Earths Water in a Ball

Posted by: Mike Kremer

Earths Water in a Ball - 05/16/12 05:15 PM


How much of planet Earth is made if Water? Very little actually.
For if all of the water on or near the surface of the Earth were bunched up into a ball. The radius of this ball would be only about 700 kilometers, less than half the radius of the Earth's Moon.
I find the picture below, visually astounding.

http://apod.nasa.gov/apod/ap120515.html
Posted by: Ellis

Re: Earths Water in a Ball - 05/17/12 12:17 AM

What a very scary picture that is Mike. I am so used to knowing water is scarce that I had not thought I could have been shocked again, but I certainly was. This image should be everywhere, and we should stop using water as though the supply is never-ending.

Thanks for the post. Astounding is right.
Posted by: samwik

Re: Earths Water in a Ball - 05/17/12 12:49 AM

...and that is ALL water. It is a similarly small fraction, 1-3%, which is freshwater or usable freshwater--sustaining our food supply.



...if you can even see the small dot of freshwater to the far right!

~ wink
Posted by: redewenur

Re: Earths Water in a Ball - 05/17/12 01:46 AM

Water gets recycled, so the global quantity need not necessarily be a problem; but I think possession and unequal distribution are likely to result in violent conflicts between the 'haves' and 'have nots'.
Posted by: Bill S.

Re: Earths Water in a Ball - 05/17/12 12:23 PM

Here it has rained a significant part of almost every day since 2nd. April; yet they insist we have a drought, and there is a hose-pipe ban in place. How wet can a drought be?

Then, if you go to London you can see sprinklers running all the time on any patch of grass that might be spotted by any visitor to the Olimpics. What was that about "haves" and "have nots"?
Posted by: Bill

Re: Earths Water in a Ball - 05/17/12 02:11 PM

Well, here in Oklahoma we have a sort of a water problem. There is a water board down in North Central Texas that wants to buy water from Southeastern Oklahoma. A couple of Indian tribes are suing to keep the water from being sold, because they are afraid that there won't be enough for Oklahoma then. And of course the Indians have an interest in the matter because when the benevolent white man made the treaties with the tribes they got the land and water, but for some reason they don't want to let the tribes have a say in the use of the water.

In the mean time they have had watering restrictions in Texas. I don't think they apply of course to important things like golf courses.

Bill Gill
Posted by: Revlgking

Re: Earths Water in a Ball - 05/17/12 09:41 PM

Originally Posted By: samwik
...and that is ALL water. It is a similarly small fraction, 1-3%, which is freshwater or usable freshwater--sustaining our food supply.



...if you can even see the small dot of freshwater to the far right!

~ wink
Sam, which is it, 700 miles diameter? Or is it 860 miles in diameter? as it says in this link http://boingboing.net/2012/05/10/if-you-put-all-the-water-on-ea.html Or does it matter?

Sam, I am amazed at how little fresh water we do have for our use. What if some super villain, from space, or earth, gets control of that "little blue planet" as you have depicted it? smile frown
Posted by: paul

Re: Earths Water in a Ball - 05/19/12 03:16 AM

we have plenty of water.

our problem is what we use for energy.

or the price of that energy would be better because it is
the price of energy that causes us to think we dont have much water.

because if energy were cheaper or ((( FREE ))) then we could
desalinate sea water with the cheap or ((( FREE ))) energy.
Posted by: Bill

Re: Earths Water in a Ball - 05/19/12 02:45 PM

Originally Posted By: Revlgking

Sam, I am amazed at how little fresh water we do have for our use. What if some super villain, from space, or earth, gets control of that "little blue planet" as you have depicted it?

Well Rev, Ethan Siegel in his blog, Starts With a Bang has just discussed something on that order. He talks about Reverse Terraforming. If a supervillain disrupts the Earths magnetic field he can cause the Earth to dry up. The magnetic field is what keeps the Solar Wind from blowing the atmosphere away and that would be bad.

Bill Gill
Posted by: Ellis

Re: Earths Water in a Ball - 05/20/12 06:31 AM

I wish I could be as hopeful as paul--- I feel more like Bill. This is a very grim thread for someone like me in the driest continent on Earth.

We are building a huge desalination plant in my state and since we had rain and some flooding (not huge flooding here, just what used to happen before we had drought), people are saying we will never use it. I do hope they are right!

Bill S do you have water restrictions in your part of the UK, or just a ban on garden watering? I was horrified to hear about that happening in some areas of the UK, and it isn'e even summer yet.
Posted by: Bill S.

Re: Earths Water in a Ball - 05/20/12 08:07 PM

At the moment we have just a hose pipe ban, but our suppliers, Thames Water, are threatening worse later in the summer. Fortunately, with the amount of rain we have had over the past couple of months, there is no need to water the gardens.
Posted by: paul

Re: Earths Water in a Ball - 05/25/12 10:37 PM

just put down a shallow well to water your garden.
theres probably water only a few feet below you.

you say I guess that the thames water company is your supplier so
does that hint that your water comes from the thames?

if so then if your property is less than 29 ft higher in elevation than the thames you could easily get the water from the water table.

unless the uk gov has made natural water usage illegal.

which is what is happening all over the us also.
sad , but there are ways around it.

when they ( the gov ) steps in and causes the the water in the water table to stagnate by refusing to allow people in cities
to use the water that is just a few feet below their property they are causing the water in the water table to retain the toxins that would naturally be cleansed by garden watering.

P.S.

you can put down a shallow well using a 1/2 inch - 3/4 inch pvc pipe !!!

just hook up a 20 ft pvc pipe to your water hose , point the open end downwards and the water coming out of the pipe will drill the well for you.

unless you hit a rock , that is.







Posted by: Revlgking

Re: Earths Water in a Ball - 05/30/12 03:09 AM

WATER HAS MEMORY? Is this a fact, or a fiction?
If so, maybe there really is such a thing as holy water.

Which reminds me of the old joke. Making holy water is easy to do. All one has to do is: Put ordinary water on the stove and boil hell out of it. laugh

http://odewire.com/170441/scientists-investigate-water-memory.html
Posted by: Ellis

Re: Earths Water in a Ball - 05/30/12 09:33 PM

:-) Rev!

If Bill S's water comes from the Thames area then his locality may be part of the Artesian Basin under London. If this is so then I doubt anyone would be able to drill into it at will. But I could be wrong.

Here on Oz some people, in previous droughts, drilled bore holes in their gardens but there were a lot of rules. In the last drought most of these dried up anyway.

Capturing rain and grey water is effective for garden watering, though probably not too good for drinking, especially off city roofs.

No problems now though. We have had a very nicely rainy May-- though Will the Pug and Wallace the fluffy cat hate getting wet. I suspect that's because rain is really unusual for them. They are both 11 and the drought lasted 10 years!
Posted by: paul

Re: Earths Water in a Ball - 05/31/12 02:23 AM

there is another method of getting free water as long as you live in a humid environment.

use several 2 litre coke bottles and fill them with water.
put them in your freezer and let them freeze.
then you can use them to get fresh water by placing the
bottles in a pan and setting a fan beside them , this will also
cool down a room a little.

condensation will form on the bottles and by the time the ice has melted you will have apx 8 oz of water in the pan.

of course the amount of water will depend on the humidity in your area.

and there will also be some particulates in the water that are in the air.

I have never had the water tested.

I suppose that if you no longer can get water from your tap but
you still have electricity this could save your life.

and its most likely much cheaper than buying bottled water for drinking.

I would say that you could get apx 8 oz of condensated water per hour this way , so in a day you could get the 8 glasses of water you should drink.

I like the large chest type freezers because they dont allow all the cold air to escape when you open the door.

then theres the problem of refreezing the bottles of course.
I suppose it would take a full day to refreeze the bottles.


you could catch the water that comes off the airconditioning system , but I wouldnt drink it , theres alot of bacteria that grows in the pipes of a draining system.

but you could use that water for gardening.








Posted by: paul

Re: Earths Water in a Ball - 05/31/12 03:31 AM

getting back on topic.

with good ole global warming there is also good ole water vapor.

so water is no problem as long as there is also electricity.

http://ga.water.usgs.gov/edu/earthwherewater.html




http://en.wikipedia.org/wiki/Atmospheric_water_generator
Posted by: Bill

Re: Earths Water in a Ball - 05/31/12 02:11 PM

Originally Posted By: paul


I suppose that if you no longer can get water from your tap but
you still have electricity this could save your life



If the water is off where do you get the water to fill the bottles?

Bill Gill
Posted by: Mike Kremer

Re: Earths Water in a Ball - 06/01/12 05:12 PM

Originally Posted By: Revlgking
Originally Posted By: samwik
...and that is ALL water. It is a similarly small fraction, 1-3%, which is freshwater or usable freshwater--sustaining our food supply.



...if you can even see the small dot of freshwater to the far right!

~ wink
Sam, which is it, 700 miles diameter? Or is it 860 miles in diameter? as it says in this link http://boingboing.net/2012/05/10/if-you-put-all-the-water-on-ea.html Or does it matter?

Sam, I am amazed at how little fresh water we do have for our use. What if some super villain, from space, or earth, gets control of that "little blue planet" as you have depicted it? smile frown



Originally Posted By: Mike Kremer

Mike Kremer said,

Greetings Revking,
I think you will find, its 700 kilometers, as it states in the original NASA picture,
a couple of letters back.

Posted by: Mike Kremer

Re: Earths Water in a Ball - 06/01/12 07:04 PM

Originally Posted By: paul
getting back on topic.


so water is no problem as long as there is also electricity.



http://en.wikipedia.org/wiki/Atmospheric_water_generator


Originally Posted By: Mike Kremer


Mike Kremer said:-
You are correct Paul, go out and buy a small portable De-humidifier, thay are cheap
to run and will extract enough water out of the air to keep two or three people hydrated

Posted by: paul

Re: Earths Water in a Ball - 06/02/12 01:49 AM

Quote:
go out and buy a small portable De-humidifier


not a bad idea !!

this way even if there is no water to start with you might get enough to start collecting water for other things.

hmmm , water utilities charge you for sewage and water and other fees and cost are priced according to how much your water meter reads.

using one of these dehumidifiers might save you some cash also especially if you use solar cells to power/run it.



Posted by: paul

Re: Earths Water in a Ball - 06/02/12 02:43 AM

Quote:
700 kilometers


Im just curious if all the water were to be above ground
if its elevation would be 400 ft above nile river elevation !!

from what I can tell an apx guess would be

1145 ft


volume of a sphere v=4/3 x (pi x r3)
v=4/3 x (pi x r^3)

700 km = 434 miles

434 miles
434 x 5280 = 2291520 ft
d=2291520 ft
r=1145760 ft


r^3 = 1504114746494976000

pi x r^3 = 4722920303994224640

4722920303994224640 / 3 = 1574306767998074880

1574306767998074880 x 4 = 6297227071992299520

v= 6297227071992299520 cu ft

surface area of the earth

a=4 x (pi x r2)

7926 miles
41849280 ft
r = 20924640
r^2 = 437840559129600
pi x r2 = 1374819355666944
4x(pi x r2)= 5499277422667776 sq ft

6297227071992299520 / 5499277422667776 = 1145.10 ft


wow , that means the earth must have been really hot back
when the pyramids were sitting almost underwater in an ocean with an elevation of 400 ft above the nile river's current elevation.

because it was already in the process of evaporating its ground water.





Posted by: Bill S.

Re: Earths Water in a Ball - 06/04/12 10:18 PM

A mineralogist whose name I have forgotten calculated that there could be more water locked up in the wadsleyite in the mantle than in all the world’s oceans. If I remember rightly, wadsleyite occurs between about 400 and 500 kilometres depth.
Posted by: paul

Re: Earths Water in a Ball - 06/04/12 11:03 PM

if we think about the water molecule H2 and O

and we consider that almost everything has hydrogen in it
we could even account for the height of the waters during
Noah's flood in the Bible.

ie...
as long as there were enough Oxygen molecules to bind to the Hydrogen molecules.

suppose hydrogen gasses were released as the solid rock became liquid magma as the earth heated up in the past.

these gasses would travel to the earths surface and if there were enough Oxygen molecules and a spark (lightning) there would be an explosion and then even more water.

if this is possible then the Bibles account for the height of the waters that covered everything on the earth to a height of 15 cubits above everything would be a feasible height.

Im not trying to start a argument here , just pointing out that the Bibles account would be feasible if the above were possible.

heres a very interesting read I found that covers the volume
of hydrogen in rock.

Quote:
A NASA exobiology/evolutionary biology grant will enable Freund to pursue this research


http://astrobiology.nasa.gov/articles/deep-hydrogen/




Posted by: Bill S.

Re: Earths Water in a Ball - 06/05/12 12:33 PM

Quote:
suppose hydrogen gasses were released as the solid rock became liquid magma as the earth heated up in the past.


Could we be be finding a way in which oceans could have formed during/after Pre's collision scenario?
Posted by: paul

Re: Earths Water in a Ball - 06/05/12 01:06 PM

I think that pre's collision would have consumed all the oxygen really fast through combustion.
so no this would not allow for the oceans forming because there
would not be enough oxygen to bind with the hydrogen.

this could be a way that the oceans formed as long as there was
oxygen producing life on the earth such as plants.

I think that what is important is that this shows that the flood that is described in Genesis could have happened from a scientific / physical standpoint.
Posted by: Orac

Re: Earths Water in a Ball - 06/05/12 02:29 PM

Paul where do you get your numbers from above

The radius of earth is 6400 km or 4000 miles

You seem to have lost a decimal point :-)

Next 80% of the earth's water is surface water the other 20% is either ground water or atmospheric water vapour.

These are Graces numbers (http://earthobservatory.nasa.gov/Features/WeighingWater/weighing5.php)

The earth's total amount of water is about 344 million cubic miles made up of

315 million cubic miles is seawater
9 million cubic miles is groundwater
7 million cubic miles is frozen in polar ice caps

From => http://en.wikipedia.org/wiki/Current_sea_level_rise

Quote:

The melting of small glaciers and polar ice caps on the margins of Greenland and the Antarctic Peninsula melt, would increase sea level around 0.5 m. Melting of the Greenland ice sheet or the Antarctic ice sheet would produce 7.2 m or 61.1 m of sea level rise, respectively


So if 7 million cubic miles only lifts see level by 61-70m then it is reasonable to assume 9 million cubic miles of groundwater will only lift it by around same say 80m.

Altogether if the poles all meleted and all the groundwater was lifted we have maxium of 150 meters or 400 ft so just at the top of the pyramids.

Given the ground heights around the middle east there would still be a hell of a lot of land above water.

Thats just going off know facts without any calcs but if you redo and recheck your calcs you should hopefully agree with those figures.
Posted by: paul

Re: Earths Water in a Ball - 06/05/12 03:52 PM

Quote:
Paul where do you get your numbers from above

The radius of earth is 6400 km or 4000 miles

You seem to have lost a decimal point :-)


diameter of the earth -- google

12,756.2 kilometers

Quote:
12756.32 kilometers or 7926.41 miles at the equator


and here is what I wrote ;-)

Quote:
surface area of the earth

a=4 x (pi x r2)

7926 miles



Quote:
You seem to have lost a decimal point :-)


it does not look that way to me , perhaps you didnt read or follow the post correctly.


----------------- next ----------------------

http://boingboing.net/2012/05/10/if-you-put-all-the-water-on-ea.html


Quote:
Put all the water on this planet into a single sphere and it would have a diameter of about 860 miles, says the United States Geological Survey.


and again here is what I said

Quote:
volume of a sphere v=4/3 x (pi x r3)
v=4/3 x (pi x r^3)

700 km = 434 miles

434 miles


when you put up the following quote

Quote:
The melting of small glaciers and polar ice caps on the margins of Greenland and the Antarctic Peninsula melt, would increase sea level around 0.5 m. Melting of the Greenland ice sheet or the Antarctic ice sheet would produce 7.2 m or 61.1 m of sea level rise, respectively


you must have thought that ice sheets were the only ice that would melt.

the above quote only includes the ice sheets in greenland and the antartic . not the entire volume of ice.

PLUS **** ice sheets are floating on water...
melting of ice sheets will cause sea levels to decline.

so , if the above is considering that a sea level rise of 61 m
would be the result in the melting of only that tiny fraction of ice (glaciers and ice sheets).

then your 400 ft rise does not even come close to a final sea level rise from only counting all the ice that can melt.

the volume of ice on the antartic is structured as follows.

land mass = 13,720,000 km2 (5,300,000 sq mi)

ice thickness = About 98% of Antarctica is covered by ice that averages at least 1 mile (1.6 km) in thickness.

13,720,000 km^2 x 1.6 km = 21,952,000 km^3

Quote:
Given the ground heights around the middle east there would still be a hell of a lot of land above water.

Thats just going off know facts without any calcs but if you redo and recheck your calcs you should hopefully agree with those figures.


I didnt include any land mass above water , so any land mass above water would increase the final height of the waters.











Posted by: Ellis

Re: Earths Water in a Ball - 06/05/12 10:59 PM

This is probably not scientific, but it is about water, its shortage and worth a :-).

During the 10 years drought in my state of Victoria the government went ahead to construct a massive desalination plant to supply Melbourne's water needs until 2100. Yesterday we had more rain in one day than we usually have in all of June, and this followed a wet spring, summer and autumn.

Yesterday water was being pumped OUT of the not quite finished plant. It had been flooded by RAIN!

________________


Whilst we are all mocking happily however, (who doesn't like to see our politicians squirm a bit?), at least, in the next drought, we will not have to be sorry we did not build the plant when we had the chance!
Posted by: Orac

Re: Earths Water in a Ball - 06/06/12 01:54 AM

Paul go an read the wiki reference again and even read carefully what is in your quote above.

I assure you the figure for a full ice melt that is an ice free earth is 70m (61m from antarctica). The work was done by NASA for the IPCC and has been signed off by most scientists.

Ice that isn't on land that is already floating, if that melts will not change the sea level or slightly reduce as you noted, so the 61m sea rise is from land based antarctica all melting.

If you have any remaining doubt goto the NASA website and do a search I am sure you will find the work and it was part of a series for an "ice free" earth and its complete opposite a "snowball" earth. Those two extremes give you max and min sea level limits.

Edit: I actually tried searching public NASA site the presentation isn't available hmmm I will see if I can get a release authority and put out on uni site for you but will take some time.

Edit: Perhaps try searching GRACE website I am out of time. I ran across this anti-AGW site in a google search the numbers are basically the same as NASA and it has broken the ice up between grounded and ungrounded but I don't know who this source is so treat it as general data that matches what I am saying and may be useful(http://www.johnstonsarchive.net/environment/waterworld.html)

The only change you have added is dragging out the ground water which is slightly less than the stored ice water.
Posted by: paul

Re: Earths Water in a Ball - 06/06/12 01:31 PM



I cant find ANY of the numbers your using on the link you provided above.

ie...

Quote:
The earth's total amount of water is about 344 million cubic miles made up of

315 million cubic miles is seawater
9 million cubic miles is groundwater
7 million cubic miles is frozen in polar ice caps


this is the number I used to get my calculations.
it is not from any space agency it is from the
United States Geological Survey.

Quote:
Put all the water on this planet into a single sphere and it would have a diameter of about 860 miles, says the United States Geological Survey.


----------------- the math -----------------------
860 miles / 2 = 430 miles
---------------------------------------------------

volume of a sphere v=4/3 x (pi x r3)
v=4/3 x (pi x r^3)

700 km = 434 miles
(I did the math myself to make sure the 860 mile diameter would be correct --> the reason I used a 434 mile radius )

434 miles
434 x 5280 = 2291520 ft
d=2291520 ft
r=1145760 ft

(edit) I did make a mistake , ( old age brain fart ? ) but it was in my favor
I used 434 as the diameter above when 860 was already given as the diameter.
this will greatly increase the volume of the total water in the sphere.

(I really do wish that the people who operate this forum would widen the post window or at least make is adjustable , It is really hard to make a post that looks decent because everything looks different when you post it than it looked in the posting window)

starting all over again because of my mistake..

THE VOLUME OF THE SPHERE OF WATER

v=4/3 x (pi x r^3)

r = 2291520 =ft

r^3 = 12032917971959808000

pi x r^3 = 37802526701957526482.928142247451

/ 3 = 12600842233985842160.976047415817

x 4 = 50403368935943368643.904189663267

v= 50403368935943368643.904189663267 cu ft

the above calculation shows the volume of water in the
860 mile diameter sphere of total water on the earth
that the USGS reports.

lets break that number into cubic miles.

1 cubic mile = 5280 ft x 5280 ft x 5280 ft = 147197952000 cubic feet

50403368935943368643.904189663267 cu ft / 147197952000 cubic feet = 342418955.230 cubic miles

so the 344 million cubic miles you posted is pretty close to the above calculation of 342 million cubic miles.

THE SURFACE AREA OF THE EARTH

a=4 x (pi x r2)

7926 miles diameter
41849280 ft diameter
r = 20924640 ft radius
r^2 = 437840559129600
pi x r2 = 1375516684005198.8361281412832575
4x(pi x r2)= 5502066736020795.34451256513303 sq ft

STACKING THE VOLUME OF WATER IN THE SPHERE ON TOP OF THE SURFACE OF THE EARTH


sphere 50403368935943368643.904 cu ft/ earth 5502066736020795.344 sq ft = 9160.806 ft height

I had originaly posted 1145.10 ft but now the height has greatly increased to 9160 ft !!!

thanks orac for pointing that out.


this does not include all the sinking of land masses that are in the vicinity of rebounding land masses.

nor does it include any land currently above sea level.

nor does it include any other processes that would produce even more water , such as the earth resettling and cracking causing hydrogen to be released and that hydrogen binding with oxygen in the atmosphere.

Mount Everest, at 29,035 feet above sea level, is the highest spot on our planet.

but it would most likely sink into the ground , some if not all.

the more I think about it , the more I believe that the earth actually could be completely covered in water !!!

even as high as the 15 cubits above everything described in Genesis.


.
Posted by: Bill

Re: Earths Water in a Ball - 06/06/12 02:30 PM

Originally Posted By: paul
I had originaly posted 1145.10 ft but now the height has greatly increased to 9160 ft !!!

Now back to a comment you made earlier about this explaining the flood of Noah. You said it explained how the water rose above the highest mountains. Now your own (incorrect) calculations don't cover that situation, since the highest mountain is Mt. Everest at 29,000 feet (8,839.2 meters). There a lot of mountains in the world above 9,000 feet.

Bill Gill
Posted by: paul

Re: Earths Water in a Ball - 06/06/12 03:01 PM

Quote:
There a lot of mountains in the world above 9,000 feet.


yes there are.

so what do you think will happen to those mountains when the pressure underneath them lowers?

they do sit on top of magma.

and currently the ice caps are pressurising that magma.

when the ice caps melt that pressure is removed.

when that pressure is removed , land will sink.

most likely the heaviest land first.

the earth is like a balloon , the earths crust is like the skin of the balloon.

the magma is like the air in the balloon



Quote:
Now your own (incorrect) calculations don't cover that situation


incorrect?

lets see your calculations then Bill !!!

I suppose I could calculate the volume of hydrogen in the volume of rock in the earth , apx 1 liter per cubic meter of rock.

and then calculate the extra volume of water that could be produced by that hydrogen binding with oxygen in the atmosphere.

and the hydrogen found in the magma as deep as 400 km.

http://answers.yahoo.com/question/index?qid=20071101084216AAoMWaW

Quote:
without indicating pressure or temperature

1 liter of water contains (approx) 55.56 moles of water, so 111.11 moles of hydrogen.

Using the ideal gas equation, PV=nRT at 1 atmosphere (sealevel), and room temperature (22C, 295K)

V = 111.11 * 0.08205784 * 295 / 1

this would give 2689.7 liters of hydrogen.


knowing this there would be 1 liter of water produced
from 2689.7 cubic meters of rock when the hydrogen binds with oxygen in the atmosphere.

also the volume of hydrogen that the earth leaches would reduce the mass of the rock so for each cubic meter of rock that leaches hydrogen the earths mass of rock would shrink because it has lost that hydrogen.


causing even more sea level rise !!!

