Re: Re: Re: Re: Re: starship-design: Re: Perihelion Maneuver

[kuo@bit.csc.lsu.edu (Isaac Kuo)]

KellySt@aol.com wrote:
>In a message dated 11/29/97 5:54:21 AM, kuo@bit.csc.lsu.edu wrote:
>>KellySt@aol.com wrote:

>>>Actualy we do currently do VLBI with optical ground telescopes, and NASA is
>>>tinkering with a project to scatter 1 meter drone scopes across an area of
>>>hundreds of miles of lunar surface.

>>We do LBI with optical ground telescopes.  So far as I know, VLBI is
>>impossible with known technology.

>>The V in VLBI stands for "Very".  What that means is that the elements
>>are so far apart that they aren't rigidly locked wrt to each other
>>within the tolerance of about 1/4 the working wavelength.

>>The moon's surface provides a very stable nearly rigid "structure"
>>to lock a bunch of elements wrt to each other, but this isn't necessary
>>with VLBI.

>A few sats parked on lunar soil is hardly a structure "rigidly
>locked to each other within the tolerance of about 1/4 the
>working wavelength."

Yes it is, actually.  It's nearly perfect--and among the best we
can hope for in the Solar System.

Unlike Earth, it has extremely little seismic activity, and unlike
most larger bodies in the Solar System, it has no atmosphere.

That makes it a big hunk of rock which doesn't vibrate much.  You
can stick things on it and be sure they're not moving with respect
to each other.

>Also we do synthetic appiture imaging over 100's of yards or even kilometers
>of fighters and space craft.  So if you prefer we could consider that as an
>example of VLBI using one insterment over a period of time.

>>>>Cars are a bit better, but not outrageously better, than several
>>>>decades ago.

>>>Cars speeds are governed by highway speed limits.

>>Not on the racetrack.

>Especial on race tracks.

Huh?  What?  You're saying that car speeds are governed by highway
speed limits on race tracks?

>>>Unrestricted the max speed
>>>for a car a hundred years ago was tens of miles per hour, just recently
>>>supersonics (700+) were runing.

>>Not on the racetrack.

>So?  .. actually it was on a race track.

"The racetrack" refers to racing tracks on which races like Indy and
Monaco are run.

>>Admittedly there was a vast improvement in automotive technology
>>between 100 and 50 years ago.  However, since then improvement
>>has largely leveled off.

>You really need to read more.  Auto tech has imptoved dramitically in
>performance, effocency and cleanlyness.  Sports cars now produce more
>horsepower with engines that were tiny by 1960's standards, while producing
>about 1/40th the polution, and with better relyability then any car of the
>60's.

The size of the engines are smaller, but not much lighter.

>>Well, since you seem unconvinced by what I deemed a blatant example,
>>I'll give another--small arms.  Today's military small arms don't
>>significantly outperform those from 40 or 50 years ago except in
>>improved reliability.

>Theres no reason to since the military personel of today can't point
>significantly more acurately then those of 40-50 years ago.

Actually, there is every reason to increase the performance of small
arms in terms of reducing ammo size/weight, which has a dramatic
impact on logistics.  (It also allows carrying more ammunition and
weight).  Also, if ammunition size/weight can be dramatically reduced,
it allows firing much larger bursts, which _does_ increase hit
probability.

However, the physics of aerodynamics and chemistry of explosives has
prevented us from making any dramatic advances in small arms.
Logistics concerns _have_ prompted reducing ammo size/weight, but
at the expense of performance.
-- 
    _____     Isaac Kuo kuo@bit.csc.lsu.edu http://www.csc.lsu.edu/~kuo
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/___________\ "Mari-san...  Yokatta...
\=\)-----(/=/  ...Yokatta go-buji de..." - Karigari Hiroshi