Just finished reading "Existence", it feels like a good follow up to David Brin's earlier work "Earth". The book starts off around 2050 with the discovery of an artifact sent by an alien civilization. The book then uses different personalities to explore reactions to the find and also present a possible future based on current technology and trends. Gerald Livingstone is the finder of the crystal, Tor Povlov is a reporter on the web, Hamish Bookeman is an author interested in holding technological progress back and Peng Xiang Bin is a 'shoresteader' who finds a crystal who landed on Earth thousands of years ago.

By moving from viewpoint to viewpoint, Brin creates a tapestry of a possible future where everyone is wired in to the web, everything is monitored and people continue to try and find solutions for climate change, disasters while also trying to figure out what the aliens really want from humanity.

The seeds of this technical world can be seen in our modern day dilemmas and provides an interesting critique and optimistic view of how people will react to a world changing event, alien contact, and finding out that we are not alone in the universe. The ending is also optimistic with the belief that humans will overcome and be pushed to greater achievements when facing a crisis that has destroyed other worlds. A good read for those looking for harder science fiction with 'what-ifs' solidly built on what-is happening today.