Nature Notes - TM Natural History Association

The End of the World Postponed – Part 2

Details: Created: Tuesday, 05 February 2013 00:00; Written by Nadia O’Carroll

One of the most popular end of the world scenarios depicted in science fiction and Hollywood blockbusters is the impact event, when a large celestial object such as a comet, asteroid, planet or meteorite on a collision course with Earth threatens to devastate the planet. This is not pure fantasy, we are constantly bombarded from space, but fortunately there appears to be an inverse relationship between the size and frequency of impact events. Small celestial objects such as meteorites frequently collide with Earth but are either vapourised by the atmosphere or are too small to have an effect when they hit with the Earth's surface. However, when larger objects strike the planet the impact can cause abrupt, global changes that effect climate, biodiversity and even the Earth's magnetic field.

The End of the World Postponed – Part 1

Details: Created: Tuesday, 15 January 2013 00:00; Written by Nadia O’Carroll

Since time immemorial there have been predictions of Doomsday, now with instant global communication these prophecies attract international attention and have even created an end of the world industry selling trips to safe havens, bunkers, water purifiers and emergency supplies.

Apparently many end of the world events were scheduled for 2012. The most popular being on 21 December, inspired by a misinterpretation of the end of a Mayan calendar cycle. Many cataclysmic scenarios involve cosmic accidents such as collisions with rogue planets, wayward comets, reverses of Earth's rotation, polar shifts and other manifestations of cosmophobia – an irrational fear of the cosmos. Yet it is a reminder that all life on Earth is totally dependent upon the predictability of our planet's motion in relation to the universe, because this determines day, night, tides, seasons, weather, atmosphere, climate, currents, cycles etc.

North and South

Details: Created: Tuesday, 11 December 2012 00:00; Written by Nadia O’Carroll

At this time of year we tend to think of white Christmases and snowy scenes. Cards, cartoons and decorations often depict a cast of animals such as penguins, polar bears, seals, walruses and reindeer inhabiting these cold regions together. However the Arctic and Antarctic are not mirror images and the wildlife is very different. Polar bears, walruses and reindeer only live in the Arctic, penguins only live in the Antarctic, different species of seals can be found in both regions.

The Ancient Greeks derived names of the far north from the northern stars. Polaris or the North Star is the brightest star in the constellation of Ursa Minor. Another northern constellation, Ursa Major, was called the Great Bear and Artikos was the country of the Great Bear. The Ancient Greeks also realised that there would be an opposite to balance the world, and this was Antarktikos, the opposite of the Bear.

Clear and White

Details: Created: Tuesday, 18 December 2012 00:00; Written by Nadia O’Carroll

In Australia Christmas occurs in midsummer and is associated with long hot days, shimmering heat, cicadas' chorus and trips to the beach, yet many of our Christmas trappings and traditions relate to frosty midwinter weather. The experience of a snowy winter is certainly entrancing with its biting, crisp air; the crunch of snow underfoot; an indescribable clear scent and the muted shades of a landscape dominated by gleaming white snow.

Ice is translucent, yet snow, which is composed of millions of ice crystals, appears white. To understand why, we have to consider light and how we perceive it.

Whining and irritating females

Details: Created: Tuesday, 27 November 2012 00:00; Written by Nadia O’Carroll

Mosquitoes belong to a family of flies called Culicidae. There are over 3,000 species of mosquitoes worldwide and 300 species in Australia.

Although mosquito species are very diverse in habits, behaviour, flight range, diet, habitat and impact on humans, all species do share some characteristics. They are all small slender insects with 6 legs, 2 scale-covered wings and have a four stage life cycle – egg, larva, pupa and adult, of which the first three stages are aquatic, only the mature adult is terrestrial.