Earth Science Stack Exchange is a question and answer site for those interested in the geology, meteorology, oceanography, and environmental sciences. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Suppose we have two stones, the first being lighter than the second. Release the two stones from a height to fall to Earth. Stone 2, being heavier than stone 1, falls more rapidly. If they are joined together, argues Galileo, then the combined object should fall at a speed somewhere between that of the light stone and that of the heavy stone since the light stone by falling more slowly will retard the speed of the heavier. But if we think of the two stones tied together as a single object, then Aristotle says it falls more rapidly than the heavy stone.

The question is how do the stones know if they are one object or two?

share|improve this question

closed as off-topic by casey Aug 1 '14 at 21:24

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "This question does not appear to be about earth science, within the scope defined in the help center." – casey
If this question can be reworded to fit the rules in the help center, please edit the question.

You say that the heavier one falls more rapidly. Wrong! They accelerate at the same speed, thus fall at the same speed. This sing course neglecting air resistance (eg falling feather vs falling rock). – Michael Aug 1 '14 at 13:39
This is a Physics question... – Schism Aug 1 '14 at 18:43
up vote 5 down vote accepted

The two stones will accelerate at the same rate due to gravity. This is usually attributed to Galileo although it was known before that - eg. John Dee was aware of it and didn't think it a new revelation.

So if the two stones have the same shape and size - ie. so aerodynamic effects are identical, they will fall at the same acceleration and speed. There are plenty of experiments to demonstrate this, but perhaps one of the most well known was by one of the Apollo astronauts (the Moon being essentially airless has no aerodynamic effects). The result can also be derived from Newton's Inverse Square Law of Gravity and his Second Law of Motion.

If I were you, I would forget about Aristotle when it comes to trying to understand the world around us. He didn't have any concept of forces, inertia, and momentum as we would understand it today. His concept of forces was provably wrong with knowledge available to him at the time.

share|improve this answer
you convinced me with your answer, thanks. – LifeIsToShortToCompile Aug 1 '14 at 13:44

Not the answer you're looking for? Browse other questions tagged or ask your own question.