Space Forum / Space Science / July 2008

LOL, how did Vikings establish trade routes to
Ellesmere Island (1100AD) , when Baffin 1600 AD
couldn't do it ??? and he had a better ship!
Once again, I'm afraid your understanding of history
is less than complete :-). zinger...........
Ken

The Vikings did usually not row their ocean-going vessels, these were
sailing ships.
But you are right about the icebergs, those are usually not a threat
to shipping in the late summer and autum.

-> I wrote, that's a start. You certainly can't expect an
-> expert to research for a student!
-> Regards
-> Ken
 
Do you consider yourself to be an expert in Norse history?
 
Whose head has swelled?
 
                        dow

-> LOL, how did Vikings establish trade routes to
-> Ellesmere Island (1100AD) , when Baffin 1600 AD
-> couldn't do it ??? and he had a better ship!
-> Once again, I'm afraid your understanding of history
-> is less than complete :-). zinger...........
-> Ken
 
What are you trying to prove? That there was less ice in about 1000 CE
than in 1600? That may well be true. The climate cooled significantly
in the 1200s, with the result that the Viking colonies west of Iceland
died out. So what?
 
                      dow

-> The Vikings did usually not row their ocean-going vessels, these were
-> sailing ships.
 
But they lacked the ability to tack into the wind. When the wind was
blowing from the west, as it usually does in the North Atlantic, the
only way the Vikings could move westward was by rowing.
 
But they didn't have to cross the whole ocean in one voyage. They
established colonies on islands, Orkney, Shetland, Faroes, Iceland,
Greenland, and possibly Ellesmere Island, before reaching the mainland
of North America in what is now northern Quebec, and travelling
southward to the settlement at the northern tip of Newfoundland, which
is the furthest west that their presence can be definitely established.
Each hop of the journey would have taken only a few days.
 
This time next week I'll be in Iceland...
 
                       dow

-> Well then it's news to you, study up there kid :-).
-> And use accurate terms, it's inaccurate to misquote
-> by implication "settlers" on E island, I specifically
-> wrote "traders", as in "sea access".
-> Recently, much more exploration activity has been
-> done up north, and reveals factual evidence of Viking
-> trade at that latitude, btw it's a surprise to me too.
-> What does that mean visa-via the ice cap?
-> Regards
-> Ken
 
What have been found are Viking artifacts up on Ellesmere Island and
other places. This does *not* prove that Vikings actually went there,
any more than the presence of Roman coins in the Royal Ontario Museum
proves that ancient Romans came here. It is quite plausible that
Vikings traded them to Inuit in southern Greenland, and the Inuit then
carried them north.
 
It has been suggested that Vikings travelled northward up the west
coast of Greenland, until they reached the very narrow strait that
separates Greenland from Ellesmere Island. From there, they *might*
have travelled southward along the coasts of Ellesmere and Baffin
Islands. They *might* have done it by ship, if the weather was warm
enough, or by walking on the land and ice if not. But this is all just
hypothesis. There is no proof, and not even strong evidence.
 
It is certain that Vikings were at L'Anse aux Meadows, near the
northern tip of the island of Newfoundland. The remains of their
settlement there are known, and have been investigated. But everything
else about the Viking presence west of Greenland is purely speculative.
 
                       dow

-> > It is certain that Vikings were at L'Anse aux Meadows, near the
-> > northern tip of the island of Newfoundland. The remains of their
-> > settlement there are known, and have been investigated. But everything
-> > else about the Viking presence west of Greenland is purely speculative.

-> Dave I'm worried about you.
-> "near the northern tip of the island of Newfoundland"
->  "west of Greenland is purely speculative"
-> is a historic and geographic contradiction.
-> Read what you post. Lately, there are too many logic
-> bombs for me to correct.
-> Regards
-> Ken
 
Look at a map of Newfoundland. There is a long peninsula pointing
northward from the north-west coast of the main part of the island. The
tip of this peninsula is the northernmost point of the island, and
L'Anse aux Meadows is close to this tip, on the eastern side of the
peninsula.
 
Look at a map of the earth. North America is further west than
Greenland. The Vikings were certainly in Greenland, but there is only
one piece of really solid evidence that they ever travelled further
west, i.e. to North America. This solid evidence is the settlement at
L'Anse aux Meadows, the remains of which still exist. All the other
so-called evidence, the Norse artifacts that have been found on
Ellesmere Island, for example, is open to other interpretations. They
could have been taken there by Inuits who traded with the Vikings in
Greenland.
 
If you are unable to appreciate the logic of this, then maybe you
should worry about yourself.
 
                         dow

-> > This time next week I'll be in Iceland...

-> I am already here.
 
If you like, send me a private e-mail with your address. I might get a
chance to visit you.
 
                         dow

-> That's cool, we have an Icelander, nice.
-> Where Viking navigation is concerned, I think the
-> Phoenicians perfected that in BC times, it's even
-> rumored the Pho's did Scandanavia, hence our
-> friend Sigvaldi may be of Pho descent.
 
So may you. So may I. If you go back a few hundred generations,
everyone is related to everyone else.
 
 
-> Recall that Longitude needs a time piece for measure
-> and Latitude is rather simple off the North star...etc.
-> Pho's had hour glass type devices , don't know for
-> sure what the Vikings used to establish Longitude,
-> but probably a similiar deal.
 
Thye star we now call the Pole Star wasn't close to the celestial pole
in Phoenician times. The precession of the earth's axis has carried it
close to the pole only in the past 1000 years or so, allowing it to be
used as a simple indicator of latitude. This may explain why many
peoples e.g. the Polynesians and Chinese, as well as Europeans, began
to travel long distances by sea only quite recently.
 
->  As I'm sure you are aware of, the English developed
-> a chronometer for purposes of Longitude.

-> Anyway, in my understanding of history, the Pho's
-> had Longitudinal navigation capablity and led
-> expeditions over deserts and through forests, and
-> that skill was a secret skill for which they were well
-> paid.
-> That was back in the good ole days before any
-> idiot could buy a GPS unit!
-> So the Vikings could have easily used a hour glass
-> to do Longitude.
-> Regards
-> Ken
 
To "do longitude" at all accurately, you need a timepiece that will
gain or lose very little time over the period you will take to do your
voyage. If your clock is wrong by an hour, your estimate of longitude
will be wrong by 15 degrees. If it is wrong by only a minute, you'll be
wrong by 15 arc-minutes, i.e. about 15 nautical miles. Since long
voyages took months or years, chronometers were needed that would gain
or lose no more than a few minutes in that much time. The British were
the first to achieve this accuracy, which helped them in their
explorations.
 
The notion than an hour-glass would be sufficient is ludicrous.
 
                       dow

-> LOL, Dave thinks Inuits carried Viking stuff from Nfld to E-island!
-> Dave turn OFF the TEEVEE and learn from real experts.
-> Ken
 
Which real experts? You?! L&L&L&L&LOL
 
People carry trinkets all over the place. If an Inuit had a nice bit of
Viking jewellery, he might carry it anyplace an Inuit might go,
including to Ellesmere Island.
 
                      dow

-> We're using a Rotating Coordinate System, connecting
-> the Earth to the Moon, so we reduced the gravitational
-> field effect of the Earth on s/c to nil at the Moon by
-> a centrifugal force expression. That enables us to keep
-> the Earth and Moon on the x-axis.
-> Very cool, a bit of General Relativity in that.

-> Btw, hows that mission to Jupiter going?
-> Regards
-> Ken
 
Presumably you have also included Coriolis forces, which crop up when
anything moves radially in a rotating frame of reference.
 
Incidentally, you should enjoy the current (July '08) issue of
Scientific American magazine. There's a piece in it about simulations
of the structure of spacetime.
 
                               dow

-> More Red Herrings, read "North star...etc.".
 
A few thousand years ago, there was no "North Star", i.e. a bright star
close to the North Celestial Pole, just as there is no "South Star"
now.
 
