Neural nets have been around for quite some time. Why are they working now?

Geoffrey Hinton has 2 slides addressing this question in the talk:

Geoffrey Hinton quickly addresses the question in his 'talk':https://www.youtube.com/watch?v=IcOMKXAw5VA&feature=youtu.be&t=21m29s

 
!<{margin-right: 20px; auto;display:block;border: 1px solid gray;}blog/deep-learning-what-was-wrong-in-1986?wrong1986.jpg !

!<{margin-right: 20px; auto;display:block;border: 1px solid gray;}blog/deep-learning-what-was-wrong-in-1986?wrongview1990.jpg !

I recommend the whole talk
https://www.youtube.com/watch?v=IcOMKXAw5VA&feature=youtu.be&t=21m29s

!<{margin-right: 20px; auto;display:block;border: 1px solid gray;}blog/deep-learning-what-was-wrong-in-1986?wrong1986.jpg !