There is a fascinating article that answers many ‘issues’ with the timing of historical disasters and Bond Events here:
Proceedings of the National Academy of Sciences of the United States of America
The 1,800-year oceanic tidal cycle: A possible cause of rapid climate change
Charles D. Keeling* and
Timothy P. Whorf
Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093-0244
Contributed by Charles D. Keeling
Variations in solar irradiance are widely believed to explain climatic change on 20,000- to 100,000-year time-scales in accordance with the Milankovitch theory of the ice ages, but there is no conclusive evidence that variable irradiance can be the cause of abrupt fluctuations in climate on time-scales as short as 1,000 years. We propose that such abrupt millennial changes, seen in ice and sedimentary core records, were produced in part by well characterized, almost periodic variations in the strength of the global oceanic tide-raising forces caused by resonances in the periodic motions of the earth and moon. A well defined 1,800-year tidal cycle is associated with gradually shifting lunar declination from one episode of maximum tidal forcing on the centennial time-scale to the next. An amplitude modulation of this cycle occurs with an average period of about 5,000 years, associated with gradually shifting separation-intervals between perihelion and syzygy at maxima of the 1,800-year cycle. We propose that strong tidal forcing causes cooling at the sea surface by increasing vertical mixing in the oceans. On the millennial time-scale, this tidal hypothesis is supported by findings, from sedimentary records of ice-rafting debris, that ocean waters cooled close to the times predicted for strong tidal forcing.
Aside from a tendency to use “forcing” all over the place where, IMHO, the word ought to be “force”, “forces” or “forced” (or better yet, just state what actual physical force is doing what and skip the “forcing” non-noun all together), the article is pretty well written.
Sidebar: As an example of my ‘pet peeve’ on ‘forcing’, I think that last line would read much better as “that ocean waters cooled close to the times predicted for strong tidal forces”.
Among other useful bits, it answers the question of why the Bond Event average is 1470 years yet many events seem to land on ‘near 2000 year nodes’. As I’ve often pointed out, averages hide more than they reveal. In this case, one can have a period of 1800 years and a couple of anomalous events (often at about a 1/2 period) can shift the average significantly.
The IRD events identified by Bond et al. (1, 2) show high spectral power density in a broad band centered at about 1,800 years (0.55 ± 0.15 cycles/kyr). The authors do not explain why this period is so much larger than the 1,476-year average pacing of cool events, but the time-distribution of pacing (ref. 1, Fig. 6c; G. Bond, private communication) suggests that a majority of the events were about 2,000 years apart, with occasional additional events occurring about half-way between, evidently too infrequent to cancel out a dominant spectral peak near 1,800 years. Bond et al. (2) in addition found a spectral peak near 5,000 years whose possible cause was also not explained. We now propose an oceanic tidal mechanism that may explain the basis for both of these spectral peaks, consistent with the actual times of IRD events.
This is a nice thing to know. It means that looking at 1000 and 2000 year periods may be more fruitful than 1500 -/+ 500… It also opens the door for a 3000 year beat period of some sort. This will matter when we get to Taurids. It also matters now when looking at the 2000 BC, 0 BC, 2000 AD similarities. Basically, if you find a 1000, 2000, or 3000 year period in climate or history events, they are not in conflict with a 1500 year Bond Event cycle average.
The authors basic notion is ‘the tides did it’:
We propose that variations in the strength of oceanic tides cause periodic cooling of surface ocean water by modulating the intensity of vertical mixing that brings to the surface colder water from below. The tides provide more than half of the total power for vertical mixing, 3.5 terawatts (4), compared with about 2.0 terawatts from wind drag (3), making this hypothesis plausible. Moreover, the tidal mixing process is strongly nonlinear, so that vertical mixing caused by tidal forcing must vary in intensity interannually even though the annual rate of power generation is constant (3). As a consequence, periodicities in strong forcing, that we will now characterize by identifying the peak forcing events of sequences of strong tides, may so strongly modulate vertical mixing and sea-surface temperature as to explain cyclical cooling even on the millennial time-scale.
