--- In spacesettlers, "Robert" wrote:

> building a star crossing colonizing ship would be an extreamly
> expensive undertaking. unless all the colonist were exceedingly
> rich, its unlikely they could afford to finace it themselfs.

But they will be. They will all be so rich as to make Bill Gates look
like a povety-stricken begger... who doesn't know how to beg.

actually they have taken photographs of objects in the ort cloud,
barely a dot on the film, that is suppose to be about the size of a
locomotive engine.

--- In spacesettlers@yahoogroups.com, Douglas May wrote:
>
> On Jul 28, 2006, at 9:08 AM, Robert wrote:
>
> > im not sure where you got the idea that the oort cloud spread out
> > that far into interstellar space. when i was reading about the
object
> > they are calling the 10th planet, it was discussing the fact that
> > that was very near the point where solar gravity would no longer
keep
> > the planets in orbit. there was some discussion on wheither or
not it
> > was really a rogue object that happen to be passing though the
fringe
> > of our solar system. orbits around the sun dont extend as far as
one
> > light year, let alone two.
>
> There have been several planetoids called the 10th planet, most in
> the Kuiper belt. Sometimes called TNO's (Trans-Neptune objects).
The
> Kuiper belt starts around 30 AU's out (just past Neptune) and
drops
> off pretty quickly at around 50 AU's (around 5 billion miles). The
> Oort cloud doesn't begin until 50,000 AU's (5 Trillion miles). We
> don't know where the Oort cloud ends. Probably different distances
in
> different directions thanks to new data from the Voyagers (yes,
> they're still working hard out there). The Kuiper belt is a ring,
> while the Oort cloud is a shell, completely surrounding the Sun.
The
> nearly 5 trillion miles of space in between is sometimes called an
> "outer Kuiper belt" or an "inner Oort cloud". No Oort cloud object
> has actually been seen at the Oort cloud distance. Its existence
is
> calculated by many different means. The small-moon sized object
Sedna
> is considered an Oort Cloud object even though it is in the empty
> zone less than 1000 AU's out.
>
> We don't know how many objects exist in this empty zone between
the
> Kuiper belt and Oort cloud, its simply too dark to see with a
> telescope. Sedna could be an oddball planetoid adrift in the trans-
> kuiper desert, or there could be many other objects floating
around
> out there waiting for us. Voyager is probably not sophisticated
> enough to answer that, but within 50 years, we may know.
>
> We have no visual sighting of any planetoid beyond 1000 AU's. The
> Oort cloud goes out to at least 100,000 AU's, if not more, and
Alpha
> Centauri is just under 300,000 AU's away.
>
> For those who don't know, 1 AU is the distance from the Earth to
the
> sun, about 93 million miles. The voyagers are still less than 100
AU

On 7/28/06, Robert wrote:
(...)
> actually they have taken photographs of objects in the ort cloud,
> barely a dot on the film, that is suppose to be about the size of a
> locomotive engine.
(...)

Planet-sized objects like Sedna appear as blurs a few pixels wide
using the Hubble Space Telescope (see
http://www.space.com/scienceastronomy/hubble_sedna_040414.html), and
one would think that locomotive-sized objects are well below the
minimum size detectable by current technology.

On Jul 28, 2006, at 6:27 PM, Robert wrote:

> actually they have taken photographs of objects in the ort cloud,
> barely a dot on the film, that is suppose to be about the size of a
> locomotive engine.

I'm sure that many Oort objects must be captured on existing photos,
and careful analysis will reveal a few, but at present, most will be
indiscernible.

I guess the real issue for starfaring space settlers is this:

If there is a 5 trillion mile gap between the Kuiper belt and the
Oort cloud, does this represent an inpenetrable barrier to diffusion
settlement? The edge of the Kuiper belt is 1% of the journey to the
Oort cloud. This seems to mean that colonists would have to undertake
a long crossing of several years to get to the Cloud (several
thousand years using todays technology), and once they do, they would
have little (no) trade with Kuiper colonies. Those settlements in the
Kuiper belt would be basically right next door to their Earthly
ancestors, when compared to their distance to their Oort cloud
descendants.

Also, if every star has an Oort cloud, it would be possible for the
colonists to simply "sail the galactic ocean" hopping from comet to
comet for supplies without ever actually entering the heliosphere of
a solar system for billions of years. Not only would they not be
bound to planets, they wouldn't even be bound to suns. The closest
suns to them would simply be among the brightest stars in the sky.
Very slight improvements in radiation shielding and genetic
adaptation would allow them to sail through the Orion Arm of the
galaxy, and even into the core. As the millions of years go by, and
the galaxy spins and spirals around them, these Galactic Ocean
colonists will be scattered about by the galactic current, spreading
to every corner of the galaxy with little effort on their part.

