A Matter Darkly

A hard limit on the mass of dark matter has been set.  So that’s cool, right?

There are a couple things that I like about this story.  First, consider that this hard limit is set at 40 giga-electron volts.  This is a unit of measurement so tasty and geeky that it makes my brain noodles just tingle with excitement.  It’s like the ultimate in nerd speak because fewer than 1% of the world’s population actually know what it means.  They are the 1%.

Next, consider the following passage:

“The observational measurements are important because they cast doubt on recent results from dark matter collaborations that have reported detecting the elusive particle in underground experiments. Those collaborations — DAMA/LIBRA, CoGeNT and CRESST — say they found dark matter with masses ranging from 7 to 12 GeV, less than the limit determined by the Brown physicists.”

There are two ways that you can read this, depending on how you define the word “underground.”  On the one hand, there is my basic assumption that we have a whole subculture of scientists who wear baggy pants and like to skateboard. Not to mention, they are making all sorts of frankly audacious claims about the mass of WIMPS.  It makes DAMA/LIBRA, CoGeNT, and CRESST sound like the names of gangs. 7-12 GeV?  Those damned kids and their crazy ideas.

Indeed, this is how I initially read the article.  And then I realized that they were probably just referring to the fact that these experiments took place underground.  As in, in a cave.  The 40 GeV result is from data collected from outerspace.  That dichotomy makes a lot more sense.  But still, it’s an important lesson about the ambiguity of language.

But perhaps the most important lesson here is in the numbers themselves.  A frequently overlooked issue surrounding Dark Matter is the actual source of its mystery.  It does not interact except with its gravity.  As we all know, gravity is by far the weakest of the forces.  Dark Matter neither reflects nor emits electromagnetic radiation of any kind.  It is only detectable by its gravitational effects.

And yet, it accounts for around 23 percent of the universe.  Ordinary matter, the stuff we deal with on a day to day basis, the stuff we have wars over and have sex with, only makes up 4%.  Dark Energy, a far more mysterious substance which is responsible for the acceleration of the universe’s expansion, accounts for the rest of the universe.  Over 70%.

So, what to make of this?  There are two ways you can look at it.  On the one hand, you can relish the mystery that the majority of the universe is made up of something completely intangible and possibly unknowable.  This is admirable.  It is the source of all sorts of sci-fi tropes and wild flights of fancy.

But two important facts needs to be taken into consideration when it comes to Dark Stuff, which accounts for some 96% of reality: they don’t do anything and they are the rule, rather than the exception.  Put another way, ordinary matter is the exception, the exciting stuff.  Dark Stuff is mundane and ordinary.

Indeed, the vast majority of the interesting things that happen in the universe happen as a result of interactions of ordinary matter.  Dark Stuff doesn’t do squat.

If I were a powerful scientist with a lot of clout, I might even be inclined re-label these things.  Dark Stuff–once it’s determined just what, exactly, it is–would be better renamed Mundane.  Ordinary matter, rather than being labeled as merely “ordinary” is actually the exciting stuff.  It might be far more appropriately termed “Bright Matter” and “Bright Energy.”  It is tiny in proportion, but it packs a hell of a kick.

I am a fan of Bright Matter.  I am made of it.  My body is star dust made flesh.

Ich bin aber Sternenstaub.

How anti-matter is not anything like dark matter.

picard meets skywalker

I always sort of assumed that the galaxy far, far away (though, to be fair, all galaxies except the Milky Way are “far, far away”) was one of those theoretical galaxies made primarily out of anti-matter. Of course, if you lived in an anti-matter galaxy, you’d simply think of it as matter. To think that the Star Wars galaxy is made out of anti-matter doesn’t explain anything about the Force or anything. It just conjures up some interesting “what if?” scenarios.

Like what if Captain Picard met Luke Skywalker? It just seems to me that a messiah meeting a man of science would definitely be awkward. Though in this case, not for the obvious reasons.

So it’s often the case in science that you have two hypotheses that explain the same phenomenon. This is a good thing in most cases, because it means that there are multiple avenues in which research and experimentation can be conducted. Take, for example, the fact that there are a lot of unexplained gamma rays buzzing around the galaxy in an unexpected and unexplained distribution. It’s a mystery that’s been plaguing astronomers and physicists for some time.

You have two possible explanations for it: it’s either evidence of dark matter (matter that is undetectable and yet makes up the vast majority of the mass in the universe and has only been observed via its gravitational effects) or it’s not. In this case, it’s not. I am not altogether certain if it was an unexpected discovery or if the researchers were specifically testing this positron hypothesis.

I find it interesting because, by itself, the fact that these positrons are being generated in supernovae, flying for millions of years only to annihilate the first time they come into contact with normal matter, is not that significant–though very cool. It solves a nagging mystery that had, up until now, been considered possible evidence for dark matter. But one thing it does do, in the search for dark matter, is narrow the search down.

I’m not sure if this rules out the possibility that Dark Matter is made of Weakly interacting massive particles (WIMPs)–focusing the search on other possible forms that dark matter might take–or if WIMPs are still on the table.

In the end, it’s what you make of it. But dark matter, along with string theory and the Higgs boson, is one of those scientific enigmas that, if solved, would change our understanding of everything. And speaking of string theory, one of its predictions was confirmed and published. Totally sweet.

Singen Sie süße Lieder.