Re: [ATM] Wind resistance & golf balls

["Alan Scott" <alanne1956@hotmail.com>]

I suspect that the reason that this works with golf balls has to do with the 
size of the indentations.  I suspect that you need to keep the size of the 
indentations the same.  So, you would need gazillions of little tiny divits 
- NOT round hammer head dings.

Also, realize that is happening with the golf ball.  There is less 
resistance at 100 miles/hour, which says NOTHING about vibration.  You want 
to change the vibrational characteristics of the scope with a wind of 10 or 
20 miles per hour, and how the wind is causing that vibration.  Generally, I 
believe that this means changing the harmonics of the scope (maybe make it 
stiffer or add/subtract weight), and/or dampen the vibration (some folks 
hang chains that seem to do this).

You would also almost definately do better by putting your car upwind of the 
scope, thus picking up a bit of shelter from the wind.  Better yet would be 
a wall or building or wind screen.  I use the car upwind with the trunk open 
method all of the time.


Alan Scott
http://www.xmission.com/~alanne/Astronomy.html

>From: Ken Lowther <hermit@outofoptions.org>
>To: atm@atmlist.net
>Subject: Re: [ATM] Wind resistance & golf balls
>Date: Thu, 31 Mar 2005 15:33:11 -0500
>
>
>
>Quoting Roger Chisholm-Batten <rogecb@tiscali.co.uk>:
>
>>At a recent viewing session the wind got up a bit and started shaking
>>my 8.75 inch sonotube scope.  A friend who was observing with me
>>commented adversely. He is a keen golfer and suggested that I think
>>laterally and take the example of a golf ball.
>>
>>To cut resistance golf balls have regular indentations all over. The
>>suggestion was that I do the same with my tube.
>>
>>Advice please.  How many indentations per square inch would you
>>recommend and would hitting a round hammer head against the tube be
>>sufficient to create permanent dents?
>>
>>I appreciate that objective views may be a little thin on the ground
>>as this is such a giant leap in ATM thinking.so few ATMers would have
>>contemplated let alone performed the proposed.  All ideas appreciated.
>>
>Golf balls are designed to be smacked at what?  Average Golfer: 82 mph -95 
>mph
>
>Tour Professionals: 110 mph – 127 mph
>
>Long Drive Professionals (like Pinnacle’s and RhodyGolf.com’s Dan
>Boever) 135 mph –145 mph
>
>It is a little round sphere that is expected to travel about 300 yards
>average max?  And it rotates adding another dimension.
>
>This relates to your scope design how?  It was suggested years ago that
>baseball players should do this to their bats.  Hasn't happened. Why?
>Probably no practical gain in return for the effort.
>
>I would think the same would be true here.  Adding a little mass would
>probably be easier and more effective.
>
>But I am not an engineer.  I could be all wrong.  As usual. ;-)
>
>Ken
>
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