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  #11  
Old June 21st 06, 03:45 AM posted to sci.space.science
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Default Question about early Earth

wrote:
blue.planet wrote:

Did the Moon siphon off much of the Earth's
atmosphere in earlier times.



No. Earth's gravity is substantially stronger than the moon's, so the
moon couldn't pull away atmosphere.

IIRC, oceans are pretty good about sucking up excess CO2.


Would being in the right orbit around the right sized star be
enough to creat the conditions for terrestrial type life, or is
a double planet like our Earth-Moon neccessary?



I don't think it's necessary, but it can help. At a minimum, a large
moon helps by minimizing random flips in a planet's tilt, which can
have drastic effects on the environment.

Mike Miller


That's right. Discovery Channel did a bit a few months ago called "If we
had no moon." It asserted that the presence of the moon makes a big
difference in the ability of the earth to support life. There's much
more to it than simply stabilizing the earth's spin; it also causes (or
at least, helps to cause) the tides, which keep the water of our oceans
moving around, which in turns helps promote sea life. It also tends to
sweep up meteorites that would otherwise hit the earth.

I must admit, I don't understand all I know about the stabilizing
effect. And my Ph.D. was in the dynamics of rotating bodies. I think
the issue has to do with the rotation of _FLEXIBLE_ bodies, rather than
rigid ones. Remember, the earth's crust is really a very thin thing
that floats on a liquid mantle. From fundamental physics, there is no
_WAY_ that the earth's angular momentum vector is going to change. It
precesses, because of luni-solar perturbations, at a slow rate (12,000
years per cycle) but it doesn't and can't change in magnitude.

But the earth's crust _CAN_ slip and slide around on the mantle. I
think maybe it's this that is stabilized by the moon, though I've not
found anyone who can explain the physics to me.

jack
  #12  
Old June 21st 06, 03:48 AM posted to sci.space.science
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Posts: n/a
Default Question about early Earth

wrote:
blue.planet wrote:

Was the Moon in a close Earth orbit essential in preventing a runaway
greenhouse effect like we see on Venus. The Earth was much more
volcanically active in it's youth and would have put out much more CO2
and other greenhouse gases. Did the Moon siphon off much of the Earth's
atmosphere in earlier times.



In the 60s it was speculated that the Moon is the reason the Earth's
atmosphere isn't like that of Venus. The idea was that, even though
its gravity is so much less than Earth's, it would perturb enough
molecules to escape velocity over time that the amount of atmosphere
would be depleted. Larry Niven picked up on that and incorporated it
into at least two stories. It was never a widely held hypothesis, and
since it was first proposed better modeling indicates that Venus' fate
was sealed simply by its proximity to the Sun.

I once asked about that here years ago, and Henry Spencer said that a
lot of science speculation that Niven used in his stories came from
Tommy Gold, an iconoclastic astronomer who was part of the steady state
universe crowd (with Fred Hoyle) and also is known for having gotten in
a row with NASA during Apollo. All of this is from memory and possibly
way inaccurate.

Thomas Gold was the one who predicted that the dust layer on the moon
was some 200 feet thick, and flowed like a fluid, due to the fact that
the dust particles would have a static charge and repel each other. He
predicted that any spacecraft landing on the moon would simply sink into
the dust and disappear.

Fortunately, he was way wrong.

Jack
  #13  
Old June 21st 06, 03:54 AM posted to sci.space.science
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Posts: n/a
Default Question about early Earth

Maury Markowitz wrote:
wrote:

Was the Moon in a close Earth orbit essential in preventing a runaway
greenhouse effect like we see on Venus. The Earth was much more
volcanically active in it's youth and would have put out much more CO2
and other greenhouse gases. Did the Moon siphon off much of the Earth's
atmosphere in earlier times.



As we learn more the answer increasingly seems to be that the earth
was "unstable" before life became so dominant. Prior to this there were
a number of complete freeze-overs where the entire planet was covered in
ice. It is believed C02 built up from volcanoes, causing rnaway
greenhouse and melting the ice. The CO2 would then be react chemically
with the now-open oceans, scrubing it back out.

lot of science speculation that Niven used in his stories came from
Tommy Gold, an iconoclastic astronomer who was part of the steady state
universe crowd (with Fred Hoyle) and also is known for having gotten in
a row with NASA during Apollo.