The basic thesis of the article is that there is an 1800 year periodicity to tides caused by an interaction of the alignment of the moon and earth (syzygy: one of my favorite scrabble words along with zymurgy, though hard to play… ;-) interacting with the periods of perigee and nodal crossings of the ecliptic. Perigee depends on the lunar orbit of the earth seen from the moon, the anomalistic month. Syzygy is dependent on the synodic month (the new and full moon as it aligns with the sun). Crossings of the ecliptic relate to the nodic month.
Nodic is 27.2 days. Anomalistic is 27.6 days. Synodic is 29.5 days. These all have a ‘beat frequency’ on tides. (Basically, the moon is only directly in line with the sun/earth axis AND most close to the center of the earth sun line node AND closest to the earth itself at perigee when all those different cycles line up).
This is asserted to account for much of the known periodic changes in climate.
There are several charts in the article that bring you, step by step, to this chart. I’m just going to put this (rather complicated) punch line chart here. Hit the article for a gentle lead up.
You can click on this for a larger version.
OK, we have the fall of the Akkadian Empire right on top of one of the peak tide events along with a dust peak layer in Elk Lake in North America (this stuff is global, not just in the Middle East..) Bond Events are numbered in the right half (actually described as ‘ice rafted debris’ events but described as ‘Bond events’ in the caption with solid being conformant and dashed being ones that do not conform with the tides). The ones with a dashed line are NOT on a tidal node, so may have some other cause or may be a harmonic in some way (they tend to fall near the half period). The Younger Dryas is marked with YD. Asterisks mark events that are associated with a longer near 5000 year cycle. I presume that the things labeled Hx are Heinrich Events. The lower case letters are unclear.
OK, what is clear is that there IS a long term tidal cycle. It seems to have a striking correlation to significant swings in our climate. It is asserted that this is likely due to various interactions with ice shelves (during glacial periods, by other authors speculating about Heinrich Events) or with ‘ocean mixing’ increases during non-glacial periods (in this paper). I’ve asserted that tidal variation could have an impact via changing the volume of water trying to get through the Drake Passage and this changing how much cold water gets diverted up the West Coast of South America and how fast the jet of water of the circumpolar current spins the South Atlantic. In any case, the methods available for a change of tides and hemispheric water volumes to interact with the oceans and climate is fairly large and can easily account for the changes of climate we see (IMHO).
If you want to read how the cycle is calculated, read the article, I don’t see the need to repeat it here. I’m willing to accept that it DOES exist, and look at what that implies.
Is there anything else of particular interest noted in that article?
[A cause for such greater regularity in tidal forcing might be resonances of other bodies of the solar system, especially the outer planets. We are struck by the close correspondence of the average period of the 180-year tidal cycle of 179.5 years (1/10 of that of the 1,800-year cycle) and the period of the sun's rotation about the center of mass of the solar system of 179.2 years, the latter a manifestation of planetary resonances (13).]
Resonance is a constant feature of orbits. Things tend to end up in a resonant relationship to other things. Why is pretty straight forward (though often presented in arcane ways). If things are ‘out of sync’ they get unbalancing forces on them. Those forces either cause the object to have an orbital decay and leave the system (one way or another…) or they drift the object into a more stable ‘resonant’ orbit. There are resonances all over the solar system. They are critical to maintenance of stable orbits AND they are the cause (for the imbalanced case) of things like comet breakups and asteroid impacts. The junk getting kicked out of unstable non-resonant orbits. It’s a critical concept to understanding why the solar system is as it is.
So once you have a period based on something orbital, it’s a really really good idea to look around for what is in resonance with those things…
But what about all those impact events that are coincident with some of the Bond Events and the Fall Of Empires? How in the world can tides be the cause with all those rock falls? And how can rock falls be causal if the events fall so neatly on top of tides?
