[amsat-bb] Re: AMSAT-NA totally metric? and now almost totally off topic.

[kc6uqh]

OK, But what is a quick rule of thumb to determine the number if threads per 
cm from pitch? Threads per inch is a simple concept and easy to apply and 
measure. Metric bolts with pitch in degrees is something I can't easily 
relate to.

Art, KC6UQH
----- Original Message ----- 
From: "Luc Leblanc" <lucleblanc6 at videotron.ca>
To: <amsat-bb at amsat.org>
Sent: Monday, January 22, 2007 2:33 AM
Subject: [amsat-bb] Re: AMSAT-NA totally metric? and now almost totally off 
topic.


> On 22 Jan 2007 at 17:43, Tony Langdon wrote:
>
>> At 03:38 PM 1/22/2007, Sil - ZL2CIA wrote:
>
> There is a lot of folks who experience free falls in their dreams...it is
> probably not related to gravity but as much scary than a real one. Could 
> be a
> dream interpreter can be usefull here.
>
> As Einstein says all is relative to the context the astronauts are falling 
> but
> they don't feel it as they remain at the same level.
>
> Is the astronauts make also free falling dreams?
>
> Back to normal programming...
>
>
>>
>> >Are you really weightless in space? Surely you're just in free fall.
>> >When the  term "weightless" is used to describe the condition
>> >astronauts experience, this is surely a literary term, rather than a
>> >scientific one.
>>
>> As it turns out, the answer is "yes" or "no".  It depends on your
>> frame of reference and the definition you use.  Using the definition
>> that weight is the force exerted by gravity, then one would presume
>> at a point near the Earth - Moon L1 point, you would be very nearly
>> weightless (there would be some unbalanced gravitational influence of
>> the Sun most of the time, but you could move around and null that out 
>> too...).
>>
>>
>> >Why spend the $20.000.000 (or 20,000,000 if that's your custom) you
>> >mention, when you could achieve that same "weightlessness" by
>> >jumping out of a building (if for a shorter time, of course, and
>> >with a riskier outcome).
>>
>> A _much_ shorter time (remember air resistance quickly builds up so
>> you soon have the same reaction force from air resistance as you do
>> standing on the ground - i.e. you quickly reach terminal velocity).
>>
>>
>> >Am I weightless when I jump off a chair?
>>
>> Depends who you ask, but most physics sources do say "no" as they
>> define weight purely in terms of gravitation.
>>
>>
>> >Are orbiting satellites "weightless"?
>>
>> See above, but after looking at a number of sources, I'll concede
>> "no" (assuming the strict gravitational definition of weight).
>>
>> 73 de VK3JED
>> http://vkradio.com
>>
>
>
> Luc Leblanc VE2DWE
> Skype VE2DWE
> www.qsl.net/ve2dwe
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>
>
>
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