$1.5 billion: The cost of cutting London-Tokyo latency by 60ms

Sat Mar 24 04:51:37 UTC 2012

On Fri, Mar 23, 2012 at 7:11 PM, Marshall Eubanks
<marshall.eubanks at gmail.com> wrote:
> On Fri, Mar 23, 2012 at 5:14 PM,  <Valdis.Kletnieks at 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...

> 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.

> By the way, here is the original paper : http://arxiv.org/pdf/1203.2847v1.pdf

Yep.  I meant to include the URL but forgot.

-- 
-george william herbert
george.herbert at gmail.com