Déjà vu

 Déjà vu

Reality Checkpoint Cambridge

... the feeling of having been somewhere or experienced something before when you know you haven't.  Déjà vu demonstrates that knowing we've been somewhere before and feeling that we have are different things.

What makes it so difficult to convince skeptics of the reality of Everett's parallel worlds is that it feels as if time flows through the present moment like water flowing through a hosepipe.  It doesn't feel like the present moment just exists as a droplet in a sea of moments, some of which happen to be a bit future-like, some a bit past-like (but most neither).  Past-like moments invoke a feeling of recognition in us, and we line them up like dominoes and call them the past.  But if you've ever experienced déjà vu you know that such feelings of recognition can't be trusted.

So, if we could determine what neural activity or hormone, is associated with déjà vu, then maybe we could develop a drug that suppressed that feeling of recognition for those moments we call our past.  No information would be lost. One would still be able to reconstruct a past by querying records that exist in the present moment, including the structures in our brains we call memories.  The only change would be the loss of any feeling of recognition for that reconstructed past.  What we call The Past would then become a bit like what we call The Future, in that we'd be able to predict it (with varying degrees of certainty) but we wouldn't feel like we'd "been there" or "done that".

We feel instinctively uneasy about theories like Everett's that require us to discard the concept of time "flowing".  We say it "doesn't feel right".  But once the drug had taken effect, it would no longer feel wrong.  And it would become easier to take the scientific approach and just ask "is the theory consistent", "does it predict the facts", and "is it the simplest such theory?"

But maybe there's a simpler way to achieve the same effect as the posited pill.  The goal of meditation is to train the the brain to calm down and focus on the present, to stop rehearsing a narrative of how it arrived where it is and to stop worrying about where it will be going next.  Meditation guides tend to avoid using past and future tenses, the imperative, and even pronouns, leading to syntactically orphaned sentences like "Breathing now ... noting thoughts .. not dwelling ... and returning to the breath."  As if the future, the past, and individual identity didn't exist.  Which they don't - at least not in the ways people think they do, if Everett is to be believed.

So next time someone tells you MWI can't be right because it doesn't feel right, suggest learning to meditate!

POSTSCRIPT

I've been reading The Black Swan by Nassim Nicholas Taleb, and I came across the quote below.  The author says it's a consequence of the structure of the brain that we impose causality and narrative onto the information that we store in it. Related information is so much easier to compress, and information ordered serially is easier to retrieve (as each idea pulled out drags the next one behind it).  His argument is that it's this false understanding leads us to ignore the possibility of the uncommon but important events that he calls Black Swans, and he explains - almost as if this were a side note - how this creates an innate belief in time as linear and flowing thing:

"Our tendency to perceive - to impose - narrativity and causality are symptoms of the same disease - dimension reduction.  Moreover, like causality, narrativity has a chronological dimension and leads to the perception of the flow of time.  Causality makes time flow in a single direction, and so does narrativity."