Taming the multiverse

Online Critical Thinking course -- free for a short time!

This week, we're launching a course called Introduction to Critical Thinking through Udemy!  It includes about forty short video lectures, problem sets, and other resources to challenge your brain, totaling about an hour and a half.  The link for purchasing the course is here, but we're offering it free to the first hundred to sign up!  (The free promotion is available only here.)  We'd love it if you'd review the course for us, and pass it on to anyone you know who might be interested!

Thanks!

**************************

I had a rather mind-blowing experience yesterday, as I was reading a BBC Online article called "Professor Stephen Hawking's Multiverse Finale," by Pallab Ghosh.

You know how sometimes when you're reading a book or watching a movie, and suddenly you realize that a major plot twist is about to happen?  At first, you're thinking, "No... no, that can't be what's happening...  Really?"  Then you think, "C'mon... wow... that couldn't be what this is leading up to!"  And finally, "OMG it actually happened!"

That's how I felt reading this article.

It'd have been interesting even without the sucker punch.  It's about Stephen Hawking's last academic paper, co-authored with American physicist James Hartle and submitted to the Journal of High-Energy Physics ten days before his death, which proposed a solution to the result of the Big Bang (and largely unrelated to the issue of cosmic inflation I wrote about in yesterday's post, except that they happened at the same time) that simultaneously solved several "loose ends" regarding the beginning of the universe.

The problem was, their first attempt at a solution generated another problem; an infinite number of parallel universes, each with their own physical laws, and seemingly no particular reason why a given universe had a given set of rules.

Thomas Hertog, of the Katholieke Universiteit Leuven in Belgium, who contributed to the research, wasn't satisfied with this.  "Neither Stephen nor I were happy with that scenario," he said in an interview with BBC News.  "It suggests that the multiverse emerged randomly and that we can't say very much more about that.  We said to each other: 'Maybe we have to live with it'.  But we didn't want to give up."

So they didn't.  And their investigations concluded something earthshattering:

The multiverse is only composed of universes with physical laws similar to our own.

[Image is in the Public Domain]

I first ran into the concept that the properties of the universe were controlled by a small number of seemingly arbitrary constants when I read Sir Martin Rees's book Just Six Numbers: The Deep Forces that Shaped the Universe, wherein we find out that there are six that seem "fine-tuned" to generate a universe that can support life: N (the ratio between the electromagnetic and gravitational forces), ε (the strength of the strong nuclear force), Ω (the ratio of the mass of the universe to the critical mass), λ (the cosmological constant), Q (the ratio of the gravitational energy required to pull a large galaxy apart to the energy equivalent of its mass), and D (the number of spatial dimensions).

Rees's book goes into the fascinating details of what a universe would look like if one of those constants was even slightly different than it is.  The end result for most of these nudges is a universe that would be profoundly uninhabitable; in many of them, stars couldn't form, and in some of them, there would be no atoms, only a homogeneous soup of quarks.  Rees himself seems inclined to use this seeming "fine tuning" as support for the Strong Anthropic Principle -- that our universe was created with the physical constants it has so that it will be conducive to the formation of matter, stars, and ultimately, life.

 

Predictably, that solution has never really appealed to me.  I'm much more inclined toward the Weak Anthropic Principle -- that of course our universe has constants set in such a way as to allow life, because if they hadn't been, we wouldn't be here to ask the question.

But Stephen Hawking's final contribution toward physics may render all of this a moot point.  If the mathematics of quantum physics restricts the Big Bang from forming universes except those with physical constants like our own, it may have been constrained -- and these seemingly un-derivable constants may come from the physics of the Big Bang itself.

Which is mind-blowing.  From the chaos of an infinite number of universes with random physical laws, we have the possibility of a multiverse composed of universes much like our own.  Of course, it still seems certain that there is no travel between our home and these parallel worlds, which invalidates the premise of about half of the plots of Star Trek: The Next Generation (not to mention my own novel Lock & Key).  But that's a price I'm willing to pay.  The contribution of Stephen Hawking, along with his colleagues James Hartle and Thomas Hertog, have brought order to a universe that seemed random, and may have provided us the answer to one of the most fundamental questions -- why our universe has the laws it does.

What more fitting Swan Song could Hawking have had?

************************************

This week's featured book is a wonderful analysis of all that's wrong with media -- Jamie Whyte's Crimes Against Logic: Exposing the Bogus Arguments of Politicians, Priests, Journalists, and Other Serial Offenders.  A quick and easy read, it'll get you looking at the nightly news through a different lens!