My assertion is pretty simple. I’m going to assert that the Taurids are in a resonant orbit with all the other stuff ‘nearby’. I see no reason for them to be ‘out of sync’ with tides, when both the tides and the Taurid orbit will be a result of the same resonance forces. Basically, I assert that tides and rock falls ought to arrive together. (Someone else can do the math ;-)
On the other hand, while the orbits of some particles are quite dispersed, it is still likely that the Taurid stream has a narrow and dense core consisting of particles concentrated near the orbit of the stream’s parent object, which is presumably related to Comet 2P/Encke. As the orbits of the material constituting this narrow, dense core have been subject to perturbations over thousands of years, it may be inferred that intense bombardment episodes have resulted at epochs when the material reaches Earth intersection. Dynamical calculations show that, as a Taurid-like orbit precesses, the northern daytime intersection occurs just a little (a few centuries) before the southern nighttime one, and the southern daytime one just before the northern nighttime one. That is, the four intersections occur in two pairs, and the influx of material to Earth is enhanced during epochs lasting a few centuries and spaced by a few millennia. The term “coherent catastrophism” has been used by astronomers at Armagh and elsewhere to describe the idea that there are strong patterns in the influx of extraterrestrial material to Earth.
“Coherent Catastrophism”, eh? Two pairs, separated by a couple of hundred years, returning every ‘few millenia’. Sures sounds like that ‘two impacts’ in 2200ish BC that Timo was talking about with a couple of hundred years between them.
Now, my blind leap of intuition here is pretty simple. Tides are driven by solar system bodies. Bodies that move in resonance. Comets are solar system bodies, and Encke (the surviving parent of the Taurids) is settled into a stable (and so, resonant) orbit now along with its debris ‘trails’. We intersect those trails periodically. They are likely to be ‘lumpy’ in the material distribution (as Encke itself attests). Is it really THAT far of a leap to hypothesize that the lumps might just be in a resonant relationship with the Earth / Sun / Moon that cause the tidal cycle? In fact, I’d go so far as to assert that if resonance were NOT present, it would not have hung around for the 30,000 ish years that are supposed.
We review the theoretical and observational evidence that, on timescales relevant to mankind, the prime collision hazard is posed by temporally correlated impacts (coherent catastrophism, t ~ 10 2 10 4 yr) rather than random ones (stochastic catastrophism, t ~ 10 5 10 8 yr). The mechanism whereby coherent incursions into and through the terrestrial atmosphere occur is described as being the result of giant cometary bodies arriving in orbits with perihelia in the inner solar system. Hierarchical fragmentation of such large (100 km-plus) bodies due to thermal stresses near perihelion, collisions in the asteroid belt, or passages through the Jovian Roche radius results in numerous ~kilometre-sized objects being left in short-period orbits, and appearing in telescopic searches as Apollo-type asteroids. Many more smaller objects, in the 10 100 metre size range and only recently observed, by the Spacewatch team, are expected to be in replenished clusters in particular orbits as a result of continuing disintegrations of large, differentiated, cometary objects. Gravitational perturbations by Jupiter bring these clusters around to have a node at 1 in a cyclic fashion, leading to impacts at certain times of year every few years during active periods lasting a few centuries, such periods being separated by intervals of a few millennia. Furthermore, fragmentations within the hierarchy result in significant bombardment commensurabilities ( t ~ 10 10 2 yr) during active periods occurring at random intervals ( t ~ 10 2 10 3 yr). It appears that the Earth has been subject to such impacts since the break-up of such a comet ~2×10 4 years ago; currently we are not passing through a high-risk epoch, although some phenomena originating in the products of this break-up have been observed in the 20th century. This most recent hierarchical disintegration, associated with four well-known meteor showers and termed the Taurid Complex, is now recognized as resulting in a dozen apparently asteroidal objects almost 10% of the discovered Apollo population as well as Comet P/Encke. A substantial asteroidal remnant of the Taurid progenitor may still be present in resonance with Jupiter. The implications of the existence of any asteroidal or meteoroidal cluster due to the progenitor are briefly discussed. We emphasize finally the relative importance of active and inactive comets in the cratering record, pointing out the potentially significant contribution by disintegrating large comets to the population of inactive Earth-crossers.
