Square Kilometre Array 2 - Major Science Goals.
THE SQUARE KILOMETRE ARRAY 2 - MAJOR SCIENCE GOALS.
The sensitivity and wavelength range of the SKA are ideal to investigate the vast clouds of hydrogen that filled the universe in the darkness between the fading of the big bang fireball and the formation of the first stars.
Virtually nothing is known about this mysterious era because the hydrogen clouds emitted no light. The processes that formed the first stars can only be guessed at. The SKA however does not work with light but with radio waves and as it happens the clouds of Hydrogen emitted radio waves of known wavelength. Although the radio waves are unbelievably weak, having traveled over 13 billion light years, the SKA is powerful enough to receive and monitor the movement of these clouds.
The SKA should tell us about the currents and winds of the dark ages of the universe and how these forces produced the first stars and how the universe of stars and planets came to be.
Was Einstein right? So far the General Theory of Relativity has passed all tests with flying colours but will it continue to be accurate in the extreme environments of pulsars and black holes? We don’t know. The SKA will be able to tune in on these environments and measure accurately what is happening possibly opening up a new world of physical phenomena.
Galaxies are not distributed evenly through space but are arranged in a pattern – called the “large scale structure” - consisting of a network of knots, walls, and filaments. This pattern gives a lot of information about the structure and makeup of the universe. In it’s first year of operation SKA will map the Hydrogen in a billion galaxies, some of which are so distant that the light from them has taken over 9 billion years to reach us. The information gained will increase our understanding of how the present structure of the universe came to be and should give an insight into the workings of the recently discovered Dark Energy which is causing the rate of expansion of the universe to increase.
Magnetic fields are everywhere. The Earth has a magnetic field, so does the Sun and many of the planets. Galaxies, giant gas clouds, stars and many other astronomical objects have magnetic fields. Magnetism even exists between the galaxies. Because magnetism exists throughout the universe it has an important effect on the way astronomical objects form and evolve. Because of it’s amazing sensitivity the SKA will be able to map these fields and for the first time answer many questions about cosmic magnetism.
Are we alone in the universe? The SKA will be able to detect radar signals from civilisations 900 light years away, an area encompassing thousands of stars. If the SKA picks up a signal then the question of other intelligent life in the universe will be answered. If not, it may require a rethink of the whole question. Either way the SKA will address the matter in a way impossible previously.
The most exciting questions will be those we haven’t thought of yet. Radio astronomy has many fundamental discoveries to it’s credit and no doubt the SKA will add to that proud tradition. With this in mind the SKA’s versatile multi-purpose design will have the flexibility to undertake many different types of observations.