MemberlistThe Library Index  FAQFAQ   SearchSearch   RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
Mega-Talk (Megalithic)
Reply to topic Goto page Previous  1, 2, 3, 4, 5, 6 ... 52, 53, 54  Next
View previous topic :: View next topic  
Boreades


In: finity and beyond
View user's profile
Reply with quote

Mick Harper wrote:
(is there a name by the way for the second longest side of a right-triangle?)


Yes, it's the Adjacent side.

As in the old-fashioned aide-memoire from O-Level Maths for Sines, Cosines and Tangent angles in triangles

SOH CAH TOA

Sine = Opposite / Hypotenuse
Cosine = Adjacent / Hypotenuse
Tangent = Opposite / Adjacent
Send private message
Boreades


In: finity and beyond
View user's profile
Reply with quote

Mick Harper wrote:
Yes, Boreades, but we are dealing with real sailors.


Which means what?

Real sailors do it by eyeball navigation, with no instruments, probably in the nude.
Send private message
Boreades


In: finity and beyond
View user's profile
Reply with quote

What larks and witty banter, we should do this more often.

Actually, I agree with the notion of Lundy Island being a necessary waypoint on the journey.

Not least because it was home to one of the Navigation Schools. a.k.a. Hermit/Beaconage places, that became a monastery, etc.

Pass Lundy to pay your dues, drop off a Pilot, pick up a new one, etc

http://en.wikipedia.org/wiki/Lundy
says that "In 1627 Barbary Pirates from the Republic of Salé occupied Lundy for five years. "
which should be good for any pub quiz on when parts of Britain were last invaded by foreigners.
Send private message
Ishmael


In: Toronto
View user's profile
Reply with quote

Mick Harper wrote:


a) are these two places at significant points along their respective lines


If we draw a line connecting Glastonbury with Avebury, what is the ratio between this small triangle and the large triangle?

If we draw a line from Avebury to Cardif, and also northward from Glastonbury, all three lines appear to converge on the same point along the hypotenuse of the larger triangle---the middle of that inlet within Bristol Channel (any chance this was ever causewayed?).
Send private message
Tilo Rebar


In: Sussex
View user's profile
Reply with quote

Ishmael wrote:
...any chance this was ever causewayed?.


The Bristol Channel is deep with a high tidal range and fast current, so a causeway is unlikely. However, that line would take you pretty close to the small island of Flat Holm.

There is evidence that this island was settled at least as far back as the bronze age and in more recent times was visited frequently by Gildas, a follower of St. Cadoc who used the island as a retreat.
Send private message
Hatty
Site Admin

In: Berkshire
View user's profile
Reply with quote

I wondered about this possibility but like you say the high tidal range would seem to preclude a causeway. Flat Holm however is between two tidal causewayed islands, Birnbeck on the English side (north-west point of Weston Super-Mare) and Sully at the Welsh end, so it looks like something was afoot.
Send private message
Mick Harper
Site Admin

In: London
View user's profile
Reply with quote

MegaBritain Part Twenty-Four

Passing over for the moment the various issues connected with professional jealousy, one of the causes of the estrangement between the two sides is that it would require the academics to tear up one or more of their cherished paradigms.

The scholars have always routinely dismissed any notions of scientific sophistication among the rude Ancient Brits, believing that science like all the civilised arts was introduced at the time of literacy, and indeed Civilisation itself, in Mesopotamia c. 3,000 BC.

For the Preseli Triangle to be a reality it would mean that the scholars would have to recast the Ancient Britons into a culture that is capable of some or all of the following characteristics:
1. Knowledge of Pythagorean triangles
2. The ability to survey straight lines over hundreds of miles across both land and sea
3. The ability to follow these notional navigational lines for practical transportation purposes
4. Some remarkable capabilities in large scale terraforming.

But things are not necessarily as they seem. Let us briefly consider the last of these. Since the Preseli Hills and Lundy Island are presumably fixed by nature, in order to form the triangle, Stonehenge would seem to have been sited in relation to these two fixed positions. This is of course perfectly possible so long as you are free to site Stonehenge wherever the Pythagorean triangle demands. But actually this is a non-starter because the Preseli bluestones are considered a very late addition, long after Stonehenge was constructed, ie fixed in position.

As it happens, this is not possible anyway because Stonehenge is itself to some extent 'fixed'. It is the only historical 'plain' in Britain, that is a flat but elevated stretch of land with horizons visible in all directions, and called 'a plain'. But, if Stonehenge too is 'a given', a fixed point to go along with the other two fixed points, we are presented with a dilemma. Either the Ancients scoured Britain (the world?) for three things -- a plain, an island and a rock quarry -- that happened to form a Pythagorean triangle, or the Ancients constructed one or more of the following: Salisbury Plain, Lundy Island, the Preseli mines.

Since they did create the Preseli mines, it ought to be pointed out that there is nothing absolutely 'special' about Lundy either. Constructing a magic 5,12,13 right triangle A,B,C becomes suddenly rather simple to explain. The process goes like this:
1. You build Stonehenge at Point A (the best 'plain' you can find for astronomical purposes)
2. Sooner or later someone is going to spot that Lundy Island is due west of Stonehenge (lots of things are) giving us Point B. There is nothing significant about the distance A-B.
3. Until a Pythagorean enthusiast comes along and says, "Hey, if we measure line AB and then survey a line at right angles so that Line BC is in the relationship 5:12 with AB we will have produced a Pythagorean triangle."
4. Then some bright spark will say, "And then if we take some stones from C (wherever that might be, it'll be somewhere in south Wales) and re-erect them at A (Stonehenge) we'll really bamboozle future archaeologists."
Send private message
Wile E. Coyote


In: Arizona
View user's profile
Reply with quote

Wiley has become marooned.