Perhaps SETI need not bother pointing their dishes at stars. Maybe
there's no one there. Perhaps all the colonists are in the blackness
and they shun stars and solar systems. Since 99.99999% of the galaxy
is interstellar (using the heliopause at 100 AU as the boundary of
the solar system proper), It seems logical that, if we can get there
at all, and if we can meet our energy and supply requirements, that
interstellar space is where most people will end up living. Once
settlements set out on the several generation journey to a star,
eventually they will get used to it and good at living. Perhaps they
will wonder why anyone would want to be bound to a star.

All this is if its possible to make the leap from the Kuiper belt to
the Oort cloud. The Voyagers have left the Kuiper belt. They should
be in the Oort cloud in a few thousand years. Hopefully, we'll be
waiting for them. Wouldn't that be something if the aliens who
discover Voyager with its golden record are our own descendants?

doug

depends on how reflective it is. i believe it was only one pixil in
size. some how they came up with the determination of "likely to be as
small as a locomotive"

--- In spacesettlers@yahoogroups.com, "Lucio de Souza Coelho"
wrote:
>
> On 7/28/06, Robert wrote:
> (...)
> > actually they have taken photographs of objects in the ort cloud,
> > barely a dot on the film, that is suppose to be about the size of
a

On 7/28/06, Robert wrote:
(...)
> depends on how reflective it is. i believe it was only one pixil in
> size.

Sedna's albedo is 0.25 . It has an estimated diameter of 1700 Km
(larger than Texas, for sake of comparisons). It appears as something
4 pixels wide in the pictures. An object of corresponding reflexivity
one pixel wide would still be 435 Km wide. In order to a
locomotive-sized object (say 10 meters wide) to be as bright as an
object 435 Km wide with an albedo of 0.25 , it would need an albedo of
7,3x10^9 .

Unfortunately albedo beyond 1 are physically impossible, for that
would mean a miraculous object that reflects more light than it
absorbs. In the case of the huge albedo found above, your "locomotive"
would put the brightest quasars in the Universe to shame.

> some how they came up with the determination of "likely to be as
> small as a locomotive"
(...)

As you can see from the simple calculation above, somehow they made an
error of nine orders of magnitude at some point.

On 7/28/06, Douglas May wrote:
(...)
> Perhaps SETI need not bother pointing their dishes at stars. Maybe
> there's no one there. Perhaps all the colonists are in the blackness
> and they shun stars and solar systems. Since 99.99999% of the galaxy
> is interstellar (using the heliopause at 100 AU as the boundary of
> the solar system proper), It seems logical that, if we can get there
> at all, and if we can meet our energy and supply requirements, that
> interstellar space is where most people will end up living. Once
> settlements set out on the several generation journey to a star,
> eventually they will get used to it and good at living. Perhaps they
> will wonder why anyone would want to be bound to a star.
(...)

I (and many others) have also wondered about that possibility. But the
problem with that hypothesis is that planetary systems offer quite
definitive advantages in terms of density of matter. Instead of
traveling hundreds of millions of kilometers to the next comet, inside
a planetary system you will have regions were a given asteroid is just
a few thousand kilometers away. And there will be even densest regions
in planetary rings and the like. So I find it hardly believable that
no colony among the trillions surrounding a planetary system would not
be tempted to tap all those tightly packed resources.

Years ago, this same hypothesis popped in this list (I think), and the
conclusion was that in such a scenario you would have a Galactic Ocean
(using your catchy poetic name) civilization very disperse and inside
this Galactic Ocean you would have many "Solar Island" civilizations
proliferating tightly packed around stars.

its possible or its also possible that im misremembering the exact
nature of that part of the article. perhaps it was somewhat closer
than the oort cloud.

--- In spacesettlers@yahoogroups.com, "Lucio de Souza Coelho"
wrote:
>
> On 7/28/06, Robert wrote:
> (...)
> > depends on how reflective it is. i believe it was only one pixil
in
> > size.
>
> Sedna's albedo is 0.25 . It has an estimated diameter of 1700 Km
> (larger than Texas, for sake of comparisons). It appears as
something
> 4 pixels wide in the pictures. An object of corresponding
reflexivity
> one pixel wide would still be 435 Km wide. In order to a
> locomotive-sized object (say 10 meters wide) to be as bright as an
> object 435 Km wide with an albedo of 0.25 , it would need an albedo
of
> 7,3x10^9 .
>
> Unfortunately albedo beyond 1 are physically impossible, for that
> would mean a miraculous object that reflects more light than it
> absorbs. In the case of the huge albedo found above,
your "locomotive"
> would put the brightest quasars in the Universe to shame.
>
> > some how they came up with the determination of "likely to be as
> > small as a locomotive"
> (...)
>
> As you can see from the simple calculation above, somehow they made
an

On Jul 29, 2006, at 1:53 AM, Robert wrote:

> its possible or its also possible that im misremembering the exact
> nature of that part of the article. perhaps it was somewhat closer
> than the oort cloud.

