Trending: jituTechnology

Sunday, April 8, 2012

Nature and source of light

Light is a form of energy which on entering our eyes gives the sensation of sight, and enables us to see various objects. Since the early times, scientists have made discussion on the true nature of light and have postulated various theories. These are discussed below:
A.      Newton’s corpuscular theory: Newton, in 1678, put forward this theory that light consists of tiny particles, called corpuscles, which are shot out by luminous objects such as an electric lamp, candle, etc. the corpuscles are tiny mass less particles, shot out at a speed of about 3*10⁸ ms⁻¹ from the lighted object. According to newton, these particles travel in straight lines and bounce off or pass into an object on striking it. On entering the eyes, these corpuscles cause the sensation of vision and the various colors are due to different sizes of the corpuscles. The phenomenon of refraction was explained by starting that these corpuscles are attracted by the material of the denser medium. Thus, the speed of light is increased in the denser medium and this resulted in a change in the direction. This theory is based on the fact that the speed of light must be greater in the denser medium. However, it was found later that light travels slowly in a denser medium than in rarer medium. This theory could not explain interference, diffraction and polarization of light also. Therefore, the corpuscular theory was discarded as an incomplete and inaccurate theory.
B.      Huygens wave theory: christian Huygens, a Dutch physicist, in 1690 proposed a new theory about the nature of light. According to this theory, light propagates from the source in the form of a wave. For the propagation of wave a medium is necessary. So, it was assumed that all space including vacuum is filled with medium called ether, which had the property of both elasticity and inertia. From the source of light, periodic disturbances are produced, which travel in the form of waves and thus energy is equally distributed in all directions. Huygens assumed that light waves are longitudinal. But Fresnel, using the phenomenon of polarization, proved that light waves are transverse in nature. Using wave theory, Huygens could explain reflection and refraction. Young explained interference and Fresnel explained diffraction and polarization on the basis of the wave theory.
C.      Electromagnetic theory: Maxwell in 1905 proved theoretically that light gets propagated in the form of electromagnetic waves, consisting of electric and magnetic fields mutually perpendicular as well as transverse to the direction of propagation of light. The electromagnetic waves propagate in free space with the velocity of light. Hertz demonstrated experimentally that electromagnetic propagate waves with the velocity equal to that of light.

D.      Quantum theory: Einstein in 1905 proposed a new theory of light, called a quantum theory. In order to explain the photoelectric effect. According to this theory, light is transmitted as tiny packets of energy called photons and energy of each photon is given by, E=hf, where f is the frequency of light and h is the plank’s constant.

E.       Duel nature of light: From the discussion of the various theories of light, we conclude that light can exist in particle form as well as wave form. Using quantum theory,we can explain photoelectric effect.But this theory could not explain interference, diffraction and polarization. These phenomena can be explained using wave theory. but wave theory could not explain photoelectric effect. so we have to accept the dual form of light viz. particle form and wave form.

25 Responses to “Nature and source of light”

IE tushar said...
November 9, 2014 at 6:12 AM

effective as wella as interesting
jealousy quotes

neeraj mishra said...
January 24, 2015 at 3:46 AM

Packers along with Movers : Detract Relocation Strain

Click Here:
packers and movers pune
packers and movers in pune
movers and packers pune
movers and packers in pune

hari sh said...
May 9, 2015 at 3:47 AM

Thanks for Nice post. This article is having lot more info about relocation. packers and movers Bangalore marathahalli . packers and movers in bangalore movers and packers hyderabad

shariful said...
May 9, 2015 at 9:03 AM

This post is educational blog. facebook There discus subject of scientific. This article is having lot more info about relocation

Lita Alie said...
May 19, 2015 at 2:04 PM

realy nice post article this blog and good job thank admin

Jaket Kulit Tozca Leather
produsen jaket kulit
jaket kulit sukaregang
distributor jaket kulit
jaket kulit pria
jual jaket kulit asli

hanna alisha said...
October 13, 2015 at 9:13 AM

Good recommendation is typically bound to grow to get ignored,can see my blog tozca leather several a few other then that is no motive to never provides it.

