Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 86 (8936 total)
41 online now:
AZPaul3, Captcass, jar, PaulK, Tangle, Theodoric (6 members, 35 visitors)
Chatting now:  Chat room empty
Newest Member: ssope
Post Volume: Total: 861,596 Year: 16,632/19,786 Month: 757/2,598 Week: 3/251 Day: 3/23 Hour: 1/1


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Water As An Element of Fine-Tuning
RAZD
Member
Posts: 20108
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


Message 91 of 100 (157026)
11-07-2004 5:59 PM
Reply to: Message 87 by Silent H
11-07-2004 5:29 PM


DOH!
and the worst part is that I "corrected" it -- should a stuck with the first (like they tell you to do when taking tests...)


we are limited in our ability to understand
by our ability to understand

RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}


This message is a reply to:
 Message 87 by Silent H, posted 11-07-2004 5:29 PM Silent H has not yet responded

Replies to this message:
 Message 92 by Tony650, posted 11-07-2004 6:25 PM RAZD has not yet responded

  
Tony650
Member (Idle past 2286 days)
Posts: 450
From: Australia
Joined: 01-30-2004


Message 92 of 100 (157029)
11-07-2004 6:25 PM
Reply to: Message 91 by RAZD
11-07-2004 5:59 PM


Re: DOH!
Heh, I noticed that, too. I'm just too nice to say.

But since holmes got to make fun of you...Har har! *points and laughs*


This message is a reply to:
 Message 91 by RAZD, posted 11-07-2004 5:59 PM RAZD has not yet responded

  
Nic Tamzek
Inactive Member


Message 93 of 100 (157136)
11-08-2004 2:29 AM


Water is not a universal solvent
One other misconception of RustyShackelford that should be corrected is that water is a "universal solvent." It's a good solvent but not universal.

As my chemistry prof once carefully explained it to our class, water is a universal solvent...of stuff that dissolves in water. Notably, large nonpolar/hydrophobic compounds are *not* very water soluble (they will have solubility constants of, say, 10^-49 or whatever, so that in a swimming pool full of water you will dissolve less than one molecule. This is good, because otherwise our bodies would dissolve into goo.

Sulfides are also very, very resistant to dissolving in water, which is why you can remove dissolved toxic ions from solution by adding sulfide.

See this Solubility product table

quote:
Actetates
AgC2H3O2 -- 2 x 10-3

Bromides
AgBr -- 5 x 10-13
PbBr2 -- 5 x 10-6

Carbonates
BaCO3 -- 2 x 10-9
CaCO3 -- 5 x 10-9
MgCO3 -- 2 x 10-8

Chlorides
AgCl -- 1.6 x 10-10
Hg2Cl2 -- 1 x 10-18
PbCl2 -- 1.7 x 10-5

Chromates
Ag2CrO4 -- 2 x 10-12
BaCrO4 -- 2 x 10-10
PbCrO4 -- 1 x 10-16
SrCrO4 -- 4 x 10-5

Fluorides
BaF2 -- 2 x 10-6
CaF2 -- 2 x 10-10
PbF2 -- 4 x 10-8

Hydroxides
Al(OH)3 -- 5 x 10-33
Cr(OH)3 -- 4 x 10-38
Fe(OH)2 -- 1 x 10-15
Fe(OH)3 -- 5 x 10-38
Mg(OH)2 -- 1 x 10-11
Zn(OH)2 -- 5 x 10-17

Iodides
AgI -- 1 x 10-16
PbI2 -- 1 x 10-8

Sulfates
BaSO4 -- 1.4 x 10-9
CaSO4 -- 3 x 10-5
PbSO4 -- 1 x 10-8

Sulfides
Ag2S -- 1 x 10-49
CdS -- 1 x 10-26
CoS -- 1 x 10-20
CuS -- 1 x 10-35
FeS -- 1 x 10-17
HgS -- 1 x 10-52
MnS -- 1 x 10-15
NiS -- 1 x 10-19
PbS -- 1 x 10-27
ZnS -- 1 x 10-20



Replies to this message:
 Message 94 by Silent H, posted 11-08-2004 5:43 AM Nic Tamzek has not yet responded

  
Silent H
Member (Idle past 4073 days)
Posts: 7405
From: satellite of love
Joined: 12-11-2002


Message 94 of 100 (157160)
11-08-2004 5:43 AM
Reply to: Message 93 by Nic Tamzek
11-08-2004 2:29 AM


One other misconception of RustyShackelford that should be corrected is that water is a "universal solvent." It's a good solvent but not universal.

If he can't figure out that water doesn't freeze in the tropics, do we really think he's going to get the complicated explanation of hydrophobic compounds?

What's funny is he says he has a friend in chemistry that told him the world would freeze over if water froze from the bottom up. I suppose this same friend was the one who told him it was a universal solvent.

One trip to an organic chem lab would dispell that. Water's nonsolvency on many materials is a great way to separate them into different components based on density.


holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)
This message is a reply to:
 Message 93 by Nic Tamzek, posted 11-08-2004 2:29 AM Nic Tamzek has not yet responded

Replies to this message:
 Message 95 by RAZD, posted 11-08-2004 8:18 AM Silent H has responded

    
RAZD
Member
Posts: 20108
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


Message 95 of 100 (157179)
11-08-2004 8:18 AM
Reply to: Message 94 by Silent H
11-08-2004 5:43 AM


sinking ice only half the story ...
The idea that the oceans would freeze solid if ice sank is based on the idea that once frozen it would not thaw.

for it to sink to the bottom it would have to pass through warmer water without thawing and then the bottom would have to be colder than the freezing point.

thermal conductivity of the earth means there is alway a flow from the center outward (yes in billions of years the earth will get colder) that keeps the mantle at a temperature well above 32F\0C

This is a fairly accessible geology site that discusses earth temperature and the different layers:
http://www.enchantedlearning.com/subjects/astronomy/planets/earth/Inside.shtml

Mantle: Under the crust is the rocky mantle, which is composed of silicon, oxygen, magnesium, iron, aluminum, and calcium. The upper mantle is rigid and is part of the lithosphere (together with the crust).

