Sunday, April 14, 2013

Unsolved mysteries as large as the Universe itself

One night a long time ago, I was camping with my family in Arkansas.  We were far from any city lights, and so the sky was very dark.  I walked out from under the trees where my family's tent was pitched, and I looked up.  I immediately jumped backwards in amazement - the entire sky was filled with stars.  There were stars EVERYWHERE!  Having grown up near a city (St. Louis), I was never able to see the night sky with so many stars as I did that night.  I am not sure I have since...

Despite that rather sentimental opening paragraph, I am not writing today to talk about all those stars (though, I highly recommend you go out to a dark site on a clear night and look up - you won't regret it!).  Instead, I am going to talk about the stuff that I couldn't see that night.  Yes, despite all of the beautiful stars that I could see (and even the really faint stars and galaxies that I would have been able to see with a sufficiently powerful telescope), MOST of what was up there is invisible to our telescopes: dark matter and dark energy.  

So, what are dark matter and dark energy?  Good question - thanks for asking!  The answer is, we simply do not know!  However, we do know that dark matter provides the necessary gravity for galaxies to form, and we do know that dark energy is causing our Universe to accelerate its expansion.  Yes, that's right - not only is our Universe expanding (i.e., galaxies are moving away from each other), but it's expanding faster and faster with time.  But other than that (and a few other things about dark matter, which I won't get into), that's really all we know. 

Now, I could go on and on and on about the various ways that scientists are studying these two mysterious phenomena, but that would lead to a lack of brevity, and even as someone who likes to read, I prefer when things are brief and to the point ;)  Perhaps I will devote a future post to each one.  But here is the amazing thing, and it is the bottom line of this post.  Both dark matter and dark energy make up almost the ENTIRE Universe!

Recently, scientists have launched a telescope into space to observe fluctuations in the background temperature of the Universe.  This telescope, called Planck, has led to very precise measurements of the percentage of different types of matter and energy in the Universe.  And here is the result:

Courtesy: USCB Deep Space Group
Everything that we see in our daily lives in addition to all the stars, planets, black holes, galaxies, and gas in the Universe - ALL of that is contained within that small yellow wedge!  Yes, that's right - we only know what 4.9% of the Universe is made of!

What's in front of us lies one of the biggest jigsaw puzzles of all time - as an analogy, we are trying to put together a 1000 piece puzzle to figure out what the picture on the puzzle is, but currently we only have 50 pieces! 

Personally, I really hope we can figure this out before my time on this planet is up because.... well, I really really freakin want to know!  Anyway, before I go onto the last segment of my post, I just want to direct you here for more information - of course, feel free to ask me questions as well.

Finally, it's been far too long since I've insulted Background Dominated. To him I say: get off your lazy butt and post something!  Geez!  Some people I know (who will remain nameless, but they know who they are) have commented on how much I am kicking your ass with posts.  As much as I love out-posting you, it's even more fun when I outsmart you on your very own topics! 

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