Articles are notorious for hyping up their stories. The old line is
"if it bleeds, it leads." As much as I love them, the Discovery
Channel and the History Channel ought to rename themselves "The
Controversy Channels" cause that's the angle they always try to play
up. Somebody is always overturning everything we thought we always
knew about everything.

A lot of people define the Oort cloud as beginning immediately after
the Kuiper belt. Observations of objects drop off VERY sharply at 50
AU's suggesting a definite end to the Kuiper belt proper. Also, about
100 AU's is the heliopause and termination shock where the sun's
whirlpool basically ends. This Heliopause would tend to push most
objects either in or out, not a lot would just hang out right there.

All of the planets, asteroids, and Kuiper belt are the material that
got sucked to the bottom of the sun's whirlpool. The Oort cloud are
the objects that are surrounding it.

Try taking a bathtub full of water and a thin layer of bubbles on
top. Create two whirlpools with your hands a short distance apart.
The whirlpool itself will seem pretty clear (unless you have too many
bubbles, like Epsilon Eridani) because most of the bubbles are sucked
down. Halfway between your two whirlpools, if they're spaced right,
you'll see the bubbles concentrate into a kind of stream or current
with very complex, bizarre motion. Now try making 400 billion
whirlpools and you get a galaxy.

The funnel, or whirlpool is the Solar system, all the planets and
Kuiper Belt. Where the whirlpool gives way to the flat water is the
heliopause, and the slightly concentrated current of bubbles halfway
in between the two whirlpools is (possibly) the main part of the Oort
cloud.

Note that if your whirlpools are too close together, there are no
bubbles in between, like in a binary star system or cluster (where
most stars are). Also, if the whirlpools are too far apart, there are
bubbles, but they don't concentrate into a stream or current..

Hopefully there are enough objects in the heliopause to allow
diffusion settlement. There are some great new telescopes in the
works that will soon give us much better answers.

Of course bathtub experiments may not apply directly to cosmic
questions, but the whirlpool seems to be a basic theme in physics.

All this talk about settling beyond the solar system is getting me
excited! Where do I get my ticket?

doug

interesting, lot of things i had never though of before.

--- In spacesettlers@yahoogroups.com, Douglas May wrote:
>
> On Jul 29, 2006, at 1:53 AM, Robert wrote:
>
> > its possible or its also possible that im misremembering the exact
> > nature of that part of the article. perhaps it was somewhat closer
> > than the oort cloud.
>
> Articles are notorious for hyping up their stories. The old line
is
> "if it bleeds, it leads." As much as I love them, the Discovery
> Channel and the History Channel ought to rename themselves "The
> Controversy Channels" cause that's the angle they always try to
play
> up. Somebody is always overturning everything we thought we always
> knew about everything.
>
> A lot of people define the Oort cloud as beginning immediately
after
> the Kuiper belt. Observations of objects drop off VERY sharply at
50
> AU's suggesting a definite end to the Kuiper belt proper. Also,
about
> 100 AU's is the heliopause and termination shock where the sun's
> whirlpool basically ends. This Heliopause would tend to push most
> objects either in or out, not a lot would just hang out right there.
>
> All of the planets, asteroids, and Kuiper belt are the material
that
> got sucked to the bottom of the sun's whirlpool. The Oort cloud
are
> the objects that are surrounding it.
>
> Try taking a bathtub full of water and a thin layer of bubbles on
> top. Create two whirlpools with your hands a short distance apart.
> The whirlpool itself will seem pretty clear (unless you have too
many
> bubbles, like Epsilon Eridani) because most of the bubbles are
sucked
> down. Halfway between your two whirlpools, if they're spaced
right,
> you'll see the bubbles concentrate into a kind of stream or
current
> with very complex, bizarre motion. Now try making 400 billion
> whirlpools and you get a galaxy.
>
> The funnel, or whirlpool is the Solar system, all the planets and
> Kuiper Belt. Where the whirlpool gives way to the flat water is
the
> heliopause, and the slightly concentrated current of bubbles
halfway
> in between the two whirlpools is (possibly) the main part of the
Oort
> cloud.
>
> Note that if your whirlpools are too close together, there are no
> bubbles in between, like in a binary star system or cluster (where
> most stars are). Also, if the whirlpools are too far apart, there
are