<p>Of course unknown &quot;strange Quantum Effects&quot; could do anything, but <a href="https://phys.org/news/2016-10-ligo-black-holes-gravastars.html" rel="nofollow noreferrer">this letter</a> (<em>Did LIGO detect black holes or gravastars?</em>) reports calculations which suggest that at least one of the LIGO gravitational wave events is consistent with black holes but not with gravastars. That doesn't rule out the possibility of gravastars <em>and</em> black holes existing, but it speaks quite strongly against the idea that all the phenomena attributed to black holes are actually due to gravastars.</p>

CC BY-SA 3.0
2018-03-11T17:43:55.803Z
all the phenomena attributed to black holes are actually due to gravastars? Can you explain? Gravastars is just a hypothetical.
malkesh2911
CC BY-SA 3.0
2018-03-11T18:25:10.193Z
Some of the people who make that hypothesis claim that black holes don't exist at all, and all the things we observe that we think are due to black holes are really due to gravastars. These calculations suggest that that is not the case.
Steve Linton
CC BY-SA 3.0
2018-03-12T09:19:00.313Z
Yes you are true but, Gravastars has no close theories to understand and will be proved in soon compare to black holes theories. Even now Astronomers and Scientist comprehend that every galaxy contains a black holes in a center. And every data came with belongs to that theory. A gravastar type of star that changing a star's definition as well when it came up with no horizon.
malkesh2911
CC BY-SA 3.0
2018-03-12T09:21:48.673Z
https://www.popularmechanics.com/space/deep-space/a19375199/black-hole-sun-part-neutron-star-part-black-hole/
malkesh2911
CC BY-SA 4.0
2018-03-10T19:27:45.490Z
2022-10-29T14:47:53.947Z
2022-10-29T14:47:53.947Z
Steve Linton
<p>Is that possible with some strange Quantum Effect could give rise to a completely new kind of a star? Gravastar(Gravitational Vacuum Star) an object hypothesized in astrophysics as an alternative to the black hole theory.The notion of gravastars builds on Einstein's theory of general relativity and imposes a universal "smallest size" that is known to exist according to well-accepted quantum theory. This size is known as the Planck length and is derived using the speed of light, Planck's constant and the gravitational constant. Quantum theory says that any scale smaller than the Planck length is unobservable and meaningless to physics and physicists. This limit can be imposed on the wavelength of a beam of light so as to obtain a limit of blue shift that the light can undergo. However, in the presence of an event horizon, the blue shift diverges.</p>

<p>In the original formulation by Mazur and Mottola, gravastars contain a central region featuring a p=-ρ false vacuum or "dark energy", a thin shell of p=ρ perfect fluid, and a true vacuum p=ρ=0 exterior. The dark energy like the behavior of the inner region prevents collapse to a singularity and the presence of the thin shell prevents the formation of an event horizon, avoiding the infinite blue shift. The inner region has thermodynamically no entropy and may be thought of as a gravitational Bose-Einstein condensate. Severe red-shifting of photons as they climb out of the gravity well would make the fluid shell also seem very cold, almost absolute zero.</p>

<black-hole><astrophysics><quantum-mechanics><quantum-field-theory>
Is a Gravastar with no horizon with ultracompact and extreme density possible?
malkesh2911
# Is a Gravastar with no horizon with ultracompact and extreme density possible?

(Asked by: username_0 on 2018-03-10)

Is that possible with some strange Quantum Effect could give rise to a completely new kind of a star? Gravastar(Gravitational Vacuum Star) an object hypothesized in astrophysics as an alternative to the black hole theory.The notion of gravastars builds on Einstein's theory of general relativity and imposes a universal "smallest size" that is known to exist according to well-accepted quantum theory. This size is known as the Planck length and is derived using the speed of light, Planck's constant and the gravitational constant. Quantum theory says that any scale smaller than the Planck length is unobservable and meaningless to physics and physicists. This limit can be imposed on the wavelength of a beam of light so as to obtain a limit of blue shift that the light can undergo. However, in the presence of an event horizon, the blue shift diverges.

In the original formulation by Mazur and Mottola, gravastars contain a central region featuring a p=-ρ false vacuum or "dark energy", a thin shell of p=ρ perfect fluid, and a true vacuum p=ρ=0 exterior. The dark energy like the behavior of the inner region prevents collapse to a singularity and the presence of the thin shell prevents the formation of an event horizon, avoiding the infinite blue shift. The inner region has thermodynamically no entropy and may be thought of as a gravitational Bose-Einstein condensate. Severe red-shifting of photons as they climb out of the gravity well would make the fluid shell also seem very cold, almost absolute zero.

**Tags:** black-hole, astrophysics, quantum-mechanics, quantum-field-theory

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## 1 answers

### Answer by username_1 on 2018-03-10. Score: 5 | Accepted answer

Of course unknown "strange Quantum Effects" could do anything, but [this letter](https://phys.org/news/2016-10-ligo-black-holes-gravastars.html) (*Did LIGO detect black holes or gravastars?*) reports calculations which suggest that at least one of the LIGO gravitational wave events is consistent with black holes but not with gravastars. That doesn't rule out the possibility of gravastars *and* black holes existing, but it speaks quite strongly against the idea that all the phenomena attributed to black holes are actually due to gravastars.

> **Comments:**
> **username_0**: all the phenomena attributed to black holes are actually due to gravastars? Can you explain? Gravastars is just a hypothetical.  
> **username_1**: Some of the people who make that hypothesis claim that black holes don't exist at all, and all the things we observe that we think are due to black holes are really due to gravastars. These calculations suggest that that is not the case.  
> **username_0**: Yes you are true but, Gravastars has no close theories to understand and will be proved in soon compare to black holes theories. Even now Astronomers and Scientist comprehend that every galaxy contains a black holes in a center. And every data came with belongs to that theory. A gravastar type of star that changing a star's definition as well when it came up with no horizon.  
> **username_0**: https://www.popularmechanics.com/space/deep-space/a19375199/black-hole-sun-part-neutron-star-part-black-hole/  

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