Showing posts with label multiverse. Show all posts
Showing posts with label multiverse. Show all posts

Thursday, August 30, 2012

Whence the Universe

  I guess I'm not cut out for metaphysics.  Either I'm not sufficiently sophisticated to understand metaphysical arguments, which generally fly over my head, or I'm especially allergic to the sophistry that I detect in most of them.

  I'm particularly puzzled by metaphysical discourses on the age-old question of why there is something rather than nothing—that is, why the universe actually exists—which William James called the darkest question in all philosophy.  There are many recent writings about this conundrum, two of which underlie my musings today.  The first, A Universe from Nothing: Why There Is Something Rather than Nothing by cosmologist Lawrence M. Krauss, attempts to give a scientific answer.  The second, Why Does the World Exist? An Existential Detective Story by science writer Jim Holt, explores various physical and metaphysical answers that have emerged over the eons.

  I discussed Krauss' book in a previous posting.  Although its title may sound metaphysical, it is not, but rather is based on sound science as far as our understanding of the cosmos can now take us.  Krauss adduces theoretical and experimental evidence to assert that our universe was spawned from an eternal multiverse, which continually gives birth to universes like ours in big bangs.  Each new universe arises as a spontaneous eruption of particle-antiparticle pairs from the quantum froth that is known to pervade space; and each might develop its own set of physical laws as it unfolds from its primal fireball.  I refer you to the latter half of my previous posting for additional details.

  This cosmology, mind-blowing as it may seem, satisfies my senses of simplicity, order and coherence.  An eternal, steady-state multiverse that continually engenders new universes removes the perennial bafflers: "What happened before our big bang?" and "What first cause started it all?".  Before our own big bang, the multiverse had always been starting new universes.  And a first cause isn't needed for a process that has been going on eternally, because there is no first instant.

  But "it has always been and will always be" is not as entrancing to some of my readers as it is to me. They ask, "Why does the multiverse exist at all?"  In answer, most scientists throughout the ages have agreed with Bertrand Russell's dictum, "I should say that the universe is just there, and that is all."  Adolf Grünbaum, a professor of the philosophy of science at the University of Pittsburgh, goes deeper by pointing to unstated premises behind the question: not only that everything needs an explanation, but that a priori the preferred state of the multiverse is its nonexistence, not its existence, so that an explanation is needed to explain why it indeed exists.  But why should not the preferred state be its actual state of existence, no explanation needed?

  Despite my satisfaction with the cosmology Krauss describes, I decided to read Holt's book, which explores sundry other physical and metaphysical models proposed throughout history, most of them metaphysical.  It starts annoyingly, however,  with a prologue that plunges one into the fuzzy argumentation that I associate with all of metaphysics.  I reproduce it here in its entirety:

A Quick Proof That There Must Be Something Rather Than Nothing, for Modern People Who Lead Busy Lives

Suppose there were nothing.  Then there would be no laws; for laws, after all, are something.  If there were no laws, then everything would be permitted.  If everything were permitted, nothing would be forbidden.  So if there were nothing, nothing would be forbidden.  Thus nothing is self-forbidding.

Therefore, there must be something.  QED.

  This argument is at best semantic confusion, at worst casuistry. The verbal shenanigans arise from the conflation of two meanings of the word "nothing": the antonym of the word everything, i.e., no thing; and the state of nothingness, i.e., the nonexistence of the universe, which is a thing.  In the fourth sentence, then, if "everything were permitted," so too would a nonexistent universe be permitted; it is one possibility among all possibilities (every thing) for the universe.  Likewise, if "nothing would be forbidden," then a nonexistent universe couldn't be forbidden as a possibility.  The paradox that Holt seeks thus vanishes.

  Even if Holt was not purposefully being sophistic here, but was just poking a bit a fun at the fogginess of some metaphysical argumentation, he still has done a disservice to his readers, who will either swallow the paradox uncritically, or have to spend time resolving it, as I did.  He compounds the offense by using "nothing" in both meanings indiscriminately until some 45 pages later in the book, when he finally distinguishes them in the context of the sentence "Nothing is greater than God."  (Try reading that sentence using each of the two meanings—totally opposite statements!)  Not a good introduction to his tome.

