Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Could we be living in a black hole?

  1. Mar 20, 2004 #1
    Is it possible that the universe we are living in is nothing but a big black hole in another universe? That the event horizone of our universe is also the event horizone of the black hole in the universe that contains it?

    Please don't laugh. :smile:
    Last edited: Mar 20, 2004
  2. jcsd
  3. Mar 21, 2004 #2
    I don't know the answer to that question. However some physicists seem to think so. In fact there was an article on this in the American Journal of Physics, i.e.

    The observable universe inside a black hole W.M. Stuckey, Am. J. Phys. 62(9) Sep 1994, pp 788-795

    The last sentance in the abstract reads In the resulting cosmology model, the observable universe may lie inside a black hole.

    So I see no reason for anyone to laugh.
  4. Mar 21, 2004 #3
    would the "flow of time" variate (or increase) as we get closer and closer to the centre of the universe?
    if so, then would objects approximately at the centre move so fast that light emitted from them would be seen as a bright horizontal line?

    i have no idea what i'm talking about. sorry for wasting valuable bandwidth/reading time, but i just want to post what is on my mind now.
  5. Mar 21, 2004 #4
    Actually, as far as I know (i could be incorrect), the universe has no center.
    How can the Great Attractor be attributed to this topic (as specified in the American Journal of Physics)?

    About that article...
    How is this possible? What evidence is presented?
  6. Mar 22, 2004 #5


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    My initial reaction is 'no', but as pmb_phy mentioned, there is some speculation about it. But it remains a highly unproven idea.
  7. Mar 22, 2004 #6
    In my response I wanted to give the idea that it may be possible in that it doesn't violate the laws of physics. Whether this is actually the case is an entirely different story.

    E.g. when I die I want to be cremated and have my ashes spead over Britney Spears. While that does not violate the laws of nature and is thus a possibility in that sense I don't think it will acually happen in this or any other universe.
  8. Mar 22, 2004 #7


    User Avatar
    Science Advisor

    If this observable universe of ours is a black hole, does it of necessity have a naked singularity lurking somewhere in it? Would astronomers be able to tell that something strange is going on out where such a singularity lies? Kind of a "navel of the universe" sort of thing, I guess you could call it. I reckon a science-fiction novelist could do something with that. :wink:
  9. Mar 22, 2004 #8
    can someone please provide a link to that article? I'll check if there's a link too. i'm dying to read this article!
  10. Oct 19, 2009 #9
    I think we are living in a black hole. The Physicists say that the further away a galaxy is from us the faster it moves away. This continues until they get faster than the speed of light. Beyond a certain point (the event horizon), we cannot see the light as is limited in its speed. Similarly, we cannot ever reach those faraway galaxies as the space between us and them is growing faster than any speed we could gather. This situation seems awfully similar to what goes on in a black hole, don't you think?
  11. Mar 12, 2010 #10
    Well, let's find out!
    First, I'll ask Wolfram Alpha what the average mass of a star is.
    (1.65x10^29 to 2.983x10^32) kg
    Then I'll ask it how many stars are in the observable universe.
    We'll ignore planets and asteroids and such, as these are mere rounding errors compared to stars and the estimate for average star mass has a large range already. Multiplying these two terms gives us an estimate of the mass of the observable universe.
    (1.155x10^52 to 2.088x10^55) kg
    Now we need to know what the radius of the observable universe is, so I ask that.
    4.4x10^23 km
    We know from Schwartzchild that if you put enough mass in a tight enough space, it forms a black hole. The formula is:
    r = 2 G M / c^2
    So the radius of (1.155x10^52 to 2.088x10^55) kg is... oh look, Wolfram Alpha has a helpful little box to set the mass. I don't even have to do dimensional analysis.
    1.715x10^22 km forms a black hole at the lightest end of our range estimate for stellar masses. 3.101x10^25 km forms a black hole at the heaviest end of our range estimate. The observable universe has 4.4x10^23 km. And remember, this method of estimation excludes anything that isn't a star, as well as energy, charge, and any angular momentum.

    I find it unsettling how exactly in the middle of that range we are. I suspect the universe is a black hole, and the radius of the observable universe is exactly what we should expect if it were the event horizon of a black hole with the mass of the observable universe. The big bang would thus be the event horizon we came in through, an event horizon which the speed of light is insufficient to approach.
  12. Mar 21, 2011 #11
    raising the dead here, is there any published papers to this theory?

    If going from the stand that our OU is in a black hole would that disprove a singularity? would this change the predictions or math for the observable state on the 'inside' of the horizon? since theoretically that's where our universe would be located in that theory.

    or is this more of a unprovable theory one way or the other?
  13. Mar 21, 2011 #12
    So it's a black hole in a black hole in a black hole in a black hole? we need to go deeper! ;)

    More seriously though, how can those calculations be correct? if the average density is high enough to be a black hole then shouldn't anything denser than average (meaning everything not empty space) be a black hole?
  14. Mar 21, 2011 #13
    another thought, would the dark matter be the singularity in that case? and why it's accessible.
  15. Mar 24, 2011 #14


    User Avatar
    Science Advisor
    Gold Member

    Hmm, what observational consequences would you expect given that premise? Are they consistent with current observational data?
  16. Mar 24, 2011 #15
    Hi All
    http://mypage.iu.edu/~nipoplaw/physics.html [Broken] has recently suggested that our Universe has exploded as a White Hole from a Black Hole in another Universe. Just how big a Black Hole? He computes ~1,000 solar masses will suffice to create a fresh Big Bang via another Black Hole/White Hole duo...

    On the mass of the Universe born in a black hole
    Last edited by a moderator: May 5, 2017
  17. Mar 24, 2011 #16
    Since I probably won't understand that document, how exactly can 10^3 solar masses turn into 10^26 solar masses?
    Last edited by a moderator: May 5, 2017
  18. Mar 25, 2011 #17
    a black hole has a lot of gravitation, crushing everything that enters it. if we were in a black hole we would be crushed.
  19. Mar 25, 2011 #18
    What have you guys been smoking lol? How could we possibly be inside a black hole? A Black hole is just a singularity from which nothing can escape because it's gravity is so strong. If we were inside the event horizon of some sort of "super" black hole then the entire universe would be moving towards the singularity in a "Big Crunch" kind of way, but we know the Universe is expanding, everything is moving away from everything else so therefore I conclude we are not in a black hole.
  20. Mar 25, 2011 #19
    All the gravity we measure is inside of our visible universe with us now.
  21. Mar 27, 2011 #20


    User Avatar
    Staff Emeritus
    Science Advisor

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook