A New Earth?

Here's an interesting link:

http://www.dailymail.co.uk/pages/liv...echnology.html
?in_article_id=450467&in_page_id=1965

I did a quick calculation of the surface gravity, based on the following
inputs:

M is the mass of Glise 581c which, according to the article, is 5 times
as massive as Earth. The mass of Earth is 5.9736x10^24 kg. G =
6.6742x10^-11. The radius of Glise 581c, converted to meters, is r =
9,656,083.

Therefo

a = GM/r^2 = (6.6742x10^-11)[(5)(5.9736x10^24)]/(9656083)^2 = 21.4 m/s^2.

On Earth, the acceleration, g, is 9.8 m/s^2, so on Glise 581c it is
21.4/9.8 = 2.1 g.

That means if you weigh 200 lbs on Earth, you will weigh 420 lbs on the
surface of Glise 581c. The question is, how many people would be able to
walk around if their body weight suddenly doubled? And even among those
who could, how many would be able to live that way? Sure, there are
lot's of fat guys huffing around, but they all have desk jobs, or no
jobs at all. Who could be a plumber, or a mechanic, or a construction
worker, at that kind of body weight? Damn few, I'll bet. And without
people to do those sorts of jobs, what kind of civilization could
subsist there?

Bottom line: as much as I would like a chance to live somewhere other
than on Earth, I would walk past the desk where people were signing up
to colonize Glise 581c without regrets. :-)

Mitchell Jones

************************************************** ***************
If I seem to be ignoring you, consider the possibility
that you are in my killfile. --MJ

"Mitchell Jones" wrote in message
...

Bottom line: as much as I would like a chance to live somewhere other
than on Earth, I would walk past the desk where people were signing up
to colonize Glise 581c without regrets. :-)

What makes you think the inhabitants there would even
consider you for immigration? ;-)

This all assumes that Gliese 581 C has the same composition as the Earth.
Then the figure for radius would be close to the mark. I assume it takes
into account increased density due to greater interior pressure.

However it quite likely has different composition. The planet may have
formed beyond the "frost zone" for water and possibly other volatiles. In
which case it would be considerably less dense, being comprised largely of a
deep ocean of water. Its radius would be considerably larger than reported
in the press and its surface gravity more comfortable.

If the latter is true would you consider migrating there? The gravity
problem would be eliminated but you would have to grow gills (assuming the
planet has oxygen!). And big eyes too because Gliese doesn't emit much
visible light.

On Sun, 29 Apr 2007 18:15:29 -0500, Mitchell Jones wrote:

|Here's an interesting link:
|
|http://www.dailymail.co.uk/pages/liv...echnology.html
|?in_article_id=450467&in_page_id=1965
|
|I did a quick calculation of the surface gravity, based on the following
|inputs:
|
|M is the mass of Glise 581c which, according to the article, is 5 times
|as massive as Earth. The mass of Earth is 5.9736x10^24 kg. G =
|6.6742x10^-11. The radius of Glise 581c, converted to meters, is r =
|9,656,083.
|
|Therefo
|
|a = GM/r^2 = (6.6742x10^-11)[(5)(5.9736x10^24)]/(9656083)^2 = 21.4 m/s^2.
|
|On Earth, the acceleration, g, is 9.8 m/s^2, so on Glise 581c it is
|21.4/9.8 = 2.1 g.
|
|That means if you weigh 200 lbs on Earth, you will weigh 420 lbs on the
|surface of Glise 581c. The question is, how many people would be able to
|walk around if their body weight suddenly doubled? And even among those
|who could, how many would be able to live that way? Sure, there are
|lot's of fat guys huffing around, but they all have desk jobs, or no
|jobs at all. Who could be a plumber, or a mechanic, or a construction
|worker, at that kind of body weight? Damn few, I'll bet. And without
|people to do those sorts of jobs, what kind of civilization could
|subsist there?
|
|Bottom line: as much as I would like a chance to live somewhere other
|than on Earth, I would walk past the desk where people were signing up
|to colonize Glise 581c without regrets. :-)
|
|Mitchell Jones
|
|************************************************* ****************
|If I seem to be ignoring you, consider the possibility
|that you are in my killfile. --MJ

______________________________________________
*
* _-_|\
* / \ Daggaz
* \_.-._/--Sydney, Australia
* v

Email address is valid (no spamblocks) but temporary.
I change it when spam levels become too high.