Posted by: Orac

Re: Earths Water in a Ball - 06/07/12 04:24 AM

Originally Posted By: paul

I cant find ANY of the numbers your using on the link you provided above.


You didn't look very hard try your own link that started this
http://ga.water.usgs.gov/edu/earthhowmuch.html

Quote:

The volume of the largest sphere, representing all water on, in, and above the Earth, would be about 332,500,000 cubic miles (mi3) (1,386,000,000 cubic kilometers (km3)), and be about 860 miles (about 1,385 kilometers) in diameter.


332,500,000 cubic miles (mi3) = 332.5 MILLION cubic miles a fraction smaller than NASA's number of 344 MILLION


NEXT FOR YOUR ERROR IN LOGIC IN YOUR CALCULATION

Quote:

315 million cubic miles is seawater
9 million cubic miles is groundwater
7 million cubic miles is frozen in polar ice caps


Note: 315+9+7 = 331 Million cubic miles which is almost the same as USGS's.

315 million cubic miles of that number is ALREADY IN THE CURRENT SEA LEVEL you cant add it in on top.

If you keep it in like you have then you need to put the reference height in from the bottom of the current sea bed NOT FROM CURRENT SEA LEVEL.

At the moment you have stacked all the ocean water ontop of all the ocean water and why you are getting ridiculously high numbers.

So the easiest way to recalc the sea level because the sea bed is up and down is to simply remove the ocean water out and add all other sources of water in which is what NASA does :-)
Posted by: paul

Re: Earths Water in a Ball - 06/07/12 03:09 PM

Quote:
You didn't look very hard try your own link that started this


amazing !
I was commenting on the amount of information I found on
YOUR LINK , not mine ;-)

its usually best to make sure that a link that you put up
pointing to information actually contains the information on the page that the link displays when someone clicks on it.

Quote:
and be about 860 miles


I was using the following 700 km posted by Mike.

Quote:
Mike Kremer said,

Greetings Revking,
I think you will find, its 700 kilometers, as it states in the original NASA picture,
a couple of letters back.


700 km = 434 miles

http://www.google.com/webhp?hl=en#hl=en&...280&bih=616

Quote:
332,500,000 cubic miles (mi3) = 332.5 MILLION cubic miles a fraction smaller than NASA's number of 344 MILLION


since I was using 434 miles as the diameter then that is why
I had 342 million cubic miles vs the 332 million cubic miles


Quote:
NEXT FOR YOUR ERROR IN LOGIC IN YOUR CALCULATION


error?

why would you say error?

didnt I clearly emphasize that I was stacking the volume of water on top of the surface area of the earth?

lets look

Quote:
7926 miles diameter
41849280 ft diameter
r = 20924640 ft radius
r^2 = 437840559129600
pi x r2 = 1375516684005198.8361281412832575
4x(pi x r2)= 5502066736020795.34451256513303 sq ft

STACKING THE VOLUME OF WATER IN THE SPHERE ON TOP OF THE SURFACE OF THE EARTH


sphere 50403368935943368643.904 cu ft/ earth 5502066736020795.344 sq ft = 9160.806 ft height

I had originaly posted 1145.10 ft but now the height has greatly increased to 9160 ft !!!

thanks orac for pointing that out.



yes I did clearly point that out.

Quote:
So the easiest way to recalc the sea level because the sea bed is up and down is to simply remove the ocean water out and add all other sources of water in which is what NASA does :-)


its much harder that that orac , because of geographical elevations , also you would need a computer program that takes into consideration the amount of rebounding and the amount of sinking of land masses and sea floor due to the melting of the ice.

this rebounding and sinking of land and sea bed would crack the earth deep down , and would cause the release of hydrogen from the rock.

this would also need to be included into the computer program to calculate anything close to a possible scenario.

considering that the earths hydrosphere is only 0.023 percent of earths total mass , this leaves room for a deluge of water from binding hydrogen and oxygen atoms forming water molecules as the earth resettles into a stable shape over time due to the land and sea floor rebounding and the land and sea floor sinking that will be a result of the ice melting.
Posted by: Orac

Re: Earths Water in a Ball - 06/07/12 03:26 PM

I am confused is this an excercise in ridiculous or are you actually trying to calculate something?

So what you just calculated was the average depth of the current ocean give or take because 97% of that water is already on the sphere surface exactly where you are trying to put it.

So unless you have another 315 Million cubic miles of water up your sleeve not much is going to radically change sea levels.
Posted by: Orac

Re: Earths Water in a Ball - 06/07/12 03:40 PM

Originally Posted By: paul

its much harder that that orac , because of geographical elevations , also you would need a computer program that takes into consideration the amount of rebounding and the amount of sinking of land masses and sea floor due to the melting of the ice.

this rebounding and sinking of land and sea bed would crack the earth deep down , and would cause the release of hydrogen from the rock.

this would also need to be included into the computer program to calculate anything close to a possible scenario.

considering that the earths hydrosphere is only 0.023 percent of earths total mass , this leaves room for a deluge of water from binding hydrogen and oxygen atoms forming water molecules as the earth resettles into a stable shape over time due to the land and sea floor rebounding and the land and sea floor sinking that will be a result of the ice melting.


I looked at glacial rebound because of some crap from pre-earth and that will take hundreds of thousands of years if not longer probably millions.

Plate tectonics and/or preearth theory whichever you want to believe will have the world looking very different to today anyhow so sea level discussions are rather meaningless on these scales.

So I guess I come back to the point .... what is the meaning of what your calculating.
Posted by: paul

Re: Earths Water in a Ball - 06/07/12 04:03 PM

Quote:
I looked at glacial rebound because of some crap from pre-earth and that will take hundreds of thousands of years if not longer probably millions.


Glacial rebound !!!

I guess you dont know that continents loaded down with ice would rebound much faster than the more stable land underneath glaciers.

also I guess you dont know that greenland is already showing the effects of rebounding.

http://www.skepticalscience.com/greenland-rising-faster-as-ice-loss-accelerates.html


Quote:
We have several independent lines of evidence that Greenland is losing ice at an accelerating rate. Satellite altimetry find glaciers are sliding faster downhill and dumping more ice into the ocean. Altimetry data also find the ice sheet is thinning. An overall picture is obtained by satellites measuring the gravity around the ice sheet. Another line of evidence has now been added to this picture with GPS measurements finding that Greenland is losing ice so quickly, the land is now rising up at an accelerating rate.

These results are published in Accelerating uplift in the North Atlantic region as an indicator of ice loss (Jiang 2010). The study looks at high-precision global positioning system (GPS) data that measure the vertical motion of the rocky margins around Greenland, Iceland and Svalbard. The weight of ice sheets push down on the bedrock it rests on. As the ice sheets lose mass, the bedrock rises. This process, known as Glacial Isostatic Adjustment (GIA), has been happening since the planet came out of an ice age around 17,000 years ago. How do we know whether current uplift might be a delayed response to glacial retreats from thousands of years ago? To avoid the effect of past events, this study focuses on vertical acceleration rather than velocities. The results are therefore insensitive to GIA-related motions from past ice mass changes.

What they find is crustal uplift in Greenland, Iceland and Svalbard is accelerating. Extrapolating the acceleration backwards in time finds the acceleration began after 1990. The acceleration of uplift over the past decade represents an essentially instantaneous, elastic response to recent accelerated melting of ice throughout the North Atlantic region.


Quote:
and that will take hundreds of thousands of years if not longer probably millions.


would you consider that the above text is speaking about thousands or millions of years ?

does instantaneous, elastic response mean thousands or millions of years or does it mean instantaneous, elastic response.

Posted by: Orac

Re: Earths Water in a Ball - 06/07/12 04:08 PM

WOW 0.6mm per year

6 mm in 10 years
60 mm in 100 years
600 mm (0.6m) im 1000 years
6000 mm (6m or 19 ft) in 10000 years
60000 mm (60m or 196 ft) in 100000 years

Assuming that rate kept constant and as usual with all pressure things it won't it will drop away.

