0.10-bortle.jpg from stellarium.org
Interactive 3D model of Solar System Planets and Night Sky
The Scale of the Universe Light travels at 300,000 kilometres per second (186,000 miles per second). In one second, a beam of light can travel SEVEN TIMES around the Earth. This table shows a number of distances to various objects expressed in terms of how long a beam of light takes to travel that distance.
Large-scale structure of the Universe
<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,28,0" width="920" height="518" title="scale"><param name="movie" value="/content/begin/cells/scale/Scale.swf" /><param name="FlashVars" value="mydate=2519" /><param name="quality" value="high" /><embed src="/content/begin/cells/scale/Scale.swf" quality="high" pluginspage="http://www.adobe.com/shockwave/download/download.cgi?P1_Prod_Version=ShockwaveFlash" type="application/x-shockwave-flash" width="920" height="518"></embed></object> Some cells are visible to the unaided eye The smallest objects that the unaided human eye can see are about 0.1 mm long.
Alien Earths Online - www.alienearths.org
The Elegant Universe: Part 3 PBS Airdate: November 4, 2003 NARRATOR: Now, on NOVA, take a thrill ride into a world stranger than science fiction, where you play the game by breaking some rules, where a new view of the universe pushes you beyond the limits of your wildest imagination. This is the world of "string theory," a way of describing every force and all matter from an atom to earth, to the end of the galaxies—from the birth of time to its final tick, in a single theory, a "Theory of Everything." Our guide to this brave new world is Brian Greene, the bestselling author and physicist. BRIAN GREENE (Columbia University) : And no matter how many times I come here, I never seem to get used to it.