[meteorite-list] Re:Comet hit Britain in mid sixth, century, AD?

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Sun Jul 23 03:10:11 2006
Message-ID: <002001c6ae27$222d0090$7f45e146_at_ATARIENGINE>

Hi, List (and Marco)



    Marco, I seem to have a talent for annoying you.

I apologize for annoying you. However, I would like

to point out that my posting was addressed to The List

and to Paul Barford who asked the question in the

first place. I did not even copy you. Could I point

out that not every posting to The List is directed at

you, personally. True, you had also answered him,

and I referred to your reply because I disagreed

with it.

>
> Don't lecture me that condescendingly man.

> Who's got the PhD in prehistoric
> archaeology here?
>

    However, disagreement is not condescension. If you

read what I wrote, you might see that I was addressing

The List generally, and presenting the historical background

of the hypothesis. I narrated what Napier and Clube

thought (and wrote) when they first suggested it in the

1970's. (At least I think they were first.) I made no

evaluation of their notion, nor gave my own personal

opinion of it.

>
> Which is a naive "Pompeii Premise" about general

> taphonomic processes and ignores that in the 19th century, taphonomic and

> post-depositional processes were concepts still completely ignored. And

> catastrophic thinking reigned those days.
> Have you ever been to a peat excavation?

> It looks like Tunguska allright, fallen tree trunks everywhere. Only it
> isn't.
>

    I have not read the original they cited for this discovery,

so I can't evaluate it, either. I don't even know if it WAS a

peat excavation. Are you familiar with the citation, or are

you just making the assumption that it was a peat bog?

    I would also point out that Britons have been digging

in peat bogs for millennia and are probably pretty familiar

with what one looks like... If that's what it was. If they

thought this excavation, peat or not, was different, they

could probably tell. Anglesey has peat bogs, and they

have been dug for fuel since prehistoric times, and

Anglesey has lots of prehistory, so I assume a familiarity

with peat on the part of Anglesey excavators.

>
> Large impact phenomena come with a suit of

> identifiable things. If there was such an event in Britain as recent as AD
> 540,

> then where are the ejecta layers, the dust layers, the spherule layers,
> the impact

> glasses, the shocked quartz, the impact craters, the extinction events in

> flora and fauna? There is no reason why these should have vanished from
> the

> geological record in this case.
>

    You should really become familiar with the hypotheses you

are ridiculing. Neither Napier and Clube nor Baillie nor anyone

else that I am aware of have ever suggested any impact like that

(or any impact), with an accompanying cratering event, ejecta,

spherules, glasses, shocked quartz -- none of that, for which

there is no evidence. Dust, yes, and climatic change, and effects

on flora and fauna (but not extinctions) for all of which there

is evidence. What you put forward in this remark is a "straw

man" argument, in which you grossly mischaracterize a

hypothesis, then proceed to demolish your own

misrepresentation of it very effectively.

    The term "cometary impact" could, in this context, refer to

a series of atmospheric entries and disintegration of many

low-density objects which would load the Earth's atmosphere

with dust to the extent of reducing solar input and causing

sudden and irregularly distributed "coolings." No objects

would ever get within 20-40 miles of the Earth's surface.

And large, very high-altitude airbursts could produce loads

of catastrophic results and leave little physical evidence

except its extremely disruptive effects. There would be surficial

damage to flora, "years without summers," dustfalls, crop

failures, ecological disruptions which could include sudden

outbreaks of diseases due to the forced migration of their

vectors. This last happened in 541 AD with the first known

pandemic of bubonic plague in Europe.

    We have seen here on The List in many exciting news

flashes of huge fireballs and the hope for object recovery,

how rarely that happens, but every one, in fragmenting, dropped

dust into our atmosphere. There are Hiroshima sized airbursts

every year in the upper atmosphere, sometimes two or three

a year. Just increase the frequency to where there are

Hiroshima sized airbursts EVERY DAY and dozens of huge

fireballs somewhere on Earth EVERY NIGHT. There would

be 100's of meteorite falls a year, and still no "impacts" or

craters, perhaps for years, and even then, likely only small ones.