We have Jupiter being a major contributor to the solar barycenter period of 179.2 years, we have a theoretically calculated 179.5 year tidal cycle on earth (that is specifically disclaimed as not being measured exactly and not being adjusted for all the other planet influences on cycle times, so could easily be off in the 4th place by a fraction) and we have a 10 times that beat frequency of tides impacting climate. Sure looks to me like we can easily get a similar resonance impact on the arrival of ‘impacts’…
The origin of the Taurids was reexamined by Whipple and S. Hamid during 1950. They calculated the effects of secular perturbations by Jupiter on the orbital inclination and longitude of perihelion of nine photographic meteor orbits and found the orbital planes of four of the meteors to coincide with that of comet Encke 4700 years ago. Three other orbits coincided with one another, but not with comet Encke 1500 years ago. The authors theorized “that the Taurid streams were formed chiefly by a violent ejection of material from Encke’s Comet some 4700 years ago, but also by another ejection some 1500 years ago, from a body moving in an orbit of similar shape and longitude of perihelion but somewhat greater aphelion distance….” It was suggested that this unknown body had separated from Encke some time in the past.
Hmmm… 1500 years ago… just about 500 AD start of the Dark Ages. 4700 years ago. Just a couple of hundred off from that 2300 BC start of the events leading to the 2200 BC collapse of the Akkadian Empire… Within the error bars, I’d wager.
So we’ve got a ‘dark passenger’ of some sort that seems to periodically whack into Enke or gravitationally perturb it and it’s train sufficient to kick up some junk and cause us grief. One can only hope it has already been consumed by the process…
Then again, if that consumption is what created the debris field we intersect periodically…
Shows a way to find a chemical signature from the Haber process in comet strikes:
Unveiling Mysterious Possible Comet Strikes On Earth
ScienceDaily (Dec. 14, 2009) — It’s the stuff of a Hollywood disaster epic: A comet plunges from outer space into the Earth’s atmosphere, splitting the sky with a devastating shock wave that flattens forests and shakes the countryside.
In June 1908, a puzzling explosion rocked central Siberia in Russia; it came to be known as the “Tunguska event.” A later expedition found that 20 miles of trees had been knocked down and set alight by the blast. Today, scientists have coalesced around the idea that Tunguska’s devastation was caused by a 100-foot asteroid that had entered Earth’s atmosphere, causing an airburst.
Some 13,000 years earlier, an occurrence thought by some researchers to be an extraterrestrial impact set off cooler weather and large-scale extinctions in North America. The “Younger Dryas event,” as it is known, coincided with the end of the prehistoric Clovis culture.
Melott and fellow researchers examined data from ice cores extracted in Greenland to compare atmospheric chemistry during the Tunguska and Younger Dryas events. In both instances, Melott’s group found evidence that the Haber process — whereby a nitrogen fixation reaction produces ammonia — may have occurred on a large scale.
I note in passing that the Tunguska Event happened on a Taurid date… (the ones where the approach is not visible due to the sun being in the visual field…)
Ties the Taurids with the major extinction event in North America in 11,000 BC:
Was a Giant Comet Responsible for a North American Catastrophe in 11,000 BC?
ScienceDaily (Apr. 1, 2010) — Some 13,000 years ago the Earth was struck by thousands of Tunguska-sized cometary fragments over the course of an hour, leading to a dramatic cooling of the planet, according to astronomer Professor Bill Napier of the Cardiff University Astrobiology Centre.
He presents his new model in the journal Monthly Notices of the Royal Astronomical Society.
The cooling, by as much as 8°C, interrupted the warming which was occurring at the end of the last ice age and caused glaciers to readvance. Evidence has been found that this catastrophic change was associated with some extraordinary extraterrestrial event. The boundary is marked by the occurrence of a “black mat” layer a few centimetres thick found at many sites throughout the United States containing high levels of soot indicative of continental-scale wildfires, as well as microscopic hexagonal diamonds (nanodiamonds) which are produced by shocks and are only found in meteorites or impact craters. These findings led to the suggestion that the catastrophic changes of that time were caused by the impact of an asteroid or comet 4 km across on the Laurentide ice sheet, which at that time covered what would become Canada and the northern part of the United States.