No, pretty good actually. Gold was the guy that got onto TV by
claiming the moon probes would sink in the miles-thick dust on the moon.
OF COURSE it's miles thick, its been there practically forever and
there's no mechanism to solidify it back into rock like there is here.

So they built the landers and tested. Nope, no problem. But Gold
wouldn't stop even when confronted by direct counterexample. The TV
robots eventually gave up listening to him -- something that no longer
happens unfortunately.

He still turns up, unnamed, in various creationist books. Why? Because
the lack of thick dust on the moon means it can't be very old, right?


Exactly right. And, as you said, there's really no limit -- at least no
practical one -- to the depth of the dust.

For that matter, it's not much different here on earth. Imagine trying
to sweep up all the dirt on a desert. You can sweep up the top layer,
but there's always more below it. It's the same way most places on the
moon, because debris from impacts has been raining down everywhere, for
like forever.

On the earth, eventually you'll hit bedrock. Same on the moon, but the
depth varies greatly depending on where you are.

For the record, I'm a Christian myself, but those crazy creationists are
always saying stupid things that reflect badly on the rest of us. I
wish they'd just shut up and go away.

Jack


Maury

  #14  
Old June 3rd 11, 01:12 AM
neilzero neilzero is offline
Junior Member
 
First recorded activity by SpaceBanter: May 2011
Posts: 22
Default

Quote:
Originally Posted by Jack Crenshaw View Post
Maury Markowitz wrote:
wrote:

Was the Moon in a close Earth orbit essential in preventing a runaway
greenhouse effect like we see on Venus. The Earth was much more
volcanically active in it's youth and would have put out much more CO2
and other greenhouse gases. Did the Moon siphon off much of the Earth's
atmosphere in earlier times.



As we learn more the answer increasingly seems to be that the earth
was "unstable" before life became so dominant. Prior to this there were
a number of complete freeze-overs where the entire planet was covered in
ice. It is believed C02 built up from volcanoes, causing rnaway
greenhouse and melting the ice. The CO2 would then be react chemically
with the now-open oceans, scrubing it back out.

lot of science speculation that Niven used in his stories came from
Tommy Gold, an iconoclastic astronomer who was part of the steady state
universe crowd (with Fred Hoyle) and also is known for having gotten in
a row with NASA during Apollo.



No, pretty good actually. Gold was the guy that got onto TV by
claiming the moon probes would sink in the miles-thick dust on the moon.
OF COURSE it's miles thick, its been there practically forever and
there's no mechanism to solidify it back into rock like there is here.

So they built the landers and tested. Nope, no problem. But Gold
wouldn't stop even when confronted by direct counterexample. The TV
robots eventually gave up listening to him -- something that no longer
happens unfortunately.

He still turns up, unnamed, in various creationist books. Why? Because
the lack of thick dust on the moon means it can't be very old, right?


Exactly right. And, as you said, there's really no limit -- at least no
practical one -- to the depth of the dust.

For that matter, it's not much different here on earth. Imagine trying
to sweep up all the dirt on a desert. You can sweep up the top layer,
but there's always more below it. It's the same way most places on the
moon, because debris from impacts has been raining down everywhere, for
like forever.

On the earth, eventually you'll hit bedrock. Same on the moon, but the
depth varies greatly depending on where you are.

For the record, I'm a Christian myself, but those crazy creationists are
always saying stupid things that reflect badly on the rest of us. I
wish they'd just shut up and go away.

