[meteorite-list] Re: Tektites II (PART TWO)
From: meteorites_at_space.com <meteorites_at_meteoritecentral.com>
Date: Thu Apr 22 09:43:32 2004
PART 2 from Part One Re: "Tektites II"
> The question is how big an object can airburst? The lower its
> density, the bigger it can be and still airburst. But there is an upper
> limit to an airburst imposed by the lower limit on density.
> Fiddling with the limits set by tidal forces, self-gravity, and
> structural limitations (below the densities of frozen gasses, only voids
> will lower the density further), I'm willing to postulate that an object
> with a density of 1/10th that of water could conceivably exist.(Frankly,
> I doubt it, but I notice you never say how fluffy you think fluffy is,
> just that it's fluffy enough.) Such an object would be about 85% voids.
> That's really foamy.
Again you are reading words into the "fluff ball" that I never intended nor
implied. What you are doing is what I remember in my studies of philosophy
not to do-- Create "straw men to knock down to support one's argument"
Franky, I also doubt that the objects that you describe in the above exist.
The fact is, and as I repeatedly stated before, comets ARE NOT as solid as
asteroids that the impact models are based on. The fact is that we do not
know the physical structure of comets, and or whether Solar radiation can
penetrate its surface and to what extent that penetration is.
In this regard, it is quite possible that the jetting observed on comets,
Halley's in particular is due to the penetration of light and infra-red
energy deep into its the surface. This could, and most likely is the
reason for the jetting of gasses that were observed from its nucleus. And
this could also be a major reason for them breaking up in the first place.
And it could also explain the reason why the Great Comet of 1882
(Biela's Comet)broke up into at least 6 discrete objects. Again, what
would the effect of transparency be as such fragile a comet entered the
Earth's atmosphere? Rapid disruption would most likely be the result as
solids in the comet absorbed energy generated by atmospheric friction,
converting it to heat which would then vaporize the gas around it causing
it to break off the layers above it, further exposing fresh ice
(perhaps more transparent than the layers above it-- on and on and in a
millisecond of the start of the process--
MEGA-TUNGUSKA EVENT-- MILES ABOVE THE GROUND. But with the bottom of that
atmospheric crater touching the ground. It would be a huge and hot "crater
in the air" vaporized cometary material, and terrestrial material as well
as jetting it thousands of miles up into space---
]Now do you see the picture that I see?
My brain works like a MAC- Not a PC
I see things in pictures-- It is the way I think. And I see it clearly.
> Huge, mega-Tunguska events also produce blast waves that are "exactly"
· like thermonuclear blast waves, but on a much, much larger scale….
> There will then be a bright and very intense flash-- just as
> in a thermonuclear explosion. In this regard, Dr. Roddy and previous to
> that, the late Dr. Shoemaker both told me that the energy release
> dynamics of Tunguska type events, are "identical" to the energy release
> dynamics of thermonuclear airburst explosions.
> No one disagrees with this, Steve. You're making my point for me. In
> a sufficiently energetic event, nothing matters but the raw parameters
> of energy. There's no difference; energy is energy. Whether the energy
> comes from a fast dumb rock or a sophisticated gadget like a super bomb.
> If it's a kinetic event, above a certain energy level it just doesn't
> matter about its composition or structure or anything, whether it's a
> million tons of iron or a million tons of goose feathers.
WRONG! Back to the drawing board for you.. Structure does play a part
in not only the release of that energy in the terminal blast-- but WHEN.
Up to the terminal blast the meteoroid is behaving differently than when
that blast occurs. For most impactors that produce craters on the ground
they are vaporizing all the way, dissipating energy all along the way.
There is a shell of plasma in front of them and pressure is being exerted
against them till they either break or impact the ground. When or if they
break up, often it produces nothing more than a shower of meteorites.
But if they hit the ground at hypersonic speed ALL of their remaining
kinetic energy is release in an instant-- Result-- KABOOM-- a crater
If the structure of the impactor (comets) is such that they not only break
up but vaporize in a cascade (such as the Russian researchers proposed with
Tunguska) then all of that energy is released in that instant or near to it.
Until then, hypersonic objects are behaving pretty much in the realm of
Newtonian physics. But once they abruptly stop at that speed, either in the
air, or on the ground a entirely different dynamic takes place.
Conservation of energy, thermodyanamics, enormous kinetic energy turns
to enormous heat. Whether it be on the ground in a cratering event or high
up in the Earth's atmosphere in a terminal blast (crater in the air)
structure does play a part.
