Will it ever be possible for adults to learn a Second Language as easily as babies who learn their First Language? [closed]

Question

As of April 2016 ^■most linguistics textbooks answer 'no' to the entitled question above, but can 'yes' ever prove the answer? If so, how distant is linguistics from some breakthrough, quantum leap or paradigm shift that can turn the answer into a 'yes', to the joy of L2 learners like me?
I am hoping for astute linguists to discover and then reveal to us the cure, magic bullets, or panacea that can make L2 Acquisition as easy as L1 Acquisition.

^■From p 188, The Study of Language (5 ed, 2014) by George Yule:

[...] there are some individuals who seem to be able to overcome the difficulties and develop an ability to use the L2 quite effectively, though not usually sounding like a native speaker (i.e. someone for whom it is an L1). However, even in ideal acquisition situations, very few adults seem to reach native-like proficiency in using an L2. There are individuals who can achieve great expertise in the written language, but not the spoken language. One example is Joseph Conrad, who wrote novels in English that became classics of English literature, but whose English speech retained the strong Polish accent of his L1. This might suggest that some features of an L2, such as vocabulary and grammar, are easier to learn than others such as pronunciation. Indeed, without early experience using the sounds and intonation of the L2, even highly fluent adult learners are likely to be perceived as having an “accent” of some kind.

Answer 1

Let me answer this question with a question—is it really that easy for babies to learn a first language? While learners of a second language can walk away from day one able to greet and bid farewell to native speakers, babies will take around a year of exposure before they form their first words. Adults can learn sentence structure over a few weeks or months, babies and small children will take years. If you consider a ten year old child speaking his or her native language and an adult who spent the last ten years completely immersed in the same language but learning it as his or her second, which do you think will be more fluent? Even if the adult retains an accent, he or she will likely have a greater vocabulary and more knowledge about grammar and structure.