    Increase the frequency again ten-fold or more, but hypothesize

it's all from a swarm of small weak objects -- never a crater,

never a tsunami, never an overt "disaster." Increase it ten-fold

again if you want it. And again... What's happening? Countless

millions of tons of dust are raining into the atmosphere, persisting

for years, the sunlight is dim and watery, there's ice on the pond

in July. As the dust accumulates, it just gets worse and worse, a

progressive disaster. Human functioning societies and agriculture

at 50 degrees N. and S. become impossible, then at 40 degrees

N. and S., then 35... Populations begin to migrate, societies

break down, nations become fictions, order disintegrates.

We all know the scenario, if we've seen enough bad movies,

except of course, they're never bad enough... Mad Max just

isn't crazy enough, much too elegant and well-fed for reality.

    We don't even need that swarm of small weak bodies.

Just the dust is enough all by itself. It's hard to get people to

take this seriously, it's so UN-spectacular. Big deal, dust...

    One might doubt how much dust could be dumped in the

atmosphere by "cometary" (or other) bodies, and ask where

is the evidence, the layers of deposits, but it would all

be washed into the oceans and their sediments are in fact

fat with interplanetary and cometary dust, untagged as to

origin and method of dispersal.

    And then the eposide would be over, the swarm out of

the way, or the interstellar dust stream passed, and we start

to recover. The eposide might be minor, might be severe,

might return in a few decades, might vanish for a century.

There would be little physical evidence left behind but the

reports of the damage, hence the interest in old chronicles.

    On to history...

>
> Complex societies are inherently instable. There's no need

> for a clear-cut external prime-mover to make such a society

> collapse.
>
    Since the Roman empire (E. Division) under Justinian was

virtually as complex as Western Civilization over most of the

past half millennium, why, I expect we'll go under any day

now, then? Western Civilization has managed to avoid this

"inherent" potential for destruction for at least 500 years.

We ought to be ready to just go "poof!" any minute now...

Should have already done it. Wonder why not?

>

> DON'T NEED TO HAVE a clearly identifiable prime-mover.

> Thinking in prime-movers only to explain (pre-)historic change

> is utterly simplistic.

>

    What you call "prime-movers" is what we call "cause," as in

that familiar duo of "cause and effect." I realize that you regard the

notion of "cause and effect" as "in my opinion... pseudo-science,"

etc., etc. At the risk of labeling myself as an intellectual dinosaur,

as insufficiently post-modern, hopelessly naive, as un-hip, as

definitely not-with-it, I will confess that I ACTUALLY BELIEVE

that events HAVE causes! Gasp! What an archaic idea.

    Oh, wait a minute...

>

> That's why the whole neo-catastrophic movement of

> primarily ASTROPHYSICISTS who bring up cosmic impact as a prime-mover in
> far too many cases of (pre-)

> historic change is just a too simplistic look on (pre-)history

>

    I see, it's only "cosmic impacts" that can't be causes. Any

other cause or causes is OK with you. Now I get it. I thought

you just denied all causality as a philosophic principle (like

Hume), but it's just one particular cause that you object to.

>
> Clube, Napier, Steel and such have their own agenda to see

> "impacts" in history and recent pre-history everywhere. It ties

> in with their idea's on the evolution of the Taurid meteor

> complex as being derived from the arrival and breakup of a
> giant comet a few millenia ago...

>

    You gotta read'em before you stomp on'em: that "few millenia"

is 20,000 to 60,000 years ago, possibly 100,000 years ago,

says N & C. That is a FEW millennia. It is a strong hypothesis

because this kind of progressive breakup and evolution of bodies

is exactly how objects get supplied to orbits of limited lifetimes,

like Near-Earth and Apollo orbits, something we did not understand

well in the middle 1970's and that they helped to highlight. Remember,

in the 1970's there were still many Ph.D geologists who ridiculed

the idea that the craters on the Moon were from impacts, a silly

American notion, they said, when it's obvious they're volcanic.

They had to be right; they had Ph.D's, didn't they?

    Impact was a struggling new idea when N & C wrote. It's not

an agenda; it's an hypothesis, and they not hiding it.

    OK, astronomically, their notion about the breakup of the

Comet Encke parent body is not bad, really well-done. But

(like you, I suspect), I thought the Von D?niken tone of their

books was silly and their reading of most of the history in those

books silly and childish. I can see how it would more than

annoy you. Since their astronomy is good and the rest of their

writings are ridiculous, I like to imagine an editor at their

publishing house pushed them to accept that best-seller

style crap as filler for the sake of sales...

