DESKTOP 3173 - FIBRES

A photomicrograph (photograph taken through a microscope) of the cellulose fibres making up a sheet of lens cleaning paper, magnified about 100 times. The image has been pseudocolourised with LUT (look up table) corresponding to intensity of light transmission.

This post is part of the My Sunday Best meme

DESKTOP 1966 - XANTHOPHYLL

Xanthophylls (originally phylloxanthins) are yellow pigments that occur widely in nature and form one of two major divisions of the carotenoid group; the other division is formed by the carotenes. The name is from Greek xanthos (ξανθός, "yellow") and phyllon (φύλλον, "leaf"), due to their formation of the yellow band seen in early chromatography of leaf pigments.

The molecular structure of xanthophylls is similar to that of carotenes, but xanthophylls contain oxygen atoms, while carotenes are purely hydrocarbons with no oxygen. Xanthophylls contain their oxygen either as hydroxyl groups and/or as pairs of hydrogen atoms that are substituted by oxygen atoms acting as a bridge (epoxide). For this reason, they are more polar than the purely hydrocarbon carotenes, and it is this difference that allows their separations from carotenes in many types of chromatography. Typically, carotenes are more orange in colour than xanthophylls.

This post is part of the Wordless Wednesday meme,

and also part of the ABC Wednesday meme,
and also part of the Nature Notes meme.

DESKTOP 1826 - JANTAR MANTAR, INDIA

The Jantar Mantar is a collection of architectural astronomical instruments, built by Sawai Jai Singh who was a Rajput king. The title of (King) and Sawai was bestowed on him by Emperor Mohammad Shah. Jai Singh II of Amber built his new capital of Jaipur between 1727 and 1734. It is also located in Ujjain and Mathura. It is modelled after the one that he had built at the Mughal capital of Delhi.

He had constructed a total of five such facilities at different locations, including the ones at Delhi and Jaipur. The Jaipur observatory is the largest and best preserved of these. It has been inscribed on the World Heritage List as "an expression of the astronomical skills and cosmological concepts of the court of a scholarly prince at the end of the Mughal period".

Early restoration work was undertaken under the supervision of Major Arthur Garrett, a keen amateur astronomer, during his appointment as Assistant State Engineer for the Jaipur District. The Jantar Mantar was made by Sawai Jai Singh as he was particularly interested in learning about the sky above his head.

The name is derived from jantar ("instrument"), and mantar ("formula", or in this context "calculation"). Therefore jantar mantar means literally 'calculation instrument'. This observatory has religious significance, since ancient Indian astronomers were also Jyotisa (Indian astronomy and astrology) masters.

This post is part of the Our World Tuesday meme,

and also part of the Ruby Tuesday meme,

and also part of the Travel Tuesday meme,

and also part of the Wordless Wednesday meme.