While some things about computers are “virtual,” they still must operate in the physical world and cannot ignore the challenges of that world. Rear Admiral Grace Hopper (one of the most important pioneers in our field, whose achievements include creating the first compiler) used to illustrate this point by giving each of her students a piece of wire 11.8 inches long, the maximum distance that electricity can travel in one nanosecond. This physical representation of the relationship between information, time, and distance served as a tool for explaining why signals (like my metaphorical sign above) must always and unavoidably take time to arrive at their destinations. Given these delays, it can be difficult to reason about exactly what “now” means in computer systems.
Although you can’t really define “now” – you can timestamp things as having happened at an agreed UTC moment. You can also schedule for things to occur at a particular wall-clock time in a given time-zone (Long form) without knowing at the present time when that will actually transpire (since a leap second might be declared or a time zone alteration occur in the middle) – but once that time has occurred, you stamp it as having occurred at that moment, UTC.
Factoid: Electrons in the CERN LHC proved that electrons can move faster than that. 0.999999991c, or about 3 meters per second slower than the speed of light (c)
Yes, in a near perfect vacuum, and with a huge amount of energy behind and in front and on the sides of them, you can accelerate electrons to near the speed of light.
The problem is, in almost any medium, and more specifically wire, they travel orders of magnitude slower, and people often forget that.
Actually, the velocity of individual electrons has little importance to the current inside the conductor because what is important is the propagation of the perturbation to the electrical field and, as you probably guess, it is close to c (slightly less) on good conductors (i.e., when you alter the position of an electron inside the conductor, other electrons will sense it by the alteration of the electrical field on that medium). It is, though, important on insulators.
At least, that is what I recall from learning electromagnetism many years ago.
There is no proper “now” even in our brain – we perceive reality with a delay as the signals from all our nerves has to takes some time to reach our brain and brain needs some time to process this info. And actually brain does some buffering for processing. So our perceived reality is actually few milliseconds in the past.
In sound, timing is everything, especially in music.
We all hear in stereoscopic sound, and as we move our heads our brain calculates the delay changes between the ears to determine the distance, the direction, and the timbre of the sound.
This issue is also at the root of why wireless stereo speakers are problematic – you can’t keep those 2 signals in sync over the wireless network well enough to present a consistently accurate soundstage.
This does not affect transmitting stereo files wirelessly, because the two channels are joined in 1 file. But when transmitting them to individual speakers, wired delivers far more clock stability than anything wireless in 2015.
Never heard about this problem. Are you sure the problem is not on the quality of the receivers and transmitters?
Perhaps, a well made device operating a fast protocol and frequency would fix the delays.
Something to check …
Edited 2015-03-12 15:01 UTC
Or you are walking head first into audiophile territory…
Nope, really not.
More and more this global network of ours reminds me of a nervous system, with every computer (routers etc included) some kind of neuron.
This with mixed emotions, as i find myself wondering what will happen when it trips the self-awareness threshold.