Convection (heat) currents carry heat from the hot inner mantle to the cooler outer mantle. The mantle is about 1,700 miles (2,750 km) thick. The mantle gets warmer with depth; the top of the mantle is about 1,600° F (870° C); towards the bottom of the mantle, the temperature is about 4,000-6,700° F (2,200-3,700° C). The mantle contains most of the mass of the Earth. The Gutenberg discontinuity separates the outer core and the mantle.

Surface and crust: The Earth's surface is composed mostly of water, basalt and granite. Oceans cover about 70% of Earth's surface. These oceans are up to 3.7 km deep. The Earth's thin, rocky crust is composed of silicon, aluminum, calcium, sodium and potassium.

This site talks about the crust:
http://volcano.und.nodak.edu/vwdocs/vwlessons/lessons/Earths_layers/Earths_layers4.html

The temperatures of the crust vary from air temperature on top to about 1600 degrees Fahrenheit (870 degrees Celcius) in the deepest parts of the crust.

Oceanic crust being significantly thinner than continental crust means that there would be more thermal conductivity, more flow of temperature, through the oceanic crust.

Ice sinking could actually cause the oceans to be warmer than they are because it would cause more mixing of the water as the thawed bottom ice water would rise to the surface and the ice blocks sank. This would add convection heat transfer into the system.


we are limited in our ability to understand
by our ability to understand

RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}


This message is a reply to:
 Message 94 by Silent H, posted 11-08-2004 5:43 AM Silent H has responded

Replies to this message:
 Message 96 by Silent H, posted 11-08-2004 9:09 AM RAZD has not yet responded
 Message 97 by Loudmouth, posted 11-08-2004 1:29 PM RAZD has responded

  
Silent H
Member (Idle past 4073 days)
Posts: 7405
From: satellite of love
Joined: 12-11-2002


Message 96 of 100 (157187)
11-08-2004 9:09 AM
Reply to: Message 95 by RAZD
11-08-2004 8:18 AM


Hey don't tell me, tell him! Right now he thinks he has three sources to my just asserting things like water hotter than it's boiling point can't freeze, or that salt prevents freezing, or that it's hot in the tropics.


holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)
This message is a reply to:
 Message 95 by RAZD, posted 11-08-2004 8:18 AM RAZD has not yet responded

    
Loudmouth
Inactive Member


Message 97 of 100 (157303)
11-08-2004 1:29 PM
Reply to: Message 95 by RAZD
11-08-2004 8:18 AM


Re: sinking ice only half the story ...
quote:
Ice sinking could actually cause the oceans to be warmer than they are because it would cause more mixing of the water as the thawed bottom ice water would rise to the surface and the ice blocks sank. This would add convection heat transfer into the system.

Also, we can't forget about the reflectivity of floating ice. Icebergs and floating ice reflect solar energy back out into space. If, for instance, the northern polar ice cap was at the bottom of the ocean the world would be warmer than it is now. Also, surface winds blowing over unfrozen water is warmer than surface winds blowing over ice that is well below 0 celcius (unfrozen sea water is always warmer than about -2 celcius I believe).


This message is a reply to:
 Message 95 by RAZD, posted 11-08-2004 8:18 AM RAZD has responded

Replies to this message:
 Message 98 by RAZD, posted 11-08-2004 2:37 PM Loudmouth has not yet responded

  
RAZD
Member
Posts: 20108
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


Message 98 of 100 (157329)
11-08-2004 2:37 PM
Reply to: Message 97 by Loudmouth
11-08-2004 1:29 PM


Re: sinking ice only half the story ...
unfrozen sea water is always warmer than about -2 celcius I believe

yes, based on my experience that would be about right ... we have an annual swim for winter solstice in buzzards bay MA ...


we are limited in our ability to understand
by our ability to understand

RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}


This message is a reply to:
 Message 97 by Loudmouth, posted 11-08-2004 1:29 PM Loudmouth has not yet responded

  
contracycle
Inactive Member


Message 99 of 100 (157561)
11-09-2004 6:07 AM


I don't think the proposition that life can only arise in water-based environments was as much off the mark as has been suggested; IIRC Isaac Asimov made that argument in his book on evolution from the 60's, which title I forget. I also think he argued the possibility of methane/silicon life, but also agreed this would be extremely slow-padced life, if possible at all.

On sulphur, don't the worms around black smokers use a sulfur-based metabolism?


Replies to this message:
 Message 100 by Loudmouth, posted 11-09-2004 11:13 AM contracycle has not yet responded

  
Loudmouth
Inactive Member


Message 100 of 100 (157611)
11-09-2004 11:13 AM
Reply to: Message 99 by contracycle
11-09-2004 6:07 AM


quote:
I don't think the proposition that life can only arise in water-based environments was as much off the mark as has been suggested;

I don't think it's far off the mark either. Water is probably the best solvent for life, and it makes a stable byproduct for metabolism. I just have a hard time with the "fine-tuning", anthropic argument.

quote:
On sulphur, don't the worms around black smokers use a sulfur-based metabolism?

The worms are filter feeders. They feed on autotrophs, some of which metabolize sulfur.


This message is a reply to:
 Message 99 by contracycle, posted 11-09-2004 6:07 AM contracycle has not yet responded

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2019