Jaket Kulit Jakarta said...
October 13, 2015 at 10:25 AM

continue to provide information that is useful to all who visit this blog. a visit back in jaket kulit jakarta.... thank you

jaket kulit pria said...
October 13, 2015 at 11:10 AM

we can no longer deny each blog provide useful news and useful for all who visit. jaket kulit pria visit back LOL

jaket kulit murah said...
October 13, 2015 at 12:09 PM

many places to add useful knowledge, such as a visit to this website thank you admin..jaket kulit murah visit my website

jual jaket kulit said...
October 14, 2015 at 8:49 AM

add insight into a broad and obtain useful information thanks admin.jual jaket kulit visit back my website

distributor jaket Kulit said...
October 15, 2015 at 10:56 AM

many blogs that are useful as this blog because it provides an interesting news visit back distributor jaket kulit .... thank you admin

jaket kulit pria said...
October 15, 2015 at 11:59 AM

The first thing to visit this blog is a useful article and lots of information visit back jaket kulit pria .... thank you admin

Plumbers in Thiruvanmiyur said...
December 17, 2015 at 10:02 PM

Very interesting,good job and thanks for sharing such a good blog.your article is so convincing that I never stop myself to say something about it.You’re doing a great job.Keep it up

Nijam Nayon said...
January 6, 2016 at 10:05 PM

i find very helpful information from this site. there are enough information about this. i see everything of this site especially article, topic, are amusing and mind blowing. I designed a site as like as u. heritage park.
heritage park
heritage park
weight loss
weight loss

Raju Khan said...
January 12, 2016 at 11:46 PM

Thank you for your amazing post.This post is very helpful for everybody buy facebook likes............................

phương anh nguyễn said...
May 26, 2016 at 9:36 PM

Your article is very useful for me now I'm working on canvas printing service ads (in phông bạt quảng cáo) that you can contact and support me but

phương anh nguyễn said...
June 2, 2016 at 1:45 AM

Thank you for sharing a great article I will share this with my friends. Those of my friends are doing the interior design (thiết kế nội thất), and also employees of accessories cupboard (phụ kiện tủ bếp) I currently want to buy a sofa corner (sofa góc) but I do not know how to have a room couch guest (sofa phòng khách) suitable for your apartment, especially the leather sofa material (sofa da) or the sofa kind of felt (sofa nỉ), my friends are experts at fitting (thi công nội thất), and my apartment is about was finished I wanted to own a luxury sofa (sofa cao cấp) if you know who provide sofa please introduce me.

phương anh nguyễn said...
June 2, 2016 at 1:46 AM

Thank you for this article is useful to me, I read a great article on this forum I want to share to everyone to be able to read or access your url to read offline.

Jaket Kulit Garut said...
June 7, 2016 at 6:15 AM

be a reflection and a lot of knowledge to visit this blog and interesting to read thanks admin, my site can visit jaket kulit garut much koleksi leather jacket.

Detect Hidden Cameras said...
July 5, 2016 at 8:40 AM

Very interesting,good job and thanks for sharing such a good blog.your article is so convincing that I never stop myself to say something about it.You’re doing a great job.Keep it up.

Tuấn Lê Quang said...
July 10, 2016 at 6:50 PM

Thank you for sharing of information for me. If you wish to care about sound field, I would like to share information so that you learn. Currently our company is providing and distribution of audio devices such as speakers hall (Loa hội trường), hall sound (âm thanh hội trường), hall sound system (dàn âm thanh hội trường), audio conferencing (âm thanh hội nghị), audio conferencing (âm thanh hội thảo), sound stage (âm thanh sân khấu), sound weddings (âm thanh đám cưới), wedding speakers (loa đám cưới), speaker karaoke (loa karaoke), karaoke microphones (micro karaoke), wireless microphones( micro không dây)

Máy khắc An Khánh said...
December 13, 2016 at 1:18 AM

Thank you for sharing of information for me. If you are interested in the field of laser engraving machine, I would like to share with you some information for your reference as follows: laser cutting engraving machine ( Máy khắc cắt laser ), laser engraving machines ( Máy khắc bằng tia laser ), laser seal engraving machine ( Máy khắc dấu laser ) , industrial laser marking machine ( Máy khắc laser công nghiệp ), laser cutting machine decal ( Máy cắt laser decal ), laser cutting machine on canvas ( Máy cắt laser trên vải ), laser 1390 ( Máy khắc laser 1390 ), laser 9060 ( Máy khắc laser 9060 ), laser 3020 ( Máy khắc laser 3020 ), laser 1325 ( Máy khắc laser 1325 ).

Blogger said...
January 15, 2017 at 6:00 AM

Did you know you can shorten your long links with AdFly and receive dollars for every visitor to your shortened links.

Blogger said...
January 18, 2017 at 6:30 PM

By going to CarRental8 you can get the cheapest rental cars at over 50,000 locations globally.

phương anh nguyễn said...
February 10, 2017 at 8:34 PM

phụ kiện tủ bếp, phụ kiện tủ bếp inox, phụ kiện tủ bếp giá rẻ, báo giá van công nghiệp, báo giá van giảm áp, van công nghiệp, van bướm khí, van bướm điện

Post a Comment

All Rights Reserved Pooza Creations | Designed by Jitendra
Sponsored by MinuteLancer