Every time a new discovery is made about the universe, it opens up a new box of unanswered questions. One of these boxes is marked dark energy/dark matter.
Whenever we look up at the universe at night everything we see, that is all the protons, neutrons and electrons, make up for only 4% of the mass and energy of the Universe.
The rest is the dark and mysterious stuff known as dark energy (70%) and dark matter (26%).
Scientists know that dark matter acts like regular matter when it comes to gravity but it doesn’t release light which makes it very different to what makes up the stars and planets that do their celestial dance about us.
One way they are trying to learn more about dark matter is by studying clusters of galaxies, in fact it was galaxies that gave us the first evidence that dark matter existed.
Because galaxy clusters move around so quickly there has to be a lot of matter to hold them together with their gravity. Most of the normal matter is hot gas but there is not nearly enough mass in this hot gas to hold all the normal matter together and that’s where invisible, dark matter comes into the equation.
To study some of the interesting properties of dark matter like whether it interacts with itself, the study of galaxy clusters violently colliding with other galaxy clusters has shown that dark matter can been wrenched free of normal matter which is something that doesn’t generally happen in the universe.
Dark energy is perhaps the biggest mystery in all of physics
Studying clusters of galaxies is a good way of estimating how much matter there is in the universe and this helps to work out how much dark energy there is.
Another way to look at dark energy is to look at how galaxy clusters grow with time.
It seems that galaxies haven’t grown much over the last 6 or 7 billion years and it could be that dark energy is limiting the growth of these objects.
- So if it is so that we only know about 4% of the macrocosm, I wonder if the same applies for the microcosm?
- Is their dark matter, dark energy that goes into the making of our own internal universes?
- What holds all the molecules and atoms that go into making the structure of our bodies together?
- Is it another form of dark matter or dark energy?
- If there is how would we know, what would it do if we found out and does it really matter anyway?
All of these questions I am going to mumble over as I toss back a pint or two at my local and let the universe get on with its merry way, revealing its mysterious workings in its own good time which by our standards is too bloody long anyway to really make much difference to we, who are mere blinks in the existence of creation.
(the information for this article has been shamelessly collected and reassembled from an article titled “The Universe Darkly” by Megan Watzke from the Chandra website)