Is the gravitational equation valid?

[awaterpon]

My first thread about this topic:

F=GmM/r²
This equation is not valid and wrong.
What is wrong with this equation?
Mathematics equations are a away to measure quantities related to other quantities .
Equations works for finite values, I measure r = 4 meters and find out F to be x Newtons
Equations won't work for infinite values , that is equations themselves  works finitely but not infinitely .

Let say F decreases without bound while r increases without bound, then the equation itself as a functional tool will approach infinity and the equation limit as r approaches ∞ is ∞, the equation is undefined and wrong.
If the equation definition is the tool that finds values of F for each value of r, then I can't find all values of F for all values of r , then the equation won't work for all values of F and r and it is useless and invalid.That means the equation itself approaches ∞ in measuring the quantities and undefined

I can say at F=0 , r doesn't exist and equals ∞, so the equation won't work  and undefined in such case and invalid, but some scientists might say F won't reach 0 ever , so I presented the explanation above.

[Bufofrog]

Since infinity is not a number this is no problem.  Any number you put in for R will result in a valid result.  Since infinity is a concept it is not surprising that substituting a concept for a number will result in an invalid result.

Glad we cleared that up!  

[Strange]

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Moderator Note

You were warned.

Closed pending moderator discussion.

 

On 5/6/2019 at 10:53 AM, swansont said:

 

Moderator Note

Do not bring up any other models of gravity. You've demonstrated that you are not willing/able to discuss science with enough rigor to make it worthwhile.

 

 

[Strange]

 

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Moderator Note

@awaterpon The problem you see here is nothing to do with gravity, it is a general problem in many equations. If you want to understand how mathematics (and therefore physics) handles equations that can lead to infinities, then I suggest you read up on the concept of "limits" and how to determine (using calculus) how an equation behaves as values approach infinity.

If you want to start a thread on this (in the Mathematics forum) then do so, but stick to asking questions (and not claiming things are wrong when they obviously are not).

 

[swansont]

2 hours ago, awaterpon said:

I can say at F=0 , r doesn't exist and equals ∞, so the equation won't work  and undefined in such case and invalid, but some scientists might say F won't reach 0 ever , so I presented the explanation above.

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Moderator Note

Dependent and independent variables seems to be another thing to discuss, in addition to limits that Strange has mentioned.