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December 2020

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From:
Yasha Karant <[log in to unmask]>
Reply To:
Yasha Karant <[log in to unmask]>
Date:
Wed, 23 Dec 2020 11:25:58 -0800
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I replied off-list on this topic, with similar thoughts as to what is 
stated below.  There are numerous issues, particularly with 
non-professional software applications not designed for "broadcast" use 
in addition to the physics and implemented technological limitations 
discussed below.  Any one who has watched "live" video plus audio using 
these non-professional applications and hardware, probably has noticed a 
speaking human in which the lips and voice are not in synchronous (audio 
and video tracks mistimed, or jitter, or both).  Even with high 
throughput non-military/clandestine service networks (for which quality 
of service keeps throughput close to purchased bandwidth), the latency 
(and in some cases jitter) of the routers, etc., make the network 
unsuitable for the purpose requested.  An alternative, that does not 
solve the speed of light issue (no Star Trek, Star Wars, etc., 
instantaneous transmission across the galaxy -- we do not know the 
physics to do that, wormholes notwithstanding), is a direct laser 
transmitter to a reflector in low earth orbit that allows the "beam" to 
be aimed to the receiver at each end of the data stream -- not feasible 
for standard civilian commercial use.

On 12/23/20 6:41 AM, Steven C Timm wrote:
> In theory light could go 5000 km in 16ms.  In practice it takes 105ms to 
> get packets from FNAL to CERN.
> (speed of light is slower in fiber, fiber doesn't go straight, there are 
> several switches).
> Even 16ms is more of a delay than you want in a musical performance. 
>   And you have to do the round trip.
> Try singing together with someone on zoom if you want to prove the 
> point.  The high-speed network doesn't give much benefit over the 
> regular internet in terms of latency.  it improves bandwidth but not 
> latency all that much.  The only way all these virtual choirs work is 
> that they send out a base track to everyone that the people have locally 
> and then each person records their part on top of it.
> 
> Steve Timm
> (Physicist and amateur church musician, computing and recording remotely 
> for last 10 months)
> 
> 
> ------------------------------------------------------------------------
> *From:* [log in to unmask] 
> <[log in to unmask]> on behalf of Keith 
> Lofstrom <[log in to unmask]>
> *Sent:* Tuesday, December 22, 2020 6:24 PM
> *To:* scientific-linux-users <[log in to unmask]>
> *Subject:* Way Off Topic - HEP Network Symphony Orchestra
> This isn't Scientific Linux, though SL and the team that
> supports it would be involved in implementation.
> 
> ----
> 
> AFAIK, we are still in the middle of Long Shutdown 2,
> with the Large Hadron Collider /not/ sending terabytes
> of experimental data through the dedicated HEP network.
> 
> Meanwhile, gathering musicians on stage for a symphony
> orchestra is a big health risk during the COVID pandemic.
> 
> The speed of sound across a symphony stage is 500,000 times
> slower than bits on an optical fiber.  In theory, musicians
> could be connected through the HEP network, spread out over
> 5000 kilometer distances compared to the 10 meter distance
> across a symphony stage.  Distances are smaller than that
> between groups of European or North American cities.
> 
> There are probably more symphony fans than high energy
> physics fans (many physicists are both), so using the HEP
> network for concerts during the COVID crisis could earn
> a LOT of political capital, and help with future funding,
> including funding for the next upgraded HEP network.
> 
> It would also develop new techniques for synchronizing
> planet-scale sensor networks.  There are likely some
> excellent astronomical and geophysical uses for that.
> 
> I'd guess that readers of this list know the people who
> know the people who know how to do this.  What could we
> slap together in a hurry?
> 
> Keith
> 
> -- 
> Keith Lofstrom          [log in to unmask]

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