Concept explainers
BIO Resolution of the Eye. The maximum resolution of the eye depends on the diameter of the opening of the pupil (a diffraction effect) and the size of the retinal cells. The size of the retinal cells (about 5.0 μm in diameter) limits the size of an object at the near point (25 cm) of the eye to a height of about 50 μm. (To get a reasonable estimate without having to go through complicated calculations, we shall ignore the effect of the fluid in the eye.) (a) Given that the diameter of the human pupil is about 2.0 mm, does the Rayleigh criterion allow us to resolve a 50-μm-tall object at 25 cm from the eye with light of wavelength 550 nm? (b) According to the Rayleigh criterion, what is the shortest object we could resolve at the 25-cm near point with light of wavelength 550 nm? (c) What angle would the object in part (b) subtend at the eye? Express your answer in minutes (60 min = 1°), and compare it with the experimental value of about 1 min. (d) Which effect is more important in limiting the resolution of our eyes: diffraction or the size of the retinal cells?
Want to see the full answer?
Check out a sample textbook solutionChapter 36 Solutions
University Physics (14th Edition)
Additional Science Textbook Solutions
The Cosmic Perspective (8th Edition)
The Cosmic Perspective
Conceptual Physics (12th Edition)
College Physics (10th Edition)
An Introduction to Thermal Physics
Physics for Scientists and Engineers with Modern Physics
- How far apart must two objects be on the moon to be distinguishable by eye if only the diffraction effects of the eye’s pupil limit the resolution? Assume 550 nm for the wavelength of light, the pupil diameter 5.0 mm, and 400,000 km for the distance to the moon.arrow_forwardIn a thermally stabilized lab, a Michelson interferometer is used to monitor the temperature to ensure it stays constant. The movable mirror is mounted on the end of a 1.00-m-long aluminum rod, held fixed at the other end. The light source is a He Ne laser, =632.8 nm . The resolution of this apparatus corresponds to the temperature difference when a change of just one fringe is observed. What is this temperature difference?arrow_forwardRadio telescopes are telescopes used for the detection of radio emission from space. Because radio waves have much longer wavelengths than visible light, the diameter of a radio telescope must be very large to provide good resolution. For example, the radio telescope in Penticton, BC in Canada, has a diameter of 26 m and can be operated at frequencies as high as 6.6 GHz. (a) What is the wavelength corresponding to this frequency? (b) What is the angular separation of two radio sources that can be resolved by this telescope? (c) Compare the telescope’s resolution with the angular size of the moon.arrow_forward
- The angular resolution of a radio telescope is to be 0.100 when the incident waves have a wavelength of 3.00 mm. What minimum diameter is required for the telescopes receiving dish?arrow_forwardThe diffraction limit, the smallest angle in degrees that can be resolved, is 250,000 arcsec × (wavelength/diameter of telescope). Humans have two eyes separated by about 7.8 cm and a marvelous computer between their ears. If this optical interferometer is just as good as one eyeball and as large as the separation of two regular eyeballs, what is the diffraction limit in arcsec of human vision for visible light at 525 nm?arrow_forwardPlease don't provide handwritten solution ....arrow_forward
- The diffraction limit, the smallest angle in degrees that can be resolved, is 250,000 arcsec × (wavelength/diameter of telescope). Humans have two eyes separated by about 8.1 cm and a marvelous computer between their ears. If this optical interferometer is just as good as one eyeball with a diameter as large as the separation of two regular eyeballs, what is the diffraction limit in arcsec of human vision for visible light at 612 nm?arrow_forwardThe maximum resolution of the eye depends on the diameter of the opening of the pupil (a diffraction effect) and the size of the retinal cells. The size of the retinal cells (about 5.0 mm in diameter) limits the size of an object at the near point (25 cm) of the eye to a height of about 50 µm. (To get a reasonable estimate without having to go through complicated calculations, we shall ignore the effect of the fluid in the eye.) (a) Given that the diameter of the human pupil is about 2.0 mm, does the Rayleigh criterion allow us to resolve a 50 -µm -tall object at 25 cm from the eye with light of wavelength 550 nm? (b) According to the Rayleigh criterion, what is the shortest object we could resolve at the 25 cm near point with light of wavelength 550 nm? (c) What angle would the object in part (b) subtend at the eye? Express your answer in minutes 160 min = 1°2, and compare it with the experimental value of about 1 min. (d) Which effect is more important in limiting the resolution of…arrow_forwardProblem 3. A 1mm filament produces a 1mm × 1mm electron beam incident on an anode disk with anode angle = 13°.The center of the focal spot is 1 m away from a detector which is centered at the center of the focal spot on the anode disk and is 50 cm wide. Determine the effective focal spot dimensions on the disk and the dimensions of the focal spot in the center of the detector, at the far anode edge of the detector, and at the far cathode edge of the detector (see figure below which is definitely not to scale). 1 m աալ 0 40 cmarrow_forward
- A telescope can be used to enlarge the diameter of a laser beam and limit diffraction spreading. The laser beam is sent through the telescope in opposite the normal direction and can then be projected onto a satellite or the Moon. If this is done with the Otto Struve telescope, producing a 2.10 m diameter beam of 613 nm light, what is the minimum angular spread of the beam? minimum angular spread: rad Neglecting atmospheric effects, what is the size of the spot this beam would make on the Moon, assuming a lunar distance of 3.84×108 m? size of spot on the Moon:arrow_forwardFind the radius of a star image formed on the retina of the eye if the aperture diameter (the pupil) at night is 0.78 cm and the length of the eye is 2.3 cm. Assume the wavelength of starlight in the eye is 500 nm. (1 nm -9 10 m) O a. 2.1E-3 m O b. 1.7E–9 m c. 3.6E–6 m d. 1.8E–6 m O e. 6.4E–7 marrow_forwardProblem 2. A) A Michelson interferometer uses light of wavelength 500 nm. The irradiance of the beam exiting the laser is IL. What are the possible differences in the lengths of the arms of the interferometer when the irradiance at the detector is IL/3? B) Young's Double slit experiment is performed with HeNe laser wavelength 632.8 nm. The screen is 2 m from the slits and the slit separation is 0.2 mm. Find the distance of the 3th bright fringe from the center of the interference pattern on the screen (call the central bright fringe the "Oth" fringe).arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningUniversity Physics Volume 3PhysicsISBN:9781938168185Author:William Moebs, Jeff SannyPublisher:OpenStaxPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning