gistfile1.rb

class Foo
  Object = nil
  def getBinding()
    binding()
  end
end

Foo::Object #returns nil
Object #returns Object

eval("Object", Foo.new.getBinding()) #returns nil
eval("::Object", Foo.new.getBinding()) #returns Object

class Foo
  ::Object = nil # warning: already initialized constant Object
end

Object #returns nil