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nekote
join:2000-12-16
Hopkinton, MA
2 edits | 1 nanosecond per foot, isn't it
I thought "radio" / light traveled at ~ 1 foot per nanosecond, in round numbers, so to speak.
65,000 feet up, right?
So, 65,000 nanoseconds, give or take, right?
6.5 micro-seconds, right?
So, double that as the length of a hypothetical "hypotenuse" to 13 usec and even multiply by 4 (2 full round trips).
The full 2 round trip latency would be 52 usec, right?
Call it 1/20'th of even 1 lousy milli-second (msec) of added latency.
That'd fit in, rather swimmingly, with today's existing technology (Internet / cell phone) running toward tens or low hundreds of milliseconds latency.
As to wind at 65,000 feet.
The claim is that at that altitude it is above the jet stream.
Also, that the air density is only 1/18'th of sea level.
Thus, a 60 MPH wind at 65,000 ft has the same *force* equivalent of 3 MPH at sea level.
Wouldn't take much energy / power to hold a fixed position.
But would take some comparatively pretty dang big propellers in such thin atmosphere!
Probably more toward windmill sized, I would think. | |
Phrogz
join:2001-07-18
Saint Louis, MO
| Close
Off by one order of magnitude. Ask google to do your hard computations for you:
»www.google.com/search?hl=en&q=65···e+Search
66usec one way, 132usec ideal round trip, 186usec round trip with 45 degree angle LoS, or (as you had it) 264usec "worst-case" round trip.
Your point is still valid - it's 1/4 of a millisecond. Not a noticable addition, in and of itself. | |
nekote
join:2000-12-16
Hopkinton, MA
| reply to nekote
Re: 1 nanosecond per foot, isn't it
How the heck did I screw up by an order of magnitude!
Sheesh.
65 usec base number.
2 full round trips max of 520 usec
Call it 1/2 of 1 milli-second, rather than 1/20'th.
My bad!
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