-> > To "do longitude" at all accurately, you need a timepiece that will
-> > gain or lose very little time over the period you will take to do your
-> > voyage. If your clock is wrong by an hour, your estimate of longitude
-> > will be wrong by 15 degrees. If it is wrong by only a minute, you'll be
-> > wrong by 15 arc-minutes, i.e. about 15 nautical miles.

-> What's 15 miles, nothing, it's a matter that they could
-> predict within a day or so of arrival, close enough.

-> > Since long
-> > voyages took months or years, chronometers were needed that would gain
-> > or lose no more than a few minutes in that much time. The British were
-> > the first to achieve this accuracy, which helped them in their
-> > explorations.
 
I said that the clock has to be accurate to *a few* minutes, which
would translate to a few tens of nautical miles. Anything much more
inaccurate than that would lead to ships missing islands altogether,
and similar mishaps.
 
In the early 1700s, I think, the British Admiralty offered a large
prize to anyone who could invent and construct a chronometer of
sufficient accuracy. A lot of people tried developing large machines
with carefully compensated pendulums, and so on. Many of these were
superbly accurate clocks when used on land, but totally failed when
carried on ships that were being tossed in stormy seas. Finlly, a man
named Harrison realized that pendulums were useless, and that a
mechanism much more like that of a pocket watch, with a balance-wheel
as the basic oscillator, would have a much better chance of working. He
constructed several chronometers which were really just oversized
watches and submitted them to the Admiralty. They won him the prize.
Similar mechanisms were the basis for navigational chronometers until
just a few decades ago, when quartz-crystal oscillators came into use.
Now, I am wearing a $10 watch that would have easily won the prize 300
years ago.
 
-> You have a habit of underestimating the ingenuity of
-> everyone except brits :-).
-> Ken
 
If Galileo, Einstein, the Wright brothers, Tsiolkovsky, Von Braun,
Turing, etc., etc., were all Brits, then I guess you're right. If you
think I underestimate your own ingenuity, you may be right too. But if
you think Newton, Babbage, Stephenson, Watt, Brunell, Hawking, etc.,
are undeserving of respect just because they are or were Brits, then
your judgement is a lot worse than mine.
 
                          dow

-> > Presumably you have also included Coriolis forces, which crop up when
-> > anything moves radially in a rotating frame of reference.

-> Not sure I even understand the problem, though I
-> did ponder it when I used the Rotating CS, (RCS).

-> In an Ordinary non-rotating CS, (OCS),  I can shoot
-> a missile directly vertical  from earth on a perfectly
-> straight *path* and hit the moon....((maybe, better assume
-> lunar gravity is zero to start)), but then one would need
-> to aim the missile to where the moon will be at impact.
-> So relatively to an axis (use lasers) connecting the
-> Earth to the Moon, that straight *path* will be relatively
-> curved, does that make sense to you?
 
Imagine there's a string stretched between the Earth and Moon, and
your spacecraft is attached to it with some sort of pulleys. If the
co-ordinate system is not rotating, and the moon is somehow stationary
relative to earth, there will be no forces in the pulleys. If the frame
of reference remains stationary, but the moon is in orbit around the
earth, there will have to be some "sideways" force from the string that
accelerates the spacecraft to the moon's transverse speed by the time
it gets there. If the frame of reference rotates to keep pace with the
moon, the force will still exist to make the spacecraft travel in the
straight path. If no string or pulleys exert the force, the spacecraft
will, in the rotating frame of reference, accelerate sideways as if it
were being acted on by a force. This is the Coriolis force. Like
centrifugal force, it appears only in rotating frames of reference. It
is real, and cannot be ignored.
 
In the earth's atmosphere, if there is low pressure to the north and
high pressure to the south, the wind does *not* blow from south to
north! In the northern hemisphere, it blows roughly from west to east.
This is the result of the Coriolis force produced by the earth's
rotation.
 
-> Thanks, I'll see if it's online, I haven't renewed sciam,
-> no time for pop mags anymore.
 
