Every question on Reddit can be googled, I asked because every article I read and both those links you gave just describe how it works on surround sound speakers, I'm specifically asking how this surround sound effect is achieved in headphones. I understand it's a "3d audio landscape" but how can you achieve 3d audio on headphones?

The distant universe is that standard term used, same reason If you were in England you could say Japan is the distant earth.