1 / 13

Refraction and its uses

Aldric Bek 3I301 Physics ACE 2010. Refraction and its uses. Introduction. [pic 1].

kory
Télécharger la présentation

Refraction and its uses

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Aldric Bek 3I301 Physics ACE 2010 Refraction and its uses

  2. Introduction [pic 1] • Refraction occurs because light travels in different speeds in different media. In [pic 1], the bottom part of the light ray reaches the medium of higher optical density first, thus it slows down first, while the top part of the light is still moving at the speed of light in air, thus bending of the light occurs.

  3. Application of Refraction – Lenses Most of the inventions made with the application of refraction involves lenses. Thus we will look at how lenses work before looking at the inventions made using refraction.

  4. Lens • Light in lenses follow the normal rules of refraction. It is the arrangement of the surface of the glass that gives it the converging and diverging properties. [pic 2] [pic 3]

  5. Inventions applying the concept of refraction and lenses The spectacles The binoculars The refracting telescope The projector Beam splitter (Image splitter)

  6. The spectacles [pic 5] HYPEROPIA • Importance: to correct imperfect eyesight (which most of us have). • The spectacles work by cancelling out the too strong/weak focus of the cornea in the eye. • For myopia (nearsightedness): • The light is focused too much, thus the lens diverge the light rays away from the centre of the eye to balance the offset of the eye’s lens. • For hyperopia (farsightedness): • The opposite of myopia stands. [pic 4] MYOPIA

  7. Binoculars • Important tool in warfare and observing wildlife. • The binoculars helps us see far objects by focusing the image onto our eyes with the help of lens. [pic 6]

  8. Binoculars • The objective lens is usually a biconvex lens. • This will cause the image to be inverted when viewing at the far objects. • The two prisms solve the above problem, by inverting the image again. • The eye piece is usually made up of more than one lens, often includes a biconvex and a negative meniscus lens.

  9. Refracting telescope [pic 7] A simple refracting telescope • Used in studying astronomy. • Using lens to focus very far objects onto a smaller area for us to see the image of the object. • The light from the object is focused by the objective lens, which will converge near the focal length of the eyepiece, which will invert the image again for the eyes to see it upright. [pic 8] How does a refracting telescope works

  10. Projector • Used in schools/lectures for presentations and in cinemas for movies. • The image is inverted before it is projected, as when the image is magnified, it would be inverted from the projected image. • The projector allows the little light used in the image projector to become a large image for everyone to see, saving energy in a way. [pic 9]

  11. Beam splitter [pic 10] • Used in stereoscopy, or in producing 3D images (by having two images to create impression of depth). • Traditionally made up of two prisms with a layer separating the prisms, the thickness depends on what wavelength of light is supposed to exit straight through horizontally. • This is made possible by frustrated total internal reflection (occurs when a very thin layer (less than the wavelength of the light) of low R.I. material is between two materials, allowing the light to pass through the material).

  12. References • [pic 1] http://www.school-for-champions.com/Science/images/waveobstacle-refraction.gif (2010 , March 2) • Refraction of Light. Retrieved (2010, March 2) from http://hyperphysics.phy-astr.gsu.edu/Hbase/geoopt/refr.html • Refraction. Wikipedia. Retrieved (2010, March 2) from http://en.wikipedia.org/wiki/Refraction • Lens (optics). Wikipedia. Retrieved (2010, March 2) from http://en.wikipedia.org/wiki/Lens_(optics) • [pic 2] http://upload.wikimedia.org/wikipedia/commons/thumb/e/ef/Lens1.svg/522px-Lens1.svg.png (2010 , March 2) • [pic 3] http://upload.wikimedia.org/wikipedia/commons/thumb/a/ab/Lens1b.svg/522px-Lens1b.svg.png (2010 , March 2) • How Do Glasses Work. eHow. Retrieved (2010, March 2) from http://www.ehow.com/how-does_4564464_glasses-work.html • [pic 4] http://upload.wikimedia.org/wikipedia/commons/thumb/3/30/Myopia.svg/500px-Myopia.svg.png (2010 , March 2) • [pic 5] http://upload.wikimedia.org/wikipedia/commons/thumb/f/f3/Hypermetropia.svg/500px-Hypermetropia.svg.png (2010 , March 2) • Stereoscopy. Wikipedia. Retrieved (2010, March 3) from http://en.wikipedia.org/wiki/Stereo_photography • Total Internal Reflection. Wikipedia. Retrieved (2010, March 3) from http://en.wikipedia.org/wiki/Total_internal_reflection • Interferometry. Wikipedia. Retrieved (2010, March 3) from http://en.wikipedia.org/wiki/Interferometry • Beam splitter. Wikipedia. Retrieved (2010, March 3) from http://en.wikipedia.org/wiki/Beam_splitter • Cragar. (2009, May 26). Re: what inventions (or other wise) use light refraction? [Online Forum Comment]. Retrieved from http://www.physicsforums.com/showthread.php?t=316262 • Binoculars – How Binoculars Work?. AZOOptics. Retrieved (2010, March 3) from http://www.azooptics.com/Details.asp?ArticleID=142 • [pic 7] http://www.daviddarling.info/images/refracting_telescope.gif (2010 , March 3) • [pic 8] http://library.thinkquest.org/J0112188/refracting_telescope.gif (2010, March 4) • Refracting and reflecting telescope. Thinkquest. Retrieved (2010, March 4) from http://library.thinkquest.org/J0112188/refracting_and_reflecting_telescopes.htm • [pic 10] http://upload.wikimedia.org/wikipedia/commons/thumb/8/8f/Beam_splitter.svg/155px-Beam_splitter.svg.png (2010, March 4)

  13. Thank you. “If light travelled at the same speed in all media, everyone would be blind”.

More Related