    See, I like to think the best of everybody. Maybe it was

their idea. Maybe they needed the money. Maybe they

wanted, politically, to worry enough people to get the

notion taken seriously... Their history is goonish,

wherever it came from.

    You've got to separate the good idea from its all-too-human

context. Kepler was a famed and money-making astrologer,

yet equal areas are swept out in equal times, nevertheless.

>
> As far as short-term climatic fluctuation is concerned,

> there is much more cause to look at variations in solar flux

> as a possible explanation .
>

     I want to stop and savor this moment when we agree

almost perfectly. That's obviously not a frequent event.

What better way to explain SHORT-TERM solar flux

variation than the short but intense dumping of opaque

(or reflective) particulate matter into the Earth's atmosphere?

It would settle on a time scale much shorter than what we

know of innate solar variation.

    You see, I think you, and perhaps some "neo-catastrophists,"

think of the term "impact" in a much too restricted sense. A dust

grain stumbling into the Earth's atmosphere and getting stuck there

is a kind of cosmic impact. Enough dust in a short enough time

could be more catastrophic than anyone imagines.

    We just don't appreciate the role of dust, but we're learning.

I reference the recent discovery of supernovae iron isotopes in

sediments only 2.3 million years old, the heavy dust layer deposited

on the Earth 8.3 million years ago by the breakup of the Veritas

asteroid family. The 2.2-2.3 mya dust event has been proposed

as the cause of a marine mass extinction at that time.

    And then, there's even more recent isotope anomalies

discovered by Firestone, over which we disagreed, I recall.

His hypothesis was utterly ridiculous, a "comet" formed in

a supernovae. OK, he's an idiot (outside of his expertise)

with a perfectly idiotic explanation of how these materials

got here, mammoths being shot with interstellar particles and

becoming extinct. Because it was so silly, you questioned totally

the validity of their presence and dating on "depositational"

arguments, wanting to dump the whole thing, dismissing

the isotopic evidence as irrelevant and proving nothing, but

these isotopes have since been found and similarly dated in

Antarctic ice cores, where "depositational" issues are moot.

They fell out of the atmosphere. They're almost certainly the

dust from supernovae, possibly the Scorpius-Centaurus

supernovae complex, possibly a closer former supernovae

as yet undiscovered.

    Not all catastrophes are Hollywood-style. If you insist on a

Hollywood spectacular, Google up HR 8210 (aka IK Pegasi B).

Could it find an extra 0.15-0.27 solar mass in dust or a stray

super-Jupiter-body and let go tomorrow? It would certainly be

spectacular, during the interval when we were still alive, that is.

    Granted, wisps of interstellar dust or sudden effusions of

asteroidal or cometary dust or even a swarm of small weak

bodies breaking up in the Earth's upper atmosphere are not as

picturesque nor as suitable for Hollywood movies as big

splashy impacts, but they can deliver as much or more

disruption as all but the best of the planet crashers. Of course,

direct exposure to a nearby supernovae is a spectacular

possibility, but interstellar drifts of supernova dust can

be almost as bad, not only unspectacular but hardly

noticeable... until it's too late.

    Since I've disagreed with you (and extensively), I'll

apologize in advance for annoying you again, Marco.

Isn't strange how everybody doesn't agree on everything?





Sterling K. Webb

-------------------------------------------------------
----- Original Message -----
From: "Marco Langbroek" <marco.langbroek_at_wanadoo.nl>
To: "meteorite list" <meteorite-list_at_meteoritecentral.com>
Sent: Saturday, July 22, 2006 5:54 AM
Subject: [meteorite-list] Re:Comet hit Britain in mid sixth, century, AD?


