Missing sial, iron, and nickel explains Fermi paradox

Ian Parker wrote:

:On 3 Aug, 03:13, Fred J. McCall wrote:
: Ian Parker wrote:
:
: :On 2 Aug, 16:35, Fred J. McCall wrote:
: : Ian Parker wrote:
: :
: : :
: : :We have had surprises already. Accepted wisdom said that Jupiter and
: : :Saturn were where they are because at their distance volatiles were
: : resent. Jupiter could not be close than Mercury because volatiles
: : :would not condense out.
: : :
: : :Wrong! - There have been many Jupiters found within the orbit of
: : :Mercury.
: : :
: :
: : Are you living in the same solar system with the rest of us?
: :
: :
: :No, the whole point was comparative solar systems and extrasolar
: lanets. Jupiter I have used to denote the generic gas giant. the
: :whole point is we make theories of the Moon. With one solar system you
: :can't draw conclusions. That is the point.
: :
:
: Cite for "many Jupiters found within the orbit of Mercury"?
:
:http://en.wikipedia.org/wiki/Extrasolar_planet
:

This doesn't appear to support your position. Please list the
"Jupiters" that you think are applicable. Keep in mind the varying
size of the stars involved.

:
:Remember when you click on the chart that Mercury has a period of 88
:days.
:
:http://www.obs-hp.fr/www/nouvelles/gl876.html
:

Look at the low mass of the star.

:
:http://curious.astro.cornell.edu/extrasolarplanets.php
:
:This explains "hot Jupiters" in more detail. In fact it may well be
:true that a normal solar system is like ours. The statistics are in
:fact skewed by observational technology. This site explains this
:fully.
:

This only supports your claim if you equate "very close" to "within
the orbit of Mercury". That's certainly not a given.

Mass and luminosity of the star matters.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn

Joe Strout wrote:
In article .com,
Einar wrote:

[Re. cryonics]

Hmm, well - what then remains is that one has to be sufficiently
financed

Well, not really -- you pay for it with life insurance. If your income
is low, hopefully that's because you're still a student, and young,
which makes life insurance cheap. My wife and I signed up when we were
still in grad school, and the insurance cost about as much as a couple
of pizzas per month.

Sorry we've wandered so far off-topic here, but I thought this worth
clearing up -- who knows, maybe I've just saved Einar's life.

Best,
- Joe

--
"Polywell" fusion -- an approach to nuclear fusion that might actually work.
Learn more and discuss via: http://www.strout.net/info/science/polywell/

LOL

Einar

Fred J. McCall wrote:
Ian Parker wrote:

:On 3 Aug, 03:13, Fred J. McCall wrote:
: Ian Parker wrote:
:
: :On 2 Aug, 16:35, Fred J. McCall wrote:
: : Ian Parker wrote:
: :
: : :
: : :We have had surprises already. Accepted wisdom said that Jupiter and
: : :Saturn were where they are because at their distance volatiles were
: : resent. Jupiter could not be close than Mercury because volatiles
: : :would not condense out.
: : :
: : :Wrong! - There have been many Jupiters found within the orbit of
: : :Mercury.
: : :
: :
: : Are you living in the same solar system with the rest of us?
: :
: :
: :No, the whole point was comparative solar systems and extrasolar
: lanets. Jupiter I have used to denote the generic gas giant. the
: :whole point is we make theories of the Moon. With one solar system you
: :can't draw conclusions. That is the point.
: :
:
: Cite for "many Jupiters found within the orbit of Mercury"?
:
:http://en.wikipedia.org/wiki/Extrasolar_planet
:

This doesn't appear to support your position. Please list the
"Jupiters" that you think are applicable. Keep in mind the varying
size of the stars involved.

:
:Remember when you click on the chart that Mercury has a period of 88
:days.
:
:http://www.obs-hp.fr/www/nouvelles/gl876.html
:

Look at the low mass of the star.

:
:http://curious.astro.cornell.edu/extrasolarplanets.php
:
:This explains "hot Jupiters" in more detail. In fact it may well be
:true that a normal solar system is like ours. The statistics are in
:fact skewed by observational technology. This site explains this
:fully.
:

This only supports your claim if you equate "very close" to "within
the orbit of Mercury". That's certainly not a given.

Mass and luminosity of the star matters.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn

I am not entirelly sure what you two are quarelling about, but here is
a convenient list of known planetary systems, which inclutes links for
further information.

This hot Jupiter has an incredibly short orbital perid:
http://www.spitzer.caltech.edu/Media.../release.shtml

http://www.princeton.edu/%7Ewillman/planetary_systems/

Another information page:
http://exoplanets.org/

Still another information page:
http://astronautica.com/owds.html

Einar

Einar wrote:
Matt Giwer wrote:
Somehow I am missing the connection to the paradox. It appears to lie solely in
the assumption that if there is no moon event the planet will be all ocean. That
does not compute unless we can explain the disappearance of the moon of Venus.
If Venus had had the same amount of water as earth, and there is little way to
explain a significantly different amount, there should be enough water vapor in
its atmosphere to 9000psi (600 At.) of pressure on the surface. But last I heard
there is negligible water in the atmosphere and clearly no such pressure.

We have no idea if there is a minimum amount of ocean needed to approximate an
ecology like our own however it appears reasonable that all else being equal the
amount of rainfall is proportional to the evaporative surface of the oceans. It
also follows as a reasonable assumption (but which cannot be supported in the
least, that the more life the faster evolution but we are not in a rush so a few
extra billion years does not matter.

However surface area only would be a factor in rainfall. Depth would not be. So
without a moon and nothing lost there is nothing prohibiting large and shallow
seas. The South China Sea with a depth averaging over a few hundred feet has all
the characteristics of any other ocean save it is warming at all depths. This
would speed evolution among the cold bloods.

Tectonic forces would still raise mountains and and volcanoes broad expanses
like the Deccan Plains. As long as the planet is large enough there is no reason
to suggest plates would not form and move. The only different would be the
longevity of the created land above the surface. Given Earth we find old and new
mountains in proximity such as in the US so we can expect there would always be
dry land. So maybe a world with shallow seas needs also have greater tectonic
activity requiring a somewhat more massive planet and the world average being
more like Japan. So maybe the funny thing about ET is if the ground shakes he
curls into a ball.

Am I missing something?

--
An entire cool summer is trumped by a warm day in January if you are a
global melter.
-- The Iron Webmaster, 3836
nizkor http://www.giwersworld.org/nizkook/nizkook.phtml
Mission Accomplished http://www.giwersworld.org/opinion/mission.phtml a12

Venus has no plate tectonics. However, it might if it had oceans.

Maybe I missed that too but I thought plates moved because of convection
current in the mantle.

I think it´s believed Venus' oceans evaporated, once the Sun warmed
up, and that the water left the planet altogether being blown away
into space. What remains is possibly the most hostile to life plase in
the solar system.

I see no way for water to preferentially be removed as at that temperature was
is a gas like any other.

--

Joe Strout wrote:
In article ,
Matt Giwer wrote:
Somehow I am missing the connection to the paradox. It appears to lie solely
in the assumption that if there is no moon event the planet will be all ocean.
That does not compute unless we can explain the disappearance of the moon of
Venus.

We can; Venus is too hot to have liquid water.

So it has gaseous water. If comets delivered it, what is there to selectively
take it away and not all gases? If earth were that temperature H2O would be
around 99% (a guess) of the atmosphere with the rest as trace gases. A guess
because there is a question if it would be gaseous at the resulting pressure at
Venus temperature.

But the case for the Moon being responsible for continents is made
pretty convincingly in the book Rare Earth. IIRC, it basically goes
like this: without the impact event that blasted much of the Earth's
crust into orbit (forming the Moon), our crust would be too thick to
support plate tectonics (just like Venus, I think). So they would end
up a very uniform thickness, and the only mountains that would form
would be from volcanoes, and these would quickly be eroded back down,
leaving a uniform planet-spanning ocean. It's only because our crust is
so thin that we can have tectonics and enough variation to produce
continents and oceans.

As for volcanoes, I mentioned the Deccan plains whose creation was at one time
considered an alternate explanation for the dinosaur extinction and has been
around 65 million years and little sign of disappearing any time soon. Similarly
the Americas separated from Euro-Africa because of what we call the mid-Atlantic
rift which is new seabed being formed. With shallow seas the ridge becomes
mountains. As room has to be made for them wherever the "rock meets the hard
place" more mountains form.

As for quickly eroding one has to ask what is meant by quickly. Add another
billion years for evolution to work its magic and the dominant species are those
which can live on land but never lose the ability to migrate to new lands across
oceans as the olds wear away.

Hm. I'm not explaining this very well, but check out the book, it
spends a chapter or two on this topic.

I have yet to find something that is a killer explanation of the paradox. They
all have some earth-centric assumption that is considered a sine qua non for
advanced life. Frankly I think they are all just to sell books.

In this one an earth with nothing removed would have a layer of oceans about 2
miles deep Moana Loa is the tallest mountain on earth if you measure from the
sea bed.

But then all we need to do is have a larger Jupiter or maybe a couple of them
or fewer comets and there is less water to reach an earth. Most sea life is
within the top 600 feet and it increases the closer to the surface. As that is
based upon sunlight penetrated water and photosynthesis. A planet builder would
be over-charging to have more water. Once water then carbon life and we run out
of earth-centric essentials for life as we know it.

However there is no clear reason that 600 feet is the minimum necessary water
and there should be no problem with non-tectonic planets having 1200 ft
variations in altitude even if it is. Without looking it up I'm fairly certain
Venus has more than that. So we don't need volcanism to have dry land. As long
as plant life adapts to land it should produce organic material faster than the
rock can wear away so the land above the water is forever. (Once dead organic
matter covers the rock, the organic matter rather than the rock wears away.) All
we need is life to adapt to land before it erodes away.

So I am still missing the point of the article.