Jack


Maury
Likely some of the details, even the mainstream thinking will change, and still be wrong after the change. My math does not go much beyond high school, so I often cannot check the work of the experts, so I don't know what will change, but there does seem to be suspicious comparisons.
The moon likely has and had little effect on green house warming. Earth has always had some green house warming, otherwise it would be almost as cold as Mars is now. My guess is more green house gas might warm Earth 9 degrees f = 5 degrees c, but not much more, unless the atmospheric pressure increases drastically as at Venus which has about 90 times more atmosphere than Earth. I have not seen a graph or chart that shows the the amount of green house warming that results from higher atmospheric pressure, but I am quite sure Venus is hot, partly because it has a thick atmosphere. My guess is neither Earth nor Venus ever had "run away" green house warming of significance, as the hockey stick graph has been discredited in my opinion.
No fosil evidence has been found for ice age at Earth the first 3.6 billion years = all the ice ages have occured in the most recent one billion years, and only about half of Earth's surface was covered by the worst ice caps.
This is surprising, as the Sun produced only about half as much energy 4 billion years ago. This is the result of nuclear fusson math and theory, which was sufficiently correct to produce reliable fusion = H bombs.
It is difficult to measure, with extreme accuracy, the distance to the sun, because the surface is very hot plasma, but some reports of Earth moving a few millimeters per year away from the Sun have not be debunked as far as I know. A few billion millimeters does not put Earth lots closer to the Sun, but it could account for no ice ages the first 3.6 billion years. The recent recession from the Sun, if real, may be a recent change, but there is little reason to think the resession rate has changed a lot over the past 3.6 billion years. I'm also a Christian, but I also have little use for much of the ceationist's sudo-science. Neil
  #15  
Old June 3rd 11, 01:12 AM
neilzero neilzero is offline
Junior Member
 
First recorded activity by SpaceBanter: May 2011
Posts: 22
Default

Quote:
Originally Posted by Jack Crenshaw View Post
Maury Markowitz wrote:
wrote:

Was the Moon in a close Earth orbit essential in preventing a runaway
greenhouse effect like we see on Venus. The Earth was much more
volcanically active in it's youth and would have put out much more CO2
and other greenhouse gases. Did the Moon siphon off much of the Earth's
atmosphere in earlier times.



As we learn more the answer increasingly seems to be that the earth
was "unstable" before life became so dominant. Prior to this there were
a number of complete freeze-overs where the entire planet was covered in
ice. It is believed C02 built up from volcanoes, causing rnaway
greenhouse and melting the ice. The CO2 would then be react chemically
with the now-open oceans, scrubing it back out.

lot of science speculation that Niven used in his stories came from
Tommy Gold, an iconoclastic astronomer who was part of the steady state
universe crowd (with Fred Hoyle) and also is known for having gotten in
a row with NASA during Apollo.



No, pretty good actually. Gold was the guy that got onto TV by
claiming the moon probes would sink in the miles-thick dust on the moon.
OF COURSE it's miles thick, its been there practically forever and
there's no mechanism to solidify it back into rock like there is here.

So they built the landers and tested. Nope, no problem. But Gold
wouldn't stop even when confronted by direct counterexample. The TV
robots eventually gave up listening to him -- something that no longer
happens unfortunately.

He still turns up, unnamed, in various creationist books. Why? Because
the lack of thick dust on the moon means it can't be very old, right?


Exactly right. And, as you said, there's really no limit -- at least no
practical one -- to the depth of the dust.

For that matter, it's not much different here on earth. Imagine trying
to sweep up all the dirt on a desert. You can sweep up the top layer,
but there's always more below it. It's the same way most places on the
moon, because debris from impacts has been raining down everywhere, for
like forever.

On the earth, eventually you'll hit bedrock. Same on the moon, but the
depth varies greatly depending on where you are.

For the record, I'm a Christian myself, but those crazy creationists are
always saying stupid things that reflect badly on the rest of us. I
wish they'd just shut up and go away.

Jack


Maury
Likely some of the details, even the mainstream thinking will change, and still be wrong after the change. My math does not go much beyond high school, so I often cannot check the work of the experts, so I don't know what will change, but there does seem to be suspicious comparisons.
The moon likely has and had little effect on green house warming. Earth has always had some green house warming, otherwise it would be almost as cold as Mars is now. My guess is more green house gas might warm Earth 9 degrees f = 5 degrees c, but not much more, unless the atmospheric pressure increases drastically as at Venus which has about 90 times more atmosphere than Earth. I have not seen a graph or chart that shows the the amount of green house warming that results from higher atmospheric pressure, but I am quite sure Venus is hot, partly because it has a thick atmosphere. My guess is neither Earth nor Venus ever had "run away" green house warming of significance, as the hockey stick graph has been discredited in my opinion.
No fosil evidence has been found for ice age at Earth the first 3.6 billion years = all the ice ages have occured in the most recent one billion years, and only about half of Earth's surface was covered by the worst ice caps.
This is surprising, as the Sun produced only about half as much energy 4 billion years ago. This is the result of nuclear fusson math and theory, which was sufficiently correct to produce reliable fusion = H bombs.
It is difficult to measure, with extreme accuracy, the distance to the sun, because the surface is very hot plasma, but some reports of Earth moving a few millimeters per year away from the Sun have not be debunked as far as I know. A few billion millimeters does not put Earth lots closer to the Sun, but it could account for no ice ages the first 3.6 billion years. The recent recession from the Sun, if real, may be a recent change, but there is little reason to think the resession rate has changed a lot over the past 3.6 billion years. I'm also a Christian, but I also have little use for much of the ceationist's sudo-science. Neil
  #16  
Old June 3rd 11, 01:13 AM
neilzero neilzero is offline
Junior Member
 
