4to40.com

What is 4-D cinema?

What we see today are two-dimensional movies with multi-channel sound. In three-dimensional movies, viewers are required to wear special glasses which creates 3-D images of objects. ‘Chhota Chetan’ and ‘Shiva Ka Insaaf’ were such movies released two decades ago. Fourth dimension in a movie creates a different experience. Besides the 3-D effects, viewers can experience the movie through other senses …

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What imparts fragrance to flowers, fruits and spices?

The fragrance in flowers, fruits and spices is due to the evaporation of certain volatile chemicals into the air. Flowers produce a scent which is a complex mixture of low molecular weight, with volatile compounds such as esters, is emitted into the atmosphere. No two floral scents are exactly the same because of these compounds. Plants pollinated by bees and …

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What happened to the men of the Mary Celeste?

The mystery of the Mary Celeste has occupied men’s minds for a hundred years. She was a ship of 282 tons and she sailed from New York on 7 November 1872 bound for Genoa, with a cargo of alcohol. Her master was Benjamin Briggs, and with him sailed his wife, their two-year old daughter, and five seamen. On 5 December, …

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What gives sunrise and sunset an orange glow?

At sunrise and sunset, we see the sun through a greater thickness of air because it is low in the sky. Therefore, we are looking at it across the earth’s surface rather than directly up into the sky. At these times, the sky often turns orange-red because the photons of red and orange light are scattered through the atmosphere around …

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What dyes are used to ink tattoos?

A majority of dye pigments are derived from metals. Red dye comprises mercury sulphide, cinnabar and vermilion, yellow dye uses cadmium, while blue dye is made from cobalt salts. Other colours are made from chromium, manganese, ferric oxide or zinc oxide. Black dye is non-metallic and is made from carbon, black ink or logwood. Most of the metallic dyes are …

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