Redirect to new Page in AngularJS using $location
$location won't help you with external URLs, use the $window service instead:
$window.location.href = 'http://www.google.com';
Note that you could use the window object, but it is bad practice since $window is easily mockable whereas window is not.
If you want to change ng-view you'll have to use the '#'
$window.location.href= "#operation";