Even using your data the timescale is immense.
Posted by: paul

Re: Earths Water in a Ball - 06/07/12 04:16 PM

Quote:
Assuming that rate kept constant and as usual with all pressure things it won't it will drop away.


Assuming will not slow the acceleration of ice melt.
and to assume that the rate of ice melt will stay constant is hardly feasible.

the more ice that melts the more water that forms on top of the ice , this melted water collects heat from the sun more rapidly.

because of its color / its ability to reflect light is removed and its ability to collect and store heat from the sun is increased.

acceleration does not mean constant.
a constant acceleration at a given rate of the ice melt is not possible.

pressure will not remain constant.
the amount of pressure that is released from the underlying bedrock will also be accelerating but not at a constant rate of acceleration.

the faster the ice melts the quicker the land rebounds.
Posted by: Orac

Re: Earths Water in a Ball - 06/07/12 04:32 PM

It works nothing like that from what I read unless you have a new theory now I am no expert I am just going by what I read.

Originally Posted By: http://en.wikipedia.org/wiki/Post-glacial_rebound

Studies have shown that the uplift has taken place in two distinct stages

The initial uplift following deglaciation was near-instantaneous due to the elastic response of the crust as the ice load was removed.

After this elastic phase, uplift proceeded by slow viscous flow so the rate of uplift decreased exponentially after that.


That inital stage wont last forever and the second stage will kick in and it will decrease.

Given that the ice has only just melted from greenland with the last few years it's fairly obvious it is in the initial phase and it will drop away and thats what my statement is based on.
Posted by: paul

Re: Earths Water in a Ball - 06/07/12 04:42 PM

Orac

its obvious that greenlands glaciers are not even a tiny fraction of the total weight of the ice on top of greenland
wouldnt you say?

so why are you using greenlands glaciers when talking about the rebounding of the entire greenland landmass.

Quote:
The initial uplift following deglaciation was near-instantaneous due to the elastic response of the crust as the ice load was removed.


deglaciation --> as the ice load was removed

near-instantaneous due to the elastic response of the crust

even your example of glaciers show a near-instantaneous elastic response of the crust.

granted that responce would be small , nothing to really get concerned with.

but the rebounding of a continent would be something to really be concerned with.

lets hope it all goes smoothly and the solid rock beneath the continents are actually very elastic like rubber and there will be no devastation due to the cracking of the crust.

lets also hope that we win the lottery.


Posted by: Orac

Re: Earths Water in a Ball - 06/07/12 04:50 PM

Basic physics pressure is per square area.

Changing the area doesn't change the problem divid the mass by the volume it sits on. If you are saying the thickness on the glaciers is thinner per square meter than the mainland then maybee it's not an indicator.

To explain above you let air out of car tyres to drive on beaches so the tyre spreads out the load and it doesn't sink into the sand very similar problem to what you are looking at. Weight per area is the key thing not total weight.

Again I am no expert on geology I am simply applying simple physics principles and what I would have natively guessed should happen wiki says does.

There may be mechanisms I do not undertsand if so explain away.

To me this is like a classic ice block problem when put out on table initially the melt rate increases but eventually it slows down and declines because you start running out of surface area on the iceblock to keep up the melt rate increase. The more the iceblock melts and smaller it becomes the less surface area it has.

So taking that to greenland what i would expect happen if what you suggest happened the melt rate would initially increase then level and decrease and the instantaneous glacial rebound should do the same.
Posted by: paul

Re: Earths Water in a Ball - 06/07/12 05:06 PM

Quote:
Changing the area doesn't change the problem divid the mass by the volume it sits on. If you are saying the thickness on the glaciers is thinner per square meter than the mainland then maybee it's not an indicator.


no...

think about it this way.

you have a 50 ft x 50 ft x 10 ft deep swimming pool sitting on a weight scale.

the water in the pool weighs 1,559,520 pounds.

you have a water hose leading from the pool to the ground.

you are using the water hose to siphon off water from the pool.

the pool of water is greenland.
the water hose is a greenland glacier.


the weight scale is sitting on a huge spring and the spring is compressed due to the weight of the water in the pool.

will the weight that the scale shows be greatly affected
if you remove the water hose?

will the compressed spring be greatly affected by removing the water hose?

will a glacier melting greatly affect the rebounding of greenland?
Posted by: Orac

Re: Earths Water in a Ball - 06/07/12 05:59 PM

Again totally wrong way of looking at it.

There is an exact equivalent in how much weight can an egg shell support that is identical in all respects to our issue with weight on earth crust.

Answer a hell of a lot if if you spread the load out

http://www.stevespanglerscience.com/experiment/walking-on-eggshells

http://www.sciencefairadventure.com/ProjectDetail.aspx?ProjectID=176

The deformation of the egg shell per unit area decides whether it breaks or not the total weight sitting on the egg.

I assure you that is the exact same situation and weight per unit area matters on earth not the weight itself.

There are no springs involved you have a thin crust which is being deformed based on the pressure per area on it. The crust will flex in the same way as the eggshell does based on that pressure and so long as the pressure isnt on a singular point it will tolerate alot.

It's also why semi trailers have multiple wheels to keep the weight spread out so the wheels don't sink into and crack the tarmac.

If you still aren't convinced get a party ballon and blow it up. Put a finger tip from each hand on either side and push and note the deflection you should be able to touch finger tips if it is moderately inflated. Now use the flats of your hands and try and get the walls to move anywhere near as close .... Area matters :-)
Posted by: paul

Re: Earths Water in a Ball - 06/07/12 08:03 PM

Quote:
There is an exact equivalent in how much weight can an egg shell support


Come on Orac you shouldnt use an egg shell when making an example of the earth , however your use of a balloon was a good example.

that is about as wrong as you could get , I could see if you were to use a egg whose shell has been cracked several times and the cracks were all connected.

as in the below egg shell whose cracks are all connected!



do you think that this egg shell would support that much weight?



extremely wrong Orac ;-)

ie...

the earth has cracks in it , as below in much the same manner as the cracked egg shell above does.



find a mirror look into it at yourself and say this.

Quote:
Again totally wrong way of looking at it.



Quote:
I assure you that is the exact same situation and weight per unit area matters on earth not the weight itself.


get a really thin sheet of cardboard.
apx 1/8 inch x 12 inch x 12 inch
fill you bathtub with water.
place the sheet of cardboard on top of the water.

now go to mcdonnalds and get a large coke.

slowly take ice from your drink and place the ice on the thin sheet of cardboard. (starting at the center of the thin sheet of cardboard)

notice how the cardboard begins to sink into the water.

now take a picture of it.

then wait until the ice melts.

take another picture of it.

compare the differences in height above water level.


repeat the experiment only this time cut the cardboard into
squares.
make (9) 4 inch x 4 inch squares.

place the small squares in the water in your bathtub.
assemble the small squares into a large square

note : do not use superglue, nails, cement or any other means to reconnect the squares together in order to sabotage the experiment just to prove your point.

when you place the ice on the center 4 x 4 inch square
does the center square sink more rapidly than the 12 x 12 square used in the previous experiment?

can it hold as much ice as the 12 x 12 square used in the previous experiment?

knowing that water is not as thick as magma is you should repeat the experiment using strawberry pudding.

will the strawberry pudding support the ice sitting on top of the center square better than the water?

if not do you think it would be better to pour concrete into your bathtub to use as the supportive structure that the earths crust sit on?

do you think it would be even better if you allow the concrete to fully dry before performing the experiment?


is there any way out of this?

Quote:
Now use the flats of your hands and try and get the walls to move anywhere near as close .... Area matters :-)


yes it does.

and applying an example correctly also matters.

hers a good one.

place your balloon between two surfaces then put your fingers on the top and bottom of the balloon.

press your fingers into the balloon until the balloon touches the two surfaces in a manner that the periphery (equator) of the balloon is touching the two surfaces.

now consider the fingers as the ice caps.
as long as you hold pressure on the balloons north and south poles the balloons periphery will support the balloon because it is in contact with the two surfaces.

as soon as you release pressure from the poles the balloon will drop.

the pressure is distributed evenly inside the balloon.

so... why didnt the 4 x 4 inch square support as much ice as the 12 x 12 inch square.

would this mean that the areas further away from the poles will not be as affected as those areas closer to the poles?

when you moved your fingers didnt the balloon regain its original shape?










