# Tagged Questions

140 views

### How was Newton able to guess that gravitational force is inversely proportional to distance squared?

This question is puzzling me since I learnt about the gravitation law in school. Why did Newton guess/assume that gravitational force is inversely proportional to the square of distance? Did he ...
144 views

### Didn't anybody see an apple falling before Isaac Newton? [closed]

We all know that Isaac Newton developed the gravitational theory (as is often told) when an apple fell on his head. But my question is, didn't anyone before him notice it?
96 views

### Newton's original proof of gravitation for non-point-mass objects

Suppose we have two bodies, one very large (Earth), and one very small (a cannon ball). If the cannon ball is some distance away from the Earth, to find out the force produced on the cannot ball, we ...
363 views

### Infinities in Newtons law of gravity (for point particles)

Newtons law of gravity for two particles of mass $m_1$ and $m_2$ is: $G\frac{m_1.m_2}{r^2}$. Supposing that the particles are point particles then gravitional attraction will bring them closer ...
121 views

### Is Galilei's reasoning on free fall valid?

Galileo Galilei discovered by experiments that all bodies tend to fall with the same rapidity (I use it in an intuitive sense, you can replace it by 'acceleration' used in today's physics language), ...
99 views

### Victorian cosmology after the second law of thermodynamics but before relativity?

In the 19th century, most astronomers adopted an island universe model, in which our galaxy was the only object in an infinite space. They didn't know that the "spiral nebulae" were other galaxies. ...
161 views

### History of Newtons law of gravitation

I have some questions about the history of Newtons law of universal gravitation. Did Newton discover his three laws of motion before he discovered the universal law of gravitation? I know two ...
769 views

### Combining Proportions to get Newton's Law of Universal Gravitation

I've read a little on the history of Newton's Law of Gravitation and noticed that the formula can be separated into 3 distinct parts that lead to the end result of $F_g = G \frac{m_1 m_2}{r^2}$; the ...