> Sterling K. Webb wrote:
>
>> The scientist you're referring to is Michael Baillie,
>> an Irish dentrochronologist (not Bailey).
>
> Too many Bailey'/Baillie's around, sorry... And its dendrochronologist,
> not
> dentrochronologist.
>
>
>> Their suggestion arose from uncovering a 19th century
>> account of an excavation on the island of Anglesey (which
>> is the least forested portion of the UK, less than 0.5%)
>> of an ancient forest which had been flattened and crushed
>> wholesale and apparently instantaneously and which to
>> them greatly resembled a naive description of the flattened
>> forest on the Tungus River caused by the Tunguska object,
>> only much larger.
>
> Which is a naive "Pompei Premise" about general taphonomic processes and
> ignores that in the 19th century, taphonomic and post-depositional
> processes were concepts still completely ignored. And catastrophic
> thinking reigned those days.
> Have you ever been to a peat excavation? It looks like Tunguska allright,
> fallen tree trunks everywhere. Only it isn't.
>
>
>> Yes, Marco, History is Change. But there are also
>> those "with a known fetish" AGAINST impacts or any
>> other physical event as a source" for any historical change.
>> The sudden collapse of the "Byzantine" or eastern Roman
>> Empire after 534 AD is without known social, political,
>> economic, military nor other human cause. It is the sudden
>> commencement of the Dark Ages for no apparent reason.
>> Dark Ages are rare, and always without apparent explanation
>> (1200 BC to 800 BC is another, and there was another
>> about 4000 years ago, too).
>
>
> Don't lecture me that condescendingly man. Who's got the PhD in
> prehistoric
> archaeology here?
>
> The point is that many (pre-) historic events indeed DON'T HAVE and DON'T
> NEED
> TO HAVE a clearly identifiable prime-mover. Thinking in prime-movers only
> to
> explain (pre-)historic change is utterly simplistic. That's why the whole
> neo-catastrophic movement of primarily ASTROPHYSICISTS who bring up cosmic
> impact as a prime-mover in far too many cases of (pre-)historic change is
> just a too simplistic look on (pre-)history, and in my opinion is
> pseudo-science.
>
> Complex societies are inherently instable. There's no need for a clear-cut
> external prime-mover to make such a society collapse.
>
> Volcanic super eruptions, cosmic impacts and other natural disasters
> happen. And
> when they happen, they can have a profound impact on human society in the
> affected area, no doubt (an appendix to my own dissertation explores the
> possible effekts of the Australasian impact for early Asian Homo erectus,
> in fact). And there are some good historic examples of that too (for the
> case of volcanic eruptions at least).
> But some people use them as Dei ex Machinae to explain everything we don't
> readily understand.
>
> Large impact phenomena come with a suit of identifiable things. If there
> was such an event in Britain as recent as AD 540, then where are the
> ejecta layers, the dust layers, the spherule layers, the impact glasses,
> the shocked quartz, the impact craters, the extinction events in flora and
> fauna? There is no reason why these should have vanished from the
> geological record in this case.
>
> A set of narrow tree rings that can have multiple causes is not enough to
> see an impact evidenced. And its all we have here. A very meagre set of
> proxy data by all means. I do not doubt Baillie's tree ring analysis, but
> the whole hypothesis attached to it I do doubt for it is founded on very
> flimsy multi-interpretable proxy data.
>
> As far as short-term climatic fluctuation is concerned, there is much more
> cause to look at variations in solar flux as a possible explanation than
> to impact.
>
> Clube, Napier, Steel and such have their own agenda to see "impacts" in
> history
> and recent pre-history everywhere. It ties in with their idea's on the
> evolution
> of the Taurid meteor complex as being derived from the arrival and breakup
> of a
> giant comet a few millenia ago. They believe this showered the earth with
> impact
> fragments. As a result, they have a strong tendency to see everything
> which in
> their perception is "odd" in the history of the past few millenia as
> "evidence"
> for their theory. Even Stonehenge is a giant memorial to celestial Taurid
> displays in e.g. Steels opinion. In my opinion, this conceptually is very
> near
> to Von D?niken seeing Alien influence and references to Alien visitors
> everywhere as its the result of a similar simplistic and biased idee-fixe
> look
> at (pre-) history.
>
> And please note that "Dark age" is an often misused and misunderstood
> concept. It says more about our inability to access the character of that
> period, than about that period itself.
>
> - Marco
>
> -----
> Dr Marco Langbroek
> Dutch Meteor Society (DMS)
>
> e-mail: meteorites_at_dmsweb.org
> private website http://home.wanadoo.nl/marco.langbroek
> DMS website http://www.dmsweb.org
> -----
>
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Received on Sun 23 Jul 2006 03:10:50 AM PDT