Re: Analog is bunk, Digital is funk

Dejan Vucinic (
Sat, 22 Mar 1997 14:07:40 -0600

John K Clark wrote:
> Mass, energy, momentum, electric charge, spin, charm, and color, are
> all digital quantities.

Digital they aren't, discrete is what you probably meant. And
discrete they are not either. Spin and charge of particles are
observed as discrete values, the discreteness of color charge is
deduced indirectly, but mass, energy and momentum are observed
as continuous. Once you get to the level of quantization of gravity,
it's not clear that discreteness will have anything to do with the
quality of your theory of everything. (There's an infinite number
of correct ways to formulate QM.)

> It's true that nobody has found a quantum theory of
> gravity yet, but there is not a Physicist alive who doesn't
> think we need one,

Well, I don't really think we humans _need_ one, but I sure would
give ten years of my life to be the first to invent a working and
testable one! :) (Yes, I consider myself a physicist, lowercase,
and I'm alive to a very good approximation.)

> General Relativity is not compatible with Quantum theory and breaks
> down completely when things get smaller than the Plank Length or less
> the Plank Time. The idea of continuos spacetime is looking
> increasingly suspect.

In fact, the idea of _Euclidean_ spacetime seems to be the culprit.
Spacetime as we see it is generaly believed to be an emergent
phenomenon by some popular theorists. But, as we experimentalists
(what tribalism!) say, until I can make it go boom...