Comment by bothide on [LINK] An amazing breakthrough in wireless communication, or a pipe dream? · 2012-03-05T01:16:26.486Z · LW · GW

Not correct! The Hilbert space for spin angular momentum has dimension 2 (-1, +1; left, right; up, down). The Hilbert space for orbital angular momentum has a denumerably infinite dimension (..., -3, 2, -1, 0, 1, 2,3 , ...).

Comment by bothide on [LINK] An amazing breakthrough in wireless communication, or a pipe dream? · 2012-03-05T01:12:01.506Z · LW · GW

Not correct! Linear momentum and angular momentum are entirely different things. This was shown by Euler already 1776. Any good mechanics book will show why. Read the books by Clifford Truesdell to get all the details right.

Comment by bothide on [LINK] An amazing breakthrough in wireless communication, or a pipe dream? · 2012-03-05T01:09:15.957Z · LW · GW

Not correct. MIMO is essentially a radio transmitter/antenna combination trick; angular momentum is a fundamental property of all fields and matter. Angular momentum comes in two distinct forms, spin angular momentum (like the Earth spinning around its own axis one revolution per day) and orbital angular momentum (like the Earth orbiting the Sun one revolution per year). All vector fields, including the EM field, has this property,