I don't subscribe to it, but sometimes I pick up a copy from a store if
the headlines look interesting. This month's did.
 
                      dow

-> Well perhaps you culd recommend the appropriate
-> algorithm we could employ to keep Earth and Moon
-> on the x-axis.
-> We're pretty excited about Project Constellation and
-> we want to review it via sim.
-> Next we're going to sim Earth Orbit Rendevous.
-> Ken
 
If I were you, I think I'd do all the calculations in a non-rotating
frame of reference, and have an output routine that would present
everything so earth and moon are on the x-axis. The output routine
would look at the positions of earth and moon in the non-rotating frame,
figure out the transformation (rotation and maybe translation) that
would have to be done to put them both on the x-axis, and do the same
transformation on the position of the spacecraft to display it. But
this would just be an output procedure (a separate SUB), which would
not affect the computed positions of the objects in the non-rotating
frame of reference.
 
This would avoid all complications with centrifugal and Coriolis
effects.
 
                      dow

-> That's a good idea. Recall I wrote a program for us
-> using the sun and 9 planets all grav interlinked that
-> permitted choosing anyone as the center and then
-> locking in an axis between any two planets, but I
-> can't find the darn thing right now. Did I give you a
-> copy?
-> There is no evidence of complications from Coriolis,
-> but centrifugal is inevitable and has been perfectly
-> accounted for....onward!
-> Ken
 
If you're doing it in two dimensions, all you need is a couple of
routines that will convert polar coordinates to Cartesian and vice
versa. You may already have them in your program to handle the
acceleration vectors. Then, to make your display, just convert the
moon's and spacecraft's coordinates to polar, subtract the angles, so
the moon's is zero, then convert back to Cartesian and plot the point
for the spacecraft. Very easy. In three dimensions, it's only slightly
more complicated. There are 3D conversion routines in the "Sunalign"
program I posted here a while back.
 
When you launch your craft toward the moon, on the rotating display its
path will curve markedly to the right, if you're looking from the
north. That's the result of the Coriolis effect. But you don't have to
calculate this, or the centrifugal one. Using a non-rotating frame for
your calculations and just making the display rotate will handle all
the details for you.
 
                      dow
 
P.S. No. I don't have a copy of your earlier program.

On 07/09/2008 12:24 PM, dynamics@vianet.on.ca wrote to All:

-> What we need to do is dig up a dead Viking off E-island.
-> But according to DOW, that could have been carried from
-> NFLD, so there is no point in introducing evidence and
-> confusing people whose minds are made up.
-> Been there, tried it.
-> Ken
-> "you can't teach pigs to sing"

It´s wonderful how Ken invents other people´s reactions to events which
have not happened and, in all probability, never will happen.

He lives in a dream world.

                              dow

On 07/11/2008 6:24 AM, dynamics@vianet.on.ca wrote to All:

-> > On 07/09/2008 12:24 PM, dynam...@vianet.on.ca wrote to All:
-> >
-> > -> What we need to do is dig up a dead Viking off E-island.
-> > -> But according to DOW, that could have been carried from
-> > -> NFLD, so there is no point in introducing evidence and
-> > -> confusing people whose minds are made up.
-> > -> Been there, tried it.
-> > -> Ken
-> > -> "you can't teach pigs to sing"
-> >
-> > It´s wonderful how Ken invents other people´s reactions to events which
-> > have not happened and, in all probability, never will happen.
-> > He lives in a dream world.
->
-> Dave if you have a "bias" to green technology,
-> financially or otherwise then your objectivity is
-> excluded, do you?
-> If so you want to believe any pop-TEEVEE
-> show that favors your investment above actual
-> science that you conviently marginalize, don't
-> be ashamed that's a typical human property :-).
->
-> I happen to hold investments in Green technology,
-> however that has nothing to do with Global warming,
-> so I'm unbiased.
-> Ken

What pop-TV show are you imagining?

I have some investments in nuclear technology. I that green or not?

