The actual size of the universe

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Saint, Jul 26, 2023.

  1. Saint Valued Senior Member

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    4,752
    I read that, the visible universe is 93 billion light years wide,
    and the actual universe could be 10 million bigger than this, means 930 million billion-light years.
    930X1000000X1000000000 light-years.
    93x10^16 light years wide.

    Am I right?
     
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  3. C C Consular Corps - "the backbone of diplomacy" Valued Senior Member

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    Yah, a radius of 46.5 is a commonly tossed around.

    No one knows, aside from "at least" proposals. Estimates like the 37 trillion light years below regard a minimum size required for the speculative possibility of its apparent flat topology beginning to assume a different shape.

    Is the Universe infinite?
    https://bigthink.com/starts-with-a-bang/universe-infinite/

    EXCERPT (Ethan Siegel): So what can we say about the part of the Universe that’s beyond the limits of our observations? We can only make inferences based on the laws of physics as we know them, and the things we can measure within our observable Universe. If space were positively curved, like we lived on the surface of a 4D sphere, distant light rays would converge. If space were negatively curved, like the surface of a 4D saddle, distant light rays would diverge. Instead, distant light rays move in their original direction, with the fluctuations we have indicating perfect flatness.

    Our best measurements indicate that the Universe is spatially flat on the largest scales: it’s neither positively nor negatively curved, to a precision of 0.25%, or about 1-part-in-400. Because we live in three dimensions, 400 times the radius means (400)3 times the volume, or more than 64 million times as much space. If we assume that our current laws of physics are correct, we can set limits on how large, at least, the Universe must be before it curves back on itself.

    But, big as that is, it still isn’t infinite. A lower bound of the Universe being at least 18 trillion light-years in all directions is tremendous, but it’s still finite. Assuming that the Universe contains no topological weirdness, like curving back on itself while still being spatially flat (like having a geometry akin to a hypertorus), observations of the cosmic microwave background and the large-scale structure tell us that the unobservable part of the Universe must be at least 37 trillion light-years in diameter.

    However, there are good theoretical reasons to believe that our entire Universe, whether finite or infinite, is even larger than that. The hot Big Bang might mark the beginning of the observable Universe as we know it, but it doesn’t mark the birth of space and time itself. Before the Big Bang, the Universe underwent a period of cosmic inflation...
     
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  5. Pinball1970 Valued Senior Member

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    All good stuff posts above and mind blowing to me (an enthusiast not a scientist)
    Webb will shed light on some of these questions.
    One recent study (Gupta) suggests the universe could be double its current age, 27 billion years. Explain well formed galaxies that do not fit the current understanding.
    I suppose that means the universe is a lot larger too.
     
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  7. Zero Point Native Registered Member

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    Personally, I believe the Universe has no size, but I know that the concept of infinity scares a lot of people and is usually put into the same category as some esoteric woo-woo hogwash because infinity is beyond our comprehension.
     
  8. Pinball1970 Valued Senior Member

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    Spoken to few of the guys on this and I know describing this stuff gets you so far with words then mathematics should take over.

    Same with GR and QM.

    Finite and our bit (observable) appears to be flat

    Infinite in size but temporally finite

    Cyclic (Penrose, Turok have different ones)


    I am sure there are others.
     
  9. Tiassa Let us not launch the boat ... Valued Senior Member

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    STFC Rutherford Fellow James O'Donoghue noted, about a year ago↱:

    The observable universe is 93 billion light years wide and contains two trillion galaxies EACH containing countless billions of stars

    The UNobservable universe beyond is at least 250 times wider, so its volume and galaxy content is 15 million times larger
    ____________________

    Notes:

    @physicsJ. "The observable universe is 93 billion light years wide and contains two trillion galaxies EACH containing countless billions of stars The UNobservable universe beyond is at least 250 times wider, so its volume and galaxy content is 15 million times larger Enjoy your Monday". (thread) Twitter. 25 July 2022. Twitter.com. 28 July 2023. https://bit.ly/3qaC8jo
     
  10. Mr. G reality.sys Valued Senior Member

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    "...the visible universe is 93 billion light years wide..."

