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What If Humans Could Live on Titan, Saturn's Moon?

"Imagine standing on the surface of  Titan , Saturn's largest moon. The sky glows orange, methane lakes  stretch beyond the horizon, and the air is so thick you could almost fly with wings strapped to your arms. But could humans really live here?" Saturn -- image credit: NASA Titan: Earth's Distant Cousin * Titan is the only moon with a thick atmosphere --- and it's mostly nitrogen, just like Earth. * It's the only world besides Earth with stable liquids on its surface. Instead of water, Titan's rivers, lakes, and seas are filled with liquid methane and ethane. * The atmosphere is rich in complex chemistry, producing "organic" molecules made of carbon, hydrogen, nitrogen, and oxygen. In other words, Titan doesn't just look alien -- it might also hold clues to how life begins. A laboratory for the Origins of Life Scientists believe Titan could be the best place in the solar system to study prebiotic chemistry -- the kind of chemistry that may ...

What is DEJA VU? What is DEJA VU?

                            Have you experienced deja vu?


         
 It's that shadowy feeling you get when a situation seems familiar.   A scene in a restaurant plays out exactly as you remember.  The word moves like a ballet you've choreographed, but the sequence can't  be based on a past experience because you've never eaten here before.


     This is the first time you've had claws so what's going on ?  Unfortunately, there isn't one single explanation for deja vu. The experience is brief and occurs without notice, making it

 nearly impossible for scientists to record and study it.  Scientists can't simply sit around and wait for it to happen to them this could take years.  It has no physical manifestations and in studies, it's described by the subject as a sensation or feeling.

     Because of this lack of hard evidence, there's been a surplus of speculation over the years.  Since Emile Boirac introduced Deja vu as a French term meaning "already seen",  more than 40 theories attempt to explain this phenomenon.  Still, recent advancements in neuroimaging and cognitive psychology narrow down the field of prospects.  

      Lets walk through three of today's more prevalent  theories, using the same restaurant setting for each.   

      1) First up is dual processing.  We'll  need an action.  Let's go with a waiter dropping a tray of dishes.  As the scene unfolds,  your brain's hemispheres process a flurry of information: the waiter's flailing arms,  his cry for help,  the small of pasta.  Within milliseconds, this information zips through pathways and is processed into a single moment.  most of the time, everything is recorded in-sync.   However, this theory asserts that deja vu occurs when there's a slight delay in information from one of these pathways.  The difference in arrival times causes the brain to interpret the late information as a separate event.  When it plays over the already-recorded moment, it feels as if it's happened before because, in a sense, it has.


    Our next theory deals with a confusion of the past rather than a mistake in the present.  This is the hologram theory, and we'll use that tablecloth to examine it.  As you scan its squares, a distant memory swims up from deep with  your brain.  According to theory this is because memories are stored in the form of holograms, you only need one fragment to see the whole picture.  your brain has identified the tablecloth with one from the past, maybe from your grandmother's house.  However, instead of remembering that you've seen it at your grandmother's, your brain has summoned up  the old memory without identifying it.


   This leaves you stuck with familiarity, but no recollection.  Although you've never been in this restaurant, you've seen that tablecloth but are just failing to identify it.  Now, look at this fork.  Are you paying attention? 

     Our last theory is divided attention, and it states that deja vu occurs when our brain subliminally takes in an environment while we're distracted by one particular object.  When our attention returns, we feel as if we've been here before.  For example, just now you focused on the fork and didn't observe the tablecloth or the falling waiter.  Although your brain has been recording everything in your periperhal vision, it's been doing so below conscious awareness.

     When you finally pull yourself  away from the fork, you think you've been here before because you have, you just weren't paying attention.  While all three of  theories share the common features of deja vu, none of them propose to be the conclusive source of the phenomenon.  Still, while we wait for researchers and inventors to come up with new ways to capture this fleeting moment, we can study the moment ourselves.  After all, most studies of deja vu are based on first-hand accounts, so why can't one be yours?

    The next time you get deja vu, take a moment to think about it.  Have you been distracted?  Is there a familiar object somewhere?  Is your brain just acting slow? Or is it something else?

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