> The question is, as always, how big? Ok, I gave you your 1/10th of
> water density. That reduces to the following maximum airburst, that is,
> it just barely fails to hit the surface. The object is about 130 meters
> in diameter. It weighs about 90,000 tons. The impact energy is around
> 5,000,000 tons of TNT equivalent. That 5 megaton burst is sort of medium
> for a fusion or boosted fission bomb. (The biggest "H-bomb" ever
> exploded was 60 megatons, by the Russians.) That's the top yield for a
> low density object possible in an airburst. The object could be much
> bigger, of course, but then it would reach the surface and create that
> crater you're trying to avoid.
Try Tonle Sap in Cambodia--- It may very well be be just such a
"crater that I am trying to avoid"
An airburst of the magnitude that would otherwise have produced a crater
on the Earth's surface of 100 + Km in diameter would and probably did
produce some depressions on the Earth's surface. Our problem is to be
able to recognize them as they I imagine would be substantially different
than what would have been produced had the impactor reached the ground.
A model must be formulated that shows the effect of a Mega Tunguska event
not only to the air, but to the ground as well.
> The real Tunguska object produced a much bigger explosion (about 5
> times bigger). Its burst pressure of 3000 pounds per square inch
> (compared to the much lower bursting pressure on your low-density
> object) is what created the higher yield.
SRS> What "low density object" are you talking about, Kelly? Comets, or
those ultra "low density" fluff balls that you keep trying to put into
my mouth? Your idea is a as I stated before a "straw man"
Comets-- that is what we are talking about.
> There can't be a mega airburst. Airbursts, as the physics of the
> situation limit it, are confined to a narrow range. That range lies
> between, on the one hand, airbursts that occur so high up the blast is
> dissipated and unnoticed at the Earth's surface (likely very weak
> objects and/or very fast ones) and airbursts that occur just short of
> the surface and which transmit most of their force to the Earth below.
> Tunguska is an example of that. The many nearly megaton blasts at very
> high altitudes detected by early warning satellites like the DSP-647's
> (hush, hush) are examples of the former. These weak objects, whatever
> they were, are probably the closest thing in the real world to your
> hypothetical low density objects, Steve, but don't rush to the DoD to
> get the data, because they threw the data away after they decided they
> weren't weapons. Military... intelligence?
Your point? Again you seem to be going to the "low density" object.
And as Tunguska certainly demonstrates there CAN be mega airbursts.
You are talking about one thing and I another. A Mega-Tunguska event
will not be like what you propose in the above. And the dynamic pressure
of an atmospheric thermonuclear explosion at the center of the explosion
and in its plasma is close to a lab vacuum at some stage in its evolution.
Now in a Mega Tunguska event, I never said that these occur only at
very high altitudes-- they can happen and probably did happen at altitudes
between 5 and 20 miles. And forming a crater in the air can blow away
the atmosphere from he ground up to space itself. Now , go back and
figure the above for an object that explodes five to ten miles above the
Earth. Tell me that the effects will NOT be noticed. Tunguska--- And
that was a small one.
And tektites reveal that there were bigger ones-- Mega Tunguska.
> As I pointed out, Kelly. I am no "arithmatic expert" (spelling either),
> but I think that the basis of your calculations are wrong. If you start
> out with the wrong assumptions, you will get wrong answers.
> All science is at bottom quantitative. Verbal analogies and images
> are more often misleading than helpful. Only crunching the numbers, or
> even just approximating them, produces a clear mental picture.
But the product of such "crunching of numbers" is only as good as the
data that goes into the calculations. Raw data and mathematical
assumptions that do not incorporate all of the facts can be just as
WRONG as philosophical analogies.
Garbage in-- Garbage out applies just as well to mathematical approaches
as it does verbal ones. Mathematics is a language, and it abides by the
rules of logic just as much if not more than speech. So, there you have
it. Your equations only address energy yields of terminal blasts. They
only address rough density estimates for objects that YOU are speculating
about. BUT you have not, nor can I or anyone at this time provide the data
regarding the nature of comets, ie their actual density transparency to
radiation, and structure that WILL factor into whether they make it to the
ground to produce a ground crater and release essentially what will be
thermonuclear levels of energy, or whether they will do the same in
the air. What we should be talking about is the events that lead up to
that release-- not the release itself. The question here is whether
(large) comets can terminal blast in the air, instead of on the ground..
> Air bursts. Mega- Tunguska events, just as I explained, and as he
> explained could and most likely are the cause for tektites.
> Again, airbursts occur in the range between a few kilotons of TNT
> equivalent and perhaps as high as 50 megatons (dense, slow, weak
> objects) and I sure wouldn't want to stand under one. But these energies
> are insufficient to create tektites. Since airbursts this size are not
> that uncommon, if they created tektites, even little fields of them,
> there would be many small tektite fields all over the planet. But there
> ain't. And since airbursts are limited in maximum size, they couldn't
> have produced the big fields of tektites either.
