What is Dark Matter?

dark matter

It sounds like it came from a comic book.  Or perhaps its origins are from an old 1950’s Sci-Fi movie.  But would you believe that it is not only real, but it is something that current scientists are working hard to figure out? It just so happens that it is.  So let’s take a look into just what this strange sound substance is and what it might mean for mankind, but also for the layman.

Way back in the early 1990s scientists knew that the universe was expanding.  They had proven it through both calculations and observation.  However scientist felt that it only had so much energy to keep expanding.  They felt that since there was such a low level of energy that the expansion of the universe must be slowing down, since the expansion had to fight against the force of gravity.  It was the only thing that made sense.

In 1998 the Hubble Space Telescope observed a star going super nova.  It was millions of light years away. Because of the way that light travels when you look at far distant objects you are seeing them as they were, so the Hubble not only was looking at a faraway star, but a star far in the past.  However, this super nova caused quite the problem.  When it was studied, they found that the universe was expanding slower at the time of the super nova than it was currently.  Even with the low energy level and gravity to fight against the expansion of the universe was speeding up.  But how could that be?

Scientists around the world pondered.  They went through and re-examined all their old work, perhaps they had missed something.  They named this missing energy source “dark energy”.  At the time it was called dark since no one cloud observe it.  As scientists further studied observations about the universe they found that they could develop a model that would fit with everything they found.  However the breakdown of the model was somewhat shocking.

They determined that all matter that could be seen and observed in the universe accounted for about 5% of everything in the universe.  So what was the rest of the universe made up of?  They determined that about 68% of the universe was the dark energy, which they had found they couldn’t observe, but had shown had to exist.  The remainder, which is approximately 27%, is made up of dark matter.

dark matter

Einstein showed that massive objects cause light to bend due to their mass and gravity.  As such scientist can make maps of the universe to show where this dark matter exists.  But the problem is that when they go to observe those areas of space, the ones that calculations show have to hold something massive and the ones that light bends around, there seems to be nothing there.  At least nothing that we can currently observe.

The problem is that more is known about what dark matter isn’t than what it is.  We know that it is not the matter that makes up stars or planets.  It isn’t even the matter that makes up gas clouds and nebulae.  Calculations show that it isn’t even the stuff of black holes, there just isn’t enough to make up the amount to make the model work.  It boils down to there is stuff out there…stuff that currently there is no good way to observe or study.  Of course there is also the possibility that the model is wrong and we will eventually find something new to inform us that of that.

But isn’t more fun to live in a world where a mysterious dark matter exists?

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