Total internal re

Total internal reflection

Total internal reflection, in physics, complete reflection of a ray of light within a medium such as water or glass from the surrounding surfaces back into the medium. The phenomenon occurs if the angle of incidence is greater than a certain limiting angle, called the critical angle. In general, total internal reflection takes place at the boundary between two transparent media when a ray of light in a medium of higher index of refraction approaches the other medium at an angle of incidence greater than the critical angle. For a water-air surface the critical angle is 48.5°. Because indices of refraction depend on wavelength, the critical angle (and hence the angle of total internal reflection) will vary slightly with wavelength and, therefore, with colour. At all angles less than the critical angle, both refraction and reflection occur in varying proportions.

vedio of total internal reflection

 

Light rays may be conducted over long, twisting paths by multiple total internal reflection in glass or plastic rods or fibres. See also fibre optics.

     

MIRAGE AN ILLUTION

MIRAGE -AN ILLUTION

MIRAGE

A mirage is a naturally occurring optical phenomenon in which light rays are bent to produce a displaced image of distant objects or the sky. The word comes to English via the French mirage, from the Latin mirari, meaning "to look at, to wonder at". This is the same root as for "mirror" and "to admire".

In contrast to a hallucination, a mirage is a real optical phenomenon that can be captured on camera, since light rays are actually refracted to form the false image at the observer's location. What the image appears to represent, however, is determined by the interpretive faculties of the human mind. For example, inferior images on land are very easily mistaken for the reflections from a small body of water.

Mirages can be categorized as "inferior" (meaning lower), "superior" (meaning higher) and "Fata Morgana", one kind of superior mirage consisting of a series of unusually elaborate, vertically stacked images, which form one rapidly changing mirage.

  vedio about mirage

Inferior mirage

An inferior mirage on the Mojave Desert in spring

For exhausted travelers in the desert, an inferior mirage may appear to be a lake of water in the distance. An inferior mirage is called "inferior" because the mirage is located under the real object. The real object in an inferior mirage is the (blue) sky or any distant (therefore bluish) object in that same direction. The mirage causes the observer to see a bright and bluish patch on the ground in the distance.

Light rays coming from a particular distant object all travel through nearly the same air layers and all are bent over about the same amount. Therefore, rays coming from the top of the object will arrive lower than those from the bottom. The image usually is upside down, enhancing the illusion that the sky image seen in the distance is really a water or oil puddle acting as a mirror.

 

Inferior images are not stable. Hot air rises, and cooler air (being more dense) descends, so the layers will mix, giving rise to turbulence. The image will be distorted accordingly. It may be vibrating; it may be vertically extended (towering) or horizontally extended (stooping). If there are several temperature layers, several mirages may mix, perhaps causing double images. In any case, mirages are usually not larger than about half a degree high (same apparent size as the sun and moon) and from objects only a few kilometers away.

Heat haze

Heat haze, also called heat shimmer, refers to the inferior mirage experienced when viewing objects through a layer of heated air; for example, viewing objects across hot asphalt or through the exhaust gases produced by jet engines. When appearing on roads due to the hot asphalt, it is often referred to as a highway mirage.

 

 

Convection causes the temperature of the air to vary, and the variation between the hot air at the surface of the road and the denser cool air above it creates a gradient in the refractive index of the air. This produces a blurred shimmering effect, which affects the ability to resolve objects, the effect being increased when the image is magnified through a telescope or telephoto lens.

Light from the sky at a shallow angle to the road is refracted by the index gradient, making it appear as if the sky is reflected by the road's surface. The mind interprets this as a pool of water on the road, since water also reflects the sky. The illusion fades as one gets closer.

 

On tarmac roads it may look as if water, or even oil, has been spilled. These kinds of inferior mirages are often called "desert mirages" or "highway mirages". Both sand and tarmac can become very hot when exposed to the sun, easily being more than 10°C hotter than the air one meter above, enough to create conditions suitable for the formation of the mirage.

 

Heat haze is not related to the atmospheric phenomenon of haze.

  

Superior mirage

A superior mirage occurs when the air below the line of sight is colder than the air above it. This unusual arrangement is called a temperature inversion, since warm air above cold air is the opposite of the normal temperature gradient of the atmosphere. Passing through the temperature inversion, the light rays are bent down, and so the image appears above the true object, hence the name superior. Superior mirages are in general less common than inferior mirages, but, when they do occur, they tend to be more stable, as cold air has no tendency to move up and warm air has no tendency to move down. 

Superior mirages are quite common in polar regions, especially over large sheets of ice that have a uniform low temperature. Superior mirages also occur at more moderate latitudes, although in those cases they are weaker and tend to be less smooth and stable. For example, a distant shoreline may appear to tower and look higher (and, thus, perhaps closer) than it really is. Because of the turbulence, there appear to be dancing spikes and towers. This type of mirage is also called the Fata Morgana or hafgerdingar in the Icelandic language

 

 

RAY DIAGRAM OF IMAGE FORMATION

 

 

 

 

   

Pariyanampatta kavu

 

അമ്മേ  നാരായണാ:  ദേവീ നാരായണാ:ലക്ഷ്‌മി  നാരായണാ: ഭദ്രേ നാരായണാ: 

 

History

Situated at Palakkad, Kerala, Pariyanampatta Bhagavathy temple is a famous and ancient temple dedicated to Sree Bhagavathy, known as the Goddess of 14 Desams. The history of the temple dates back to 1400 years.

