What is Singularity: Definition and 429 Discussions

A gravitational singularity, spacetime singularity or simply singularity is a location in spacetime where the density and gravitational field of a celestial body is predicted to become infinite by general relativity in a way that does not depend on the coordinate system. The quantities used to measure gravitational field strength are the scalar invariant curvatures of spacetime, which includes a measure of the density of matter. Since such quantities become infinite at the singularity point, the laws of normal spacetime break down.Gravitational singularities are mainly considered in the context of general relativity, where density apparently becomes infinite at the center of a black hole, and within astrophysics and cosmology as the earliest state of the universe during the Big Bang/White Hole. Physicists are undecided whether the prediction of singularities means that they actually exist (or existed at the start of the Big Bang), or that current knowledge is insufficient to describe what happens at such extreme densities.General relativity predicts that any object collapsing beyond a certain point (for stars this is the Schwarzschild radius) would form a black hole, inside which a singularity (covered by an event horizon) would be formed. The Penrose–Hawking singularity theorems define a singularity to have geodesics that cannot be extended in a smooth manner. The termination of such a geodesic is considered to be the singularity.
The initial state of the universe, at the beginning of the Big Bang, is also predicted by modern theories to have been a singularity. In this case, the universe did not collapse into a black hole, because currently-known calculations and density limits for gravitational collapse are usually based upon objects of relatively constant size, such as stars, and do not necessarily apply in the same way to rapidly expanding space such as the Big Bang. Neither general relativity nor quantum mechanics can currently describe the earliest moments of the Big Bang, but in general, quantum mechanics does not permit particles to inhabit a space smaller than their wavelengths.

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  1. avischiffman

    B Real-Life Demonstrations of Black Holes for Video

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  2. R

    I Big Bang Singularity: Was It As "Infinitely Dense" As We Think?

    The big bang supposedly originated from an infinitely dense singularity of space/time. The concept of infinitely dense is an artifact from our current perception of how immense our universe is today and how spread-out space/time is. However, if I were present in the reference frame of that...
  3. binbagsss

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  4. C

    I Did the big bang singularity not have a history?

    Hello! Hawking has written, that the physical mechanics and the time before the big bang singularity cannot be measured, as time in this big bang singularity has been bent indefinitly and therefore has just started with the big bang. Questions: 1. Does Hawking mean, there has not been any time...
  5. M

    I Black hole event horizon confusion

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  6. binbagsss

    A Why Scalar Quantities Matter in Singularity Tests

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  7. J

    What is the singularity of e^(-1/z^2)?

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  8. D

    B Temperature of a black hole....observed from the singularity

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  9. D

    I Is it possible to stretch a singularity?

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  10. L

    MHB [Complex Analysis] Singularity in product of analytic functions

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  11. A

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  12. alex4lp

    A Why is all the mass of a BH in the singularity?

    Hi everybody, and thanks in advance. My doubt is: why should the mass go in the singularity? I'm thinking about this situation: imagine a sphere with radius R<2M; then that sphere generates a BH. Schwarzschild tensor metric is valid only in the exterior region of the mass and for this reason i...
  13. zonde

    I Coordinate singularity at Schwarzschild radius

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  14. W

    B Could time move inside a black hole?

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  15. S

    I Difference between oscillatory/cyclic model and big bounce?

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  16. wolram

    B Solving the singularity problem

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  17. T

    I Proper time to reach the singularity - rocket acceleration

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  18. wolram

    B Does the Singularity Really Exist Beyond the Standard Model?

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  19. C

    I Particle at event horizon as black hole evaporates

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  20. Zantra

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  21. B

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  22. F

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  23. A

    I Black hole - between horizon and singularity

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  24. J

    Analytic Integration of Function Containing the Exponential of an Exponential

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  25. E

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  26. vktsn0303

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  28. H

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  29. R

    I Are quark stars a realistic solution to the black hole singularity problem?

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  30. F

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  31. J

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  32. ivant6900

    B Do we still live in a Big Bang Singularity?

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  33. binbagsss

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    Homework Statement [/B] please see attached. b) The solution seems a bit vague is the idea here, what this comment is saying, that since this is a simple zero the form of ##lim_{z\to a} f_a(z) (z-a)=0## since, crudely, it is of the form ##\frac{0.0}{0}##. Compared to the point ##z=-a##...
  34. K

    I Size and shape of a black hole singularity?

    How and if singularity is related to Plank size (h) , are they be related ? If they are; can the singularity have squared shape (like pixel) , if it is h size so that is the "smallest" understand by "physics" and any curve (circle) would break the rule of h begin the smallest ? Does my question...
  35. FallenApple

    I Do Event Horizons always contain a singularity?

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  36. TGVF

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  37. D

    B The Singularity and Hawking radiation

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  38. Noisy Rhysling

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  39. Elnur Hajiyev

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  40. A

    A How to compute limit of removable singularity?

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  41. CaptDude

    I Question about "the big bang happened everywhere at once"

    Is it fair to think about the statement "the big bang happened everywhere at once." as meaning the singularity that spawned the "big bang" was very large by cosmic scales, even infinitely large? (I am aware that the word "singularity" refers to a place where the math breaks down and not a point...
  42. T

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  43. wolram

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  44. Q

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  45. Q

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  46. strangerep

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  47. S

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  48. Rishi Tharun

    Singularity After Black Hole Evaporates: What Happens?

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  49. M

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  50. Irfan Nafi

    I How is it possible for a ring singularity?

    If a star with enough mass to become a black hole is rotating before it becomes a black hole, then the singularity of the black hole will actually be a ring singularity. How is it possible?
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