> I know John Wasson (1991) first floated the idea of cometic
> airbursts to explain the Muong Nong glasses, but you'll notice that he
> hypothesized a huge number of airbursts all in the same place to do it.
> The one big airburst can't occur. The problem with the many little
> bursts is that it's a hell of a coincidence.
REALLY! I did not know that John Wasson proposed this? In fact it might
support much of what I am saying if one considers that a comet might
break up the very instant that it hits the Earth's atmosphere! 50 to
70 miles up! (the same altitude that Leonids become luminous) Then as
I proposed, the transparency of its ice could then result in the
production of numerous airbursts. BANG-- BANG-- BANG one right after the
other and in short order. Interesting, but probably not the case. We must
know more about comets to come to is conclusion. But I think Dr. Wasson's
idea very interesting considering the suspected nature of comets. And I
will be communicating with him on it.
> But the "experts" quoted in the M. Pain article are saying that to
> create the Australasian field an energy release of 10,000,000,000,000
> tons of TNT equivalent are required, that's 10 million megatons. That's
> a 100,000 times bigger than the biggest airburst possible. It's bigger
> than big. It's 2000 times bigger than a full nuclear exchange. It's
> bigger than a Hollywood movie about asteroids. It's a major piece of
> planetary asskicking. Big.
> It had to leave a mark... if it happened. Glass and Lee's 114-km
> crater --- if it existed --- would be the fourth biggest crater on
> Earth. And it's too new to hide.
NOT UNLESS IT WAS IN THE AIR! And even though YOU cannot
imagine it does not mean that it did not happen . Tektites are the Cheshire
Cat's smile-- for one very big "cat" crater in the air-- long gone.
YOU have not PROVED that such Mega Tunguska events do not and cannot occur.
The very fact that tektites exist in the forms that the do indicate that
such events do happen, either in swarms as Wasson suggested or in one
Mega Tunguska event.
> The presence or absence of water is part of its composition, isn't
> it? I call that a major disparity. Earth got water; Venus don't ---
> makes a big difference to me. If I go to Venus, I don't pack my beach
Water was vaporized in the melt, and I suspect dissociated into its
elemental components-- gaseous hydrogen and oxygen. And it makes a HELL
of a lot of sense when one considers that a temp of only 7,000 Degrees F
is required to do this.
> Actually, we have conducted experiments that could be considered
> tektite forming tests: nuclear bomb tests. Bomb tests were conducted in
> places with plenty of sandy soils (Nevada, atoll islands) to provide the
> silica. The temperatures are certainly high enough! Billy Glass has
> written about nuclear glasses and compared them to tektites. The low
> water content of 70 ppm of the driest nuclear glasses is bandied about
> as "proof" that any really energetic event on the face of the Earth
> could produce tektites. But if you looked at bomb glasses, you would
> never mistake them for any kind of tektite; they are rotten with
> xenoliths, structurally dissimilar in almost every way. (Even the ones
· produced by airbursts.)
Glad you mentioned this.. as I grew up at on the White Sands Missile Range
Base. My dad was a rocket technician there in the late 40's and early '50s.
He took me to the atom bomb site when I was five and I vividly remember it
and the glass that you mention-- Trinitite. I picked up quite a bit of it,
and still have it as a momento of that visit more than 45 years ago.
You are right, there is no similarity between it and tektite glass.
because the conditions were not the same! One 15 kiloton atomic blast is not,
even by your own and very lengthy admission anything like a Mega Tunguska
event that would presumably create tektites. Nor did the first atomic blast
blow away the atmosphere all the way to space (cavitation) so that the
vaporized materials could re-solidify in a near vacuum. Nor does atom bomb
glass (Trinitite) represent a sampling from a very, very large region, such
as a tektite producing airburst event most certainly would. Though the
temperature is there that is about as far as the similarity goes. So, your
analogy, and the assumptions derived are faulty.
> We talk about speculation?
> The fact of the matter is, and as I pointed out before, there is
> ABSOLUTELY NO solid evidence that they came from the Moon, and there is
> ABSOLUTELY NO solid evidence for a tektite parent body, and or
· I never said they came from the Moon.
SRS> Good, then what are we arguing about?
· As for the possibly of an unique impactor of tektite-like
> composition, its chief virtue as a theory is that it would explain the
> total absence of any trace "contamination" of extra-terrestial
> (meteoritic) materials in tektites. In the standard (Melosh et al.)