Professor Napier has now come up with an astronomical model which accounts for the major features of the catastrophe without involving such an improbable event. According to his model, the Earth ran into a dense trail of material from a large disintegrating comet. He points out that there is compelling evidence that such a comet entered the inner planetary system between 20 000 and 30 000 years ago and has been fragmenting ever since, giving rise to a number of closely related meteor streams and comoving asteroids known as the Taurid Complex.
This has the interesting connection that the Tunguska Event might have been a tiny taster of a Taurid catastrophic storm:
The British astronomers, Victor Clube and Bill Napier, have acknowledged that Velikovsky may have been correct in suggesting that some myths might have been derived from objects which had been prominent in the ancient sky, and caused catastrophes on Earth, but these cosmic bodies must have been comets, not planets. By extrapolating backwards in time the orbits of Encke’s Comet, the Taurid meteor stream and associated Apollo asteroids, Clube and Napier concluded that all were products of a huge comet which came into an Earth-crossing orbit around 20,000 years ago and began to break up, with particular disintegration events occurring about 7500 and 2700 BC. Fragments would have struck the Earth at intervals throughout the Bronze Age, with devastating consequences. Clube put these ideas before the general public for the first time at an SIS meeting in London in 1982, and developed them at another in Nottingham the following year.
Similarly in the next paper, David Pankenier suggests that, contrary to what has generally been supposed, legends and rituals from Bronze Age China may reflect actual events. In particular, around the time of the transition from the Xia to the Shang dynasty in the middle of the second millennium BC, there is a story of ten suns appearing in the sky and then, a few years later, of five planets criss-crossing, and stars falling like rain, after which there was an earthquake and then a drought. It would not be difficult to see this as an indication of the appearance of multiple comets in the sky, and impact-induced catastrophes. The same or a different cometary catastrophe could also form the basis for the legend of the battles between the wicked Chi You and the Yellow Emperor, which featured in ritual games.
Then there is the potential that even Stonehenge might have been built as a way to predict the periodic returns of these impacts. To know when to seek shelter (and perhaps when to store up some extra grain…)
Before The Stones: Stonehenge I As A Cometary Catastrophe Predictor?
Abstract of talk by Duncan Steel
Spaceguard Australia, P.O. Box 3303, Rundle Mall, Adelaide SA 5000, Australia. Email: dis[at]a011.aone.net.au
Presented at the SIS Conference: Natural Catastrophes during Bronze Age Civilisations (11th-13th July 1997)
Astronomical hypotheses for the purpose(s) of megalithic monuments have mostly been implicitly based upon an assumption that the designers witnessed the same phenomena as those we observe in the sky today. This assumption is not well-based for phenomena having time-constants of order centuries or millennia, such as the populations of comets and meteoroids in the inner solar system and the ephemeral meteor showers and storms which they produce on the Earth. IRAS observations have indicated that Comet Encke has a trail (not tail) of debris some tens of millions of kilometres long, presumably produced since its latest period of activity began about 200 years ago. One may further presume that the Taurid meteor showers we observe in this epoch are the result of the dispersal of trails produced in previous activity cycles which must stretch back to about 20,000 yr ago. When the comet, accompanied by such a trail, has a node close to 1 AU, one expects intense meteor storms to occur, perhaps accompanied by multiple Tunguska-type events if the disintegrating comet spawns massive lumps of debris. Determination of the epochs of such events from backwards integrations is impossible due to (i) Chaotic orbital evolution; and (ii) Non-gravitational forces, but pairs of intersections (one at the ascending node, the other descending) are to be expected a few centuries apart and separated by 2500-3000 years. It is suggested here that one such pair occurred in 3600-3500 and 3200-3100 BC, provoking the construction of the Great Cursus and Stonehenge I. From Stonehenge I, apparently the first construction at the famous site, as the comet neared the Earth it would have appeared to rise in the evening with a huge bright stripe crossing much of the sky, originating in the north-east. Passage through the trail would then result in celestial fireworks (and maybe worse); afterwards the comet and trail would have passed in the direction of the Sun, partially blocking sunlight for a few days. In order for terrestrial intersection to have occurred in that epoch (late fourth millennium BC) the mean orbital period of the comet over the past 5,000 years would need to have been slightly less than at present, and might then be expected to have produced a 19 year periodicity in meteor storm events (six cometary periods). It is suggested that Stonehenge I was built by the Windmill Hill people to allow the prediction of such events, from which they hid in the shelters we now call long- and round-barrows, and that the later developments at Stonehenge (phases II and II) by the Beaker people were a result of a misinterpretation of the original purpose of the site in terms of lunar and solar observations, a misinterpretation which was re-discovered by Newham, Hawkins and Hoyle in the 1960′s.