    Who cares?

    Can't know it. Can't prove it. It's the Hollywood take on reality. Fictional projection.

    Shakespeare said it awhile ago.

    " Um, what?"

    Please accept my apology for making a point that was not your own.

    Salmon always seem to meet waterfalls.

    Waterfalls are serene in their functional purpose.
     
  11. exchemist Valued Senior Member

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    …..and your hovercraft is full of eels.

    Please Register or Log in to view the hidden image!

     
  12. Saint Valued Senior Member

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    Maybe the concept of the Border of the Universe is wrong?
     
  13. gmilam Valued Senior Member

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    When I was a little boy, maybe 6 years old, 1964, space flight was new and exciting. I remember imagining being an astronaut and tooling around the universe in my rocket ship. I thought about what would happen when I reached the edge of the universe. Would there be a brick wall or what? Well that introduced the thought of what's on the other side of the wall? So I discarded that idea. Then I remembered my dad telling me that if I started walking and continued to walk in a straight line, that I would eventually come back to where I started. So I figured the same thing would happen in my imaginary spaceship. The universe must somehow curve back in on itself. Never acquired the math or science education to pursue that line of inquiry, but 60 years later I still find it an interesting idea.
     
  14. Saint Valued Senior Member

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    4,752
    Maybe on the other side of the universe is the so called Spiritual realm?

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  15. ThazzarBaal Registered Senior Member

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    Exactly as big as it is small, which I really have no idea how big or small that might be, but ... It appears to be fairly massive, so in terms of light years I can safely assume that it's size is greater than anything we can truly comprehend to date.
     
  16. ThazzarBaal Registered Senior Member

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    Oh, and in case you found my answer too vague it's because we have no definitive answer to how big the universe actually is.
     
  17. gmilam Valued Senior Member

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    Even the six year old me from 1964 would laugh at that one.
     
  18. ThazzarBaal Registered Senior Member

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    What if the spiritual realm is the realm where there's actually extant life and the "so called" "spiritual realm" so badly misunderstood that we view it to be something far fetched, invisible, and non existent.
     
  19. Zero Point Native Registered Member

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    Like the word "God", the word "spirit" has become such a loaded word with a ton of religious baggage attached to it, so I try not to use those words anymore as they contain so many different meanings.

    If I'm not mistaken, I believe science has already established the fact that the entire universe is energy and all energy vibrates at, I believe, infinitely varying frequencies. I do believe a major portion of the Universe to be unseen existing at vibrations that are incredibly too high for any scientific instruments currently in existence. I also believe that consciousness continues to exist in some form or another in this part of the much higher vibratory Universe and that consciousness still has the ability to harness a "physical" body of sorts within these higher vibratory areas of the Universe, meaning that the Universe could be teaming with life throughout this "infinite" universe, both seen and unseen. I believe the part of the Universe we are able to see and detect with all of our most advanced telescopes only makes up an incredibly tiny fraction of the Universe as a whole.

    I usually like to analogize the Universe with the following:

    Imagine everything our telescopes can see, including the trillions of galaxies throughout the "known" Universe, and put all of that into a tiny grain of sand. Now imagine countless grains of sand covering the entire surface of a sphere the size of Earth and this would give you a hypothetical idea of the size of the physical Universe. Everything beneath or within the surface of this sphere would be the remainder of the Universe or the unseen part of the Universe, and if you were to consider the Universe to be infinite then you could multiply this scenario countless times.

    Anyway, that's how I like to look at it.
     
  20. ThazzarBaal Registered Senior Member

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    Maybe a finger smudge on the lens, eh?
     
  21. Zero Point Native Registered Member

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    Or a piece of fuzz.
     
  22. ThazzarBaal Registered Senior Member

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    Yeah ... It's difficult to fathom the scope for sure. We see a tree, even when we're viewing the bigger forest.
     
  23. Pinball1970 Valued Senior Member

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    Not for me as I am not convinced there is a spiritual real. Also, Souls, ghosts, spirits, gods, goddesses, heaven or hell.

    That’s just me.
     

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