Thursday 6 August 2009

Ep 110: Coral, the Stone Henge of the Pacific, and more of the sights, sounds and science of Tonga

This week's podcast takes us back across the ocean to discover more of the sights, sounds and science of Tonga - see our previous episode for more on Tongan blowholes and whales.

On location in Tonga, we tackle the topics of:
  1. Haʻamonga ʻa Maui - otherwise known as The Stone Henge of the Pacific. This is an ancient 12-tonne stone trilithon whose purpose is not exactly known, much like that other Stone Henge in the UK. A previous King of Tonga, Tāufaʻāhau Tupou IV, once claimed it had an astronomical significance as it can determine the position of sunrise at solstices and equinoxes. As it was said by the King, it is the accepted explanation for what is an odd stone construction, at least in Tonga anyway.
  2. How did people get to Tonga in the first place? The generally accepted history is that the Lapita people came down through Papua New Guinea into Melanesia and Polynesia. However, Norwegian explorer Thor Heyerdahl had other ideas based on the fact that the sweet potato (kumera) is found in both South America and Polynesia. To prove that it was at least possible that Tongans came from South America, in 1947 he sailed the Kon-Tiki raft across the Pacific Ocean from Peru to Tuamotus. Heyerdahl showed that, by using only the materials and technologies available at the time, there were no technical issues that prevented South Americans coming to Polynesia. Whilst the evidence suggests that people came through South East Asia and Papua New Guinea to reach the Pacific, one school of thought suggests that Polynesians may indeed have travelled to South America and picked up the kumera from there.
Back here in Australia, I spoke to Lachlan Whatmore about coral - what is it, how does it form, and what life does it support. Lachlan is a diving enthusiast and the golden tonsils of Australian community radio - as well as a qualified Marine Biologist. In short, coral is an Anthozoan marine organism that lives in colonies of polyps. Corals build reefs in tropical oceans - the reefs are made up of their calcium carbonate skeletons. Listen in for more.

And tacked onto the end of this show, we have a Correlation of the Week - this week discussing the relationship between eclipses and the stock market - see our previous story on the topic for more.

Listen to this podcast here:

Stay tuned for our final edition on Tonga in a few weeks.