[time-nuts] Shortt Clock Recent Measurements

[Tom Harris]

The eccentric English physicist Boys made quartz fibres by attaching one
end to a crossbow bolt, heating the middle and then firing the bolt, at
what I have been unable to determine. He used this to measure the
gravitational constant by suspending iron spheres from the resultant fibre,
which of course was amazingly strong for it's diameter.

Myself I'd use a pneumatic cannon, since I have one, rather than a crossbow.


Tom Harris <celephicus at gmail.com>


On 11 December 2013 15:55, Jim Lux <jimlux at earthlink.net> wrote:

> On 12/10/13 5:57 PM, Don Latham wrote:
>
>>
>>
>>  I always thought invar was the magic metal. Quartz rod? You can get
>>> those
>>> at some reasonable cost?
>>>
>> 12 mm dia fused qtz, about $10 per ft, so under $40 to get going,
>> assuming 4 or 5 to learn how to do it right. It does break...
>> 12.7 mm dia Invar 1 m long is $530   Amazing, and quartz is better (A
>> single crystal would cost a pretty penny. I'm not sure a crystal that
>> long can be drawn using a zone furnace). Pyrex is also available.
>> These are quick 'net prices.
>>
>>
> John Strong's book tells how to make thin high-q fused silica fibers with
> an appropriate burner.  Just the thing for your torsion balance, etc. back
> in the day when a self respecting experimental physicist built their own
> equipment.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>