<article_title>Black_hole</article_title>
<edit_user>TimothyRias</edit_user>
<edit_time>Monday, February 21, 2011 3:26:10 PM CET</edit_time>
<edit_comment>/* Golden age */ some [[WP:NAMES]] MoS stuff</edit_comment>
<edit_text>In this period more general black hole solutions were found. In 1963, Roy Kerr found the exact solution for a rotating black hole. Two years later [[Ezra T.<strong> Newman|Ezra</strong> Newman]] found the axisymmetric solution for a black hole which is both rotating and electrically charged.&lt;ref&gt;{{cite journal |last1=Newman|first1=E.T.</edit_text>
<turn_user>TimothyRias<turn_user>
<turn_time>Monday, February 21, 2011 2:46:49 PM CET</turn_time>
<turn_topicname>Improving the lead</turn_topicname>
<turn_topictext>Per WP:LEAD the lead section should summarize the main points of the article, reflecting the emphasis on those points given in the main text. As it currently is, the lead has the following issues with this: The history section is not covered in any way.
Nothing is said about the formation and evolution of black holes.
The lead currently spends two paragraphs on observations. In particular the evidence for the supermassive black hole at Sag A* is discussed in too much detail and thereby overemphasized.
No mention is made of general relativity.
Remedying these points may also help alleviate the concerns of user:seneika raised above. I think the best way forward is to merge the current second and third paragraph about observational evidence and cut down on the detail. We then have space to add a paragraph on the history and a paragraph on the formation. Does this sound like a plan? TR 09:58, 2 February 2011 (UTC)
Suggestion for the first paragraph
I suggest changing the first paragraph to (something like): A black hole is a region of space from which nothing, not even light, can escape. The theory of general relativity predicts that a very compact mass will deform the spacetime around it to form such a region. Around a black hole there is an undetectable surface called an event horizon that marks the point of no return. It is called "black" because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics. Quantum mechanics predicts that black holes also emit radiation like a black body with a finite temperature. This temperature is inversely proportional to the mass of the black hole, making it difficult to observe this radiation for black holes of stellar mass. The main change is to the second sentence, which now explicitly states that black holes are a prediction of general relativity.TR 11:02, 4 February 2011 (UTC)
suggestion for merger of second and third paragraph
I would like to suggest to following as a merger of the current second and third paragraph: Despite its invisible interior, the presence of a black hole can be inferred through its interaction with other matter. Astronomers have identified numerous stellar black hole candidates in binary systems, by studying its interaction with its companion star. Moreover, there is growing consensus that supermassive black holes exist in the centers of most galaxies. In particular, there is strong evidence of a black hole of more than 4&amp;million solar masses at the center of our Milky Way. Maybe accretion discs should be mentioned more clearly?TR 11:02, 4 February 2011 (UTC)
Suggestion for a paragraph about history
This is a very rough draft for a paragraph summarizing the main points of the history section: Objects whose gravity field is too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. The first modern prediction of a black hole in general relativity was found by Karl Schwarzschild in 1916, although its black hole nature was not fully realized for another 4 decades. For a long time black holes were considered a theoretical curiosity. This changed in the 1960s when theoretical work showed that black holes were a generic prediction of general relativity, and the discovery of neutron stars sparked interest gravitationally collapsed compact objects as a possible astrophysical reality. Should it alos mention the work on gravitational collapse by Chandrashekar and TOV in 1930s?TR 11:02, 4 February 2011 (UTC)
suggestion for a paragraph about formation
The following is a suggestion about a blurb about the formation and evolution of BHs. Black holes of stellar mass are expected to form when heavy stars collapse in a supernova at the end of their life cycle. After a black hole has formed it can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, supermassive black holes of millions of solar masses may be formed. This is very rough. I'm not even sure if having a separate paragraph is necessary. I do however feel it is necessary to make the connection supernova-&gt;black hole, since that is something a wide audience may have heard about.TR 11:02, 4 February 2011 (UTC)</turn_topictext>
<turn_text>Objects whose gravity field is too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. The first modern prediction of a black hole in general relativity was found by Karl Schwarzschild in 1916, although its black hole nature was not fully realized for another 4 decades. For a long time black holes were considered a theoretical curiosity. This changed in the 1960s when theoretical work showed that black holes were a generic prediction of general relativity, and the discovery of neutron stars sparked interest gravitationally collapsed compact objects as a possible astrophysical reality.</turn_text>