## Re: [M & B] Re: Question for Pi

Expand Messages
• Thank you for the trouble.   So, if the sun s mass is compacted in a smaller space, then the gravity force increases. ________________________________ From:
Message 1 of 10 , Mar 8, 2013
Thank you for the trouble.

So, if the sun's mass is compacted in a smaller space, then the gravity force increases.

From: "PIASAN@..." <PIASAN@...>
To: Maury_and_Baty@yahoogroups.com
Sent: Thursday, March 7, 2013 8:56 PM
Subject: Re: [M & B] Re: Question for Pi

The sun's mass is thousands of times greater than the earth's mass. Yet, the gravity of the sun is only 28 times that of the earth. And a similar situation with Jupiter, whose mass is over 1000 times that of the earth, but the gravity is only I think 3 times more.

Why isn't the gravity of the sun and Jupiter more than it actually is?

Pi:
It's because of the Sun's radius.  The effect of gravity diminshes as a function of the square of the distance between the bodies.

The equation for the force of gravity is:
F=Gm1m2/(r^2)
where
F= the force of Gravity
G= the Gravitational constant
m1= the mass of the first object
m2 = the mass of the second object
r= the distance between them

The Mass of the sun is about 2e30 kg and the mass of the Earth is about 5.97e24 kg making the Sun about 335,000 times more massive than the Earth.  However the diameter of the Sun is 1.39e6 km and the diameter of the Earth is 12742 km.making the radius of the sun about 110x that of the Earth.  Dividing 335,000 by 110 squared (11900) equals 28.15.

The same would hold true for Jupiter.

• From: Ray Ausban Thank you for the trouble. Pi: You re more than welcome. Ray: So, if the sun s mass is compacted in a smaller space, then the gravity force
Message 2 of 10 , Mar 8, 2013
From: Ray Ausban
Thank you for the trouble.

Pi:
You're more than welcome.

Ray:
So, if the sun's mass is compacted in a smaller space, then the gravity force increases.

Pi:
The gravity at the surface of the sun will increase because the surface is closer to the center of mass.  At the same distance, you would encounter the same gravity.

• Pi, I m asking this question because of something I remember in elementary school. I lived in Huntsville, AL which was one of NASA s hubs and there was always
Message 3 of 10 , Mar 11, 2013
Pi,
I'm asking this question because of something I remember in elementary school. I lived in Huntsville, AL which was one of NASA's hubs and there was always lots of 'space talk' going on back then.

Several discussions talked about the gravity on Jupiter being massively huge, that if you were to be on Jupiter, you couldn't stand up and your own weight would crush your rib cage if you were laying down. In short, you would just die.

So, my question is this: do you know when the gravity formula you gave me was perfected? Has there been any modification to it since the 'space age' began?

Thanks, Ray

From: "PIASAN@..." <PIASAN@...>
To: Maury_and_Baty@yahoogroups.com
Sent: Friday, March 8, 2013 7:13 AM
Subject: Re: [M & B] Re: Question for Pi
From: Ray Ausban
Thank you for the trouble.

Pi:
You're more than welcome.

Ray:
So, if the sun's mass is compacted in a smaller space, then the gravity force increases.

Pi:
The gravity at the surface of the sun will increase because the surface is closer to the center of mass.  At the same distance, you would encounter the same gravity.

• From: Ray I m asking this question because of something I remember in elementary school. I lived in Huntsville, AL which was one of NASA s hubs and there was
Message 4 of 10 , Mar 11, 2013
From: Ray
I'm asking this question because of something I remember in elementary school. I lived in Huntsville, AL which was one of NASA's hubs and there was always lots of 'space talk' going on back then.

Several discussions talked about the gravity on Jupiter being massively huge, that if you were to be on Jupiter, you couldn't stand up and your own weight would crush your rib cage if you were laying down. In short, you would just die.

Pi:
I'm not sure where that may have come from.  The accepted value is around 2.4 or so times Earth's gravity.... even at NASA.
"Someone who weighs 100 pounds on Earth would weigh about 240 pounds on Jupiter."

Since Jupiter is a gas giant, it really has no surface as such.  Perhaps the ones you heard were thinking of the gravity if Jupiter were the size of Earth.

Ray:
So, my question is this: do you know when the gravity formula you gave me was perfected?

Pi:
1687.

Ray:
Has there been any modification to it since the 'space age' began?

Pi:
Einstein might have .... but for practical purposes, the results are the same.  Newton was pretty good.

• Thank again! ________________________________ From: PIASAN@aol.com To: Maury_and_Baty@yahoogroups.com Sent: Monday, March 11, 2013 7:33 PM
Message 5 of 10 , Mar 12, 2013
Thank again!

From: "PIASAN@..." <PIASAN@...>
To: Maury_and_Baty@yahoogroups.com
Sent: Monday, March 11, 2013 7:33 PM
Subject: Re: [M & B] Re: One more question for Pi
From: Ray
I'm asking this question because of something I remember in elementary school. I lived in Huntsville, AL which was one of NASA's hubs and there was always lots of 'space talk' going on back then.

Several discussions talked about the gravity on Jupiter being massively huge, that if you were to be on Jupiter, you couldn't stand up and your own weight would crush your rib cage if you were laying down. In short, you would just die.

Pi:
I'm not sure where that may have come from.  The accepted value is around 2.4 or so times Earth's gravity.... even at NASA.
"Someone who weighs 100 pounds on Earth would weigh about 240 pounds on Jupiter."
Source:  http://www.nasa.gov/audience/forstudents/k-4/stories/what-is-jupiter-k4.html

Since Jupiter is a gas giant, it really has no surface as such.  Perhaps the ones you heard were thinking of the gravity if Jupiter were the size of Earth.

Ray:
So, my question is this: do you know when the gravity formula you gave me was perfected?

Pi:
1687.

Ray:
Has there been any modification to it since the 'space age' began?

Pi:
Einstein might have .... but for practical purposes, the results are the same.  Newton was pretty good.
Your message has been successfully submitted and would be delivered to recipients shortly.