Legend(ഐതീഹ്യം)







According to the legends, once a aged Brahmin of Pariyaanampetta Mana undertook a pilgrimage to Mookaambika temple with his servant, who was the head of Chalavara Parola Nair Tharwad near Cheruplassery. After a while the Brahmin got blessings of the Goddess so he decided to return home to spend the rest of his days in piety. However, on reaching the bank of a small stream at Pariyanampetta he felt tired and rested there for some time. While resting there, he untied his bundle of personal belongings. To his dismay he sawa Thidambu (replica of a deity) inside the stocks of his bundle. He realized the real meaning of the development through his wisdom and decided to to make pratishta (installation) of the thidambu there. He summoned peoples of 14 desoms in old Valluvanadu taluk and did the pratishta of the thidambu under the vedic rituals of the main thanthri of Ikkaattumanakkal under the control of desam pramanies (Chiefs) of Kollam, Nallur and Pottekkad Mootha Panickers.

Architecture

Pariyanampatta Devi temple complex is spread over one acre out of the total eight acres. It has got a sreekovil with a mukha mandapam, dhwajam, deepasthambam, sub-shrine, pattukottil, thidapalli, ootupura and agrasala along with other establishments. There are some exquisite wood carvings at the mukha mandapam (ashta dikpalakas with Sree Chakra at the centre) and the Sree Mukham (motif of Goddess Bhadrakali and heads of elephants on either side).

Darsan Info 
 


Darsan Info: Pariyanampatta Devi temple is open from 5 AM to 12 noon and from 5 PM to 8 PM. The Goddess is believed to possess powers of Goddess Saraswathi in the morning, Goddess Bhadrakali at noon and Goddess Vana-Durga at evening. Inside the garbha gruham, there are three darusilpas and one idol of Bhairavan.

Darsan Dresscode:

 Devotees are supposed to bathe and wear clean clothes before entering the Pariyanampatta Devi temple . Dress code for men is Dhoti or Mundu without shirts or baniyan and Salvar sets and other modern dresses are not allowed for women. Devotees are expected not to smoke or spit inside the Temple, not to use or carry pan masala and such other things inside the Temple, or not to enter the Temple or Temple premises after consuming liquor. Devotees should not throw away the prasadam and theertham received from the Temple and handle them with respect. Cameras, mobile phones, and any other type of electronic equipment are not permitted inside the Temple and photography is strictly prohibited in the Temple premises.

Pooja Timing(പൂജ സമയം )

 Pariyanampatta Devi temple is open from 5 AM to 12 noon and from 5 PM to 8 PM. Five poojas are done daily - Usha Pooja (6 AM), Ethirthu Pooja (8 AM), Pantheeradi Pooja (10 AM), Uchcha Pooja (11 AM) and Athazha Pooja (7:30 PM).

Temple Rituals

 Darika vadhom Pattu is special for the Pariyanampatta Devi temple . Devotees come to the temple on first Sunday, Tuesday and Friday of every Malayalam month

Special Rituals

Pallipana and Kalippana are special offerings at Pariyanampatta Devi temple .
 Regular Offerings

Chantattam, Raktha Pushapanjali, neypayasam, panapayasam, Trikala pooja and Udayasthamana Pooja

karthika-vilakku(കാർത്തിക വിളക്ക് )

Steps leading to temple decorated with lamps on Karthika vilakku

 Festivals:

Main festival of Temple is known as PariyanampettaPooram(പരിയാനംപറ്റ പൂരം ). Pooramaholsavam comes on 1 to 7 of malayalam month of Kumbham( February – March) and attracts a large number of devotees. Pooram starts on 1st Kumbha with the hoisting of the temple flag.The ornamentally decorated up elephants up to 9 numbers take part in all three processions namely Vadakkanpooram (Procession coming from North side), Kizhakkanpooram (Procession coming from East side)and Patinjaranpooram(Procession coming from West side).‘Moorthiyaatom’ on the eve of Pooram (Valiyaarattu) is the unique feature of this temple.Traditional, classical and folk art forms like Pootham, Thira, Karivela, Kaalavela (Kaala means Ox in malayalam), Kuthiravela (Kuthira means Horse in malayalam), Kathakali, Chakiyarkoothu etc.

During pooram days Nadaswara melam and tholpavakoothu are performed in the temple. One of the most expensive and eminent offering is” Dravyakalasam”. It is performed as part of the festival in order to rejuvenate the divinely power of the deity. Participation of devotees in contributing the valuables for “Dravyakalasam” bring their home all fame and prosperity.Vedikkettu will be there in the last day

Vela is before the malayalam star ‘Pooram’ in the month of Makara(January- February). Vishuvilakku(വിഷുവിളക്ക് ) is celebrated on 1st of Medom. Laksharchana is performed permanently in the month of Karkitaka(July- August). Karthika Vilakku(കാർത്തികവിളക്ക് ) is celebrated in the month of Vrichika (November- December)during the star Karthika, with various programmes.



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