Black holes

Select Language Afrikaans Albanian Arabic Armenian Azerbaijani Basque Belarusian Bulgarian Bengali Catalan Chinese (Simplified) Chinese (Traditional) Croatian Czech Danish Dutch English Estonian Filipino Finnish French Galician Georgian German Greek Gujarati Haitian Creole Hebrew Hindi Hungarian Icelandic Indonesian Irish Italian Japanese Javanese Kannada Khmer Korean Latvian Lithuanian Macedonian Malay Maltese Marathi Nepali Norwegian Persian Polish Portuguese Punjabi Romanian Russian Serbian Slovak Slovenian Spanish Swahili Swedish Tamil Telugu Thai Turkish Ukrainian Urdu Vietnamese Welsh Yiddish

This is a collection of articles archived for the excellence of their content. You can help by converting these articles into an encyclopaedia-style entry, deleting portions of the kind normally not used in encyclopaedia entries. Please also fill in missing details; put categories, headings and sub-headings; and combine this with other articles on exactly the same subject. Readers will be able to edit existing articles and post new articles directly on their online archival encyclopædia only after its formal launch. See examples and a tutorial.

Two Indian Institute of Science scientists crack mystery of black holes

Rajiv Kalkod, TNN Sep 21, 2013

The Times of India

BANGALORE: A scientist from Indian Institute of Science (IISc) Bangalore, and his student have successfully applied Albert Einstein's gravity theory to unlock the mysteries of black holes.

Banibrata Mukhopadhyay, associate professor, department of physics, IISc, and his student Indrani Banerjee worked for over two years for their landmark discovery. Their study on black holes has been acknowledged by the scientific community across the globe, including professors from Harvard University. The duo has published its findings in the international journal Physical Review Letters.

WHAT ARE BLACK HOLES?

Black holes are formed when stars exhaust their 'nuclear fuel' or are 'dead'. They are abyssinian spaces that exert strong gravitational force on everything in their vicinity. The hole is called 'black' because it absorbs all the light that hits the horizon, reflecting nothing. The largest black holes are called 'supermassive'. These black holes have masses that are more than 1 million suns together.

Black holes, as stars are known postdeath, are not visible to the plain eye. Though not visible, black holes devour everything in their neighbourhood given the gravitational pulls they exercise. It was hitherto believed that mass and spin are the determining properties of black holes and they would go a long way in determining the influence of black holes on their neighbourhood as well as their pre-death star existence.

Their new study, says Banibrata, who worked in Harvard for three years before joining IISc in 2007, throws more light on black holes and their properties, particularly the correlation between mass and spin or rotation. They have proved that mass and spin are not independent of each other but actually interdependent. They have established that mass of the star could be used to calculate the spin.

"The spin of the observed black holes is still a debatable issue — the exact value of the spin is not known. On the other hand mass can be determined more easily. Rotation of the black hole is determined by the mass and rotation of the initial star. The larger the mass of the initial star the greater it tends to have a high rotational speed and turn into swiftly spinning black holes. The smaller the mass of the initial star the slower its rotation and spin. This property shows that spin and mass are correlated. Hence if mass is known, the spin can be predicted. Eventually, only one fundamental parameter characterizes the black hole," Banibrata explained.

Indrani, a PhD student of physics, said, "First we were working on how stars collapse and end up into black holes. During the research, the thought of discovering the properties emerged," she said.