To everyone in this thread bringing up things we don't understand yet: you're right, but probably missing the point he's trying to make.
What he means is that we have a theory ("Quantum Field Theory") that is mathematically capable of predicting every physical phenomenon we're capable of observing here on earth with any instruments we've invented to date. He's definitely not saying we understand everything about the universe. By analogy, it's like saying we know conceptually what a Turing machine is and how it works, but not everything about computer science and software engineering.
It may also turn out that quantum field theory is somehow wrong, in the same way that we replaced Newtonian physics with relativity and quantum mechanics. But we still use Newtonian physics in engineering because it's only wrong in ways that rarely matter in practice.
I highly recommend watching Sean Carroll's talks and picking up one of his books. A few suggestions:
What he means is that we have a theory ("Quantum Field Theory") that is mathematically capable of predicting every physical phenomenon we're capable of observing here on earth with any instruments we've invented to date. He's definitely not saying we understand everything about the universe. By analogy, it's like saying we know conceptually what a Turing machine is and how it works, but not everything about computer science and software engineering.
It may also turn out that quantum field theory is somehow wrong, in the same way that we replaced Newtonian physics with relativity and quantum mechanics. But we still use Newtonian physics in engineering because it's only wrong in ways that rarely matter in practice.
I highly recommend watching Sean Carroll's talks and picking up one of his books. A few suggestions:
* https://www.youtube.com/watch?v=GFMfW1jY1xE - "The Origin of the Universe and the Arrow of Time"
* https://www.youtube.com/watch?v=Vrs-Azp0i3k - "Higgs Boson and the Fundamental Nature of Reality"
* http://www.amazon.com/Eternity-Here-Quest-Ultimate-Theory/dp... - "From Eternity to Here: The Quest for the Ultimate Theory of Time"