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Oct 21, 1999 · How does that electronic energy get converted to heat, you ask. The key is 'radiationless transitions.'. Here's how it works: the atoms of the brick are perpetually vibrating. Some of those atoms...
Basic properties of waves: Amplitude, wavelength, and frequency. As you might already know, a wave has a trough (lowest point) and a crest (highest point). The vertical distance between the tip of a crest and the wave’s central axis is known as its amplitude.
- Overview
- Ray theories in the ancient world
Light is electromagnetic radiation that can be detected by the human eye. Electromagnetic radiation occurs over an extremely wide range of wavelengths, from gamma rays with wavelengths less than about 1 × 10−11 metres to radio waves measured in metres.
What is the speed of light?
The speed of light in a vacuum is a fundamental physical constant, and the currently accepted value is 299,792,458 metres per second, or about 186,282 miles per second.
What is a rainbow?
A rainbow is formed when sunlight is refracted by spherical water droplets in the atmosphere; two refractions and one reflection, combined with the chromatic dispersion of water, produce the primary arcs of colour.
Why is light important for life on Earth?
While there is clear evidence that simple optical instruments such as plane and curved mirrors and convex lenses were used by a number of early civilizations, ancient Greek philosophers are generally credited with the first formal speculations about the nature of light. The conceptual hurdle of distinguishing the human perception of visual effects from the physical nature of light hampered the development of theories of light. Contemplation of the mechanism of vision dominated these early studies. Pythagoras (c. 500 bce) proposed that sight is caused by visual rays emanating from the eye and striking objects, whereas Empedocles (c. 450 bce) seems to have developed a model of vision in which light was emitted both by objects and the eye. Epicurus (c. 300 bce) believed that light is emitted by sources other than the eye and that vision is produced when light reflects off objects and enters the eye. Euclid (c. 300 bce), in his Optics, presented a law of reflection and discussed the propagation of light rays in straight lines. Ptolemy (c. 100 ce) undertook one of the first quantitative studies of the refraction of light as it passes from one transparent medium to another, tabulating pairs of angles of incidence and transmission for combinations of several media.
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With the decline of the Greco-Roman realm, scientific progress shifted to the Islamic world. In particular, al-Maʾmūn, the seventh ʿAbbāsid caliph of Baghdad, founded the House of Wisdom (Bayt al-Hikma) in 830 ce to translate, study, and improve upon Hellenistic works of science and philosophy. Among the initial scholars were al-Khwārizmī and al-Kindī. Known as the “philosopher of the Arabs,” al-Kindī extended the concept of rectilinearly propagating light rays and discussed the mechanism of vision. By 1000, the Pythagorean model of light had been abandoned, and a ray model, containing the basic conceptual elements of what is now known as geometrical optics, had emerged. In particular, Ibn al-Haytham (Latinized as Alhazen), in Kitab al-manazir (c. 1038; “Optics”), correctly attributed vision to the passive reception of light rays reflected from objects rather than an active emanation of light rays from the eyes. He also studied the mathematical properties of the reflection of light from spherical and parabolic mirrors and drew detailed pictures of the optical components of the human eye. Ibn al-Haytham’s work was translated into Latin in the 13th century and was a motivating influence on the Franciscan friar and natural philosopher Roger Bacon. Bacon studied the propagation of light through simple lenses and is credited as one of the first to have described the use of lenses to correct vision.
Explain changes in heat during changes of state, and describe latent heats of fusion and vaporization; Solve problems involving thermal energy changes when heating and cooling substances with phase changes
During evaporation, water changes from liquid water to water vapor (a gas). Water also moves into the atmosphere by transpiration, or the evaporation of water from plants. Both evaporation and transpiration are driven by the sun’s energy. Water forms clouds in the atmosphere by condensation.
- Transpiration in plants occurs in all living species with few exceptions, so whether you own an orchard or are growing a lawn, transpiration is an...
- The vapor would go through it but if we use metal it would just keep all the vapor inside of the metal and when we take it off you will see a lot o...
- If you have a container of water that no water is being added to and you watch it closely, then you will eventually observe that there is less wate...
- Plants have small holes in their leaves called stomata that water evaporates through. Evaporating water through the stomata creates a capillary act...
- For water to evaporate, the environment must be heated. Air that is both warm and dry can give this heat. The evaporation of water inside a confine...
- No, water keeps changing forms but still remains unless something drinks it which im not too sure on what happens
- Water does not _form again_. It is just in a different state of matter. The water cycle doesn't stop, it keeps on going.
- _because of the water cycle .... The water cycle recycles all the water again and again which tells us that the water is really , really old ._
- If there was no sun, life on Earth would not be possible as we know it. The sun provides heat, light, and energy essential for sustaining life. Wit...
- Evaporation happens at night and during the day. Evaporation happens faster at higher temperatures and more slowly at lower temperatures. So, typic...
Water absorbs infrared energy freely from the environment; it uses that energy to convert bulk water into liquid crystalline water (fourth phase water) — which we also call “exclusion zone” or “EZ” water because it profoundly excludes solutes.
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Does a classical wave model accurately describe light?
Water is relatively transparent to visible light, near ultraviolet light, and far-red light, but it absorbs most ultraviolet light, infrared light, and microwaves. Most photoreceptors and photosynthetic pigments utilize the portion of the light spectrum that is transmitted well through water.
