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There Is No "You" In a Parallel Universe
StartsWithABang (3485481) writes "Ever since quantum mechanics first came along, we've recognized how tenuous our perception of reality is, and how — in many ways — what we perceive is just a very small subset of what's going on at the quantum level in our Universe. Then, along came cosmic inflation, teaching us that our observable Universe is just a tiny, tiny fraction of the matter-and-radiation filled space out there, with possibilities including Universes with different fundamental laws and constants, differing quantum outcomes existing in disconnected regions of space, and even the fantastic one of parallel Universes and alternate versions of you and me. But is that last one really admissible? The best modern evidence teaches us that even with all the Universes that inflation creates, it's still a finite number, and an insufficiently large number to contain all the possibilities that a 13.8 billion year old Universe with 10^90 particles admits."
like the universe does, doesn't it?
And the support for Big Bang style cosmic inflation (universe ballooning up from nothing in a trillionth of second) is sparse. (As opposed to the normal expanding universe we see that even old Steady State theory said existed.)
If cosmic inflation happened, everything real far away should be in its infancy, but we see sprial galaxies 13 billion years away.
Quasars are supposed to only be in the beginning of the universe in early times according to the Big Bang, and there are 2 of them within 800 million miles of us which should not even be possible. http://www.sdss.org/news/relea...
So we have old structures very far away well-developed with plenty of metal, which shouldn't happen.
We have "newer" structures nearby, which shouldn't happen.
Add to the fact there are no metal-free stars (Pop III) ever seen, it is difficult to see what aspect of Big Bang Theory holds true. Astronomy might be better off if it were discarded because a number of the popular conclusions double-down on bad science and result in wild goose chases (dark energy only need exist to support the Big Bang because only the Big Bang says expansion must be accelerating.)
Priest: "Universe from nothing, no laws of physics, sped up time"+ huge discrepancies. Creationism? No. Big Bang Theory
As usual for this crap, the poster gets it completely wrong. The idea of eternal inflation, that the conditions for inflation could "loop" due to tunneling back up a potential, is not that a finite number of "universes" are created, but an infinite number, so there absolutely ARE an infinite number of "you"s in such models. Of course there are tons of things than can go wrong with such models, but the description given goes against just about all the descriptions of inflation with quantum backreaction given by leading field figures (Linde/Guth et al.)
"Universes" here are shorthand for region of space that have become causally disconnected. The philosophy of identity in all this is up for grabs, and there's loads of problems making predictable models out of this stuff, even simple counting problems go wrong due to ordering ambiguities etc. Nevertheless the models that the pop-sci author is using do the opposite of what's being claimed here.
Except, it does... Inflation dictates the spatial dimensions occupied by the observable universe and distribution of matter within it. If said inflation occurred differently even in what could be described as the most insignificant value, than matter distribution could be dramatically different than what we see today in our observable universe. Different matter distributions == a universe in which said parallel universe which is inherently different than what we see around us.
However, at the same point it may as well be saying that within the multiverse where an infinite number of other universes exist, it is more plausible that there will be universes that are not like our own than there are those that are like our own as fundamental laws regarding the creation of said universes need not be identical, preventing the creation of sufficiently similar natural systems; ergo, the Goldilocks Principle.
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Nothing obvious about it. Presuming inflationary theory is correct, there will be a nigh-infinite number of other "bubbleverses" spawned within the perpetually expanding inflationary energy. Now, since in that model our own "bubbleverse" is finite, then if the the number of other bubbleverses was truly infinite then all possible bubbleverses would exist, including an infinite number of exact duplicates of our own (and every other) bubbleverse. However, if we instead presume that the inflationary energy is *not* infinite, then you must compare the number of potential bubbleverses with the same physical laws as our own to the number of potential states that such a bubbleverse could be in. If there are sufficiently more bubbleverses like our own then there are states in which our bubbleverse can be in, then by the pigeonhole principle there must by necessity be some bubbleverses that are near-perfect duplicates of our own - including being home to some "other you".
As I understand it, current theory and observation suggests that the inflationary period began *after* the birth of the universe (multiverse?) 13.8 billion years ago, so that puts a hard upper limit on how much inflationary energy can exist in the "multiverse", and thus how many "bubbleverses" like ours could have been spawned within it. Presumably they did the calculations and determined that the number of possible bubbleverses like our own is radically less than the number of possible states our bubbleverse could be in, thus establishing that it is very unlikely that any near-duplicate universes exist.
At least within that definition of parallel universe. There is of course also the many-worlds interpretation of quantum mechanics, as well as brane theory and it's ilk, which postulate two additional, and entirely different, kinds of parallel universe which may *also* exist. And the Many Worlds Interpretation at least would absolutely suggest the existence of a large number of near-identical universes - after all Schroedinger's poor cat would have to be discovered both alive and dead by alternate Schroedingers who didn't bifurcate until the experiment was performed.
(As an interesting side consideration - would you get an alternate Schroedinger for every instant in which the istotope either did or did not decay? Or would the alternates consolidate as the particular instant of decay ceased to be relevant to the timeline?)
--- Most topics have many sides worth arguing, allow me to take one opposite you.
> Yet even if they approach an infinite amount of space between each there will remain an gravitational attraction between all particles that will bring them back together given enough time, and will return to the original configuration before the explosion.
Not so. According to the currently widely accepted interpretation of Hubble observations the universe is not only expanding, but expanding at an ever-accelerating rate thanks to the influence of so-called dark energy. Under the influence of that effect - generally interpreted to be an expansion of the fabric of spacetime itself, the entire universe will expand exponentially long after the average density of both normal and dark matter is so close to zero as to make no difference, and the incredibly diffuse dark energy is effectively all that remains. The universe is destined to end not in a "big crunch", but as an eternally cold and empty void, with even the individual protons shed by long dead stars separated by such vast distances that they are no longer causally connected.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
A very limited definition of parallel. Parallel lines will never intersect, but that only implies a constant distance and identical heading when dealing with Euclidean space. Take a course in non-Euclidean geometry sometime and you'll discover far more bizarre forms of parallelism.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Agreed, and it is an unusual concept to mull over hence the article. The vernacular used is theirs, throwing out that the multiverse isn't composed of mostly identical copies of our universe spawned via wave function collapses, or in another incarnation completely separate universes that are identical until a wave function collapse at which point there is a divergence, or any number of similar theories. It is a fascinating concept, and in and of itself does not preclude the possibilities of conventional "parallel" / "mirror" universes, it simply implies that out of any like universe, there may be trillions that are completely unlike ours in every sense of the word.
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