=====

My joke answer is we are shielded from seeing signs of intelligent life in the
universe so we can be studied as to how the first intelligent life in the
universe might have evolved without seeing signs of intelligence in the sky
every night. We assume we are only average but someone had to be first. With
enough societies and lost records it would become a valid research question such
as how would a child develop without any human contact.

A joke because once you introduce intelligent intervention anything is
possible. But this might be the general answer. As there is no credible natural
answer for the paradox then it has to be intelligent intervention.

The other explanation is much simpler. If 1/10th of 1% of UFO sightings are
really aliens then earth is a quite popular destination as there are so many
sightings.

--
Hell freezing over would not convince the Warmin' Marvins of the world.
The Iron Webmaster, 3837
nizkor http://www.giwersworld.org/nizkook/nizkook.phtml
Iraqi democracy http://www.giwersworld.org/911/armless.phtml a3

Einar wrote:
Joe Strout wrote:
In article ,
Matt Giwer wrote:

Somehow I am missing the connection to the paradox. It appears to lie solely
in the assumption that if there is no moon event the planet will be all ocean.
That does not compute unless we can explain the disappearance of the moon of
Venus.
We can; Venus is too hot to have liquid water.

But the case for the Moon being responsible for continents is made
pretty convincingly in the book Rare Earth. IIRC, it basically goes
like this: without the impact event that blasted much of the Earth's
crust into orbit (forming the Moon), our crust would be too thick to
support plate tectonics (just like Venus, I think). So they would end
up a very uniform thickness, and the only mountains that would form
would be from volcanoes, and these would quickly be eroded back down,
leaving a uniform planet-spanning ocean. It's only because our crust is
so thin that we can have tectonics and enough variation to produce
continents and oceans.

Hm. I'm not explaining this very well, but check out the book, it
spends a chapter or two on this topic.

Best,
- Joe

--
"Polywell" fusion -- an approach to nuclear fusion that might actually work.
Learn more and discuss via: http://www.strout.net/info/science/polywell/

Hmm, plate tectonics does perform a pretty effective recycling of
materials. That means theyr availabilty is maintained for processes
abow ground. I have also heard speculations about effects of water
being present in the crust, about the precense of life and what
effects it may have on the crust.

It appears though certain that plate tectonics help the Earth staying
livable. Our planet really looks like an extremelly far out outlyer
variable.

The more unique characteristics of a planet you consider the more of an outlier
it appears to be. But none of those apply to life on land which we assume is a
prerequisite to visiting us.

Recycling sounds like something interesting but since the issue is life on land
how much dry land has been recycled since then? And I know of no variation in
land biomass based upon who long since the last "recycle." In other words, no
connection.

--
Republicans are more interested in protecting the president than the troops.
-- The Iron Webmaster, 3839
nizkor http://www.giwersworld.org/nizkook/nizkook.phtml
book review http://www.giwersworld.org/israel/wi...utioners.phtml a7

On 4 Aug, 06:37, Matt Giwer wrote:

A joke because once you introduce intelligent intervention anything is
possible. But this might be the general answer. As there is no credible natural
answer for the paradox then it has to be intelligent intervention.

I would be thinking in terms of s simulation.

The other explanation is much simpler. If 1/10th of 1% of UFO sightings are
really aliens then earth is a quite popular destination as there are so many
sightings.

ET in the form of UFO sightings is completely impossible. The sort of
ET spaceship we saw was in fact 1950's SF. real ET spaceships would be
very small and the exploration would be done by nanotech.
--

- Ian Parker

On Sat, 04 Aug 2007 13:34:59 -0700, in a place far, far away, Ian
Parker made the phosphor on my monitor glow in
such a way as to indicate that:

On 4 Aug, 06:37, Matt Giwer wrote:

A joke because once you introduce intelligent intervention anything is
possible. But this might be the general answer. As there is no credible natural
answer for the paradox then it has to be intelligent intervention.

I would be thinking in terms of s simulation.

The other explanation is much simpler. If 1/10th of 1% of UFO sightings are
really aliens then earth is a quite popular destination as there are so many
sightings.

ET in the form of UFO sightings is completely impossible. The sort of
ET spaceship we saw was in fact 1950's SF. real ET spaceships would be
very small and the exploration would be done by nanotech.

Yes, because Ian says so...

Ian Parker wrote:

:
:ET in the form of UFO sightings is completely impossible. The sort of
:ET spaceship we saw was in fact 1950's SF. real ET spaceships would be
:very small and the exploration would be done by nanotech.
:

Why? Just because you say so?


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn

In article ,
Matt Giwer wrote:

The more unique characteristics of a planet you consider the more of an
outlier it appears to be. But none of those apply to life on land which
we assume is a prerequisite to visiting us.

You don't know that. To take the point in this thread: without plate
tectonics, you get no land at all. Makes it a bit hard to get life on
land.

Best,
- Joe

--
"Polywell" fusion -- an approach to nuclear fusion that might actually work.
Learn more and discuss via: http://www.strout.net/info/science/polywell/