''TIME'' - definitions.

Discussion in 'Science and the Universe' started by socrat44, Jan 16, 2019.

  1. RJM Corbet

    RJM Corbet God Feeds the Ravens

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    Brahma breathes out and the universe is born, Brahma breathes in and the universe ends, Brahma breathes out and the universe is born ... eternally
     
  2. RJM Corbet

    RJM Corbet God Feeds the Ravens

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    Nothing has no properties.. A void is emptiness. It is 'there'?

    Perhaps the expanding universe is creating space?

    A two-dimensional creature born to inhabit a flat dimension is unable to form a mental picture of a three dimenional state. It is not equipped to visualuze 'up and down'.

    It can do the math and try to create two dimensional analogies for a three dimensional state, but the analogies will never be complete because it is not equipped really to visualize anything beyond forward, backward and sideways?

    Something like that, I believe?

    But perhaps I have resched the limit of what I can contribute to this enjoyable thread. I don't have enough science.
     
    Last edited: Feb 5, 2020
  3. wil

    wil UNeyeR1

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    Care to share the bundle of vids
     
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  4. OrtaYol

    OrtaYol Active Member

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    This was one of them, she did it from her laptop so I don't have the history. Another one I watched is actually mentioned in the link above(It has a badly drawn alien in it). They were the two I found most informative. The rest were pretty much just repeating the same information.

    Anything you would recommend?
     
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  5. RJM Corbet

    RJM Corbet God Feeds the Ravens

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    Is the universe bounded by the conditions of time and space? Could a state exist 'outside' time and space and still be part of the universe?
     
  6. RJM Corbet

    RJM Corbet God Feeds the Ravens

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    Response to:
    https://www.interfaith.org/community/threads/19337/page-8

    The jets are not coming out of the black hole.

    https://www.nustar.caltech.edu/page/relativistic_jets

    Super massive black holes in the centers of some active galaxies create powerful jets of radiation and particles travelling close to the speed of light. Attracted by strong gravity, matter falls towards the central black hole as it feeds on the surrounding gas and dust.

    But instead of falling into the black hole, a small fraction of particles get accelerated to speed almost as great as the speed of light and spewn out in two narrow beams along the axis of rotation of the black hole.

    These jets are believed to be the sources of the fastest-travelling particles in the universe -- cosmic rays.
     
    Last edited: Feb 16, 2020
  7. Aupmanyav

    Aupmanyav Search, be your own guru.

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    Well, that does not falsify what I wrote - 'energy spewing out of a black hole'. :)
    Where from cosmic rays get their energy?
     
  8. wil

    wil UNeyeR1

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    Flying to Hawaii onetime I sat next to an astronomer studying this black hole regurgitation.. She was headed for her slotted telescope time to point it at.one of these!
     
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  9. RJM Corbet

    RJM Corbet God Feeds the Ravens

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    Nothing comes out of a black hole, except over multiple billions of years a slow decay by leaking Hawking radiation. The cosmic rays appear to get their energy by matter being attracted by the black hole and then a small part of it sort of 'bouncing' off from the black hole and then being caught up in the vortex of the spin. I don't know.

    But the jets are definitely not emitted from within a black hole. Whatever energy goes into a black hole is forever lost.
     
  10. Cino

    Cino Big Love! (Atheist mystic)

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    Not lost. The BH gets heavier.
     
  11. RJM Corbet

    RJM Corbet God Feeds the Ravens

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    But the BH does not emit energy? There is no way to get it back? For all useful purposes, it is gone?
     
    Last edited: Feb 16, 2020
  12. Cino

    Cino Big Love! (Atheist mystic)

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    Well, the mass of the black hole increases, with all the usual gravitational consequences. The cosmic balamce sheet (conservation laws) still keeps track of it.

    The usefulness of energy is a highly subjective measure.
     
  13. RJM Corbet

    RJM Corbet God Feeds the Ravens

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    Thanks Cino :)
     
  14. RJM Corbet

    RJM Corbet God Feeds the Ravens

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    @Cino
    So in fact a black hole is really just a very dense object which occupies space? It is not a true singularity?
     
  15. Aupmanyav

    Aupmanyav Search, be your own guru.