DUNCAN STEEL is director of Spaceguard Australia and Vice-President of The Spaceguard Foundation. Steel took B.Sc. and M.Sc. degrees at the University of London, studying at various colleges, and then moved to the University of Colorado where he worked on NASA’s Pioneer Venus Orbiter program. He then moved to New Zealand, where he took his Ph.D. degree at the University of Canterbury for work on radar observations of meteors. He continued this work from 1985-96 at the University of Adelaide, Australia, spending 1987 as an ESA Fellow at the University of Lund, Sweden. From 1990 until its termination in 1996 he directed the only southern hemisphere program for the discovery and tracking of near-Earth asteroids, based at the Anglo-Australian Observatory. In connection with this he has served on various international committees, including NASA’s Spaceguard committee in 1991-92 and the International Astronomical Union’s Working Group on Near-Earth Objects since 1991, and Working Group on the Prevention of Interplanetary Pollution since 1988. He is the author of over a hundred scientific papers, and the book Rogue Asteroids and Doomsday Comets” (Wiley, Chichester and New York, 1995). In addition, he has appeared in numerous TV and radio documentary programs concerned with the impact hazard.
Presented at the SIS Conference: Natural Catastrophes during Bronze Age Civilisations.
Not exactly your “fringe” type of credentials… More like “exceptionally well educated”. Besides, he likes Stonehenge ;-)
But, just to be fair to the “other side”, here is a ‘not so academic’ page:
“Could both Stonehenge and the pyramids of Egypt have been constructed to observe and commemorate a period of phenomenal meteor storms and asteroid detonations produced by a burst of activity in the Taurid Complex 4,500 to 5,000 years ago? Author Duncan Steel examines the evidence indicating rogue asteroids and doomsday comets may have been behind these and other ancient phenomena.”
The study of Near Earth Objects (NEOs) is becoming one of the most exciting areas of modern astronomy, and as the science progresses, historical writings and the myths and legends of prehistoric times are being looked at again in a new light. The current focus on re-interpreting ancient myths about battles between ‘sky gods’, ‘dragons breathing fire’, and ‘thunderbolts from heaven’, as containing the accurate observations of ancient skywatchers, is much in the same vein as the pioneering work of Owen Morien Morgan, who decoded the druidic folklore of the South Wales valleys, revealing the druidic oral traditions that symbolically depicted the constant interplay between the Sun, Moon, Earth and planets throughout course of the natural year.
It is becoming evident (October 1997) that ancient peoples have, throughout the past several thousands of years, migrated away from areas devastated by periodic bombardments of cometary debris. These hurried migrations of refugee survivors were likely due not only to the destruction of centres of civilisation, but also as a result of the “Cosmic Winter” caused by the cometary dust-loading of the upper atmosphere which gave rise to abrupt climatic changes – rapid drops in temperature that undermined the agricultural base sustaining those societies.
Some ancient megalithic monuments have been referred to as burial chambers because evidence of burials have been discovered in many of these types of monuments. Some of these burials have not been of humans, but of animals, specifically bulls and less frequently of cows. Others have been shown to have the remains of human skeletons in their chambers, but these burials could well have occurred at a much later date than their construction, and it is now believed that one of their primary purposes may well have been as observatories for particular celestial events.
