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Originally posted by catwhoknowsplusone
reply to post by Dr Expired
I am trying to help you, Dr,
But I don't know more than I have said.
Mirrors don't reflect that well. Even if you get 99% reflection you're down to 1% after 100 reflections.
Originally posted by Dr Expired
Would say in a million years the image still get reflected on both mirrors ?...ignoring dust ect as a factor.
If so is this not strange?
I sourced this from my personal copy of "Physics" 5th edition by Giancoli page 834...
When a photon passes through matter, it interacts with the atoms and electrons. There are four important types of interactions that a photon can undergo:
- The photon can be scattered off an electron [or a nucleus] and in the process lose some energy; this is the Compton effect. But notice that the photon is not slowed down. It still travels with speed c, but its frequency will be lower.
- The photoelectric effect: a photon may knock an electron out of an atom and in the process itself disappear.
- The photon may knock an atomic electron into a higher energy state in the atom if its energy is not sufficient to knock the electron out altogether. In this process the electron also disappears, and all its en energy is given to the atom. Such an atom is then said to be in an excited state, and we shall discuss this more later.
- Pair production: A photon can actually create matter, such as the production of an electron and a positron. [A positron has the same mass as an electron, but the opposite charge, + e ]
Effects: See also: Mirror image and Specular reflection
Shape of a mirror's surfaceA beam of light reflects off a mirror at an angle of reflection equal to its angle of incidence (if the size of a mirror is much larger than the wavelength of light). That is, if the beam of light is shining on a mirror's surface at a θ° angle vertically, then it reflects from the point of incidence at a θ° angle from vertically in the opposite direction. This law mathematically follows from the interference of a plane wave on a flat boundary (of much larger size than the wavelength).
In a plane mirror, a parallel beam of light changes its direction as a whole, while still remaining parallel; the images formed by a plane mirror are virtual images, of the same size as the original object (see mirror image).
In a concave mirror, parallel beams of light becomes a convergent beam, whose rays intersect in the focus of the mirror.
In a convex mirror, parallel beams become divergent, with the rays appearing to diverge from a common point of intersection "behind" the mirror.
Spherical concave and convex mirrors do not focus parallel rays to a single point due to spherical aberration. However, the ideal of focusing to a point is a commonly-used approximation. Parabolic reflectors resolve this, allowing incoming parallel rays (for example, light from a distant star) to be focused to a small spot; almost an ideal point. Parabolic reflectors are not suitable for imaging nearby objects because the light rays are not parallel.
Mirror image; If one looks in a mirror, one's image reverses (e.g., if one raises one's right hand, his left hand will appear to go up in the mirror.)
Face-to-face mirrorsTwo or more mirrors placed exactly face to face give the appearance of an infinite regress. Some devices use this to generate multiple reflections:
Fabry–Pérot interferometer
Laser (which contains an optical cavity)
some types of catoptric cistula
momentum-enhanced solar sail
Active mirrors are mirrors that amplify the light they reflect. They are used to make disk lasers. The amplification is typically over a narrow range of wavelengths, and requires an external source of power.
Segmented mirror configurations are used to get around the size limitation on single primary mirrors. For example, the Giant Magellan Telescope will have seven 8.4 meter primary mirrors, with the resolving power equivalent to a 24.5 m (80.4 ft) optical aperture.
The resolving power is defined as the minimum angle two stars of equal magnitude should have for us to be able see them as separate stars. The resolving power also affects observation of the Sun, the Moon and the planets. In this case, the resolving power of our telescope determines how small a detail we can see on the sunspots, on the surface of the Moon or on the surface of a planet. This is also true for galaxies, star groups, comets, asteroids, etc. The resolving power of the telescope affects practically every mode of operation. We need to study what we call resolving power.
If the photon is of lower energy, but still has sufficient energy (in general a few eV to a few KeV, corresponding to visible light through soft X-rays), it can eject an electron from its host atom entirely (a process known as the photoelectric effect), instead of undergoing Compton scattering. Higher energy photons (1.022 MeV and above) may be able to bombard the nucleus and cause an electron and a positron to be formed, a process called pair production.
In the photoelectric effect, electrons are emitted from matter (metals and non-metallic solids, liquids or gases) as a consequence of their absorption of energy from electromagnetic radiation of very short wavelength, such as visible or ultraviolet light. Electrons emitted in this manner may be referred to as "photoelectrons". First observed by Heinrich Hertz in 1887, the phenomenon is also known as the "Hertz effect", although the latter term has fallen out of general use. Hertz observed and then showed that electrodes illuminated with ultraviolet light create electric sparks more easily.
The photoelectric effect requires photons with energies from a few electronvolts to over 1 MeV in high atomic number elements. Study of the photoelectric effect led to important steps in understanding the quantum nature of light and electrons and influenced the formation of the concept of wave–particle duality. Other phenomena where light affects the movement of electric charges include the photoconductive effect (also known as photoconductivity or photoresistivity), the photovoltaic effect, and the photoelectrochemical effect.
Emission mechanismThe photons of a light beam have a characteristic energy determined by the frequency of the light. In the photoemission process, if an electron within some material absorbs the energy of one photon and thus has more energy than the work function (the electron binding energy) of the material, it is ejected. If the photon energy is too low, the electron is unable to escape the material. Increasing the intensity of the light beam increases the number of photons in the light beam, and thus increases the number of electrons excited, but does not increase the energy that each electron possesses. The energy of the emitted electrons does not depend on the intensity of the incoming light, but only on the energy or frequency of the individual photons. It is an interaction between the incident photon and the outermost electron.
Electrons can absorb energy from photons when irradiated, but they usually follow an "all or nothing" principle. All of the energy from one photon must be absorbed and used to liberate one electron from atomic binding, or else the energy is re-emitted. If the photon energy is absorbed, some of the energy liberates the electron from the atom, and the rest contributes to the electron's kinetic energy as a free particle.
I have no idea what you mean by "static reflection", but it sounds to me like you're making up something that doesn't exist. It's never static. Ever.
Originally posted by Dr Expired
reply to post by Arbitrageur
So you are saying mirrors degrade a static relection? with the passing of time?
Originally posted by Arbitrageur
I have no idea what you mean by "static reflection", but it sounds to me like you're making up something that doesn't exist. It's never static. Ever.
Originally posted by Dr Expired
reply to post by Arbitrageur
So you are saying mirrors degrade a static relection? with the passing of time?
The reason is photons travel at the speed of light. They aren't static.
Regarding degradation, did you look at the infinity mirrors in the link I posted? The pictures there should be pretty self explanatory, and it's not time that's the main issue there. The reflections degrade with each additional reflection.