Dark Matters (PS)

Once again I went in search for a subject I find interesting to blog about this week, and what I came up with was dark matter. The first article I came across was about a research project being done in Italy that is seeking to produce results of the exotic particles that are claimed to be the majority of the substance of the universe. As of yet there has not been anything that confirms the existence of these particles, but the article explained why there was some hope of getting positive results. After, reading through the piece I was compelled to look for more information on dark matter. What I found was pretty interesting. Apparently, in the realm of the universe as we know it there exist phenomena that are unexplained by what we have observed. Specifically, the speed at which stars in galaxies rotate around the galaxy is greater than should be possible for the amount of mass that is measured in the galaxy. In physics, the mass of an object exerts a force called gravity on the objects around it. This force becomes less as the distance between the two objects increases. Therefore, stars at the edge of a galaxy have less gravity acting on them than inner stars. Well, according to measured speeds of these stars’ orbits they should not be able to stay within the gravitational pull of the galaxy. That is, there is not enough mass in the galaxy to create a gravitational force strong enough to hold them at the speeds at which these stars travel. Thus, scientists believe there is a component that has not been accounted for called dark matter that surrounds the galaxies. What exactly is dark matter? Yeah, no body knows what it is. There are two main ideas which boil down into the acronyms MACHO and WIMP. I gleaned this information off of a fairly easy-to-read article. Basically, a MACHO can be considered something like a black whole or a brown dwarf, which is a ball of hydrogen gas that did not have enough mass to cause the nuclear reaction to become a star (i.e. the planet Jupiter). One cannot really see either of these if they are outside a galaxy, but they can be detected using some fancy observations and calculations using Einstein’s theory of general relativity, which proposed that light bends around super massive objects. In fact, I watched an hour long video about a guy discussing this possibility of dark matter. Ultimately, the observations of MACHOs has concluded that there are simply not enough of them to make up the entire mass needed to justify the observations of the “missing mass.” Thus, scientists are now looking for WIMPs as the remaining ingredient. Basically, a WIMP is a particle that does not react with matter very often, but according to the theory they are everywhere moving through everything. Because they only occasionally interact with known matter they are very hard to measure, and impossible to see. Basically, the research in the first article and particle smashing are the types of experiments being used to discover what exactly these dark matter particles are. I found a nice article that simplifies a lot of this information, and it is kind of funny as well. Personally, I am just waiting for someone to come along with an accidental experiment that blows all of the observations out of the water, and everybody scratches their heads saying, “huh?”