Posted by: Orac

Re: Earths Water in a Ball - 06/08/12 02:16 AM

You are getting close to understanding now keep playing with the idea ... In physics it's a standard closed vessel under pressure problem.

To turn your problem to closer to reality take your cracked egg world put on the ground now get a fixed block weight and now get different cup sizes. Turn the cup upside down and place cup on your cracked world now put your standard weight ontop of the upturned base. The different cup sizes are spreading the load of the standard weight out over different areas, note the movement distances in your cracked egg shell.

As I said I am sure at what is happening I would have guessed at it. Note also that the direction is a lift it is working against sea level rise.

Infact there is a logical extension if the physics is working as I describe .... If all the ice on antarctica melted the one place I can >>> guarantee <<< you that won't be under water is antarctica.

Similarly at the moment sea levels around greenand should actually be dropping ....and the answer

Originally Posted By: http://www.cicero.uio.no/fulltext/index.aspx?id=8912

In other words, the paradoxical result will be that as the Greenland ice melts, world sea level will rise because more water enters the oceans, but the sea level around Greenland itself will drop because the island loses mass and its gravity is weakened. The map shows the expected pattern of sea level rise around the world if melting of the Greenland Ice Sheet results in an average sea level rise of one millimetre per year, or 10 centimetres in 100 years. We can see that there will be no sea level rise at all around Greenland – in fact, the sea level will sink, but this is not apparent from the simplified map.


What is described as paradoxical is infact completely obvious if you understand what is happening.

Seriously it's basic physics ... you keep telling me I am wrong but my predictions keep showing otherwise.
Posted by: paul

Re: Earths Water in a Ball - 06/08/12 03:32 AM

Quote:
To turn your problem to closer to reality take your cracked egg world put on the ground now get a fixed block weight and now get different cup sizes. Turn the cup upside down and place cup on your cracked world now put your standard weight ontop of the upturned base. The different cup sizes are spreading the load of the standard weight out over different areas, note the movement distances in your cracked egg shell.


shazam I would never have figured that one out.
now I fully understand.



Quote:
You are getting close to understanding now keep playing with the idea ... In physics it's a standard closed vessel under pressure problem.


Im so glad that you are here to explain these things
just think we have nothing to worry about because the sea levels will only rise a couple of millimeters per hundred years.

unless we live on greenland or the antartic which will be the safest places on the earth to live because the sea levels will drop there , wow


Quote:
Greenland itself will drop because the island loses mass and its gravity is weakened.

so all we have to do to weaken gravity is melt ice.
I feel as if I have been left out , I always thought that gravity was constant on the earth and did not change like that.

thanks Orac for letting me in on that secret.




Posted by: Orac

Re: Earths Water in a Ball - 06/08/12 04:20 AM

Originally Posted By: paul

Im so glad that you are here to explain these things
just think we have nothing to worry about because the sea levels will only rise a couple of millimeters per hundred years.


The sea level is moving at 3.2mm per year estimate because it is made up of multiple sources try looking at the breakdown of contributions before making stupid statements.

Originally Posted By: http://www.realclimate.org/index.php/archives/2007/03/the-ipcc-sea-level-numbers/

Greenland has contributed +0.14 to +0.28 mm/year of sea level rise over this period, while for Antarctica the uncertainty range is -0.14 to +0.55 mm/year.


Hmmmm greenland contributes max of 0.28mm to sea level and the island is lifting 0.6mm per year ... hmmm I wonder why, does your theory cover that.

Originally Posted By: paul

unless we live on greenland or the antartic which will be the safest places on the earth to live because the sea levels will drop there , wow


Antarctica can never go under water this is not enough water not already in the ocean on the planet to do that.

Antarctica has the greatest average elevation of any continent at 1,860 metres (6,100 feet). The average elevation of North America is 720 metres (2,300 feet).

That is before including the uplift of the continent if all the ice melted.

Greenland could go under because of the contribution of ice melt from antarctica and other sources into the ocean.


Originally Posted By: paul

so all we have to do to weaken gravity is melt ice.
I feel as if I have been left out , I always thought that gravity was constant on the earth and did not change like that.


Then you would be stupidly wrong gravity is not constant and thats exactly how GRACE works out changes. There are micro gravity changes around you all the time that you are blissfully unaware of. GRACE measures ice melt by monitoring the gravity changes (http://www.jpl.nasa.gov/news/news.cfm?release=2012-036) so are you suggesting GRACE doesn't work and is wrong?

http://www.space.com/11849-earth-gravity-map-geoid.html




Grace even sees Earthquakes because they change gravity here is the 2004 sumatra quake



I am sorry that the actual science of gravity messes with your actual perception and you find it gibberish but it none the less accurate to a scientist.
Posted by: paul

Re: Earths Water in a Ball - 06/08/12 11:45 AM

I suppose that the old gravity constant has been done away with
by grace.

unless the changes in gravity that grace detects are so tiny
that they really have no affect on the amount of gravity in
areas that grace detects differences.

could it be that these micro changes dont really affect the
actual weight of objects to any great extent and these miniscule micro changes in gravity can only be detected on sensitive measuring equipment?

and these really tiny miniscule micro changes in gravity are not what causes sea levels to decline.

the information that you posted seems to tell us that it is not the weight of the ice melting but a decrease in greenlands gravity that causes sea levels around greenland to sink as the information says.

since you are a scientist could you please inform us what the new gravity constant is when grace is around.

I dont want to be measuring anything valuable at the wrong time
or should I say when the gravity of the situation is declining.

maybe we wont all be trapped by these tiny miniscule micro atom sized barely detectable changes and fall up into the air.



Posted by: Bill S.

Re: Earths Water in a Ball - 06/08/12 12:40 PM

Looks like a lot of interesting stuff has been added to this thread. I'm without the internet at present, and will be so for a few days, but I look forward to catching up with this when back on line.
Posted by: Orac

Re: Earths Water in a Ball - 06/08/12 01:16 PM

Originally Posted By: paul

since you are a scientist could you please inform us what the new gravity constant is when grace is around.


It has never been an absolute constant nor is the speed of sound or many other science constants.

Gravity was standardized for one reason alone to make all weights uniform so you could trade goods and agree on the the same weight. The weight standard resides in SI in paris and there is actually a funny backstory that it has been losing weight (http://www.msnbc.msn.com/id/20744160/ns/...y-loses-weight/)

Originally Posted By: http://en.wikipedia.org/wiki/Standard_gravity

It is defined as precisely 9.80665 m/s2, or about 35.30394 (km/h)/s (&#8776;32.174 ft/s2 or &#8776;21.937 mph/s). This value was established by the 3rd CGPM (1901, CR 70) and used to define the standard weight of an object as the product of its mass and this nominal acceleration. The acceleration of a body near the surface of the Earth is due to the combined effects of gravity and centrifugal acceleration; the total (the apparent gravity) is about 0.5 percent greater at the poles than at the equator.

Although the symbol g is sometimes incorrectly used for standard gravity, g (without a suffix) strictly means the local acceleration due to local gravity and centrifugal acceleration, which varies depending on one's position on Earth (see Earth's gravity).


That kilogram bar is set against standard gravity.

Now read what Earths gravity is (http://en.wikipedia.org/wiki/Earth%27s_gravity)

So the answer is it is you that has been confused and gravity on earth was never constant, standard gravity definition to define weight is a constant.

At secondary schooling level they probably interchangably use the standard gravity in calculations but standard gravity and earth gravity always have been different and known to be so as far back as the 118 year kilogram standard bar has existed.

