U.S. CitiesCity-Data Forum Index
Go Back   City-Data Forum > General Forums > Science and Technology > Space
 [Register]
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
View detailed profile (Advanced) or search
site with Google Custom Search

Search Forums  (Advanced)
Reply Start New Thread
 
Old 07-10-2012, 07:43 AM
 
Location: Riachella, Victoria, Australia
359 posts, read 563,761 times
Reputation: 378

Advertisements

An apple aint going to pull the earth.
Reply With Quote Quick reply to this message

 
Old 07-10-2012, 11:48 AM
 
Location: Wasilla, Alaska
17,825 posts, read 20,504,794 times
Reputation: 6500
Quote:
Originally Posted by manygeese View Post
An apple aint going to pull the earth.
Everything with mass has gravity. That includes the apple. However, the mass of the apple when compared to the proximity and mass of the Earth is insignificant. The gravity of the Earth will pull the apple towards it, while the apple will pull the earth by an insignificant amount.

Everything depends on the amount of mass an object has and its proximity to other objects with mass.

If you take that same apple and put it in deep space in close proximity to say a cotton ball, the insignificant gravity of the apple will attract the cotton ball and pull the cotton ball toward the apple.
Reply With Quote Quick reply to this message
 
Old 07-10-2012, 04:10 PM
 
16,308 posts, read 25,270,527 times
Reputation: 8302
Of course it will, but only by the force an apple can exert.
Reply With Quote Quick reply to this message
 
Old 07-10-2012, 04:22 PM
 
7,249 posts, read 5,708,713 times
Reputation: 7963
Quote:
Originally Posted by manygeese View Post
An apple aint going to pull the earth.
Of course it does. It's just a very very very small effect. The acceleration of earth due to the gravitational interaction with the apple is only about 2*10^-25 m/s^2, so roughly 26 orders of magnitude smaller than the apple's acceleration.
Reply With Quote Quick reply to this message
 
Old 07-16-2012, 06:31 AM
 
Location: Riachella, Victoria, Australia
359 posts, read 563,761 times
Reputation: 378
Quote:
Originally Posted by JasonF View Post
Of course it does. It's just a very very very small effect. The acceleration of earth due to the gravitational interaction with the apple is only about 2*10^-25 m/s^2, so roughly 26 orders of magnitude smaller than the apple's acceleration.
So nobody else does.


His law of gravity is two instances of his second law. He has deemed the two instances to be identical. But they aren't.

You undoubtedly have better things to do than understand that. As you were.
Reply With Quote Quick reply to this message
 
Old 07-16-2012, 09:38 AM
 
5,206 posts, read 8,210,851 times
Reputation: 3188
Quote:
Originally Posted by manygeese View Post
So nobody else does.


His law of gravity is two instances of his second law. He has deemed the two instances to be identical. But they aren't.

You undoubtedly have better things to do than understand that. As you were.
Instead of making vague incomplete statements, it would be more helpful to clarify your point and provide some supportive references.

- What are the "two instances" of Newton's second law? You haven't identified them.

- In what way did Newton deem the "two instances' to be identical?

- What are the differences of the "two instances" and how do they make Newton's law of gravity wrong?

- How does this relate to your original statement: "An apple aint going to pull the earth"?
Reply With Quote Quick reply to this message
 
Old 07-16-2012, 12:34 PM
 
7,249 posts, read 5,708,713 times
Reputation: 7963
Quote:
Originally Posted by manygeese View Post
So nobody else does.


His law of gravity is two instances of his second law. He has deemed the two instances to be identical. But they aren't.

You undoubtedly have better things to do than understand that. As you were.
I'm not sure what you're talking about.

You really seem to be taking issue with Newton's third law that says the force of object 1 on object 2 has the same magnitude as the force of object 2 on object 1, but in the opposite direction.
Reply With Quote Quick reply to this message
 
Old 07-17-2012, 07:26 AM
 
Location: Riachella, Victoria, Australia
359 posts, read 563,761 times
Reputation: 378
Quote:
Originally Posted by JasonF View Post
I'm not sure what you're talking about.

