Re: TUNGUSKA

Article: <5fa30f$9t5@dfw-ixnews11.ix.netcom.com>
From: saquo@ix.netcom.com(Nancy )
Subject: Re: TUNGUSKA
Date: 1 Mar 1997 20:19:27 GMT

In article <5f4u98$19i8@news.ccit.arizona.edu> James Head writes:
>> I don't see aerodynamic stress as being anything that would
>> cause a large meteor to explode, and with a terrific force.
>> It slows the meteor down and the friction heats up its forward
>> side, without having time to penetrate inward at all far. True,
>> the aerodynamic pressure is greatest near the center of the
>> meteor's leading side, tapering off away from the stagnation
>> point, but that constitutes a relatively gradually applied force
>> whose gradient that tends to deform the meteor and break it
>> apart, if it is small enough and loosely enough bound, but does
>> not cause it to explode from inside out.
>>
>> Could your hypothesis be tested in the lab, to see under what
>> conditions a spherical pellet propelled towards a target would
>> suddenly explode with great force before reaching the target?
>> Jim Deardorff <deardorj@ucs.orst.edu>
>
> Suffice it to say that the dynamic pressure (rho*v^2) on an
> entering asteroid is very large, in excess of the crushing strength
> of rock (a few kilobars). ... As for lab tests, the top speeds
> achieved in two-stage gas gun experiments is 4-5 km/sec.
> Meteors hit the earth's atmosphere at a speed of at least twice
> that, more typically several times faster. We cannot directly
> simulate meteors in the lab.
> jnhead@anaxamander.lpl.arizona.edu (James Head)

(Begin ZetaTalk[TM])
Here we have wild assed theory presented as FACT again! You've OBSERVED meteors entering the atmosphere of Venus, have you? You've OBSERVED large meteors entering the Earth's atmosphere? What you have is the speed that shooting stars exhibit when they set fire and burn so as to become visible to you.

1. this occurs in the upper atmosphere, where the air is thin and provides less of a braking factor
2. this occurs in air surrounding a tiny object, which does not produce the large area air compression that a large meteor would produce, thus creating a braking factor
3. this statement contradicts your own experience with the braking factor that the Earth's atmosphere produces.

What do your SHUTTLES experience! They arrive on the ground going as fast as they did when dropping through the upper stratas of the atmosphere? Can't LPL put more than one fact together in a string, and contemplate them all at once! Is this a genetic failing of astronomers who work at it for a living, or do you take classes to learn how to micro-focus and exclude any data that interferes with a pet theory?
(End ZetaTalk[TM])