorption"? The energy of the photon is m times c squared, which is quite large, and if the energy of the thing that absorbs light is very large, such as a black hole, then the absorption of light can be realized.

I don't know, do you understand?