                           dow

dynamics@vianet.on.ca wrote to All:

-> > -> Dave if you have a "bias" to green technology,
-> > -> financially or otherwise then your objectivity is
-> > -> excluded, do you?
-> > -> If so you want to believe any pop-TEEVEE
-> > -> show that favors your investment above actual
-> > -> science that you conviently marginalize, don't
-> > -> be ashamed that's a typical human property :-).
-> > ->
-> > -> I happen to hold investments in Green technology,
-> > -> however that has nothing to do with Global warming,
-> > -> so I'm unbiased.
-> > -> Ken
-> >
-> > What pop-TV show are you imagining?
->
-> Characteristic of historical (hysterical) denial of
-> facts, such as the extremely rapid recession of
-> glaciers and the desertification of the Sahara
-> that is a MAJOR climatic variation that did in
-> fact occur. Can you explain that?

Please clarify the non sequitur.

Glacial recession and expansion of deserts is still occurring, faster than at any
other time in recent millennia. You shouldn´t refer to them in the past tense.

                            dow

On 07/13/2008 5:40 PM, dynamics@vianet.on.ca wrote to All:

-> > -> Characteristic of historical (hysterical) denial of
-> > -> facts, such as the extremely rapid recession of
-> > -> glaciers and the desertification of the Sahara
-> > -> that is a MAJOR climatic variation that did in
-> > -> fact occur. Can you explain that?
-> >
-> > Please clarify the non sequitur.
->
-> Exactly, you CANT HANDLE THE TRUTH.
-> Ken

I wonder how many people here, besides myself, are laughing at you.

                                   dow

-> I am not any where near an expert, but I enjoyed reading all of this.
-> I started researching Bosnia for fun, led me to the pyramids which
-> started my new search.  I was trying to find a geographic map of in
-> phases between 12000 and 500 bc.
-> Here's the problem:
-> I was reading that the mexican and egyptian pyramids were built first,
-> then the Bosnian pyramids.  I don't see how the mexican ones came
-> before the Bosnian ones when people originated closer to Bosnia.  In
-> the article linked below, Osmanagic believes the Bosnian pyramids to
-> be from between 12000 and 500 bc.  It almost seems like a
-> contradiction....
 
In round numbers, the Egyptian pyramids were built around 2500 BCE,
i.e. about 4500 years ago. The Mexican pyramids are *much* younger. The
Maya were constructing them in the first millennium CE, i.e. between
1000 and 2000 years ago. Pyramids in other places, e.g. China and, I
presume, Bosnia, were built at other times. Basically, it seems that
the idea of building big heaps of stuff was invented many times in
different places. Although there are superficial similarities between
pyramids in separate locations, their purposes and detailed
constructions are different. The Egyptian ones, for example, were
intended as tombs for pharoahs. Mayan pyramids had flat platforms on
top and were basically intended as elevated stages on which religious
rites could be carried out and seen by huge crowds of people.
 
The dating of pyramids has nothing much to do with where people
originally came from. Modern humans had spread over pretty well the
whole world befoe any pyramids were built.
 
-> He also says that they may be all made by the same people.  If that
 
That's poppycock.
 
-> Anyway, I am no genius, but I am sure with a little bit of math
-> skills, and a system to track the sun, and record its movement with
-> angles the Vikings or whoever else (even before the British's system)
-> could have managed a method to move longitudinally.  By looking at a
-> map though, it seems to get all the way to North America from
-> Greenland for instance, the Vikings would have made some easier gains
-> by traveling on land during some of their hops, especially with ice
-> being an issue.
 
The Vikings liked to travel by water. They went all the way across
Europe to modern Istanbul, for example, by using boats on rivers.  
They had to do occasional portages to get from one river to another,
but kept land travel to a minimum.
 
I was in Iceland a few days ago, and saw old maps of it that were made
by Vikings. They were extremely distorted in longitude. Whatever
methods the Vikings had to estimate east-west distances, they were
extremely inaccurate. However, they managed to get across the North
Atlantic by island-hopping, using simple dead-reckoning.
 
                          dow