  The book proper starts by summarizing various answers to Why is there something rather than nothing? given by savants over the centuries.  To me, most of them partake of the sort of fuzziness that disqualifies me as a metaphysicist.  For example: Something exists because it is on the whole better than nothingness.  Something exists because it was created out of nothingness by an omnipotent creator, which because of its omnipotence created itself.  Nothingness can't exist because it is literally unthinkable—for, after trying to imagine a universe with nothing in it, space itself, a thing, would be left—so nothingness must be impossible.  Something exists because the single nothingness state counts as an infinitesimal fraction of all the possible somethingness states; so, probabilistically speaking, the nothingness state has no real chance of occurring.  This summary provides a backdrop for the rest of the book, which explores current thinking about the question.

  To my mind, most of the current thinking Holt presents is metaphysical blather.  For instance: "Math creates Matter, Matter creates Mind, and Mind creates Math—the three worlds mutually support one another, hovering in midair over the abyss of Nothingness."  Or "The world is nothing but a flux of pure differences, without any underlying substance."  Or it "consists of an infinite number of infinite minds."   The exegeses of these assertions and others like it don't add any clarity to them.

  To be sure, Holt doesn't avoid scientific explanations, including the very cosmology that Krauss describes.  But he is largely unconvinced by them, saying, "The universe comprises everything that physically exists.  A scientific explanation must involve some sort of physical cause.  But any physical cause is part of the universe to be explained.  Thus any purely scientific explanation … is doomed to be circular." 

  Thus, Holt isn't satisfied, as I am, with Krauss' eternal, causeless multiverse.  He indeed asks, "Why this eternal, causeless multiverse rather than another?"  I imagine a dialog with him: I would suggest that the multiverse we actually live in is what probability theorists call ergodic—a time-shifted version of every other instantiation of the multiverse except the nonexistent one—so we are reduced to a simple dichotomy between the one existent multiverse and a posited nonexistent one (and hence to Russell's and Grünbaum's comments).  He would then ask, "Why this time shift and not another?"  Exasperatedly, I would be forced to use a response he attributes to Sidney Morgenbesser, the late Columbia University philosopher:  "Oh, even if there was nothing, you still wouldn't be satisfied!"

  I'm afraid my prejudice against metaphysics won out in assessing Holt's book.  I learned nothing that diverted me from Krauss' cosmology.  Taking my lead from Grünbaum, I have to dismiss his fundamental question Why is there something rather than nothing? as a Scheinproblem, a pseudo-problem.

Tuesday, March 27, 2012

Musings on God and Cosmology

Originally published March 6, 2012

  This is a tale of the birth of an atheist, with cosmology as midwife.

  I was raised in a moderately observant Jewish family. My maternal grandfather, a great influence on my life, set the religious tone for us.  He was trained as a rabbi in the old country but left after seeing one pogrom too many.  Arriving in America in 1896, he found that rabbis were a dime a dozen, became a successful businessman, but remained an observant Jew. He was liberal in his Judaism, never imposing his way of practicing on his children or grandchildren.  I remember once asking him whether I should fast on Yom Kippur.  His reply: "That's between you and God."

  God as a presence just came along with my upbringing. I received about the same amount of religious training as was usual for boys in the same milieu in the late 1930s and early 1940s. It culminated in my bar mitzvah in 1943.  I suppose you could say that I was a God-fearing child, fearing the anthropomorphic and often-malevolent Yahweh of the Old Testament.

  As I aged in a secular society, doubts crept in of course.  I was learning about the universe, just then being understood to have more than only our Galaxy; we gradually found out that there are hundreds of billions of galaxies, each with hundreds of billions of stars.  As a budding scientist/engineer, I couldn't help asking myself whether, as theists would have it, a Creator could be bothered with this speck of dust we call Earth.

  By my twenties I had adopted an Einsteinian view, that God is Order-in-the-Universe. Einstein couldn't abide by the idea that the universe contains the probabilistic maelstrom then being propounded by a new generation of quantum physicists. As he famously said, "God does not play dice with the universe."