First recorded activity by SpaceBanter: May 2011
Posts: 22
Default

Quote:
Originally Posted by Jack Crenshaw View Post
Maury Markowitz wrote:
wrote:

Was the Moon in a close Earth orbit essential in preventing a runaway
greenhouse effect like we see on Venus. The Earth was much more
volcanically active in it's youth and would have put out much more CO2
and other greenhouse gases. Did the Moon siphon off much of the Earth's
atmosphere in earlier times.



As we learn more the answer increasingly seems to be that the earth
was "unstable" before life became so dominant. Prior to this there were
a number of complete freeze-overs where the entire planet was covered in
ice. It is believed C02 built up from volcanoes, causing rnaway
greenhouse and melting the ice. The CO2 would then be react chemically
with the now-open oceans, scrubing it back out.

lot of science speculation that Niven used in his stories came from
Tommy Gold, an iconoclastic astronomer who was part of the steady state
universe crowd (with Fred Hoyle) and also is known for having gotten in
a row with NASA during Apollo.



No, pretty good actually. Gold was the guy that got onto TV by
claiming the moon probes would sink in the miles-thick dust on the moon.
OF COURSE it's miles thick, its been there practically forever and
there's no mechanism to solidify it back into rock like there is here.

So they built the landers and tested. Nope, no problem. But Gold
wouldn't stop even when confronted by direct counterexample. The TV
robots eventually gave up listening to him -- something that no longer
happens unfortunately.

He still turns up, unnamed, in various creationist books. Why? Because
the lack of thick dust on the moon means it can't be very old, right?


Exactly right. And, as you said, there's really no limit -- at least no
practical one -- to the depth of the dust.

For that matter, it's not much different here on earth. Imagine trying
to sweep up all the dirt on a desert. You can sweep up the top layer,
but there's always more below it. It's the same way most places on the
moon, because debris from impacts has been raining down everywhere, for
like forever.

On the earth, eventually you'll hit bedrock. Same on the moon, but the
depth varies greatly depending on where you are.

For the record, I'm a Christian myself, but those crazy creationists are
always saying stupid things that reflect badly on the rest of us. I
wish they'd just shut up and go away.

Jack


Maury
Likely some of the details, even the mainstream thinking will change, and still be wrong after the change. My math does not go much beyond high school, so I often cannot check the work of the experts, so I don't know what will change, but there does seem to be suspicious comparisons.
The moon likely has and had little effect on green house warming. Earth has always had some green house warming, otherwise it would be almost as cold as Mars is now. My guess is more green house gas might warm Earth 9 degrees f = 5 degrees c, but not much more, unless the atmospheric pressure increases drastically as at Venus which has about 90 times more atmosphere than Earth. I have not seen a graph or chart that shows the the amount of green house warming that results from higher atmospheric pressure, but I am quite sure Venus is hot, partly because it has a thick atmosphere. My guess is neither Earth nor Venus ever had "run away" green house warming of significance, as the hockey stick graph has been discredited in my opinion.
No fosil evidence has been found for ice age at Earth the first 3.6 billion years = all the ice ages have occured in the most recent one billion years, and only about half of Earth's surface was covered by the worst ice caps.
This is surprising, as the Sun produced only about half as much energy 4 billion years ago. This is the result of nuclear fusson math and theory, which was sufficiently correct to produce reliable fusion = H bombs.
It is difficult to measure, with extreme accuracy, the distance to the sun, because the surface is very hot plasma, but some reports of Earth moving a few millimeters per year away from the Sun have not be debunked as far as I know. A few billion millimeters does not put Earth lots closer to the Sun, but it could account for no ice ages the first 3.6 billion years. The recent recession from the Sun, if real, may be a recent change, but there is little reason to think the resession rate has changed a lot over the past 3.6 billion years. I'm also a Christian, but I also have little use for much of the ceationist's sudo-science. Neil
  #17  
Old June 3rd 11, 01:15 AM
neilzero neilzero is offline
Junior Member
 
