Thursday, October 7, 2010

Ice and water

I was watching a show on the preview channel Planet Green about scientists doing research on arctic pack ice (that is, the artic ice cap, which floats on the arctic ocean, not on land). A statement was made to the effect that if the arctic ice cap (the pack ice) melted, sea levels would rise worldwide. This threatens my intelligence, and I proceeded to perform an experiment to disprove this falsehood.

I took my McDonals's cup, put a large chunk of ice in it, and filled it with water to one of the lines on the side of the cup. Then i let the ice melt (with the lid on the cup to minimize evaporative loss) and checked the level after most of the ice melted. As expected, the water level was unchanged.

You see, floating ice displaces its weight in water volume. Thus, when the ice melts, the resultant water volume exactly equals the volume displaced by the portion of ice that was under water, resulting in no change in the water level.

Now, land-based ice is, of course, a different story. However, check out  this guy's article about Myths and Realities of "What If All the Ice Melts?"  Good info there. Further, read his  article on global warming - I've only skimmed it, but again, good, clear info there.

Totally unrelated, why must tv shows pad their air time with pre-commercial previews of what's coming after the commercial, and post-commercial summaries of everything that has happened in the show before the last commercial? Waste of time, it is. Just show me new material while it's not in commercial, not rehashes of what's come before or is to come next. Ok, maybe not totally unrelated, as I did mention I was watching a show, sparking the experiment and thoughts on global warming and ice vs. sea levels.

Ok, then... later!

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