The question “What is the universe made of?” is one of the most fundamental questions one could ask about reality, yet the lack of answers leads to one of the biggest problems in modern astrophysics and cosmology. It would first appear that the observable universe is chiefly composed of matter and energy, right? Well, that’s actually not true at all. Everything we can see, the Earth, the Sun, the Moon, every star and every galaxy in the sky, every atom and every photon of energy, constitute roughly five percent of the entirety of the universe. What about the rest? What else is there? Roughly twenty-seven percent is dark matter, and a whopping sixty-eight percent is dark energy. Not a single human on this planet knows what dark matter and dark energy are, unless of course they haven’t told anyone. All we can do at the moment is measure the effects of what we call dark matter and dark energy on the physical universe, and apply these labels to the unknown.
Before we get into the history and details of dark matter, know that the term “dark matter” is a misnomer. We don’t know if what’s causing the observed effects that we call dark matter is actually made of matter (although popular hypotheses suggest that it could be baryonic matter or weakly interacting massive particles), we have no clue what it is. There are observations that we can’t explain, and we call them dark matter. That’s it. We’ll come back to this and go into more detail in just a bit.
Continue reading “Problems on the Forefront of Physics – Part 2: Dark Matter and Dark Energy”
The Big Bang, apart from being a popular TV sitcom, is a cosmological event describing the origin of the universe in scientific language. It is an attempt to marry the present observable properties of the universe with our fundamental understanding of the laws of physics and to work that backwards in time as far as possible. It tends to be flung around in discussions and debates as a popular buzz word and is met with harsh criticism by proponents of supernatural creationism for example, those who assert that God created the universe. The problem, I find, is that most people who are aware of the big bang theory are very much unaware of how it works. Furthermore and perhaps most troubling, they are unaware that people far more educated than themselves, who are experts in cosmology and astrophysics, have their own doubts and criticisms about the theory, which they are still trying to square with current observational data. Having said that, if you interpret this as an admission of how weak the theory is, you are dead wrong. The reality is precisely the opposite. It’s the continued rigor of scrutiny applied by the scientific community that has refined the big bang theory to the degree of accuracy that it holds today. It is necessarily incomplete because we lack a Grand Unification Theory as well as a way to account for much of the mass in the universe but it is still the best theory available and will continue to solidify into a complete model as we inevitably uncover the missing pieces of the puzzle, given sufficient time.
The Big Bang in a Nutshell
Continue reading “The Big Bang Model – A Timeline of Events Explained”