200 years ago, Henry Cavendish weight the mass of Earth in his exp.
This exp is very simple, there were only 4 lead balls and a torsion balance in it. Can we trust this exp.
jin guangnian

200 years ago, Henry Cavendish weight the mass of Earth in his exp.
This exp is very simple, there were only 4 lead balls and a torsion balance in it. Can we trust this exp.
jin guangnian
The universal gravitational constant is difficult to measure. It has been measured a number of times since Cavendish did it.
http://www.npl.washington.edu/eotwas...bigG/bigG.html
it's almost mission impossible to weigh the mass of Himalayas. Can we really weigh the mass of Earth through such a simple exp.
It is not a question of how and whether we can measure that constant. We can. The question is, to what accuracy it is possible. The objection of claiming that we can't weigh individual mountains either is odd and certainly not an argument against measuring G for the entire Earth. You also can't easily weigh your own foot without cutting it off, but you can weigh your body as a whole.
but don't you think it's to easy?
with the concept of gravitational constant G and a simple exp, we magicly got the mass of earth.
There is no magic involved. You only have to measure the force of attraction between two bodies. If you know the mass of one, you instantly have the mass of the other.Originally Posted by tomjin2000
What is exactly the problem that you are having with it?
truth is shocking, but we have to face it.
Indeed, but how about you try answering the question asked of you... What exactly is the problem you are having? You seem to be claiming a crippling problem where none exists.Originally Posted by tomjin2000
As long as you also know the distance between the two objects.Originally Posted by Dishmaster
Cmmon, again? You already posted this discussion, and you were already proven wrong, why go for another round?Originally Posted by tomjin2000
300 years ago. we got a method to calculate gravitation beteween objects. but we still don't know where gravitation come from. is it possible?
looking into the law of universal gravitation and mass of earth, believe me, they are very vulnerable. you will found shocking truth behind them.
Answer the questions or leave us alone!
why we can't weigh the mass of Earth through 4 lead balls, you have to figure it out by youself.
just follow your instinct.
Wrong. In physics, we follow reason. I suggest, you do that, too. Instinct is and always has been one of the worst judges, when it comes to explaining Nature. Read up the experiments and learn.Originally Posted by tomjin2000
obviously you are the one who believe in mathematics, but I believe in logic.
without logic, mathematics is nothing. Cavendish's exp is too simple, there is no way to weigh the mass of earth through 4 lead balls.
the distance between balls in this exp is too close. For one ball in this exp, the gravitation from Earth is probably 10 billion times bigger than the gravitation between balls. The gravitation between balls will be affected by Earth. If you study this exp and the law of universal gravitation carefully, you will found out human being never use the mass of earth and the law of universal gravitation once when we calculate the orbit of objects in the space.
we thought we use them ,but actually we are using the Kepler's third law all the time. We just don't know it.
jin guangnian
If we don't use it. then why do you think it is so important to measure correctly?Originally Posted by tomjin2000
good question.Originally Posted by Harold14370
we thought we use the mass of earth every time when we calculate the orbit of manmade satellite, actually we don't use it. we are using kepler's third law.
because of this misunderstanding ,we trust mass of earth very much.
the mass of earth (mass of sun、mass of moon and so on) are the most important constants in earth science and astronomy.
if mass of earth is wrong, earth science and astronomy will collapse.
Answer it, then.Originally Posted by tomjin2000
No, they won't.if mass of earth is wrong, earth science and astronomy will collapse.
unfortunately, it's not up to you.
F=GMm/R^2, there are 2 masses in this formula. Without knowing the masses, the law of universal gravitation is nothing.
The mass of Earth is the real king. but it's wrong. pls stop trusting 4 lead balls.
The "lead ball" experiment is used to derive the constant G. This is possible, because the contribution from the Earth's gravity is the same for both and it has a direction that is perpendicular from the attraction between the balls. So, it cancels out. You can derive the mass of the Earth from the revolution of objects around it. Geostationary orbit satellites would not be stationary, if the value of the Earth's mass would be wrong. You can also use the revolution period of the Moon and its distance from the Earth to determine the mass of the Earth. Try it and you will be shocked how simple it is.Originally Posted by tomjin2000
http://en.wikipedia.org/wiki/Kepler%...tion#Third_law
there is no way to weigh the mass of Earth through 4 lead balls. probalby, if you stand on the moutain, you will understand me.Originally Posted by Dishmaster
k=t^2/R^3 (kepler's third law)
a=v^2/R
f=ma
these 3 fomulas can do everything. nobody need the law of gravitation. (f=GMm/R^2 )
no one can answer where gravitation comes from, but we have already got a formula to calculate it. is't ridiculous.
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there is a secret. GM is a constant. through 4 lead balls, we got G. through G, we got M (the mass of earth).
G and M are all wrong, but it doesn't matter, GM is a constant. when we calculate the orbit of satellite, we always put G and M together. so we couldn't find out what's wrong.
but when we use G and M in astronomy and Earth science, it causes trouble.
What trouble is that? And what do you think we should be doing about it?Originally Posted by tomjin2000
That is a lot (quite a number) of balls!Originally Posted by tomjin2000
we have to accept the truth we still don't know the mass of Earth. we still don't know the gravitational force between Sun and Earth.Originally Posted by Harold14370
if the mass of Earth (Sun, moon and so on) is wrong, the law of universal gravitation will become invalid (there are 2 masses in its formula). you will find out we misunderstand whole universe.
the truth is very very shocking.
please don't trust 4 lead balls exp.