You really seem to be taking issue with Newton's third law that says the force of object 1 on object 2 has the same magnitude as the force of object 2 on object 1, but in the opposite direction.
Not taking issue with Newton's third law per se. Taking issue with Newton ascribing his third law to attractions.

Gravity strength is directly proportional to quantity. The earth has more quantity than an apple. There fore it is not possible that the earth and apple attract each other equally.

The two instances of his second law.

Newton identified that the rate of acceleration towards the earth was proportional to the mass of the earth. And that at distance d from the earth the rate of acceleration was M/d/d where M is the mass of the earth.

This meant that the weight of the moon due to the earth's gravity was m(M/d/d) where m is the mass of the moon.

That's the first instance of his second law or his law of gravity if you like.

The second instance is where he assessed that the acceleration towards the moon would be proportional to m/d/d where m is the mass of the moon and d is distance from the centre of the moon.

From there the Newtonian weight of the earth due to the moon gravity would be M(m/d/d) where M is the mass of the earth.

That's the two instances of his second law and where he believed he had found a law of universal gravitation as the numerical value of each instance of his second law were identical.

Mathematically they are the same for sure. Physically they are not. In one instance M represent acceleration (a vector quality) and the other mass (a scalar quality). The same with m.

It's a flawed logic for more reasons than this.

You are entitled to believe in it just as you are entitled to believe in santa, etc.

Last edited by manygeese; 07-17-2012 at 07:37 AM..
Reply With Quote Quick reply to this message
 
Old 07-17-2012, 07:05 PM
 
7,249 posts, read 5,708,713 times
Reputation: 7963
I've tried to make sense of this and come up with a thoughtful reply, but it just doesn't make any sense.

M/d^2 is not a "rate of acceleration." M is not a "vector quality" (whatever that is). Your understanding appears to be profoundly flawed.

Do you also reject Coulomb's law?

And you are absolutely taking issue with Newton's 3rd Law. Either you accept it (because the overwhelming evidence obtained over several centuries supports it), or you don't. You clearly do not.
Reply With Quote Quick reply to this message
 
Old 07-18-2012, 06:08 AM
 
Location: Riachella, Victoria, Australia
359 posts, read 563,761 times
Reputation: 378
Quote:
Originally Posted by JasonF View Post
I've tried to make sense of this and come up with a thoughtful reply, but it just doesn't make any sense.

M/d^2 is not a "rate of acceleration." M is not a "vector quality" (whatever that is). Your understanding appears to be profoundly flawed.

Do you also reject Coulomb's law?

And you are absolutely taking issue with Newton's 3rd Law. Either you accept it (because the overwhelming evidence obtained over several centuries supports it), or you don't. You clearly do not.
You haven't followed but don't worry. 1/d/d is a rate of acceleration. This rate increases and decreases as M increases and decreases. Thus M/d/d is a measure of a rate of acceleration.

I don't think you quite know how Newton put his law together. If you do, go for it. Explain what you know about how he formulated the thing.

I accept Newton's third law. But don't accept the moon 'pulls' the earth as much as the earth 'pulls' the moon as it must if Newton's law of gravity, per chance was valid.

I know Newton's law of gravity is in invalid. This was just an inquiry as to whether anybody else did. Perhaps the opening post was a little to confronting. Apologies for that.

Every particle pulls every other particle with a force equal to the product of their masses etc. If true this means every particle has the same gravity. Newton's law of gravity is clearly ill founded. Not much else to it.

Last edited by manygeese; 07-18-2012 at 07:26 AM..
Reply With Quote Quick reply to this message
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.

Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.


Reply
Please update this thread with any new information or opinions. This open thread is still read by thousands of people, so we encourage all additional points of view.

Quick Reply
Message:

Over $104,000 in prizes was already given out to active posters on our forum and additional giveaways are planned!

Go Back   City-Data Forum > General Forums > Science and Technology > Space
Similar Threads
Follow City-Data.com founder on our Forum or

All times are GMT -6. The time now is 10:48 AM.

© 2005-2019, Advameg, Inc. · Please obey Forum Rules · Terms of Use and Privacy Policy · Bug Bounty

City-Data.com - Archive 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 - Top