In the Multiverse, Are You Just a Brain?

The idea of there being multiple, parallel universes "out there" sounds pretty cool.  But does this really make sense?  Many atheists would say yes, perhaps because it helps to avoid the conclusion that God created our universe.  In particular, it looks like our universe is exquisitely designed for the existence of life.  But if we're one of many, many universes out there, then there's bound to be one like ours that can support life, right?

Well, yes, maybe, but as we'll see, punting to the multiverse proves too much.  In essence: if there are so many other worlds out there that can be appealed to in order to explain improbable events, then anything, no matter how crazy sounding, can happen.  In particular, it should lead you to believe that only you exist.

In our previous post, we discussed how the multiverse hypothesis does not get around the problem of the beginning of the universe.  At best, it just moves the problem back one step.  We still face the problem of a cosmic beginning.  And if so, there is still the problem of a cosmic Beginner.

In this post, we focus on the fine-tuning argument, which essentially says the universe appears highly finely-tuned for the existence of advanced life.  This observation is a relatively non-controversial statement based on scientific evidence.  For example, if the strength of gravity were just slightly stronger, then only black holes or neutron stars would form.  If just slightly weaker, then space would be filled with only gas clouds.  In either case, no planets would ever form.

If our universe is unlikely to have formed naturalistically, then that argues for a God who created it. But if there are a large number of universes out there, then surely at least one can support life, right?  And it's no wonder that we live in one of those that can support life, because otherwise, we'd be dead!

Not so fast. 

It turns out that our universe, with its incredible order and structure, over a vast history of 13.8 billion years, is so improbable, that it's actually more probable for just our solar system to pop into existence randomly, fully formed.  Because remember, the quantum foam generates universes from random fluctuations in energy.  A random fluctuation in energy can much more easily produce a fully-formed solar system like ours than produce an entire ordered universe that unfolds in such a finely-tuned manner.  Cosmologist Roger Penrose calls the improbability of the solar system popping into existence "utter chickenfeed" in comparison to the improbability of our entire universe being formed.

But what does this mean for our observations of our universe?  Because it is so vastly improbable that a universe such as ours exists, even compared to our solar system inexplicably coming into existence, the only rational thing to conclude is that the rest of the universe is an illusion.  We just think we see other stars and galaxies out there, but we don't.  They're really not there.  We just think we see the cosmic microwave background radiation, but we don't.  We just think we can observe most of our universe's history, as several generations of stars formed and exploded, showering their heavy element contents across the universe.  But we don't.  In all probability, none of that is real.

But why stop there?  Why stop at concluding our solar system is real, and everything outside it is an illusion?  Because the smaller we take the real universe to be, the higher probability it can POOF into existence.  So we would have to conclude that just our planet is real, and everything else out there is an illusion.

"But wait," you might say, "we need the sun's radiation to live."  Of course!  But even the past is an illusion.  This planet poofed into existence just milliseconds ago (so that we did not have time to "need" the sun's radiation and gravity), with no cause or explanation, as simply a fluctuation in the quantum foam.  That's right, the Earth and everything in it came into being, fully formed, with all of our memories of the past in place -- but they're illusions that did not really happen -- and with everything external to our planet an illusion.

Sound far-fetched?  News flash: in the multiverse that's far more probable than our universe being real.

But why stop there?  Why say that planet earth is real?  As long as we recognize that we were most likely formed from a quantum fluctuation just milliseconds ago, with the past and the universe external to our planet as illusions, why not realize that it is far more likely that only you exist?  And that your experiences of everyone else (and all other things in your life, including your memories of the past and even your own body) are all illusions?  In other words, you are what is called a "Boltzmann Brain:"  a single brain that just poofed into existence without cause or explanation.  This is far more likely than the orderly universe as we observe it, with all of its 13.8 billion year orderly history unfolding perfectly to eventually result in the planet Earth, life, and the human race.  You are most likely a Boltzmann Brain.

Sound absurd?  It should!  But the absurdity of this conclusion is not a reason why you should reject what I am saying.  It is a reason why you should reject the theory that forces this conclusion.

To put it directly: if you accept the multiverse hypothesis, this leads you to rationally and logically conclude that, with all probability, you are the sole observer in this universe, and everything else is simply an illusion (including the thought process that led you to believe in the multiverse theory).  Since you can't really live like that (try it: it will turn you into a sociopath), the only recourse is to reject the multiverse hypothesis.  That, or delude yourself into thinking that we just live in an incredibly improbable universe with no explanation.  But that would not be following the evidence where it leads.