History Specials
Season 1 • Episode 164: Invisible • Watch with subtitles
Episode 164: Invisible
January 27, 2013
As we look at the world around us, we think we're seeing things as they really are. But in fact, our human senses can only perceive less than 1% of what's actually there. The rest is invisible. Every day, unseen rays and waves bombard us.
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