Upper limit for DSD rate determined by physicists

[Dave Zan]

...assum[e] 10 to the minus 33 seconds is the smallest quantum of time...

Carlo Rovelli's book "The Order of Time" and on p83 he says the quanta of time, or Planck time, is "around" 10 to the -44 seconds...11 orders...difference!

Don't want to be too serious in a humour thread but it turns out some of the jokes are actually quite close to the truth, must be the technical talent in ASR!
The context is that the Planck time is the numerical value of a certain combination of fundamental physical constants, it's not clear that it must necessarily correspond to any "quantum" of time.
The problem is, as Paul says, that the Planck time is around 10 to the -44 seconds and therefore so small as to be beyond any possible chance of direct experimentation.
So the idea in the source paper is (more or less) that it is possible to detect indirect effects of quantisation, similar to jitter, much better than we can directly measure small time intervals.
Even with an audio DAC and frequencies around ~20 kHz we can measure the effects of jitter in the order of a nanosecond or so (dependent on the noise floor etc).
So they look for effects in very stable oscillators and determine the hypothetical "time quantisation" jitter must be less than 10 to minus 33 seconds.
That sets a limit value for time quantisation, the frequency can be at least that so we haven't reached the DSD limit yet
It's impressive to reach 10 to the -33 but it's still 10 to the 11 short of Planck time.
End of pedantic bit, I don't want to spoil the fun (unless anyone actually likes more real physics discussion)

Best wishes
David

 

[ReaderZ]

Don't want to be too serious in a humour thread but it turns out some of the jokes are actually quite close to the truth, must be the technical talent in ASR!
The context is that the Planck time is the numerical value of a certain combination of fundamental physical constants, it's not clear that it must necessarily correspond to any "quantum" of time.
The problem is, as Paul says, that the Planck time is around 10 to the -44 seconds and therefore so small as to be beyond any possible chance of direct experimentation.
So the idea in the source paper is (more or less) that it is possible to detect indirect effects of quantisation, similar to jitter, much better than we can directly measure small time intervals.
Even with an audio DAC and frequencies around ~20 kHz we can measure the effects of jitter in the order of a nanosecond or so (dependent on the noise floor etc).
So they look for effects in very stable oscillators and determine the hypothetical "time quantisation" jitter must be less than 10 to minus 33 seconds.
That sets a limit value for time quantisation, the frequency can be at least that so we haven't reached the DSD limit yet
It's impressive to reach 10 to the -33 but it's still 10 to the 11 short of Planck time.
End of pedantic bit, I don't want to spoil the fun (unless anyone actually likes more real physics discussion)

Best wishes
David

Also Planck length has never actually been proven to be the actual smallest length possible. So how close this can get to Planck time may not be so relevant?

 

[Dave Zan]

Also Planck...not be so relevant?

Yes, the Planck distance is like Planck time (and the other Planck units), it's a numerical value from a certain combination of basic physical constants and doesn't necessarily correspond to any "quantum" of whatever.
What it does correspond to is the scale at which current physics must break down.
For instance, as @RayDunzl pointed out, the Planck mass is ~ 20 micrograms and that is sure not a quantum of mass.
But it's the amount of mass that makes a Planck sized black hole, where current quantum mechanics and relativity theories are incompatible.
Fun mind-stretch - The Planck mass is the same as about 2 mm piece of human hair.
Hard to even measure on a balance scale.
And that's the gravitational attraction of this piece to the whole planet earth.
Now think how much tinier the force between that piece and another piece the same tiny mass.
As you push them closer the force will increase, by Newton's force law that we learn in school.
Assume they are points so we can push them really close.
Push them so close that the force becomes 10 to the 40 tonnes (if we cheat and misuse "tonne" to conceptualise the force).
So the force is five thousand billion times the mass of the sum.
That's the Planck distance!
Hopefully that helps visualise why the physics moves into a realm that human experience and intuition have not yet been able to illuminate.
It always reminds me of small children who talk about sex, based on stories from other children only a bit older or a momentary look at a porno.
They think they are so sophisticated - and don't have a clue.

Best wishes
David

 

[carlosmante]

It's rather the opposite. The shocking news for analog afficionados is that vinyl, actually all analog sources are inherently digital (sampled in time, discrete volume).

Not.

 

[Hipper]

 

[bennetng]

Whatever the sample rate limit is, when it is reached, the only thing you can do is using more bits, so a single bit format like DSD will eventually lose, at least on bitrate.