![Waves Lesson 5](http://s1.studyres.com/store/data/010193558_1-2da4bb490ddc8a5a7c32f6968c95d97e-300x300.png)
Reflection and Refraction
... a wave front travel at different speeds • This happens in uneven winds or temperatures • Sound waves tend to bend away from warm ground, since it travels faster in warmer air • On a cold night, the speed of sound is slower near the ground than above, so we can hear over larger distances ...
... a wave front travel at different speeds • This happens in uneven winds or temperatures • Sound waves tend to bend away from warm ground, since it travels faster in warmer air • On a cold night, the speed of sound is slower near the ground than above, so we can hear over larger distances ...
24.3 Interference – Young`s Double-Slit Experiment
... If light is a wave, interference effects will be seen, where one part of wavefront can interact with another part. One way to study this is to do a double-slit experiment: ...
... If light is a wave, interference effects will be seen, where one part of wavefront can interact with another part. One way to study this is to do a double-slit experiment: ...
Lecture notes for Chapter 15
... Transducin activates PDE, which breaks down cyclic GMP (cGMP) In dark, cGMP holds channels of outer segment open Na+ and Ca2+ depolarize cell In light cGMP breaks down, channels close, cell hyperpolarizes Hyperpolarization is signal! ...
... Transducin activates PDE, which breaks down cyclic GMP (cGMP) In dark, cGMP holds channels of outer segment open Na+ and Ca2+ depolarize cell In light cGMP breaks down, channels close, cell hyperpolarizes Hyperpolarization is signal! ...
Atomic Emission Spectra
... Spectrum tubes, fluorescent light bulbs, novelty “plasma globes,” and glowing “neon” signs all have one thing in common—they contain a gas that glows a specific color when a high voltage is applied to it. In this demonstration, this color will be viewed through a Flinn C-Spectra™. It is a holographi ...
... Spectrum tubes, fluorescent light bulbs, novelty “plasma globes,” and glowing “neon” signs all have one thing in common—they contain a gas that glows a specific color when a high voltage is applied to it. In this demonstration, this color will be viewed through a Flinn C-Spectra™. It is a holographi ...
Interference, Diffraction and Polarization
... • Electrons fall back to normal levels emitting photons of light • Atom returns to ground state ...
... • Electrons fall back to normal levels emitting photons of light • Atom returns to ground state ...
Electromagnetic Wave
... • Mirage is an image of a distant object caused by refraction of light. • The puddles are light rays from the sky that are refracted to your eyes. • The air just above the land is hotter than the air higher up. • Light travels faster in hot air, and the light from an object traveling towards the gro ...
... • Mirage is an image of a distant object caused by refraction of light. • The puddles are light rays from the sky that are refracted to your eyes. • The air just above the land is hotter than the air higher up. • Light travels faster in hot air, and the light from an object traveling towards the gro ...
Document
... • But, photoelectric effect: When light strikes a metal surface, electrons are emitted: The kinetic energy of the emitted electrons is independent of the wave intensity (light intensity); it only depends on the frequency of the light • To explain this effect, Einstein proposed that light consists ...
... • But, photoelectric effect: When light strikes a metal surface, electrons are emitted: The kinetic energy of the emitted electrons is independent of the wave intensity (light intensity); it only depends on the frequency of the light • To explain this effect, Einstein proposed that light consists ...
Bioluminescence
![](https://commons.wikimedia.org/wiki/Special:FilePath/Photinus_pyralis_Firefly_glowing.jpg?width=300)
Bioluminescence is the production and emission of light by a living organism. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some bioluminescent bacteria and terrestrial invertebrates such as fireflies. In some animals, the light is produced by symbiotic organisms such as Vibrio bacteria.The principal chemical reaction in bioluminescence involves the light-emitting pigment luciferin and the enzyme luciferase, assisted by other proteins such as aequorin in some species. The enzyme catalyzes the oxidation of luciferin. In some species, the type of luciferin requires cofactors such as calcium or magnesium ions, and sometimes also the energy-carrying molecule adenosine triphosphate (ATP). In evolution, luciferins vary little: one in particular, coelenterazine, is found in nine different animal (phyla), though in some of these, the animals obtain it through their diet. Conversely, luciferases vary widely in different species. Bioluminescence has arisen over forty times in evolutionary history.Both Aristotle and Pliny the Elder mentioned that damp wood sometimes gives off a glow and many centuries later Robert Boyle showed that oxygen was involved in the process, both in wood and in glow-worms. It was not until the late nineteenth century that bioluminescence was properly investigated. The phenomenon is widely distributed among animal groups, especially in marine environments where dinoflagellates cause phosphorescence in the surface layers of water. On land it occurs in fungi, bacteria and some groups of invertebrates, including insects.The uses of bioluminescence by animals include counter-illumination camouflage, mimicry of other animals, for example to lure prey, and signalling to other individuals of the same species, such as to attract mates. In the laboratory, luciferase-based systems are used in genetic engineering and for biomedical research. Other researchers are investigating the possibility of using bioluminescent systems for street and decorative lighting, and a bioluminescent plant has been created.