Do a search, and on the right of the results, if relevant, you will get some info about the topic. A mini wikipedia meets google!
See a search below for Einstein:
No doubt the idea will be to have us randomly surfing and staying on Google. Now the question is, what (if any) impact will this have on those of us doing online marketing, and how can you use this change to your advantage?
Here's the Google Blog if you want to learn more:
Official Google Blog: Introducing the Knowledge Graph: things, not strings
