A lens space is an example of a topological space, considered in mathematics. The term often refers to a specific class of 3-manifolds, but in general can be defined for higher dimensions. In the 3-manifold case, a lens space can be visualized as the result of gluing two solid tori together by a homeomorphism of their boundaries. Often the 3-sphere and , both of which can be obtained as above, are not counted as they are considered trivial special cases. The three-dimensional lens spaces were introduced by Heinrich Tietze in 1908. They were the first known examples of 3-manifolds which were not determined by their homology and fundamental group alone, and the simplest examples of closed manifolds whose homeomorphism type is not determined by their homotopy type. J. W. Alexander in 1919 showed that the lens spaces and were not homeomorphic even though they have isomorphic fundamental groups and the same homology, though they do not have the same homotopy type. Other lens spaces (such as and ) have even the same homotopy type (and thus isomorphic fundamental groups and homology), but not the same homeomorphism type; they can thus be seen as the birth of geometric topology of manifolds as distinct from algebraic topology. There is a complete classification of three-dimensional lens spaces, by fundamental group and Reidemeister torsion. (Wikipedia).
The focal length is the distance between your camera’s sensor and the optical center of the camera lens. If you have a longer focal length, the overall perspective will be reduced, the subject will be closer, and areas won’t be as clear. The opposite is true for a shorter focal length. It
From playlist Digital Photography
What exactly is space? Brian Greene explains what the "stuff" around us is. Subscribe to our YouTube Channel for all the latest from World Science U. Visit our Website: http://www.worldscienceu.com/ Like us on Facebook: https://www.facebook.com/worldscienceu Follow us on Twitter: https:
From playlist Science Unplugged: Physics
One of the most amazing photographic collections ever, from the Mars Reconnaissance Orbiter, HiRISE camera. NASA/JPL/University of Arizona.
From playlist The Solar System
NASA's newest X-ray telescope will have a lengthy structure that unfolds in space, allowing it to see high-energy objects like feeding black holes.
From playlist NuSTAR
Physics 55.1 Optics: Exploring Images with Thin Lenses and Mirrors (2 of 20) The Len's Equation
Visit http://ilectureonline.com for more math and science lectures! In this video I will find the image distance, real or virtual image, magnification, and inverted or upright of an object view through a converging lens. Next video in series can be seen at: https://youtu.be/FIyc_oeYf9Y
From playlist PHYSICS 55.1 LENSES AND MIRRORS UNDERSTOOD
EARTH FROM SPACE: Like You've Never Seen Before
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From playlist Space Videos
Revel in some of the highest resolution images from the Hubble Space Telescope. Experience anew the detail in these inspiring images, snatched from distant galaxies, exploding stars, brilliant gas clouds, and black holes.
From playlist SpaceRip 4K
Physics 55.1 Optics: Exploring Images with Thin Lenses and Mirrors (19 of 20) Convex Mirror Summary
Visit http://ilectureonline.com for more math and science lectures! In this video I will review the image distance when objects are place at varies distances from a convex mirror of f=-20cm. Next video in series can be seen at: https://youtu.be/vA__Mthmax4
From playlist PHYSICS 55.1 LENSES AND MIRRORS UNDERSTOOD
Physics 55.1 Optics: Exploring Images with Thin Lenses and Mirrors (11 of 20) Diverging Lens: s--0
Visit http://ilectureonline.com for more math and science lectures! In this video I will find the image distances, real or virtual image, magnification, and inverted or upright of an object placed at s=40cm and 10cm from a diverging lens of f=-20cm. Next video in series can be seen at: h
From playlist PHYSICS 55.1 LENSES AND MIRRORS UNDERSTOOD
Simon Brain: The Gysin Sequence for Quantum Lens Spaces
This is a joint with Francesca Arici and Giovanni Landi. We construct an analogue of the Gysin sequence for circle bundles, now for q-deformed lens spaces in the sense of Vaksman-Soibelman. Our proof that the sequence is exact relies heavily on the non commutative APS index theory of Care
From playlist HIM Lectures: Trimester Program "Non-commutative Geometry and its Applications"
Design of a Cooke Triplet | MIT 2.71 Optics, Spring 2009
Design of a Cooke Triplet Instructor: Wonjoon Choi, Ryan Cooper, Qunya Ong, Matthew Smith View the complete course: http://ocw.mit.edu/2-71S09 License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu
From playlist MIT 2.71 Optics, Spring 2009
Lens Aperture Function Explained
https://www.patreon.com/edmundsj If you want to see more of these videos, or would like to say thanks for this one, the best way you can do that is by becoming a patron - see the link above :). And a huge thank you to all my existing patrons - you make these videos possible. In this video
From playlist Fourier Optics
Marc Levoy - Lectures on Digital Photography - Lecture 3 (28mar16).mp4
This is one of 18 videos representing lectures on digital photography, from a version of my Stanford course CS 178 that was recorded at Google in Spring 2016. A web site that includes all 18 videos, my slides, and the course schedule, applets, and assignments is http://sites.google.com/sit
From playlist Stanford: Digital Photography with Marc Levoy | CosmoLearning Computer Science
Stanford Seminar - Topological Data Analysis: How Ayasdi used TDA to Solve Complex Problems
"Topological Data Analysis: How Ayasdi used TDA to Solve Complex Problems" -Anthony Bak, Ayasdi Colloquium on Computer Systems Seminar Series (EE380) presents the current research in design, implementation, analysis, and use of computer systems. Topics range from integrated circuits to o
From playlist Engineering
Light and Beyond (Lecture 3) by Rajaram Nityananda
SUMMER COURSES : LIGHT AND BEYOND SPEAKER : Rajaram Nityananda (Azim Premji University) DATE : 31 May 2020 to 28 June 2020 VENUE : Online Lectures and Tutorials This short and intensive advanced undergraduate level course starts with the understanding of light as an electromagnetic wave
From playlist Summer Course 2020: Light And Beyond
Wigner Distribution Function and Integral Imaging | MIT 2.71 Optics, Spring 2009
Wigner Distribution Function and Integral Imaging Instructor: Michael McCanna, Michelle Lydia Kam Ye-Sien, Lei Tian, SHalin Mehta View the complete course: http://ocw.mit.edu/2-71S09 License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at
From playlist MIT 2.71 Optics, Spring 2009
Lecture 5: Lightfields, part 1 - Part 1
MIT MAS.531 Computational Camera and Photography, Fall 2009 Instructor: Ramesh Raskar View the complete course: https://ocw.mit.edu/courses/mas-531-computational-camera-and-photography-fall-2009/ YouTube Playlist: https://www.youtube.com/playlist?list=PLUl4u3cNGP61pwA6paIRZ30q1sjLE8b6c L
From playlist MIT MAS.531 Computational Camera and Photography, Fall 2009
Fluidic Space Telescopes with Dr. Edward Balaban
Edward Balaban is a research scientist at NASA Ames and the principal investigator of the Fluidic Telescope Experiment, or FLUTE. The idea is to create a giant lens in space out of a fluid that could maintain its shape in microgravity. The technology was recently tested during the Axiom-1
From playlist Interviews
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From playlist Physics