30 November 2011

SCIENCE VIDEOS




Nearly everyone has tuned into National Geographic or a similar science series, and watched as molten lava (often filmed in Hawaii) flows into the ocean. As it submerges, the lava tube or river cools only at its surface at first ~ the super-hot interior continues to flow, bursting through the cooling crust to continue downslope until eventually, the natural heat sink of the ocean hardens the lava flow entirely ~ until the next volcanic eruption, which can originate from land or from the sea floor.

Here is a visually similar phenomenon, except the intruding liquid is water itself. As the water component in sea water freezes, it leaves behind a briny liquid that is denser than the surrounding sea. This super-salty fluid sinks, then freezes on contact with the substrate. The sea ice spreads quickly, capturing any sea life on the bottom. These brinicles are an eerie sight.

Looking up rather than down, here is a visual explanation of the origin and occurance of auroras surrounding the Earth's polar regions. The journey from the sun's interior to the Earth's atmosphere is breathtaking in the magnitude of energies and distances involved.

Finally, here are Part 1, Part 2, and Part 3 of astrophysicist and cosmologist Carl Sagan's last interview ~ with Charlie Rose on 27 May 1996. Sagan waxes poetic on science, pseudoscience, the cosmos, much more. Sagan passed from our midst on December 20 of that year. Long may he sail !

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