The crowning achievement of any professional writer is to get paid twice for the same material: write a piece for one publisher and then tweak it just enough that you can turn around and sell it to someone else. While it’s specious to accuse Stephen Baxter and Arthur C. Clarke of this, fans of both authors will definitely notice some striking similarities between Light of Other Days and other recent works by the two, specifically Baxter’s Manifold: Time and Clarke’s The Trigger.The Light of Other Days follows a soulless tech billionaire (sort of an older, more crotchety Bill Gates), a soulful muckraking journalist, and the billionaire’s two (separated since birth) sons. It’s 2035, and all four hold ringside seats at the birth of a new paradigm-destroying technology, a system of "WormCams," harnessing the power of wormholes to see absolutely anyone or anything, anywhere, at any distance (even light years away). As if that weren’t enough, the sons eventually figure out how to exploit a time-dilation effect, allowing them to use the holes to peer back in time.For Baxter’s part, the Light of Other Days develops another aspect of Manifold’s notion that humanity might have to master the flow of time itself to avert a comparatively mundane disaster (yet another yawn-inducing big rock threatening to hit the earth); Clarke, just as he did with Trigger’s anti-gun ray, speculates on how a revolutionary technology can change the world forever.