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2. Fresnel lens - Wikipedia

   en.wikipedia.org/wiki/Fresnel_lens

   A Fresnel lens (/ ˈfreɪnɛl, - nəl / FRAY-nel, -⁠nəl; / ˈfrɛnɛl, - əl / FREN-el, -⁠əl; or / freɪˈnɛl / fray-NEL[ 1 ]) is a type of composite compact lens which reduces the amount of material required compared to a conventional lens by dividing the lens into a set of concentric annular sections.

3. Speed of light - Wikipedia

   en.wikipedia.org/wiki/Speed_of_Light

   A method of measuring the speed of light is to measure the time needed for light to travel to a mirror at a known distance and back. This is the working principle behind experiments by Hippolyte Fizeau and Léon Foucault. The setup as used by Fizeau consists of a beam of light directed at a mirror 8 kilometres (5 mi) away. On the way from the ...

4. Folding table - Wikipedia

   en.wikipedia.org/wiki/Folding_table

   Folding table of Rolls-Royce Phantom I Open Tourer Windovers (1926) A card table is a square table with legs that fold up individually, with one leg lining each edge. Card tables are traditionally used for playing card games, board games, and other tabletop games. Due to their low cost and small storage size, in the United States they are ...

5. Foucault's measurements of the speed of light - Wikipedia

   en.wikipedia.org/wiki/Foucault's_measurements_of...

   He used carefully calibrated tuning forks to monitor the rotation rate of the air-turbine-powered mirror R, and he would typically measure displacements of the slit image on the order of 115 mm. [7] His 1879 figure for the speed of light, 299944±51 km/s, was within about 0.05% of the modern value.

6. Reflecting telescope - Wikipedia

   en.wikipedia.org/wiki/Reflecting_telescope

   24-inch convertible Newtonian/Cassegrain reflecting telescope on display at the Franklin Institute. A reflecting telescope (also called a reflector) is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century by Isaac Newton as an ...

7. Faster-than-light - Wikipedia

   en.wikipedia.org/wiki/Faster-than-light

   On September 22, 2011, a preprint [73] from the OPERA Collaboration indicated detection of 17 and 28 GeV muon neutrinos, sent 730 kilometers (454 miles) from CERN near Geneva, Switzerland to the Gran Sasso National Laboratory in Italy, traveling faster than light by a relative amount of 2.48 × 10 −5 (approximately 1 in 40,000), a statistic ...