You may now be interested to search what things affect the speed of sound because it is not constant either although probably taught as a constant at secondary school :-)
Posted by: paul

Re: Earths Water in a Ball - 06/08/12 01:30 PM

http://www.webmasternow.com/copyandpaste.html

Standard gravity, or standard acceleration due to free fall, usually denoted by g0 or gn, is the nominal acceleration of an object in a vacuum near the surface of the Earth. It is defined as precisely 9.80665 m/s2, or about 35.30394 (km/h)/s (&#8776;32.174 ft/s2 or &#8776;21.937 mph/s). This value was established by the 3rd CGPM (1901, CR 70) and used to define the standard weight of an object as the product of its mass and this nominal acceleration.[1][2][3] The acceleration of a body near the surface of the Earth is due to the combined effects of gravity and centrifugal acceleration; the total (the apparent gravity) is about 0.5 percent greater at the poles than at the equator.
Although the symbol g is sometimes incorrectly used for standard gravity, g (without a suffix) strictly means the local acceleration due to local gravity and centrifugal acceleration, which varies depending on one's position on Earth (see Earth's gravity). The symbol g should not be confused with G, the gravitational constant, or g, the symbol for gram. The g is also used as a unit of acceleration, with the value defined as above; see g-force.
The value of g0 defined above is a nominal midrange value on Earth, originally based on the acceleration of a body in free fall at sea level at a geodetic latitude of 45°. Although the actual acceleration of free fall on Earth varies according to location, the above standard figure is always used for metrological purposes. (The actual average sea-level acceleration on Earth is slightly less.)
[edit]See also

Gravitational acceleration
Metre per second squared
[edit]References

^ The international system of units (SI) – United States Department of Commerce, NIST Special Publication 330, 2001, p. 29
^ The International System of Units (SI) – Bureau international des poids et mesures, 8th edition, 2006, p. 142-143
^ The international system of units (SI) – United States Department of Commerce, NIST Special Publication 330, 2008, p. 57
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Categories: Fundamental physics conceptsGravitationIntroductory physicsUnits of acceleration

The gravitational constant denoted by letter G, is an empirical physical constant involved in the calculation(s) of gravitational force between two bodies. It usually appears in Sir Isaac Newton's law of universal gravitation, and in Albert Einstein's theory of general relativity. It is also known as the universal gravitational constant, Newton's constant, and colloquially as Big G.[1] It should not be confused with "little g" (g), which is the local gravitational field (equivalent to the free-fall acceleration[2]), especially that at the Earth's surface.
Contents [hide]
1 Laws and constants
2 Dimensions, units, and magnitude
3 History of measurement
4 The GM product
5 See also
6 Notes
7 References
8 External links
[edit]Laws and constants

According to the law of universal gravitation, the attractive force (F) between two bodies is proportional to the product of their masses (m1 and m2), and inversely proportional to the square of the distance (inverse-square law) (r) between them:

The constant of proportionality, G, is the gravitational constant.
The gravitational constant is a difficult physical constant to measure to high accuracy.[3] In SI units, the 2010 CODATA-recommended value of the gravitational constant (with standard uncertainty in parentheses) is:[4]

with relative standard uncertainty 1.2×10&#8722;4.[4]
[edit]Dimensions, units, and magnitude

The dimensions assigned to the gravitational constant in the equation above—length cubed, divided by mass, and by time squared (in SI units, meters cubed per kilogram per second squared)—are those needed to balance the units of measurements in gravitational equations. However, these dimensions have fundamental significance in terms of Planck units; when expressed in SI units, the gravitational constant is dimensionally and numerically equal to the cube of the Planck length divided by the product of the Planck mass and the square of Planck time.
In natural units, of which Planck units are a common example, G and other physical constants such as c (the speed of light) may be set equal to 1.
In many secondary school texts, the dimensions of G are derived from force in order to assist student comprehension:

In cgs, G can be written as:

G can also be given as:

Given the fact that the period P of an object in circular orbit around a spherical object obeys

where V is the volume inside the radius of the orbit, we see that

This way of expressing G shows the relationship between the average density of a planet and the period of a satellite orbiting just above its surface.
In some fields of astrophysics, where distances are measured in parsecs (pc), velocities in kilometers per second (km/s) and masses in solar units (), it is useful to express G as:

The gravitational force is extremely weak compared with other fundamental forces. For example, the gravitational force between an electron and proton one meter apart is approximately 10&#8722;67 newtons, while the electromagnetic force between the same two particles is approximately 10&#8722;28 newtons. Both these forces are weak when compared with the forces we are able to experience directly, but the electromagnetic force in this example is some thirty nine orders of magnitude (i.e., 1039) greater than the force of gravity — roughly the same ratio as the mass of the Sun compared to a microgram mass.
[edit]History of measurement

The gravitational constant appears in Newton's law of universal gravitation, but it was not measured until seventy one years after Newton's death by Henry Cavendish with his Cavendish experiment, performed in 1798 (Philosophical Transactions 1798). Cavendish measured G implicitly, using a torsion balance invented by the geologist Rev. John Michell. He used a horizontal torsion beam with lead balls whose inertia (in relation to the torsion constant) he could tell by timing the beam's oscillation. Their faint attraction to other balls placed alongside the beam was detectable by the deflection it caused. Cavendish's aim was not actually to measure the gravitational constant, but rather to measure the Earth's density relative to water, through the precise knowledge of the gravitational interaction. In retrospect, the density that Cavendish calculated implies a value for G of 6.754 × 10&#8722;11 m3 kg&#8722;1 s&#8722;2.[5]
The accuracy of the measured value of G has increased only modestly since the original Cavendish experiment. G is quite difficult to measure, as gravity is much weaker than other fundamental forces, and an experimental apparatus cannot be separated from the gravitational influence of other bodies. Furthermore, gravity has no established relation to other fundamental forces, so it does not appear possible to calculate it indirectly from other constants that can be measured more accurately, as is done in some other areas of physics. Published values of G have varied rather broadly, and some recent measurements of high precision are, in fact, mutually exclusive.[3][6]
In the January 5, 2007 issue of Science (page 74), the report "Atom Interferometer Measurement of the Newtonian Constant of Gravity" (J. B. Fixler, G. T. Foster, J. M. McGuirk, and M. A. Kasevich) describes a new measurement of the gravitational constant. According to the abstract: "Here, we report a value of G = 6.693 × 10&#8722;11 cubic meters per kilogram second squared, with a standard error of the mean of ±0.027 × 10&#8722;11 and a systematic error of ±0.021 × 10&#8722;11 cubic meters per kilogram second squared."[7]

[edit]The GM product

Main article: Standard gravitational parameter
The quantity GM—the product of the gravitational constant and the mass of a given astronomical body such as the Sun or the Earth—is known as the standard gravitational parameter and is denoted . Depending on the body concerned, it may also be called the geocentric or heliocentric gravitational constant, among other names.
This quantity gives a convenient simplification of various gravity-related formulas. Also, for celestial bodies such as the Earth and the Sun, the value of the product GM is known more accurately than each factor independently. Indeed, the limited accuracy available for G often limits the accuracy of scientific determination of such masses in the first place.
For Earth, using M&#8853; as the symbol for the mass of the Earth, we have

Calculations in celestial mechanics can also be carried out using the unit of solar mass rather than the standard SI unit kilogram. In this case we use the Gaussian gravitational constant which is k2, where

and
is the astronomical unit;
is the mean solar day;
is the solar mass.
If instead of mean solar day we use the sidereal year as our time unit, the value of ks is very close to 2&#960; (k = 6.28315).
The standard gravitational parameter GM appears as above in Newton's law of universal gravitation, as well as in formulas for the deflection of light caused by gravitational lensing, in Kepler's laws of planetary motion, and in the formula for escape velocity.
[edit]See also

Physics portal
Dirac large numbers hypothesis
Accelerating Universe
Gravity expressed in terms of orbital period
Lunar Laser Ranging Experiment
Cosmological constant
Gravitational coupling constant
Strong gravitational constant
[edit]Notes

