Saturday, August 27, 2016

Dark Matter, Dark Energy & Dark Forces Of Nature

Particle Physics

Large Hadron Collider (LHC): Physicists tend to be cautious when announcing the discovery of a new particle. An anomaly in an experimental run is insufficient reason to say a new particle has been discovered; for scientific certainty, it requires five sigma effect, or 99.99994% confidence. So far, such explains the blip found in December 2015 at the world’s largest atom smasher, the LHC. Cathal O’Connell of Cosmos magazine writes: “New particle ... or nothing at all? Unfortunately, a bump in a graph from the Large Hadron Collider turned out to be the latter.”
Image Credit: David Parker; Science Photo Library


An article, by Cathal O’Connell, in Cosmos magazine discusses the possibility of whether particle physicists are on the right track to confirming another fundamental force of nature, thus adding to the four already known. Or is this just another case of an anomaly leading to nothing significant? Such describes much of the work of particle physics today: trial and error.

Particle physicists and cosmologists, among others, are working on weird, not easily explainable, areas of science. Although the connection is not direct, much of the search for a fifth force is a result of trying to make sense of dark matter—so-called non-baryonic matter that we can’t observe, and yet cosmologists and astrophysicists say it makes up a significant part of our Universe. This is, undoubtedly, a mysterious force of nature. 

In “Have physicists discovered a fifth force of nature?” (August 22, 2016), O’Connell writes:
Everything we can see is governed by just four fundamental forces of nature. Three – electromagnetism, the strong nuclear force and the weak nuclear force – are explained to wonderful precision by the standard model of particle physics. The fourth force, gravity, is the realm of Einstein’s much-feted theory of general relativity.
While we haven’t added to this list in more than 60 years, there’s no theoretical reason for there not to be a fifth.
Dark matter, for instance, is an as-yet-unopened treasure trove of potential new physics. We know dark matter is out there, and that it doesn’t interact with ordinary matter. Might it not feel some kind of “dark force” instead?
Perhaps. One of the fundamental questions is determining what is dark matter. Both dark matter and dark energy, adding up to 95%, make up most of the known Universe, astrophysicists say. So, only the 5% measured by our instruments conforms to normal matter. In a nutshell, more is unknown than known when it comes to our understanding of the universe. The Big Bang is discussed rather casually, as if it is understood, when it is not. For example, there is a galaxy—Dragonfly 44— 330 light-years from Earth, and of the same mass as our Milky Way galaxy, which is almost entirely made of dark matter.

No doubt, there is a lot of energy being expended by all kinds of scientists to try to explain some of the strange things that, for example, particle physicists are seeing with their experiments. The question on my mind is whether this fifth force would answer the questions scientists are seeking. Or would it lead to more questions? Yet, it is not time to say that this has been proven. Far from it. If so, it would be the biggest such discovery in particle physics in sixty years.

Science, it appears, has more than a hint of science fiction informing its current narrative of beginnings.

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For more, go to [Cosmos]