Mel,

Voyager is using radio waves, which travel faster than the speed of light (in a vacuum, too!).  But my point is more Earth to outside the solar system is ~24 hours so where did circumnavigating the globe get three days of latency?

On Sun, Jul 21, 2024 at 2:29 PM Mel Beckman <mel@beckman.org> wrote:

Chris,

Of course I do.

 -mel

> On Jul 21, 2024, at 8:55 AM, Chris Adams <cma@cmadams.net> wrote:
>
> Once upon a time, Mel Beckman <mel@beckman.org> said:
>> Because the speed of light is different in different mediums. It depends on the index of refraction. Most of the Internet is on fiber optics, and the speed of light in glass fiber is dramatically slower than in a vacuum. Long distance single-mode communication fiber typically has a core index of refraction of 1.4682 at 1550nm (mid-C-band). So the speed of light in this type of fiber is the speed of light in a vacuum 299,792,458 m/s divided by 1.4682 = 204,190,477 m/s. You have to add to that the latency of any optical to electrical transformations, which happens in most every router or switch. Three days is probably an underestimate.
>
> Uh, you do know that Voyager isn't unspooling fiber as it goes, right?
>
> --
> Chris Adams <cma@cmadams.net>