^ "University of Washington Big G Measurement". Astrophysics Science Division. Goddard Space Flight Center. 2002-12-23. "Since Cavendish first measured Newton's Gravitational constant 200 years ago, "Big G" remains one of the most elusive constants in physics."
^ Fundamentals of Physics 8ed,Halliday/Resnick/Walker, ISBN 978-0-470-04618-0 p 336
^ a b George T. Gillies (1997), "The Newtonian gravitational constant: recent measurements and related studies", Reports on Progress in Physics 60 (2): 151–225, Bibcode 1997RPPh...60..151G, DOI:10.1088/0034-4885/60/2/001. A lengthy, detailed review. See Figure 1 and Table 2 in particular.
^ a b P.J. Mohr, B.N. Taylor, and D.B. Newell (2011), "The 2010 CODATA Recommended Values of the Fundamental Physical Constants" (Web Version 6.0). This database was developed by J. Baker, M. Douma, and S. Kotochigova. Available: http://physics.nist.gov/constants [Thursday, 02-Jun-2011 21:00:12 EDT]. National Institute of Standards and Technology, Gaithersburg, MD 20899.
^ Brush, Stephen G.; Holton, Gerald James (2001), Physics, the human adventure: from Copernicus to Einstein and beyond, New Brunswick, N.J: Rutgers University Press, pp. 137, ISBN 0-8135-2908-5
^ Peter J. Mohr; Barry N. Taylor (January 2005), "CODATA recommended values of the fundamental physical constants: 2002" (PDF), Reviews of Modern Physics 77 (1): 1–107, Bibcode 2005RvMP...77....1M, DOI:10.1103/RevModPhys.77.1, retrieved 2006-07-01. Section Q (pp. 42–47) describes the mutually inconsistent measurement experiments from which the CODATA value for G was derived.
^ J. B. Fixler; G. T. Foster; J. M. McGuirk; M. A. Kasevich (2007-01-05), "Atom Interferometer Measurement of the Newtonian Constant of Gravity", Science 315 (5808): 74–77, Bibcode 2007Sci...315...74F, DOI:10.1126/science.1135459, PMID 17204644
[edit]References

E. Myles Standish. "Report of the IAU WGAS Sub-group on Numerical Standards". In Highlights of Astronomy, I. Appenzeller, ed. Dordrecht: Kluwer Academic Publishers, 1995. (Complete report available online: PostScript; PDF. Tables from the report also available: Astrodynamic Constants and Parameters)
Jens H. Gundlach; Stephen M. Merkowitz (2000), "Measurement of Newton's Constant Using a Torsion Balance with Angular Acceleration Feedback", Physical Review Letters 85 (14): 2869–2872, arXiv:gr-qc/0006043, Bibcode 2000PhRvL..85.2869G, DOI:10.1103/PhysRevLett.85.2869, PMID 11005956
[edit]External links

Newtonian constant of gravitation G at the National Institute of Standards and Technology References on Constants, Units, and Uncertainty
The Controversy over Newton's Gravitational Constant — additional commentary on measurement problems
The Gravitational Constant
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Categories: Celestial mechanicsGravitationFundamental constants
Posted by: paul

Re: Earths Water in a Ball - 06/08/12 01:50 PM

here is a video that covers the topic points and valuable descriptive information that you posted on the amount of changes in gravity that causes greenland to rise and the sea level surrounding greenland to sink.



I have read that the detection of differences in gravity are in the millionths of a percentage , in other words worthless to any thing other than sensitive measuring equipment.

Posted by: paul

Re: Earths Water in a Ball - 06/08/12 02:03 PM

Quote:
At secondary schooling level they probably interchangably use the standard gravity in calculations


yes they do , did you know that you can obtain a higher degree of education on the internet.
you should look into these opportunities this way you wont have to guess you will know.

I would have thought that you had attended secondary schooling being a scientist and all but there are age requirements you know.

online education oppurtunities available

Im not saying that a higher education will make you smarter
but it will give you the opportunity to get smarter.

Posted by: Orac

Re: Earths Water in a Ball - 06/08/12 02:05 PM

So basically you would rather invent your physics rather than try and understand what actual science has to say.

I don't do pseudo-science or science fiction so my discussion ends here, will leave you to it and your new and improved physics.

You remind me alot of preearth the moment you can't win an argument you start insulting and offensive behaviour like a little child doing a tantrum.

Science arguments are about logic and reasoning not name calling and bad behaviour something both you and pre need to learn. I am not always right and if I am wrong I am easily swayed by a good solid scientific argument especially in areas like this which is way outside my normal area.
Posted by: paul

Re: Earths Water in a Ball - 06/08/12 02:48 PM

I suppose that using microscopic changes in gravity to describe the reason that sea levels surrounding greenland are "sinking"
is science to you then.

but to me it is not science.

it is false science.

there may be some slight unnoticeable millionth of a degree variation in the gravity of greenland because it has lost ice
but the primary cause of greenlands rebounding and the sea level "sinking" surrounding greenland is simply a loss of weight due to ice melt.

which leads me to conclude that you do participate in pseudo-science whether you realize it or not.

Im not saying that grace is false science , what Im saying is that the use of grace data to describe a reason that the sea level surrounding greenland is "sinking" is false science.


Posted by: paul

Re: Earths Water in a Ball - 06/08/12 03:15 PM

#43925
I am confused is this an excercise in ridiculous or are you actually trying to calculate something?
#43938
Then you would be stupidly wrong
There are micro gravity changes around you all the time that you are blissfully unaware of
I am sorry that the actual science of gravity messes with your actual perception
#43944
is it is you that has been confused
#43948
So basically you would rather invent your physics rather than try and understand what actual science has to say.
will leave you to it and your new and improved physics.
You remind me alot of preearth

LOL ...

Quote:
Science arguments are about logic and reasoning not name calling and bad behaviour something both you and pre need to learn.


my video response

Posted by: Orac

Re: Earths Water in a Ball - 06/08/12 03:31 PM

Originally Posted By: orac

Then you would be stupidly wrong


Is the only comment there that would remotely qualify as offensive or bad tempered.

I actually didn't intended to suggest you were stupid just the understanding should be simple, although I can see with my english skills being so bad (English is not my native language) I conceed now that was poor choice and reading it now you are right I see what I did wrong there.

I am sorry as I read them I can't see how the other statements are in anyway offensive ... is my english that bad?

I cut and post alot for answers so I don't trip over errors in translation but I do find english difficult at times.

Someone once described my english as brutal whatever that means ... what am I doing wrong?
Posted by: paul

Re: Earths Water in a Ball - 06/08/12 05:36 PM

Quote:
I can see with my english skills being so bad (English is not my native language)


I didnt know you were a foreigner I just thought you were illiterate.
your post state that you are in Australia which has english as
the national language although there are many variants between the structure of American and Austrailian sentences and their
meanings.
still you need to use a little more in your sentences.

ie...

I conceed now that was poor choice
should be
I conceed now that was a poor choice
or
that was a poor choice on my part
etc...

not bad though , keep trying your almost there.

Quote:
Then you would be stupidly wrong


you should have wrote.

then you would be exactly correct as usual.

its a little bit sharper without using words such as stupid.

and attacking ones level of education will leave you wide open to future attacks concerning your level of education.

knowing that a high level of education does not require such
tactics in a discussion, you may find it helpful to refrain from any attack or sarcasm of another posters level of education in the future.

I normally attack my attackers in a manner that is not easily seen as an attack yet delivers a decisive crippling injury.

hope this helps and maybe you need to stop reading web sites so often and read some books where examples of proper english are found.


Posted by: Orac

Re: Earths Water in a Ball - 06/08/12 07:09 PM

Originally Posted By: paul

I didnt know you were a foreigner I just thought you were illiterate.
your post state that you are in Australia which has english as
the national language although there are many variants between the structure of American and Austrailian sentences and their
meanings.


Australia gave me political asylum but I am currently in USA working but still have uni attachment to Australia.


Originally Posted By: paul

hope this helps and maybe you need to stop reading web sites so often and read some books where examples of proper english are found.


Unfortunately that is something I have very little time to do and usually things get lost in translation. I have been given numerous books that are supposedly great but I don't get what makes them great. A friend gave me "Catcher in the Rye" to read and I am really struggling with it.
Posted by: paul

Re: Earths Water in a Ball - 06/08/12 11:03 PM

now that you said that , it might make more sense to use audio tapes not the type that are teaching a language , but just audio books that you could listen to while on a train or driving or just relaxing during your lunch breaks.

when I get an email concerning any type of business and I find these small insignificant literary errors this causes my mind to throw up warning signs and into the recycle bin they go.

If I were to go to a forum that uses your native language
I would have to use some type of translator or something
so I can definitely understand that it is difficult to say the least.