Déjà Vu

Déjà Vu is defined as the feeling that you're experiencing something you've previously experienced. I find that I often have déjà vu.  The feeling comes upon me once every other month or so, and I swear by whatever I feel like swearing upon at that moment, that I've done that before, even though I've clearly never done it before.  The feeling is fleeting though, and as quickly as it came, it goes and I'm left with this uncertain feeling that I just missed something.  But try as I might to figure it out, I'm not psychologically prepared to take on déjà vu.  I'll have to settle for a verbal argument.  But that feels like a Monty Python sketch.

I've read a bit about déjà vu.  There are many ideas out there about what it actually is.  The most interesting one that I've read is that déjà vu is a time lag disconnect in our brains between visually seeing something and the brain accessing the information telling us what we're seeing.  What this means is that we see it, and our brain instantly knows what we're seeing, but then lags when trying to get that information to the vital other areas of our brain for us to fully recognize what we're seeing.  So, by the time we are completely aware of what's in front of us, a few microseconds have passed and we've already perceived what's in front of us, so our brain interprets the information twice, thus the feeling of déjà vu.  Or something like that.  I'm not technical enough to really understand which parts of the brain are involved or which signal delays are involved and the speed at which this phenomenon occurs is mind boggling fast anyways, but yet slow enough to fool our eyes and our senses.

Of course, there's the Matrix explanation; the glitch resetting itself.  But then that's not a phenomenon of the brain, but an actual repetition of the same moment over again. But then, that repetition would mean that you're traveling through time, to be able to see the same moment again. But wait, didn't I talk about time travel in my post yesterday?  Déjà vu... I like the Matrix version of déjà vu, but can't believe that reality or perhaps that this isn't reality.  I guess I'm too plugged into the Matrix.  

But what about time travel? Could it be possible to actually travel back in time and experience a moment in time again (or for the first time if it is a time prior to your birth or a place you weren't at when the event happened).  First of all, why would we want to? Living in the past is a dangerous thing to do, and ACTUALLY living in the past could present all sorts of space-time quasality issues.  This is the old "if you went back in time and accidentally killed your dad before you were born..." argument.  I prefer the chicken or the egg paradox argument.  What I'm referring to is this:  If you build a time machine, travel into the past to interact with an event, then you change the event and therefore wouldn't have an event to build the time machine to interact with, so you wouldn't build the time machine and wouldn't change the event.  Ok, let me give it to you this way.  You build a time machine to go back and stop the JFK assassination.  You go back, jump Lee Harvey Oswald just outside of the book depository and stop him from killing JFK (this assumes non-conspiracy theorist version and that Oswald was in fact the only shooter that day), now fast forward to the future, you don't have an assassination to build a time machine in order to stop said assassination.  So you can't go back in time to change the event, thus the event in the past unfolds as it should and Oswald kills JFK.  So can you change the past, no.  The paradox won't let us.  If Oswald doesn't do it, someone else will, because JFK has to die in order for you to build the time machine to go back in time to change the event.  This is clearly displayed in H.G. Wells's "The Time Machine." 

But what about building a machine that allows you to just view the past, and not interact with it.  Sort of what Ebeneezer Scrooge experiences during his time with the Ghost of Christmas Past.  Why wouldn't this be possible, since there isn't a paradox prohibiting you from just looking at it, like a rerun on TV.  Think of all the things we could learn... like did Oswald REALLY act alone?  So many historical arguments we could put to rest with a time machine like that.  But that's just my desire to get history correct, and not politically changed by the victors who wrote the history. 

And what about traveling into the future.  Our present is the future's past, so we'd need to know how to travel to the past before we know how to travel to the future, or would it be the other way around, so we could get back to the present from the past.  What if we got the timing wrong.  Say we go into the past, then come back to the present, but time doesn't stop running in the present while we're in the past and we end up at a time that we shouldn't, but thought should be the right time. In this case, we end up coming back maybe just a few seconds later, or maybe the exact same length of time we were gone for into the future. But is it our future or our present.  And what if because we came back at the wrong time, we run into ourselves in a future that we already came back to.  Then there might be two of me at one time and place, and that'd certainly cause the world to end, unlike the Mayan calendar. Maybe we should just leave well enough alone and live in the present, it's safer that way.