1 / 38

You are living in the Golden Age of Cell Biology

You are living in the Golden Age of Cell Biology. Advances in Optics and Photonics. Wave-like Properties of Light. refraction. diffraction. Optics. Emission Theory of Vision Light is emitted from the eye and travels to the object, thereby illuminating it. Empedocles 490 - 430 CE. Euclid

mave
Download Presentation

You are living in the Golden Age of Cell Biology

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. You are living in the Golden Age of Cell Biology

  2. Advances in Optics and Photonics

  3. Wave-like Properties of Light refraction diffraction

  4. Optics

  5. Emission Theory of Vision Light is emitted from the eye and travels to the object, thereby illuminating it. Empedocles 490 - 430 CE

  6. Euclid 330 - 260 BCE Ptolemy 83 - 161 CE Emission (extramission) Theory of Vision Light is emitted from the eye and travels to the object, thereby illuminating it.

  7. Am Psychol. 2002 Jun-Jul;57(6-7):417-24. Fundamentally misunderstanding visual perception. Adults' belief in visual emissions. Winer GA, Cottrell JE, Gregg V, Fournier JS, Bica LA. Department of Psychology, Ohio State University, 142 Townshend Hall, Columbus, OH 43210-1222, USA. The authors reviewed research about a profound misconception that is present among college students, namely, the belief that the process of vision includes emanations from the eyes, an idea that is consistent with the extramission theory of perception, which was originally professed by early Greek philosophers and which persisted in scholarly circles for centuries. The authors document the strength and breadth of this phenomenon and the object failure of traditional educational techniques to overcome this belief, and they reveal that students are leaving psychology courses with a flawed understanding of one of the most studied processes in the history of psychology--visual perception. Some suggestions are offered for overcoming this misconception in traditional college classroom settings.

  8. Hero’s Principle Light rays traveling through homogeneous media in straight lines Hero(n) of Alexandria (10 - 70 CE) “Mechanics & Optics” (~55 CE) “Principle of Reflection”

  9. The “Father of Optics” “Book of Optics” (1021) Intromission Theory of Vision Light transmits “physical forms” to the eye Ibn al-Haytham (965 - 1039) Born in Basra

  10. Glass Production ~ 3000 BCE First evidence of glass production ~ 700 BCE First lenses appear (crystal) ~ 250 BCE Glass blowpipe appears ~ 1000 CE Commercial glass production ~ 1050 “Reading Stones” ~ 1250 Glass lenses manufactured

  11. Ray Optics Issac Newton (1643 - 1727) Pierre de Fermat (1601 - 1665)

  12. Fermat’s Principle In an inhomogeneous medium, light always travels the path of least time. Pierre de Fermat (1601 - 1665)

  13. Electromagnetic Flux Pond Ripples

  14. Newtonian View of Light Propagation

  15. Wave Nature of Light Under some conditions, light behaves as an electromagnetic wave (Maxwell, 1855). In this model, electric and magnetic fields oscillate perpendicular to one another and to the direction of propagation of the light wave.

  16. Some Properties of Light refraction diffraction

  17. n1 < n2 external refraction n1 > n2 internal refraction rays bend toward the “normal” rays bend away from the “normal”

  18. Refraction occurs at the interface between media of different densities due to variations in the speed of light in these media air glass water air speed of light in medium speed of light in air Refractive index (n) =

  19. Refraction at a boundary between two media of different refractive indices, where n2 > n1 monochromatic wavefront

  20. c n1 d1 = v1Dt = Dt d1 sin I1 c n2 d2 d2 = v2Dt = Dt sin I2 AB = = BC = c Dt c Dt = n1 sin I1 n2 sin I2 n1 sin I1 = n2 sin I2 “Snell’s Law”

  21. Refractive dispersion of “white’ light n varies with wavelength n(blue) > n(red)

  22. n2 sin qc = n1 Total Internal Reflection Optical Fiber Reflecting Prism

  23. Total Internal Reflection in an Optical Fiber n1 > n2

  24. Beam Splitters partially reflective mirror thin glass plate beam combiner

  25. Compression of a wave front in a medium of high refractive index

  26. Refraction of a planar wave front by a thin lens (bi) convex lens

  27. Refraction of a planar wave front by a thin lens image (real) Convergence happens at positive lens elements

  28. Divergence happens at negative lens elements image (virtual) (bi) concave lens

  29. Real and Virtual Images A “real image” is formed on the retina by light that actually passes through the image point. e.g., an image observed through a window A “virtual” image is formed by light that behaves as though it diverges from a image point through which it does not actually pass. e.g., a mirror image

  30. Reflection of light at a mirrored surface angle of reflection = angle of incidence virtual image object

  31. A mirror projects a virtual image

More Related