NPR logo 'Lost' And The Science of Alternate Universes


'Lost' And The Science of Alternate Universes

Hurley (Jorge Garcia), Jacob (Mark Pellegrino), Kate (Evangeline Lilly), Jack (Matthew Fox), and Sawyer (Josh Holloway) on Lost's alternate universe. Mario Perez/ABC hide caption

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Mario Perez/ABC

So it’s over.  No more smoke monsters.  No more “Others”. No more Man-in-Black. No more Lost.

Unless you gave up reading newspapers, watching TV or viewing any other kind of media, you know last night was the final episode of Lost.  I was a big fan of the first year of the show.  Then, like many others, I lost interest as characters and plot lines multiplied like rabbits.  I did tune in for last nights finale though.

I still don’t know exactly what the island is (and why it has a bathroom plug that should never, ever, ever be removed).  The writers did, however, finally explain the “sideways universe” where all the characters we knew from the island seemed to be living alternative lives. It was (yawn, spoiler alert!, yawn) bardo – the intermediate state between death and whatever comes next.  I’m not wild about this ending (the wonderful Jacob’s Ladder did it better) and was hoping something more cosmological.

To that end this is a good chance to briefly review a few scientific ideas about alternate realities.  “Multiverses” – which are universes of universes – have become quite popular in physics over the last few decades being called upon to explain everything from quantum physics to why our universe seems so well-tuned for life.  But different scientists mean different things when they talk about a Multiverse.  So here is a quick primer. (The idea of the different levels of alternate universes comes from physicist Max Tegmark and you can follow that link to a story I did about his ideas in DISCOVER).

Level I:  At any given moment in cosmic history light will only have traveled so far since creation.  That means any observer at any point in an infinite universe will live in the middle of a Hubble Sphere.  A Hubble sphere is the volume that encloses everything he/she/it can see.  Beyond the Hubble sphere objects recede faster than light as they are carried along with the expansion of space (space can move at any speed it wants).  Thus Hubble Spheres are surrounded by horizons.  No information from outside can get past the horizon. That means each Hubble Sphere is its own “pocket”-Universe.  In an infinite Universe there are infinite pocket-Universes.  They will all share the same physics because they formed from the same event.

With all that space every possible set of initial conditions will have occurred at least once leading to all kinds of “alternate histories”.  Thus there is a pocket-Universe out there where you are not wearing socks today.

Level II: In the scientifically popular Eternal Inflation models of cosmology there are Universes continually popping into existence from a background of ”un-inflated” space.  Each of these pocket-Universes are swept away from each other by endless cosmic expansion.  Unlike the level I pocket-Universes, these do not share a common moment of creation and so each can have different physical laws. Gravity is stronger in some of these pocket-Universes and weaker in others. You get alternate physics and alternate history. Thus somewhere out there exists a pocket-Universe in which you are not wearing socks today and you can leap 100 feet in the air like the Hulk.

Some of the pocket-Universes in the Level II will be sterile.  The laws of physics are such that life could never form.

Level III:  If you take the mathematics of quantum mechanics seriously then you (like Hugh Everett ) will be led to the conclusion that there are infinite numbers of “orthogonal” pocket-Universes.  Pocket-Universes “split” off whenever a quantum event is registered.  This is the famous Many Worlds Interpretation (MWI) of Quantum Mechanics.  Here we think of the alternate pocket-Universes as living on different braches (sheets) of a multi-dimensional reality.  In one of these pocket Universes you are not wearing socks, you can jump like the Hulk and your cat is dead.

OK, that is it for now.  There is lot’s more to say but we’ll leave that for other posts.

I was hoping the sideways Universe in Lost was going to be something cool and quantum-cosmological like one of the levels described above.  There certainly have been many good stories that have dipped deep into this well and come up with narrative gold. Oh well…

Wait, maybe there is an alternative Universe where I wasn’t wearing socks, my cat was dead and I saw a better ending to Lost!