  There matters stood with me as I pursued my career and raised a family.  When my children asked whether I believed in God, whether in fact there is a God, I would agnostically hedge by saying that I didn't know.  I asserted that acting in a godly manner would lead to a better life for them.  So I gave them religious training, much attenuated from my own, justifying it by telling them that the cradle of religion would serve them well, especially when they encountered the inevitable crises in their lives.  Even as my agnosticism grew, I continued my own observance, sometimes on Shabbat, always on Yom Kippur, both to set an example for them and because such observance within a community brought some sense of cosmic order and belonging to my own life.

  This pleasant existence was shattered when I hit my own life's worse crisis: my wife Helen was diagnosed with cancer fifteen years ago and died of it a year and a half later; she was only sixty-three.  The comforting structure of religion that I assumed would be the bedrock on which I could stand turned out to be quicksand. Shortly after Helen's death, while attending Yom Kippur services, I looked at the Ark in which God's presence is supposed to dwell and found myself engulfed in the rage of one who has been deceived, or has deceived himself.  Far from being comforted, I was plunged deeper into despair.

  When I emerged from my grieving, I had the time and need to consider more seriously my history of belief and then agnosticism. I felt I had to face the question that has puzzled millennia of humans: where did it all come from?  A standard argument against a Creator as prime cause has been the retort, "Then what was the Creator's cause?"  But cosmology seemed to have no better answer, for one had to ask what was the cause of the Big Bang.  Recent cosmological speculation is beginning to answer that latter question.

  I recently watched a splendid video lecture, then read an equally splendid book, by cosmologist Lawrence M. Krauss, both entitled A Universe from Nothing: Why There Is Something Rather than Nothing. I'm not sure that I get it all, but here's what I take from the book and the video, roughly and in very abridged form. (You should watch the video and/or read the book to get the fuller story.)

  There is a convincing case to be made that our universe is just one in a multiverse, which extends infinitely in time and space. This multiverse is seemingly mostly empty, but actually is filled on the quantum level with a theoretically indicated and experimentally verified quantum froth. In this froth, particle-antiparticle pairs constantly and spontaneously appear and then quickly annihilate each other.  (Einstein was wrong about non-randomness on the quantum scale; quantum phenomena are probabilistic.) 

  In this frothy multiverse, it is likely—in fact certain over a long-enough period of time—that there will be places and times where and when enough particle-antiparticle pairs simultaneously pop into existence that a new universe is born in a big bang such as that which engendered ours. These big bangs are unstable, undergoing the exponential inflation characterizing our own universe in its very early times, with most of the antiparticles (or in other cases possibly most of the particles) being annihilated, leaving a universe of only particles (or antiparticles). 

  Given the infinite extent of space and time in the multiverse, it therefore contains a huge number (even an infinity) of distinct universes. They are all beyond the light horizon from each other--i.e., unable to see each other--because during their inflation their spaces expand, as ours did, more rapidly than the speed of light. (This is allowed by general relativity for the fabric of space, although not for matter and energy.)  

  Krauss differentiates this very strange cosmology from equally strange sorts of theism by making two assertions: (1) so far every scientific measurement and observation we have made in our own universe allows--even points to--this cosmology, (2) no scientific measurements support the possibility of or need for a prime-mover God that started our universe at the time of our Big Bang 13.72 billion years ago (much less the Biblical 6000+ years ago). 
  
  In effect, Krauss answers the questions of when and from what it all started by the mind-blowing statements "never" and "from nothing." The multiverse has always been around, and every once in a while a universe such as ours pops out of the quantum froth.  As Alice might have said, "curiouser and curiouser." 

  But for me this very curious conclusion, or something like it, is much more comforting and coherent than requiring that a Creator or the Big Bang started it all at some initial time.  "It has always been and will always be" appeals more to my sense of order.

  Here's a final irony.  This past Yom Kippur, that solemn day of repentance and forgiveness, I was finally able to forgive God for having taken Helen so early.  After all, in his non-existence he could scarcely have been responsible.  So I was able to attend High Holiday services without animus, after a thirteen-year hiatus rejoining the community to which my grandfather belonged.