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I'm looking for the title of a book where somebody created the ability to make small wormholes. These wormholes were so small, they wouldn't be seen by the naked eye. They were one directional, meaning light could only travel through in one direction, allowing only viewing, like a telescope, through the wormhole.
Later in the book it was discovered that these wormholes could also connect to times in the past (not future) revealing any and all secrets.