In article ,
Daggaz wrote:

This all assumes that Gliese 581 C has the same composition as the Earth.
Then the figure for radius would be close to the mark. I assume it takes
into account increased density due to greater interior pressure.

However it quite likely has different composition. The planet may have
formed beyond the "frost zone" for water and possibly other volatiles. In
which case it would be considerably less dense, being comprised largely of a
deep ocean of water. Its radius would be considerably larger than reported
in the press and its surface gravity more comfortable.

If the latter is true would you consider migrating there? The gravity
problem would be eliminated but you would have to grow gills (assuming the
planet has oxygen!). And big eyes too because Gliese doesn't emit much
visible light.

***{If I were willing to live underwater, I would stay here. Earth is
mostly covered by oceans, after all, and we know there is oxygen here,
and lots of visible light from the Sun. It wouldn't be very hard to
construct an underwater habitat on the floor of the ocean, and plenty of
air could be obtained by sending a float to the top that trailed a hose,
supplemented by piston pumps as needed. Thus one could just as well
"live free or die" on the bottom of one of Earth's oceans, as on the
bottom of an ocean on Glise 581c. --MJ}***

On Sun, 29 Apr 2007 18:15:29 -0500, Mitchell Jones wrote:

|Here's an interesting link:
|
|http://www.dailymail.co.uk/pages/liv...echnology.html
|?in_article_id=450467&in_page_id=1965
|
|I did a quick calculation of the surface gravity, based on the following
|inputs:
|
|M is the mass of Glise 581c which, according to the article, is 5 times
|as massive as Earth. The mass of Earth is 5.9736x10^24 kg. G =
|6.6742x10^-11. The radius of Glise 581c, converted to meters, is r =
|9,656,083.
|
|Therefo
|
|a = GM/r^2 = (6.6742x10^-11)[(5)(5.9736x10^24)]/(9656083)^2 = 21.4 m/s^2.
|
|On Earth, the acceleration, g, is 9.8 m/s^2, so on Glise 581c it is
|21.4/9.8 = 2.1 g.
|
|That means if you weigh 200 lbs on Earth, you will weigh 420 lbs on the
|surface of Glise 581c. The question is, how many people would be able to
|walk around if their body weight suddenly doubled? And even among those
|who could, how many would be able to live that way? Sure, there are
|lot's of fat guys huffing around, but they all have desk jobs, or no
|jobs at all. Who could be a plumber, or a mechanic, or a construction
|worker, at that kind of body weight? Damn few, I'll bet. And without
|people to do those sorts of jobs, what kind of civilization could
|subsist there?
|
|Bottom line: as much as I would like a chance to live somewhere other
|than on Earth, I would walk past the desk where people were signing up
|to colonize Glise 581c without regrets. :-)
|
|Mitchell Jones
|
|************************************************* ****************
|If I seem to be ignoring you, consider the possibility
|that you are in my killfile. --MJ

______________________________________________
*
* _-_|\
* / \ Daggaz
* \_.-._/--Sydney, Australia
* v

Email address is valid (no spamblocks) but temporary.
I change it when spam levels become too high.

************************************************** ***************
If I seem to be ignoring you, consider the possibility
that you are in my killfile. --MJ

In article ,
"Greg Neill" wrote:

"Mitchell Jones" wrote in message
...

Bottom line: as much as I would like a chance to live somewhere other
than on Earth, I would walk past the desk where people were signing up
to colonize Glise 581c without regrets. :-)

What makes you think the inhabitants there would even
consider you for immigration? ;-)

***{Presumably if there were a desk at a spaceport on Earth, signing up
people to colonize Glise 581c, the permission of the inhabitants would
have already been obtained. When my ancestors signed up to colonize
America, for example, the permission of the inhabitants had already been
obtained by force of arms. Similar methods will doubtlessly be used from
time to time, as mankind moves into space--assuming, of course, that we
survive our present love affair with totalitarian slavery and, thus, do
not go extinct. --MJ}***

************************************************** ***************
If I seem to be ignoring you, consider the possibility
that you are in my killfile. --MJ

....even consider the sports... how could anyone play games and sports
there? swimming, baseball, cricket, races,....

it would be really be difficult to live there. the atmospheric
pressure and gas mixture also is very important.

