nanog mailing list archives
Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms
From: Marshall Eubanks <marshall.eubanks () gmail com>
Date: Sat, 24 Mar 2012 08:36:55 -0400
On Sat, Mar 24, 2012 at 12:51 AM, George Herbert <george.herbert () gmail com> wrote:
On Fri, Mar 23, 2012 at 7:11 PM, Marshall Eubanks <marshall.eubanks () gmail com> wrote:On Fri, Mar 23, 2012 at 5:14 PM, <Valdis.Kletnieks () vt edu> wrote:On Fri, 23 Mar 2012 13:16:59 -0700, George Herbert said:The physics is not conducive to improving the situation a lot. There's probably $1.5 billion in the ground already in neutrino detectors; the total combined detector bit rate is pretty poor. One experiment looking at neutrinos coming off the Fermilab accelerator had 473 million accelerator pulses with under 1.1 million detected neutrinos.Note that each pulse was probably millions or even billions of neutrinos, so the detection rate was even worse than you'd think. I saw a statistic that every second, 50 trillion neutrinos pass through your body. And the number that will interact is well into the single digits.Small detection numbers are not, per se, fatal to communication. What fraction of the photons generated by a GPS satellite are captured by your phone?Much higher fraction than with neutrinos. Remember their MFPs are measured in light-years...
Actually, at the energy they used it's more like 0.1 light seconds.
The neutrino interaction rate increases with neutrino energy, and sea water makes a good neutrino detector. You could, for a billion dollars, do a LOT better than they did.On the detector end, sure. On the transmitter end, it's just not a well collimated beam due to physics, and no matter how hard you try the generation of neutrinos is a low-efficiency process.
The beam width was < 2 meters after 1 km, equivalent to ~12 km after 1 Earth radius. The beam can be made tighter by going to higher energy and using more or better post collision focusing magnets. The KM3NeT detector in the Mediterranean will be more sensitive, 3 km across and will cost order 200 million euros. With better magnets, the existing beam could be made to be the size of that detector at 1 Earth radius. So, existing technology could certainly communicate across the Atlantic or the Pacific. The real question, again, would be what it would take to get the bit rate up. Regards Marshall
By the way, here is the original paper : http://arxiv.org/pdf/1203.2847v1.pdfYep. I meant to include the URL but forgot. -- -george william herbert george.herbert () gmail com
Current thread:
- Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms, (continued)
- Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms Jay Ashworth (Mar 23)
- RE: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms Leigh Porter (Mar 23)
- RE: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms Vitkovsky, Adam (Mar 23)
- Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms Marshall Eubanks (Mar 23)
- Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms George Herbert (Mar 23)
- Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms Valdis . Kletnieks (Mar 23)
- Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms Simon Lyall (Mar 23)
- Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms George Herbert (Mar 23)
- Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms Marshall Eubanks (Mar 23)
- Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms George Herbert (Mar 23)
- Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms Marshall Eubanks (Mar 24)
- Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms Joel jaeggli (Mar 23)
- Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms Joly MacFie (Mar 24)
- Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms Joe Loiacono (Mar 26)
- Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms Valdis . Kletnieks (Mar 26)
- Re: $1.5 billion: The cost of cutting London-Tokyo latency by 60ms Joel jaeggli (Mar 23)