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In the 17th century, scientists understood three phases of matter—solids, liquids and gases (the discovery of plasma, the fourth phase of matter, lay centuries in the future). Back then, solids and liquids were much harder to work with than gases because changes in solids and liquids were difficult to measure with the equipment of the time.
The 13 Most Important Numbers in the Universe - James D. Steins Cosmic Numbers - Popular Mechanics
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Have We Found The Universe That Existed Before The Big&Bang? - Home - Staple News - StumbleUpon
Incredible Space Pics from ISS by NASA astronaut Wheelock | triggerpit.com - StumbleUpon
Go Discovery! It was October 23, 2007 at 11:40am EST when I had my first ride to space on Discovery.