First recorded activity by SpaceBanter: May 2011
Posts: 22
Default

Quote:
Originally Posted by Jack Crenshaw View Post
Maury Markowitz wrote:
wrote:

Was the Moon in a close Earth orbit essential in preventing a runaway
greenhouse effect like we see on Venus. The Earth was much more
volcanically active in it's youth and would have put out much more CO2
and other greenhouse gases. Did the Moon siphon off much of the Earth's
atmosphere in earlier times.



As we learn more the answer increasingly seems to be that the earth
was "unstable" before life became so dominant. Prior to this there were
a number of complete freeze-overs where the entire planet was covered in
ice. It is believed C02 built up from volcanoes, causing rnaway
greenhouse and melting the ice. The CO2 would then be react chemically
with the now-open oceans, scrubing it back out.

lot of science speculation that Niven used in his stories came from
Tommy Gold, an iconoclastic astronomer who was part of the steady state
universe crowd (with Fred Hoyle) and also is known for having gotten in
a row with NASA during Apollo.



No, pretty good actually. Gold was the guy that got onto TV by
claiming the moon probes would sink in the miles-thick dust on the moon.
OF COURSE it's miles thick, its been there practically forever and
there's no mechanism to solidify it back into rock like there is here.

So they built the landers and tested. Nope, no problem. But Gold
wouldn't stop even when confronted by direct counterexample. The TV
robots eventually gave up listening to him -- something that no longer
happens unfortunately.

He still turns up, unnamed, in various creationist books. Why? Because
the lack of thick dust on the moon means it can't be very old, right?


Exactly right. And, as you said, there's really no limit -- at least no
practical one -- to the depth of the dust.

For that matter, it's not much different here on earth. Imagine trying
to sweep up all the dirt on a desert. You can sweep up the top layer,
but there's always more below it. It's the same way most places on the
moon, because debris from impacts has been raining down everywhere, for
like forever.

On the earth, eventually you'll hit bedrock. Same on the moon, but the
depth varies greatly depending on where you are.

For the record, I'm a Christian myself, but those crazy creationists are
always saying stupid things that reflect badly on the rest of us. I
wish they'd just shut up and go away.

Jack


Maury
Likely some of the details, even the mainstream thinking will change, and still be wrong after the change. My math does not go much beyond high school, so I often cannot check the work of the experts, so I don't know what will change, but there does seem to be suspicious comparisons.
The moon likely has and had little effect on green house warming. Earth has always had some green house warming, otherwise it would be almost as cold as Mars is now. My guess is more green house gas might warm Earth 9 degrees f = 5 degrees c, but not much more, unless the atmospheric pressure increases drastically as at Venus which has about 90 times more atmosphere than Earth. I have not seen a graph or chart that shows the the amount of green house warming that results from higher atmospheric pressure, but I am quite sure Venus is hot, partly because it has a thick atmosphere. My guess is neither Earth nor Venus ever had "run away" green house warming of significance, as the hockey stick graph has been discredited in my opinion.
No fosil evidence has been found for ice age at Earth the first 3.6 billion years = all the ice ages have occured in the most recent one billion years, and only about half of Earth's surface was covered by the worst ice caps.
This is surprising, as the Sun produced only about half as much energy 4 billion years ago. This is the result of nuclear fusson math and theory, which was sufficiently correct to produce reliable fusion = H bombs.
It is difficult to measure, with extreme accuracy, the distance to the sun, because the surface is very hot plasma, but some reports of Earth moving a few millimeters per year away from the Sun have not be debunked as far as I know. A few billion millimeters does not put Earth lots closer to the Sun, but it could account for no ice ages the first 3.6 billion years. The recent recession from the Sun, if real, may be a recent change, but there is little reason to think the resession rate has changed a lot over the past 3.6 billion years. I'm also a Christian, but I also have little use for much of the ceationist's sudo-science. Neil
 




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