Thanks to PuterMan, this makes me wonder...

"FINAL ANSWER: 1 cubic foot of air at standard temperature and pressure assuming average composition weighs approximately 0.0807 lbs."

Doing some basic math, .0807 x 5280 (feet in a mile) equals roughly 426.096 lbs. So, a column a "air", one square foot in size , 5280 feet tall would weigh roughly 426 lbs. Because, widely held perception is that place where our atmosphere "meets" space is 62.14 miles (100 km), 426 x 62.14 equals basically 26,471.64 pounds. SO, A column of "air", one sq. foot in size, extending 62.14 miles "to space", weighs a little over thirteen tons?
Does this have any impact on current speculation about what "gravity" really is? Do tell.

I can't see what effect that would have on gravity whatsoever. Also, that is a colossal overestimate of how much air there is, because at the legal boundary of space there is (almost) no air. Given that standard pressure is about 100 kPa, your calculation gives about 12 times that.

Yes, there is a force from the air pushing you down. But, there is also a force from the air pushing you up, from every surface on you that is angled downward. Because those forces balance out, there is no noticeable overall force. In fact, because there is a tiny increase in pressure between your head and toes, there is a very small resultant force up, buoyancy. Because you are about 800 times denser than air, this doesn't lift you up.

reply to post by G.A.G.


you could think of the air as squeezing you in all directions as opposed to pushing you down

reply to post by apex


Not to be pickyoonish, and not that I dont believe you, but can you provide a source to your assertion that there is less air? Please?

The stated weight, as with all weight, is a measure of a mass in a gravity well. Change the acceleration due to gravity and you change the measurement of the weight of a given volume of mass.

Besides this, your caluclation is off. You haven't taken into account the change in mass of the volume of air along the continuum between the mass at surface level and the mass of the same volume of air at any X distance above the surface. Basically, there is more air in a cubic foot at the surface of the earth than there is in a cubic foot 60 miles above the surface of the earth. Each would then weigh a different amount at the same acceleration due to gravity.

Since there is also a difference in distance to the center of the earth's mass, the volume at the surface has a greater acceleration due to gravity than the volume further away.

Originally posted by G.A.G.
"FINAL ANSWER: 1 cubic foot of air at standard temperature and pressure assuming average composition weighs approximately 0.0807 lbs."

Doing some basic math, .0807 x 5280 (feet in a mile) equals roughly 426.096 lbs. So, a column a "air", one square foot in size , 5280 feet tall would weigh roughly 426 lbs. Because, widely held perception is that place where our atmosphere "meets" space is 62.14 miles (100 km), 426 x 62.14 equals basically 26,471.64 pounds. SO, A column of "air", one sq. foot in size, extending 62.14 miles "to space", weighs a little over thirteen tons?
Does this have any impact on current speculation about what "gravity" really is? Do tell.

hmm
just thinking.

doesn't "air" at different altitudes , have different "weight",,

by your math,,( a column of air rising up to the vacuum of space..).
but yet you used Sea-level measurements of "weight" ,, times by the hight .

am i seeing a problem

reply to post by Overstuffed


.0807 lbs was an average calculated from measurements taken at, many elevations, not simply at the surface of the earth. I understand your outlook, but this still doesnt make me wonder "less". Thankyou for responding.

reply to post by Overstuffed


well said Overstuffed..

and at some point.. centrifuge of the mass of air left at the top of the column, gets Whipped off the earth, somewhat, out into space--ish

Originally posted by G.A.G.
.0807 lbs was an average calculated from measurements taken at, many elevations, not simply at the surface of the earth. I understand your outlook, but this still doesnt make me wonder "less". Thankyou for responding.

Originally posted by G.A.G.
"FINAL ANSWER: 1 cubic foot of air at standard temperature and pressure assuming average composition weighs approximately 0.0807 lbs."

Except, Standard Temperature and Pressure translates to being at or near 100kPa, which would be the pressure at sea level most likely, which then gives the density for air given in the second quote. As you increase altitude, the pressure and temperature drop, as does the density of the air.

The 0.0807 lbs is not an average for the whole atmosphere, up to the boundary of space, but an average for sea level.

reply to post by G.A.G.


i gave you a FLAG..

you made me think..

reply to post by darrman


Thankyou for the reply, Your an honest person, and I really appreciate that. g.a.g.

This is math is all coming from a guy on here named "Puter" Man.

...Just saying, carry on people...

reply to post by ThinkingCap


In all fairness, you must be so poor you cant even "pay" attention! This time actually "read" the thread, and then come back with your derogatory remarks. Puterman did not do the math.

reply to post by G.A.G.


Hi G.A.G. No indeed I did not. I am wondering if you are possibly getting a little confused here.

If understand your OP correctly you were wondering about the weight of air above you. You are wondering if the air has any effect? It does, but not on gravity.

First the gravity is the electromagnetic force being exerted by the mass of the earth upon the mass of your body. This would remain the same even in a vacuum. The weight of the column of air above you does not figure in that equation. As you ascend however your weight would decrease as the gravity would not affect you so much.

Your weighting is also a component of the gravity that is attracting you to the body of the earth and the centrifugal force that is trying to throw you out into space. If the air was removed those two forces would still be there. In reality the effect of centrifugal force is very small otherwise you would weigh much more at the equator than you would at the poles. In fact of course you do, but it is a small difference.

You are also affected by your buoyancy which in turn affects the weighing process. This buoyancy decreases as you ascend and the air density gets less.

You may find that this page explains it for you.

As you ascend a mountain you do indeed get lighter but it is only by a small amount and gravity and buoyancy partially cancel each other out.

reply to post by PuterMan


In reality the effect of centrifugal force is very small otherwise you would weigh much more at the equator than you would at the poles. In fact of course you do, but it is a small difference.

Thankyou for "coming to the rescue". I am really curious about this and want to understand. Forgive me for suggesting, that I was under the impression that space launches become "cheaper" as you get closer to the equator. They use less fuel, due to the centrifugal force you speak of.

Originally posted by G.A.G.
reply to post by PuterMan

 

In reality the effect of centrifugal force is very small otherwise you would weigh much more at the equator than you would at the poles. In fact of course you do, but it is a small difference.

Thankyou for "coming to the rescue". I am really curious about this and want to understand. Forgive me for suggesting, that I was under the impression that space launches become "cheaper" as you get closer to the equator. They use less fuel, due to the centrifugal force you speak of.

PuterMan...where are ya? Less fuel because, why?

reply to post by G.A.G.


You are absolutely right they do launch as close as possible to the equator to get the slingshot effect and my line was the wrong way round.

In reality the effect of centrifugal force is very small otherwise you would weigh much more at the equator than you would at the poles. In fact of course you do, but it is a small difference.

It should have said less since the centrifugal force would be throwing you out into space much more than at the poles.

This is what happens when you type things in the middle of your evening meal!

Epic fail on my part and my sincere apologies. Thanks for pointing that out.

Originally posted by PuterMan
reply to post by G.A.G.

 

You are absolutely right they do launch as close as possible to the equator to get the slingshot effect an my line was the wrong way round.

In reality the effect of centrifugal force is very small otherwise you would weigh much more at the equator than you would at the poles. In fact of course you do, but it is a small difference.

It should have said less since the centrifugal force would be throwing you out into space much more than at the poles.

This is what happens when you type things in the middle of your evening meal!

Epic fail on my part and my sincere apologies. Thanks for pointing that out.

PuterMan, Ive learned alot from you and your extensive time spent on your work is absolutely "selfless". Thankyou for the reply, and I really look forward to your future efforts. g.a.g.