Proof of the apple 'pulling' the earth?

[James R]

plane:

Cavendish did the sensible thing and kept the larger masses stationary and the smaller masses accelerating in his experiments? Why? Because the larger masses will accelerate more slowly for the same force (a=F/m), and the accelerations involved are very small.

Amusing. So this proves the larger mass accelerates towards the smaller mass.

No. This is the answer to your question as to why Cavendish allowed the small masses to move and not the large ones. You asked, so I provided the answer.

No. Newton's law of gravity is an independent law of nature. It cannot be derived from Newton's second law of motion. On the other hand, the reasoning process that led to Newton's law of gravity used the second law as a sensible rationale. And the law of gravity is compatible with the second law of motion, as it must be.

How was it derived then? You either know or you don't. Willing to put plenty of good money on you not having a clue on how Newton derived F = k.M.m/d x d

Sure bet.

I explained Newton's reasoning earlier in the thread for you.

Have you already forgotten?

You know, this discussion will require some effort from you. I can't do your thinking for you, you know. All I can do is to answer your questions and hope you apply your brain at some point.

Try to keep up.

Almost feel sorry for you, as if I am playing with you.

I think I'm already tiring of your game. If you really have no desire to learn from an expert, then further discussion is probably a waste of my valuable time. I have plenty of students who want to learn from me.

How does mass (the mass of the earth for example) cause an acceleration towards its self is what we are discussing. Newton's second law explains a relationship between an applied force, acceleration and mass. It does not explain how mass causes gravity, whether gravity be a force applied at a distance (you) or an acceleration through space (fundamental approach to gravity).

Correct. Newton's second law provides no "mechanism" for gravity. It is a phenomenological law, later empirically tested and confirmed. Later, it was shown to be an approximation to the more accurate theory of general relativity.

Tell me: what's your explanation of why large masses cause gravity, while smaller ones do not?

Also, please explain the following thought experiment for me:

1. I take two masses. One mass is 1 kg. The other is 0.9 kg. I observe that if I hold the 1 kg mass in place, the 0.9 kg mass is attracted to it. Agree?
2. Now, I take a lump of plasticine and stick it on the 0.9 kg mass, taking the total mass to 1.1 kg. According to you, the 1 kg mass no longer attracts the 0.9+0.2 kg mass. Correct?

What I want to know is: how does the 1 kg mass "know" to stop attracting the 0.9 kg mass?

Presumably you will say that the 1.1 kg mass will suddenly start to attract the 1 kg mass now, as well. How does the 1.1 kg mass "know" to swap over and start attracting when the plasticine is stuck onto it?

It's your choice. A truck can be driven through Newton's law of gravity. If you want to go to your grave believing education equals an apple pulling a planet, your choice. A coffin is a coffin is a coffin but your death when it happens will be the death a dishonest human being.

Are you accusing me of dishonesty? Why? Where have I lied about what I believe?

 

[plane]

You are accused of fooling around with the truth. It is not done lightly as you seem to be intelligent enough to see into your own nonsense.

To wit, the inverse square law provides relative information. Information relative and unique to individual mass. That can be demonstrated with arithmetic. We all know that without posting the sums.

Newton decided it linked up masses without further explanation.



Should point out that in no way have you explained how or why Newton arrived at his law in this thread.

You did not take us to an articulation by Newton as to why or how he came up with his formula.

Lastly, if it universally appears, by experiments and astronomical observations, that all bodies about the earth gravitate towards the earth, and that in proportion to the quantity of matter which they severally contain, that the moon likewise, according to the quantity of its matter, gravitates towards the earth; that, on the other hand, our sea gravitates towards the moon; and all the planets mutually one towards another; and the comets in like manner towards the sun; we must, in consequence of this rule, universally allow that all bodies whatsoever are endowed with a principle of mutual gravitation.

That is what Newton gave us in Principia.

There is no mention in Principia of a deduction of unlike masses exerting a like 'pull' upon each other.

End of thread I think. Appreciate the mentions of binary stars and the like but if no-one can explain how the inverse square law connects up masses, we all know the laws a dud.

“That one body may act upon another at a distance through a vacuum without the mediation of anything else , by and through which their action maybe conveyed from one to another , is to me so great an absurdity that , I believe , no man who has in philosophic matters a competent facility of thinking could ever fall into it.”

