On Continued Gravitational Contraction-Oppenheimer 1939

Medium Platform, 2023

Black holes were anticipated by Albert Einstein's general theory of relativity, which he first suggested in 1915. It was predicted that there are areas of space where gravity is so intense that nothing can escape, not even light. Many observational and theoretical studies over the last century have offered convincing evidence for black hole existence. This overview summarizes the current understanding of black hole formation and the evidence supporting this prediction of general relativity. The study of black holes continues to be an active area of research, with important implications for our understanding of the universe and the laws of physics. In this article, We claim that the general theory of relativity made a solid prediction with regard to Sir Roger Penrose's discovery of black holes. In this article, we've examined the first post-Einsteinian result in general relativity the singularity theorem where Penrose first proposed the crucial idea of a closed trapped surface.

arXiv (Cornell University), 2023

In 1939 Albert Einstein wrote a technical article that argued against the possibility that a star can be contracted to a single point: particles making up the star would end up rotating at velocities that were too high. In the same year, Robert Oppenheimer, together with his student Hartland Snyder, drew an apparently exactly opposite conclusion: that when a sufficiently heavy star runs out of nuclear fuel, it will collapse into an infinitely dense point, closed off from the rest of the universe. Both Oppenheimer and Einstein would soon be preoccupied by choices of an altogether different nature; and, again, set out on a different course. Black holes were born in 1939. In that year, J. Robert Oppenheimer and his student Hartland Snyder published their article On continued gravitational contraction. It began by observing that after a star burns through its nuclear fusion energies, the pressure of its radiation will no longer be able to counter the pull of its gravitational field. Oppenheimer and Snyder found that for a heavy star only one option remains: it can only contract. And that contraction will not halt until the star is reduced to a mere infinitesimal point. The theory of relativity, they argued, ensures that, eventually, the star "tends to close itself off from any communication with a distant observer; only its gravitational field persists." 1 Ideas that anticipated Oppenheimer and Snyder's insight were already circulating before 1939. The most important equation they used had been written down in 1916 by Karl Schwarzschild, a German astronomer who had been closely following the development of Albert Einstein's theory of relativity. Schwarzschild had determined how the gravitational field around a star should look in the new theory. To make his calculations easier, he had modeled the star as an infinitely small point. He hit upon a strange circumstance: at a small distance just outside this central mass, the gravitational field appeared to be infinitely large. Yet, for a mass that was comparable to the sun's, this distance was nearly zero. Furthermore, an infinity in the field could be expected as a mathematical artefact of such a naïve point source model, and Schwarzschild seemed not particularly concerned about it (Schwarzschild 1916a, 1916b). In any case, the small distance is now usually referred to as a star's 'Schwarzschild radius'. Many authors studied Schwarzschild's stellar model. 2 It offered the possibility to describe precisely the trajectories of planets and comets, or, for example, to determine how much the light emitted by a faraway object would be deflected when it grazes the surface of the sun. That calculation was instrumental for the British eclipse expeditions of 1919, which confirmed the

2006

… : The Astronomy and …, 2009

Contact Person: Bret Lehmer Department of Physics, Durham University, South Road, Durham DH1 3LE (UK) Email: [email protected] Telephone: +44 191 334–3773 ... The path of observational cosmology over the next decade will be focused on the exploration of the early Universe. ...

Are natural scientists gaining an ever more complete picture of reality through their objective insights, or are the truths of the natural sciences no more than consensuses that change with time? The astrophysicist Jürgen Ehlers and the social scientist Rudolf Stichweh talk to Spektrum.

In Red Hole Nebulae square gravitational patterns are seen. I show that it is possible to transform between square and circular gravitational patterns both ways. This is a major advance in Gravitational Theory. One of the main obstacles to be overcome is because I use Matter Energy Matter so everything needs proving in triplicate! That is I also show the compatibility with energy and matter fields! I will eventually drastically reduce this paper in size but you can skip to the end easily and the modification to Einstein's Equation does warrant a separate paper. Very speculatively I comment on requirements for a warp engine such as for the NASA Warp Engine although I confess not to examining the work behind it. So if I were truly professional I would not but as it I can be so forward.

Physics Today, 1971

EJ032448 - Introducing the Black Hole.

Advances in Mathematical Physics, 2015

In this year (2015), black holes (BHs) celebrate their 100th birthday, if their birth is taken to be triggered by a handwritten letter from Martin Schwarzschild to Albert Einstein, in connection with his newly found spherically symmetric vacuum solution.