I can't figure out why given that Tilo's link appears to have demonstrated (debunked the myth) that there are very few so-called Preseli Bluestones (the bluestones come from all over the place) and no evidence of a neolithic quarry in Preseli, this seems to be a quest heading off in the wrong direction.

http://www.walesonline.co.uk/news/wales-news/stonehenge-not-made-preseli-bluestones-1894944
Send private message
Hatty
Site Admin

In: Berkshire
View user's profile
Reply with quote

Prof Brian Johns has set out to demonstrate that Stonehenge is a 'brave enterprise' but essentially rather pointless, constructed with randomly selected stones lying at or near the site. Mick's scenario underlines the point that academic historians don't consider the Ancients as competent enough mathematicians/surveyors never mind transport engineers, partly because they're terrified of being labelled 'alternative' (cf. 'climate change').

There are some loose ends which perhaps Brian John tackles elsewhere though not in the article you referenced such as how much or little stones can survive being transported by ice flows and what happened to the other glacial erratics (they can't just have come from Preseli). Most if not all would surely be pulverised or severely damaged so not of much interest to henge-builders. The inescapable fact in all this seems to be that some of the bluestones come from a specific Preseli quarry or quarries.
Send private message
Mick Harper
Site Admin

In: London
View user's profile
Reply with quote

You are (slightly) misunderstanding my position, Wiley. I do not endorse the Preseli Triangle. I simply point out that lots of people do, and that their arguments are perfectly proper. Nor do I endorse the assumption that the bluestones are from Preseli, merely pointing out that archaeologists believe this to be so. (The counter-argument from Brian John et al would count as a Crazies argument by most professional practitioners).

The significant points I am making are
1) that the professionals refuse to consider the navigational problems re travelling between Preseli and Stonehenge (or indeed any long-distance journey in Britain) and
2) that the professionals refuse to consider any solutions to (1) that would require advanced surveying skills.

With the result that they have arrived at a false position, as we shall see in today's offering and subsequently.
Send private message
Tilo Rebar


In: Sussex
View user's profile
Reply with quote

Hatty wrote:
The inescapable fact in all this seems to be that some of the bluestones come from a specific Preseli quarry or quarries.


Or from somewhere else - Lundy Island perhaps, with a known quarry and a supply of dolerite...

"The island of Lundy forms the southernmost igneous complex of the British Tertiary Volcanic Province (BTVP) and consists of granite ( 90%) emplaced into deformed Devonian sedimentary rocks (Pilton Shale) and associated with a swarm of dykes of dolerite/basalt, minor trachyte and rhyolite composition."
Send private message
Mick Harper
Site Admin

In: London
View user's profile
Reply with quote

Are we to understand that "bluestone" can come from practically anywhere? If so, what is the basis of the Preseli claim in the first place?
Send private message
Tilo Rebar


In: Sussex
View user's profile
Reply with quote

Not anywhere, but Dolerite certainly occurs in other places...

"Chemical compositions and magnetic susceptibility data were compared for 12 dolerite bluestone implements including axes, axe-hammers and battle-axes, 11 Stonehenge monoliths (chemical data only), and potential source outcrops in Preseli, South Wales. Most of the studied artefacts are of spotted dolerite, a small number being unspotted dolerite. Bivariate graphs, discriminant analysis and t-tests were used singly and in combination to show, respectively, that the implements found at sites in England are mainly similar to Stonehenge monoliths, while the implements found in Wales have a variety of compositions and are much less similar to Stonehenge monoliths. The dichotomy between English and Welsh dolerite bluestone implements could be explained by exploitation of different Preseli outcrops or erratic assemblages derived from them. A small number of spotted dolerite implements have previously been shown to have chemical compositions atypical of and marginal to Preseli, suggesting the possibility of a source of spotted dolerite outside Preseli."
Send private message
Tilo Rebar


In: Sussex
View user's profile
Reply with quote

This is an interesting snippet from (health warning) Wiki...

"The term "bluestone" in Britain is used in a loose sense to cover all of the "foreign" stones at Stonehenge. It is a "convenience" label rather than a geological term, since at least 20 different rock types are represented."

This is a Dolerite scarp in Teesdale, note the vertical fracture lines which make it break into natural columns.


Here's a Teesdale house built from locally quarried Dolerite.
Send private message
Wile E. Coyote


In: Arizona
View user's profile
Reply with quote

Hatty wrote:
Prof Brian Johns has set out to demonstrate that Stonehenge is a 'brave enterprise' but essentially rather pointless, constructed with randomly selected stones lying at or near the site.


You might know more about Mr Johns than I do. I only came across him as Tilo posted a link to his blog.

When I read his blog, I saw he was attacking orthodoxy, and referenced him as a disreputable source, who was making life uncomfortable for orthodoxy and (heaven forbid) for me....I also noted that orthodoxy was having some trouble answering him.

At the same time I noticed that he previously spent time working in Antarctica and his stonehenge solution involved ice flows.....

This is ideal territory for Wile....a disreputable source, who orthodoxy can't answer, who provides a solution based on his own specialty.

You folks can go on. But this is where I pause and take a look.

For Wile it's a "critical moment" to take stock.

But then again, Wile often takes stock and jumps straight into the canyon....
Send private message
Display posts from previous:   
Reply to topic Goto page Previous  1, 2, 3, 4, 5, 6 ... 52, 53, 54  Next

Jump to:  
Page 5 of 54

MemberlistThe Library Index  FAQFAQ   SearchSearch   RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 


Powered by phpBB © 2001, 2005 phpBB Group