[time-nuts] Those pesky Neutrinos again...

Hal Murray hmurray at megapathdsl.net
Mon Nov 21 03:49:13 EST 2011


michael.cook at sfr.fr said:
> I heard on the BBC the other day that a repeat experiment is planned,
> firing neurinos from the US into Canada. The labs were not cited, but I
> expect it would be Fermilab  to Sudbury Ontario. If this is the case,  then
> there will still be the problem of not being able to run a parallel  fibre
> as the Sudbury detectors are  also deep underground. ...

I don't think that running a parallel fiber will help much.  I see two 
problems.

First, fibers don't run in straight lines.  Even if you could accurately 
survey the pipes in the ground, there is slack in the fiber within the cable 
bundle so it doesn't break if somebody pulls on the cable.

Second, the speed of light in fibers isn't known to the required level of 
accuracy.  (It's probably temperature dependent.)

In the context of fibers, having the detectors located deep underground in 
not a problem.  They have to get power and data cables down to the 
instruments somehow.  It would be easy to run a fiber in parallel with those 
cables.

There is also the delay in the amplifiers that you will need every 100 miles 
or so.  Or the low rise time if you try to avoid the amplifiers because you 
don't need much bandwidth...



-- 
These are my opinions, not necessarily my employer's.  I hate spam.







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