By his own admission, Newton was flummoxed by gravity. Dead horses can only be flogged so much.

Tell me: what's your explanation of why large masses cause gravity, while smaller ones do not?

Never said smaller ones do not.

Presumably you will say that the 1.1 kg mass will suddenly start to attract the 1 kg mass now, as well. How does the 1.1 kg mass "know" to swap over and start attracting when the plasticine is stuck onto it?

The 1.1kg mass was a 1kg mass. Think you are befuddling your self.

But through the arithmetic of opposing directions of the inverse square law is your answer.

 

[Vkothii]

Well, this is a bit of a first; someone has overturned Newton's law of gravitation.

But they haven't provided an alternative, and they haven't explained how the equations are wrong.
Or why scientists still use his equations to launch things into space. Strange, you think they might have noticed the big problem by now.

Alternatively, this is just a persistent illusion, a confused and drunken wander down a garden path that doesn't go anywhere useful.
After 10 pages and 182 posts, no-one except the thread opener understands a word of it.

Newton was wrong, we just have to accept it and accept that there aren't any alternatives, or there aren't any on offer, just a lot of rambling.

I wonder if this person can see that they haven't really said anything yet?

From the first post:

can anyone point to empirical evidence of a smaller mass 'pulling' a larger mass. The tides and cavendish experiments don't do it from all the published imformation I've seen.

We see that the problem is, in fact, an inability to understand experimental evidence. Which is complicated by an inability to accept the possibility that one has not grasped certain fundamentals. And a certain level of stubborn pride in one's ability to 'see the truth', and accept no other explanations.

I think it's called being 'pig-headed'.

 

[James R]

plane:

Since you failed to actually address anything I wrote, I won't bother continuing discussion with you.

Bye!

 

[plane]

plane:

Since you failed to actually address anything I wrote, I won't bother continuing discussion with you.

Bye!

That's highly acceptable James R. You are not honest enough to discuss gravity with.

I think it's called being 'pig-headed'.

Not pig headed at all. I have acted in good faith with all posters. Not sure if that can be said the other way. I suppose the other side of that is other posters haven't the wherewithal to handle being wrong.

Anyway, Newton's law of gravity is clearly wrong.

There's a web page that explains it for you. It's very to the point and quite irrefutable. The basic problem is the inverse square law constant is not constant. It's proportional to quantity.



Those who check into this forum seem to be prejudiced in favour of Newton's law of gravity. Do not expect that prejudice to be cast aside anytime soon.

Anyway, been honest with anyone who has posted in this thread.

 

[Vkothii]

Well, I might go and get slowly pissed somewhere.

 

[plane]

Well, I might go and get slowly pissed somewhere.

It's interesting, isn't it. Can understand your reaction. All the best with coming to grips with the constant as the hangover settles down.

 

[fedr808]

wow, First off this is elementary physics. A force of one object hitting another object will be reflected to the other object. That old toy with four balls on strings where when you pull one back and let go the one on the far end shoots up and vice versa.

ALSO there is no Newton's law. It is Newton's theory. There is no such thing as scientific fact. Anything can (main wordis "can" not "will") be disproven.

If you need more info look up the post entitled scientific fact vs. scientific theory.

 

[Steve100]

That old toy with four balls on strings where when you pull one back and let go the one on the far end shoots up and vice versa.

Newton's cradle

ALSO there is no Newton's law. It is Newton's theory. There is no such thing as scientific fact. Anything can (main wordis "can" not "will") be disproven.

Because we don't make the rules, so we can only have a best guess. Unlike in mathematics where we make the rules.

 

[fedr808]

there arent rules in mathmatics they are also theory's. there is pretty much nothing physical out there (and by physical i mean anything that is not from our imagination) that is a fact. As my physics teacher siad "If i cant prove you rdad is your dad, how can i prove quantum physics?" lolz.

 

[Steve100]

there arent rules in mathmatics they are also theory's. there is pretty much nothing physical out there (and by physical i mean anything that is not from our imagination) that is a fact. As my physics teacher siad "If i cant prove you rdad is your dad, how can i prove quantum physics?" lolz.

Yes there are rules in mathematics.

Do you think someone discovered mathematics and then people started testing theories on it until we found the ones that fit best?