> model of impact, the highest velocity ejecta is produced from the back
> central portion of the impactor as it is crushing the target surface and
> before the impactor itself vaporizes and explodes. This is the only
> ejecta that leaves the scene without mixing with "target material." If
> the tektites are produced from the terrestial "target" material by a
> common impactor (meteoritic) they will be inevitably be contaminated to
· some degree with impactor material. And they are not.
SRS> How are you so sure? Basic bulk composition is consistent with Earth
rocks. Billy Glass and others have said as much.
> The chief objection to the tektite impactor theory is the absence of
> small randomly falling pieces of tektite-like meteorites all over the
> Earth. Unless you can figure out how there can only be big tektite
· impactors and no little ones, it's a pretty good objection.
SRS> Right! We are in agreement. And if a big tektite impactor-- where's
the crater? (there goes that missing crater again!)
> I am only surprised that fewer theorists see that the absence of
> impactor contaminants is a fatal flaw in the impact theory of tektite
> origin, and that nobody much has pushed the tektite-like impactor
> theory. (I get soft-hearted over orphan theories.) Bob Haag's '97
· catalog says a good word for it.
Come on! What are we looking for? We don't even know for sure the
bulk composition of comets, the most likely culprit in tektite formation.
How much solid material besides gas and water ice is there? Estimates
have been attempted in making comparisons of the gas and dust tails of
comets, but objections to this are from those that say that the surface of
a comet may not be anything like its icy core. Dust on its surface may
be a coating caused by eons of dust bombardment, as well as being
caused as the original comet shrank over the eons, thus putting a dust
"pavement" on its surface. What are we looking for-- what are cometary
trace elements, and or gases? We plain and simple do not know enough about
them to determine what to look for.
> And if not, then I challenge one, anyone far and wide, to explain how
> such a form could be produced on any other cosmic body, other than the
> Earth, then fall to Earth at hypersonic velocity, yet still retain its
> form which was clearly, and beyond doubt formed at or very near its
> point of origin.
> I repeat it again-- The "smoking gun" for terrestrial origin of tektites
> are stretch tektites, and I think that tektite researchers should
> closely examine these forms in their quest to resolve the tektite
> Steve Schoner
> Now we're on a completely different subject. The surface features of
> tektites and their causes has been an unresolved quarrel for nearly a
> century. One school holds that the pits, grooves, and myriad surface
> features are all the result of terrestial etching, acidic erosion eating
> away at glasses of differing composition at differing rates to produce
> the features. Another school holds that the surface features are
> ablative in origin, the most obvious ablative form being the flanged
> button, of course. Shapes have been explained, successfully I think, by
> the rotation of molten spheres on single and multiple axes.
> The "stretch" form was still virtually molten liquid glass inside
> with a thin, newly solidified surface when it landed, cracking its
· "shell" and exposing the molten "taffy" inside.
SRS> Right! But I think it happened in the air, and by centrifugal force.
(at least in the very spectacular piece that I have)
· The problem is that I
> can think of many scenarios that could end this same way. I understand
> that Nininger eventually decided that the "stretch" forms couldn't have
> stayed molten all the way from the Moon and so couldn't support lunar
> origin but rather refuted it. But it does prove that the surface
> features are not terrestial etching.
> The ablative theory appeals to me, but I'll be damned if I can see
> how this crazy variety of surface features could be produced by
· ablation. I keep trying to, though.
> And since this is a completely different subject, let's save it for
> the next round of the tektite wars. Even I think this is enough... Hey,
> at this point, if anybody still reading this post? Show of hands...
> In summary, I see major flaws of one kind or another in ALL the
> major (and minor) theories of tektite origin. Since I am not by nature a
> negative nitpicker about most things, I think that is because some
> important element is missing or has been overlooked or has not yet been
> thought of. But I can't tell you what it is. Since I've been puzzling
> over these odd rocks for many years, I'd like to know the answer.
SRS> So would I. And we agree again. In my opinion, and for the
reasons previously and extensively stated, I am convinced that they
originated on the Earth in incomprehensibly immense Mega Tunguska
Now, if this is certainly the case, as the evidence seems to indicate, then
it is up to the number crunching specialists to come up with a model that
Sort of like the Pyramids of Egypt. We have no doubt that they exist, but
the never ending question is how could they have done it?
Seems that some natural mysteries, such as in tektites, offer just as much
if not more than archeological ones.
> The fact that I'm writing this on a Saturday night proves one thing,
> to me at least, and that is, I've really got to get a life...
· Sterling K. Webb
SRS> Ah… same here, we agree again… Time for me to "get a life" and
be with my family.
Steve Schoner, AMS
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Received on Tue 17 Jul 2001 09:51:49 PM PDT