The Modern Universe
Like astronomers throughout history, modern cosmologists are interested in making an accurate model of the Universe. Starting with the laws of physics which explain how fundamental particles and forces interact, physicists derive general equations describing the evolution of the Universe's structure. Cosmologists use experimental evidence to select a set of initial conditions enabling them to solve the general equations, and calculate the state of the Universe at times in the past, present, or future. This generates a possible model, which can be tested by comparing the phenomena it predicts with observational data. In this manner, following the rigorous scientific method, cosmologists work to build a successful Universal model.
In the next section we will examine evidence for the current Big Bang model, one which arises from a set of initial conditions describing a hot dense universe. But first, in order to understand what cosmologists do, we'll have to look at the fundamentals of light, matter, and time.
Looking Back in Time
The first concept we must discuss involves how cosmologists observe the Universe. Scientists use a very special tool; one that enables them to see the Universe both in the present and in the past...
Move forward to learn about the stellar time machine...
[1.3a] Cosmic Conundrums: Cosmology