A Recent Project Undertaken by the Swinburne Visualisation Team Was to Create a Series

THE SKA

A recent project undertaken by the Swinburne visualisation team was to create a series of animations of the next generation of radio telescopes.

To be able to categorically describe the creation of the Universe and the associated physics is the ultimate goal of cosmology. Cosmologists and quantum physicists have theories that account for the creation process back to 10-43 seconds after the ‘The Big Bang’. How accurate are these theories? They are generally well supported by observational evidence and some modifications have been made in the light of new observations.

However, the desire to get a better picture drives astronomers to build bigger and better telescopes.

For astronomers, bigger is generally better as the larger the collection area, the more radiation can be recorded and analysed. A common analogy is to compare the amount of rain you could catch in a cup compared to the amount a bucket could catch. The ability of a telescope to resolve detail is primarily due to its aperture. (The Hubble Space Telescope can resolve details to about 0.1 arc seconds.)

Radio telescopes need to be bigger than optical telescopes to achieve the same resolution because the wavelengths they detect are much smaller.

There are several larger radio telescopes, the largest single dish in the world being the Arecibo Telescope.

Most large radio telescopes are, however, a congregation of smaller telescopes linked together to simulate a larger single dish.

Plans are now underway to build a radio telescope along similar principles that has a collecting area of 1 km2 – The Square Kilometre Array. That is a ‘bucket’ 1,000,000 m2 in area!

Several proposals are being looked at, one of which is located in Australia. The array would look something like this:

The array consists of towers of ‘Luneberg Lenses’.

Here is an animation of how the Luneberg Lens focuses radiation:

Why is Australia being considered as a location? The following map shows the intensity of man-made radio emissions around the globe. This is the equivalent of light pollution for optical astronomers. It can be seen that Australia is relatively ‘radio quiet’. Another factor that may influence the decision is that from Australia we can ‘see’ the galactic centre. The centre of the Milky Way cannot be seen very well (or not at all) from locations in the Northern Hemisphere.