I trust it much more than some hand waving of a crack pot. Explain why you think, it does not work beyond your incapability of conceiving it. What is precisely wrong? Why exactly does it not work? Up to know you only have written that it is.Originally Posted by tomjin2000
Why do you think so? What is wrong with it? Don't say, it is too simple. This is not an argument. What exactly is wrong? Tell us or leave us alone.Originally Posted by tomjin2000
I can't help you if you don't look into Cavendish's exp by yourself.Originally Posted by Dishmaster
f=ma
a=v^2/r
k=T^2/r^3
v=2πr/T
they can do anything this foumula (f=GMm/r^2) do.
if somebody take out 4 lead balls and tell you he can weigh the Earth with them. don't believe him, that's it.
current mass of Earth is just an assumption. We built other theories on it. Earth science couldn't make progress without it.
but we have to know it's just a assumption.
Okay, this is my last attempt ... You take the lead balls (or any other material) of which you weigh their mass. The mass unit is a definition, so you can weigh their mass very accurately. At least, you can determine their mass ratio, where G (the parameter you actually want to derive) does not play a role anymore. Then you try to assess the gravitational force they are producing by using a gauge (as done in the Cavendish experiment) and measure the distance between them. In this way, the only unknown parameter is the gravitational constant G.
Simple! Of course, this involves measurement inaccuracies, but you can do it! And as I said, the gravitational force that is produced by the Earth during this experiment is irrelevant, because it pulls in another direction than the balls in the experiment.
After this, you can use any other experiment that involves two bodies with masses, of which one is the Earth.
So, you see, I understand it perfectly. Now you! Answers!
the gravitation between 2 objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them (the law of universal gravitation)
I found out, without changing distance, the gravitation between 2 objects changes all the time. this gravitation can be affected by surrounding.
we still don't know where gravity come from, can we really got a equation to calculate it.
in fact, there is no gravitational constant G.
Yes, we can.Originally Posted by tomjin2000
Show me. I (well, actually others before me like Newton) showed you that there is.Originally Posted by tomjin2000
no, you can't. if you don't know where gravity come from, you can't get a correct equation to calculate it. It’s logic.Yes, we can.
M=gR^2/G, this is how we calculate the mass of Earth. We got constant G from a 4 lead balls exp. obviously, it's impossible. but it's very hard to find out what the problem is.
the gravitation between 2 objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them (the law of universal gravitation) .
if we keep the distance between two balls 1 meter, we put them anywhere in universe, the gravitation between them doesn't change. (the Newton's law)
but in my theory (active resonance), We still keep distance 1 meter, the gravitation between two balls changes all the time, when we put them on the moon, near mountain, in the water, the gravitation will change.
if you believe the law of universal gravitation, you are in the Matrix. you have to get out of it first, then you can understand what's going on.
you will be shocked by unbelievable truth. true universe, true Earth structure, crop circles, galactic long bar, anti gravity technology and so on . very shocking ,but very exiting.
No, it isn't. Johannes Kepler was able to describe and predict the motion of planets correctly, although he did not know anything about the forces involved here.Originally Posted by tomjin2000
What is g? I explained, why G can be derived from the experiment.Originally Posted by tomjin2000
Which is not observed, thus your hypothesis is wrong.Originally Posted by tomjin2000
I don't believe, I know in a scientific sense. It is a theory well tested by experiment. So, I accept it. Whereas your ideas are lacking any evidence or theoretical background.Originally Posted by tomjin2000
please don't trust exp too much, exp can be explained in different ways.
in my theory, there is a huge energy line ( Graviton line ) between Sun and the center of Galaxy. because of it, Sun revolves around the galactic core.
Earth is going to cross it recently. what will happen?
we should pay attention to it.
I trust these experiments certainly more than your unsubstantiated ideas. What is the evidence for a "graviton line" that distinguishes it from any other idea or the commonly accepted theory? What is a "graviton line"? The only thing that keeps the Sun on its galactic orbit is the gravitational force  but not primarily the one caused by the galactic centre, but the one produced by all matter that is inside the solar orbit. There is much more mass and matter between the galactic centre and the sun than in the galactic centre itself. There is nothing that the Sun or Earth will cross or has crossed. The alleged alignment of the Sun with the GC has been debunked many times in this forum. There is no such thing happening. You can verify this with every planetarium software like Stellarium.Originally Posted by tomjin2000
In Quantum Physics, scientists predict the existance of Graviton. they think if two objects attract each other, these objects should change Graviton. Although my theory is different from theirs, but I still feel they are great. at least they don't believe curved space.
about 300 years ago, there was a theory which was accepted almost by everyone, except for Mr Newton. The most famous representatives of this theory is Rene Descartes, Christian Huygens, Gottfried Wilhelm Leibniz. In this thoery, a kind of Ether wave is the reason of gravity. My theory is very similar to this one.
our theories has one thing in common. if two objects attract each other, there is some kind of energy between them. I call is "Graviton line". (it's active resonance ether wave in my theory).
I have found more than 20 proofs which show "Graviton line" really exist. our Earth deeply affected by Graviton lines between Sun and GC, Sun and Jupiter, Sun and Saturn.
You have to abandon the 4leadball exp, it's the way to understand me.
You have to believe logic. Jupiter revolves around Sun for a reason. there is something between them. which can cause trouble to us.
global warming, extreme weather, earthquake, flood, every thing can be logically explained in my theory.
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