The argument from design

I received a response to a recent post in the form of an (actually quite friendly) email that posed a question I've been asked before, and that I thought might deserve a post of its own.  Here is an excerpt of the email:

Many atheist/skeptics base their disbelief on a lack of evidence for a deity.  If God exists, there should be evidence in the world around us.  A universe created by an omnipotent power should be different than one that was created by random processes.  If you're being honest, you have to admit that the universe we live in seems pretty fine-tuned for life, isn't it?  Scientists have identified dozens of fundamental numbers whose values are just right for the existence of matter, space, planets, stars, and life.  If any of those numbers were any different, life couldn't exist.  Doesn't it look very much like some intelligence set the values of the dials just right so as to produce a universe that we could live in?

This argument has been widely trumpeted by Christians who are not biblical literalists -- who may, in fact, accept such empirically supported models as the Big Bang and organic evolution, and who buy that the Earth is not six thousand years old, as the biblical chronology would have you believe, but six-some-odd billion years old.  But despite these non-fundamentalists' buying the whole scientific process (which is all to the good), they still can't quite let go of the idea that a higher power must be behind the whole thing.  And the "fine-tuning of the universe" is one of their main arguments.

It's called the strong anthropic principle.  The universe is such a hospitable place, they say, that god has to have set it up just for us.  But there's just one flaw in the whole thing; the central contention, that the universe is hospitable... just isn't true.

I mean, it all sounds very nice, doesn't it?  God created the universe with us in mind, and this produced awesome places like Maui and the Florida Keys.  The problem is, even here on our home planet, things aren't all that... friendly.  Much of the Earth's land surface has a climate or topography that makes it pretty unsuitable for human life.  (Being that it's midwinter in upstate New York, I'd throw my own home town into that category.)  Even some of the more congenial places, places that are warm enough and have enough water and fertile soil to keep us alive, are prone to natural disasters like hurricanes, tornadoes, earthquakes, volcanoes, and mudslides.  And if you leave the Earth, things only get worse; most of the universe is damn near a vacuum, and what's not is filled with black holes, quasars, asteroid belts, supernovae, neutron stars, and Wolf-Rayet gamma ray bursters -- the last-mentioned being capable of emitting an outburst of radiation so powerful that it could blast an entire solar system into oblivion.

Yes, well, what about the fact that all of the fundamental constants are set just right to produce matter?  This was the subject of Sir Martin Rees' book Just Six Numbers, in which he describes what the universe would be like if fundamental constants such as the curvature of space, the fine-structure constant, Planck's constant, the speed of light, and so on, were different -- and all of these alterations produce a universe that would be inhospitable to the formation of stars and planets, much less life.  And because we can't at the moment see any other reason why the constants are what they are -- i.e., there is no fundamental principle from which they can be derived, they seem arbitrary -- Rees and others argue that this is evidence of fine tuning.

I see two problems with this.  The first is that it is an argument from ignorance; because we have not yet come up with a unified theory that shows why the speed of light is three hundred million meters per second, and not (for example) 25 miles per hour, doesn't mean that we won't eventually do so.  You can't prove anything from a lack of knowledge.

Second, it seems to me that the strong anthropic principle is a backwards argument; it's taking what did happen, and arguing that there's a reason that it must have happened that way, that if it weren't designed, it wouldn't have happened that way.  It's as if I were dealt a straight flush in poker (an exceedingly unlikely occurrence) and I argued that because it's unlikely, someone must have rigged the deck.

All we know, honestly, is that it did happen, for the very good reason that if it hadn't happened that way, we wouldn't be here to talk about it.  This is called the weak anthropic principle -- even if the fundamental physical constants are arbitrary, there's no design implied, because in a universe with different physical constants, we wouldn't exist to discuss the matter.  The only place such arguments are possible are universes where life can occur.  Physicist Bob Park summarizes this viewpoint with the Yogi Berra-like statement, "If things were different, then things would not be like things are."  Put that way, it's hard to see how it's an argument for a deity, much less an omnipotent one with our best interests in mind.

Anyhow, that's my response to the Argument from Design.  Like I said, the person who wrote to me was really quite friendly about the whole thing, which (although we disagree about some fundamental ideas) is certainly an improvement from the spittle-flecked responses I sometimes get that suggest Satan is, as we speak, sharpening up his torture equipment with me in mind.  So, for that, I'll just say, "Thanks for writing."  Civilized discussion is, as always, the goal around here.