My current question is what does the <operator in Ruby mean? But my real question is: how can I find Google to find the answer?
Google for "ruby operators" (without quotes), open the first link in a new window, use your browser to search for '<<(without quotes).
"shift left ruby operator"
Google will only find something if you are looking for words and numbers ...
If you're happy to use a non-Google search engine for your Google search, try using symbolhound.com
<<ruby
A Google Code search allows you to search for source code repositories, so you might find "<" examples in Ruby to help you understand what is going on.
Use the search for "ruby operators" Joe Casadonte suggested finding the words you need, and then Google use these words?