The burial of bulls may also have been of a relatively late date compared to the dates of the construction of these stone chambers, which would have acted as ‘telescope-type’ chambers inasmuch as they would allow for the fainter stars to be observed at night. And, more importantly, they would have allowed for accurate observation of the ‘heliacal rising’ of specific stars in the final half- hour or so before actual sunrise.
As the major meteor storms of the Bronze Age and before were those that appeared to emanate from the constellation of Taurus (the Bull), then it must be considered that the ‘bull burials’ which have been found in various ancient structures all over the world could well have been the result of an apparent widespread practice of ‘sacrifices’ to appease the anger of various ‘gods’. In ancient oral traditions, this ‘anger’ was almost always shown by the sending of ‘thunderbolts’ and the like, which are recorded in the mythologies and oral traditions of almost every ancient culture in all corners of the globe. Could these sacrifces have been of bulls because of the Taurid Meteors Storms that had caused such widespread death and destruction throughout antiquity? And, how far back did this go?
Which also causes me to ponder the Minoan pictures of folks leaping over bulls (and perhaps an echo of it in Bull Fights of Iberia?)
There are a great many legends about bulls, and Gods, and retribution from the sky. Perhaps they have a more common root…
Our planet encounters the beta Taurid Complex between June 24 and July 6 each year, and it takes the Earth about 12 days to pass through these streams. The second annual encounter is generally between November 3rd and the 15th each year, when they can be seen with the naked eye as ‘shooting-stars’ in the night sky appearing to emanate from the areas of the constellations of Taurus and Aries.
With the stars of the constellation of Taurus in the background behind the Sun in May and June, the meteors appear to come directly out of the Sun. They would not actually be ‘seen’ until larger meteoroids (particles of cometary debris) came right through the upper atmosphere and impacted the Earth, or burst in the atmosphere a few miles above the ground, as did the widely reported ‘fireball’ of the Tunguska air-burst on June 30th 1908.
It goes on at some length about using caves and artificial caves to enhance seeing of the precursor stars to Taurus. Not so sure I’m buying that… It seems to me it would be easier to just watch the night sky and create a calendar. At any rate, it’s pretty clear that a few Tunguska events all happening at once could really mess up your day and there WERE more of them in the past.
And then, there is The Wiki
The Taurid stream has a cycle of activity that peaks roughly every 2500 to 3000 years, when its core passes nearer to Earth and produces more intense showers. In fact, because of the separate “branches” (night-time in one part of the year and daytime in another; and Northern/Southern in each case) there are two (possibly overlapping) peaks separated by a few centuries, every 3000 years. Some astronomers note that dates for megalith structures such as Stonehenge are associated with these peaks. The next peak is expected around 3000 AD.
The Taurids also have more frequent peaks which may result from a heavier concentration of material in the stream, which only hits Earth during some passes.
What I suspect is that the 3000 year peak is a bit optimistic. In particular, I’m expecting there to be some resonant peaks at about the 1/2 period of 1500 years and at the 1/3 and 2/3 periods of 1000 years and 2000 years. Exactly which ones are how populated TBD… That we got whacked in 2200 BC would imply a 800 AD ‘repeat’, and I don’t remember seeing one written up.
In essence, I think the emphasis ought to go on the “also have more frequent peaks” part…
I think that there is very good evidence for BOTH a tidal / ocean driven cycle and a cometary impact cycle in climate history.
Further, since both are driven by orbital mechanics, and those are full of ‘resonance’ effects, I postulate that a complete sky survey and close attention to detail will likely lead to finding a ‘resonance’ between the two. With periods of intense comet debris impacts, arriving in a couple of hundred year long ‘double hump’ event, on top of tidal nodes, is likely to account for much of the known history of catastrophic climate changes. Then we get a 1000, 1500, or occasionally 2000 year reprieve. Repeat…
Now, the big question is where are we at the moment on this wheel of fate…