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    Does it lead to another universe? :)
    https://en.wikipedia.org/wiki/Black_hole#Evaporation

    "The resulting friction is so significant that it heats the inner disk to temperatures at which it emits vast amounts of electromagnetic radiation (mainly X-rays). These bright X-ray sources may be detected by telescopes. This process of accretion is one of the most efficient energy-producing processes known; up to 40% of the rest mass of the accreted material can be emitted as radiation."

    https://commons.wikimedia.org/w/index.php?title=File:RXTE_Detects_Heartbeat_Of_Smallest_Black_Hole_Candidate.ogv

    "One puzzling feature is that the entropy of a black hole scales with its area rather than with its volume, since entropy is normally an extensive quantity that scales linearly with the volume of the system. This odd property led Gerard't Hooft and Leonard Susskind to propose the holographic principle, which suggests that anything that happens in a volume of spacetime can be described by data on the boundary of that volume."

    "This creates a paradox: a principle called "monogamy of entanglement" requires that, like any quantum system, the outgoing particle cannot be fully entangled with two independent systems at the same time; yet here the outgoing particle appears to be entangled both with the infalling particle and, independently, with past Hawking radiation. In order to resolve the paradox, physicists may eventually be forced to give up one of three time-tested theories: Einstein's equivalence principle, unitarity, or existing quantum field theory. One possible solution, which violates the equivalence principle, is that a "firewall" destroys incoming particles at the event horizon."
     
    Last edited: Feb 16, 2020
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  16. RJM Corbet

    RJM Corbet God Feeds the Ravens

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    Phew! Weird stuff ...

    A bit above my level, lol
     
    Last edited: Feb 16, 2020
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  17. Cino

    Cino Big Love! (Atheist mystic)

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    The event horizon may be what you are referring to, here. It circumscribes a volume of space, which is often referred to as the black hole, since light etc cannot "escape" from within it.

    The singularity inside it is point-like without any volume or border.
     
  18. RJM Corbet

    RJM Corbet God Feeds the Ravens

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    But of infinite mass? Infinitely heavy? And infinitely small? The compressed neutrons of a neutron star collapse and reach infinite density?

    It is the singularity I'm after here, not the complications of the BH 'veil' around it. Never mind the BH event horizon etc, for now.

    At the singularity 'everything' is destroyed and doesn't even leave a dot to show where it went?

    I'm asking, and learning ...
     
    Last edited: Feb 16, 2020
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  19. Cino

    Cino Big Love! (Atheist mystic)

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    Yes. That's why it's called singularity. Think of approaching divide-by-zero. The smaller the number you divide by, the larger the result, but division by zero, just this one number, is undefined.
     
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  20. Aupmanyav

    Aupmanyav Search, be your own guru.

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    Same for me. Let us wait till they find the answers to their questions and can describe it in a language intelligible to laymen. ;)
    Destroyed! No, never. Black-hole emissions are there. And have you heard of worm-holes or white-holes? As if black-holes were not enough! All because of Einstein and his collaborators.

    "A wormhole (or Einstein–Rosen bridge or Einstein–Rosen wormhole) is a speculative structure linking disparate points in spacetime, and is based on a special solution of the Einstein field equations. A wormhole can be visualized as a tunnel with two ends at separate points in spacetime.
    Wormholes are consistent with the general theory of relativity, but whether wormholes actually exist remains to be seen. Many scientists postulate wormholes are merely a projection of the 4th dimension, analogous to how a 2D being could experience only part of a 3D object. A wormhole could connect extremely long distances such as a billion light years or more, short distances such as a few meters, in different universes, or different points in time."
    https://en.wikipedia.org/wiki/Wormhole

    "In general relativity, a white hole is a hypothetical region of spacetime and singularity which cannot be entered from the outside, although energy-matter and light can escape from it. In this sense, it is the reverse of a black hole, which can be entered only from the outside and from which energy-matter and light cannot escape. White holes appear in the theory of eternal black holes. In addition to a black hole region in the future, such a solution of the Einstein field equations has a white hole region in its past. However, some believe this region does not exist for black holes that have formed through gravitational collapse, nor are there any known physical processes through which a white hole could be formed. Although information and evidence regarding white holes remains inconclusive, the 2006 GRB 060614 has been proposed as the first documented observance of a white hole."
    https://en.wikipedia.org/wiki/White_hole
     
    Last edited: Feb 17, 2020

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