Regards,
Divij

On Mon, 30 Apr 2007 01:22:32 -0500, Mitchell Jones wrote:

|Thus one could just as well
|"live free or die" on the bottom of one of Earth's oceans, as on the
|bottom of an ocean on Glise 581c.

You would need very advanced technology to build a habitat for the bottom of
the ocean on Gliese 581C. That ocean would probably be thousands of
kilometers deep, extending all the way to the rocky core, so the pressures
and temperatures at the bottom will be huge. We can't even build a habitat
for the bottom of the Marianas Trench, the lowest point in the Earth's
oceans at 11km deep.

A habitat that floats on the surface will be more practical. Or maybe Gliese
581C has an ice cap on the hemisphere facing away from its parent star,
since it is most likely tidally locked. But it would be very dark and cold
there.

______________________________________________
*
* _-_|\
* / \ Daggaz
* \_.-._/--Sydney, Australia
* v

Email address is valid (no spamblocks) but temporary.
I change it when spam levels become too high.

On May 1, 8:52 am, Daggaz wrote:
On Mon, 30 Apr 2007 01:22:32 -0500, Mitchell Jones wrote:

|Thus one could just as well
|"live free or die" on the bottom of one of Earth's oceans, as on the
|bottom of an ocean on Glise 581c.

You would need very advanced technology to build a habitat for the bottom of
the ocean on Gliese 581C. That ocean would probably be thousands of
kilometers deep, extending all the way to the rocky core, so the pressures
and temperatures at the bottom will be huge. We can't even build a habitat
for the bottom of the Marianas Trench, the lowest point in the Earth's
oceans at 11km deep.

A habitat that floats on the surface will be more practical. Or maybe Gliese
581C has an ice cap on the hemisphere facing away from its parent star,
since it is most likely tidally locked. But it would be very dark and cold
there.

______________________________________________
*
* _-_|\
* / \ Daggaz
* \_.-._/--Sydney, Australia
* v

Email address is valid (no spamblocks) but temporary.
I change it when spam levels become too high.

i agree with you, pressure is very important, but still, the research
is on.

Regards,
Divij

On Apr 30, 9:15 am, Mitchell Jones wrote:
Here's an interesting link:

http://www.dailymail.co.uk/pages/liv...ogy/technology....
?in_article_id=450467&in_page_id=1965

I did a quick calculation of the surface gravity, based on the following
inputs:

M is the mass of Glise581cwhich, according to the article, is 5 times
as massive as Earth. The mass of Earth is 5.9736x10^24 kg. G =
6.6742x10^-11. The radius of Glise581c, converted to meters, is r =
9,656,083.


I hope you realize that noone has a clue what the radius of 581c is.
The number 1.5 is someone's guess based on the mass and the hope that
the planet is rocky.

A more serious problem is that the planet receives 244% of the star
light that Earth does, or about 25% more than Venus. If it had water
it would be way past the runaway greenhouse threshold. I estimate the
surface temperature assuming an equilibrium steam atmosphere of about
830K.

--mt.

"Market Theory" wrote in message
oups.com...
On Apr 30, 9:15 am, Mitchell Jones wrote:
Here's an interesting link:

http://www.dailymail.co.uk/pages/liv...ogy/technology....
?in_article_id=450467&in_page_id=1965

I did a quick calculation of the surface gravity, based on the following
inputs:

M is the mass of Glise581cwhich, according to the article, is 5 times
as massive as Earth. The mass of Earth is 5.9736x10^24 kg. G =
6.6742x10^-11. The radius of Glise581c, converted to meters, is r =
9,656,083.


I hope you realize that noone has a clue what the radius of 581c is.
The number 1.5 is someone's guess based on the mass and the hope that
the planet is rocky.

A more serious problem is that the planet receives 244% of the star
light that Earth does, or about 25% more than Venus. If it had water
it would be way past the runaway greenhouse threshold. I estimate the
surface temperature assuming an equilibrium steam atmosphere of about
830K.

Your estimate does not accord with the estimate made by
the investigators, who put the temperature in the range
of liquid water.