As Spock would say, Fascinating.
http://www.sciencedaily.com/releases/2014/08/140807145618.htm
The entire universe as the 'event horizon' of a truly massive black hole?
by CJ | Aug 10, 2014 | Journal | 11 comments
11 Comments
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Until something can be nailed down—it’s a healthy thing to have other patterns to lay over the observed facts and see if anything fits the observations better than the model we do have. A theory is a construct—to which you are supposed to apply doubt when an alternate explanation is available, and see if some item turns up that suggests idea #2 or #3 is worth a closer look.
One can be convinced about the Big Bang—but to invest so heavily in it that any other explanation can’t be tried is possibly to steer scientific thought up the wrong creek entirely for a considerable time. This notion lies at the heart of scientific process: question, question, question.
My own favorite is alternate notion is membranes—in which occasionally the ‘branes bump into each other.
That goes in the mental file with the size nested universes, the possibility tree universes, and the theory that for the world’s intelligence agencies we are a soap opera. How could we find out?
When I was in college (’62-’67) someone introduced me to Riemann Geometry. That’s like taking the Cartesian Plane as a rubber sheet and stretching it over a sphere. The edges of the Cartesian Plane, the “infinities”, all come around to “very nearly” meet opposite the zero point. (I always considered it a matter of personal philosophy and preference whether the exact point opposite zero, infinity, existed or not. It was very dimplifying to postulate that it did.) The mathematically appealing aspect of plotting on a Riemann surface is that curves that are discontinuous on the Cartesian plane, e.g. y=1/x or the trigometric tangent and hyperbolic functions, all become continuous. 🙂
Then there’s the old explanation of the expanding Universe being likened to a balloon being blown-up. Inevitably the two came together and my right brain spend a lot of time puzzling out the proposition that the Universe was actually the 3D surface of a 4D inflating sphere. (So, of course, a FTL drive could break out of the 3D surface and travel across the inside of the sphere, like the shortest distance from Buenos Aires to Beijing goes through the Earth!)
I got to the place that I had a reasonable grasp of how to play with a 4D sphere. And the latest cosmological theories about ‘branes, even this 4D event horizon, feels very familiar.
“dimplifying”???? ARRRRGGGGGGHHHHHHHH!
No, I wasn’t hinting that gravity dimples space in that 4th dimension and singularities plunged down to the center of the sphere to make “wormholes” to the other side. 😉
But……
This line had me puzzled;
> It’s a bit perplexing, but it is grounded in sound mathematics and is it testable?
So i went to the ‘supplied materials’, where I found this:
> It’s a bit perplexing, but it is grounded in sound mathematics, testable, and enticing enough to earn the cover story in Scientific American,
So the question becomes “What do we have to do to test it?” I think I shall search up a magazine store and buy the August issue. They are harder to find than books stores lately, for me, anyway.
From the Science Daily article: “Of course, our intuition tends to recoil at the idea that everything and everyone we know emerged from the event horizon of a single four-dimensional black hole. We have no concept of what a four-dimensional universe might look like. We don’t know how a four-dimensional “parent” universe itself came to be….”
I’m presuming the mention of an unknowable, 4-dimensional universe is a mis-paraphrasing of the original article, as Pholy also found. I was under the impression that our own universe is indeed 4-dimensional, the fourth dimension being Time (with the quirk that one can go forwards and backwards in the other three dimensions but only forwards in Time).
P.s. I really like “dimplifying” (and presume it courtesy of auto-correct, which wanted to do some “simplifying” on my “dimplifying” here).
We’re talking four spatial dimensions obviously. It’s not exactly to me clear how this would impact GR’s considering time a dimension, since GR was based on three spatial dimensions and we know time and space get unresolvable at a singularity.
Perhaps you’ve seen the movies of a rotating tesseract. (I’m sure you can find one on YouTube.) The surface of a 4D sphere is much easier, if still not exactly easy, to, ahem, wrap your brain around–no edges–just a 3D “surface”, an inside and an outside.
Abbott’s Flatland can be helpful.
Aside: I liked “dimplifying” as an expression for how one’s face might easily contort while contemplating the oddness of other dimensions, alternate universes, and the like.
Two ideas from calculus always made me feel like there ought to be a better explanation than the standard one. Both involve edge-case or conditions. Certain operations or functions yield “Does Not Exit” or “Infinity” or “Div-By-Zero” results. A vertical line with infinite or non-existent slope, for instance. It’s just as valid. really, as a horizontal line having zero slope, but the definition of a “function” says a function can have more than one item in the domain, but only one unique result in the range, and a vertical line’s slope violates that by having infinite points in the range. You get similar things with trig functions, discontinuities, and so on. In those cases, you approach, but never reach, the point of discontinuity, or you get another vertical line case.
And yet you can graph the things in simple 2D or 3D. Demonstrably, they either have that vertical line case or that discontinuity where you approach but never reach the discontinuity point. So…a “something” exists, either place. That vertical line sure exists. I can travel anywhere up or down it I like and it’s all there. If I rotate the axes by 90 degrees, hey, all of a sudden, it’s a perfectly fine zero result, and the other is the vertical that doesn’t satisfy a function. So that feels like it needs some other way of considering it. The cases where you approach, but never can get to the discontinuous points, now those, I can see are “holes,” but they’re still (sort of) understandable. You can graph how things approach but slope away or drop out. But still, they’re simple to grasp on a graph, a very real-world 2D or 3D representation. So again, it feels like our typical explanation doesn’t go far enough of what’s actually there in the math and the reality of it.
Then there are “real” versus “imaginary” numbers, where the “imaginary” numbers (or components of the whole) are “imaginary” because…because we can have a simple mathematical representation of where another kind of discontinuity occurs: sqrt(-1). …Dang infernal auto-incorrect wants to change sqrt() to sort(). Talk about really changing intented meanings!
Well…it always seemed to me like those “imaginary” components, holes in the continuity, were just as real or reachable or understandable, by the math and the graphs, as plain old, ordinary real numbers. Never mind that the math shows they’re discontinuities, does-not-exist, unreachable in the actual universe, a different sort of hole. They’re still there somewhere. They’re conceivable in the math, fairly simply, and they’re observable in graphs (by virtue of, “look, there’s a gap!”) So it always felt / feels like there’s somehting not quite right in our usual explanation, the conceptualization.
That may not make much sense, because yes, I know the mathematics there, and that has to be that way for mathematics to work. But it still feels like it’s an incomplete sort of conceptualization or explanation for what’s there and observable (even if it’s by its absence.)
— Riemann Geometry? Wraparound reimagining of a Cartesian plane into a spherical surface or volume? Ooh, now that’s devious! But very interesting.
That sure is a big bright moon! 🙂
But the Chinese are right–it’s a jumping rabbit! I’ve always been able to see that, and never a human face.
My eyes aren’t what they used to be, and neither is our atmosphere. Now I can only see the rabbit, but in time past I could see the craters and maria distinctly.
Some see a man in the moon, some a rabbit, and some see an old, old woman bent over. The legend says that when she bends over all the way, the world will end. This would make us halfway through the world’s lifespan, which at 8.4 billion years so far gives us a pretty good run.
Apropos Riemann geometry, and 1st woman Fields Prize winner:
Ms. Mirzakhani was awarded the prize for her “contributions to the dynamics and geometry of Riemann surfaces and their moduli spaces,” which examine the symmetry of curved surfaces. Her work is primarily theoretical, but may have implications for physics and quantum field theory.
🙂