GRAVITY, and human interpretation.

[FastTrack]

What puzzles me, is why is it that people in the past assumed that a heavy object would fall at a faster rate that a light object ????

 

I could have say five small metal balls, each weighing one pound, and one ball that weighs 5 pounds.

 

If I drop them all at the same time, they will all hit the ground at the same time.

 

If I squeezed all of the five balls into a black box, and placed the 5 pound ball into another black box, then we would have 2 black boxes that each weigh 5 pounds plus the weight of the box. If I then dropped both of these black boxes, once again, both will hit the ground at the same time. Makes sense !

 

If I melt these 5 balls down and make one 5 pound ball out of them, once again if I drop this 5 pound ball it will still hit the ground after that very same specific time period that it took previously when that ball was still in its previous form of being 5 separate balls.

 

And so that question arises " Why is it that people in the past assumed that a heavy object would fall at a faster rate that a light object ???? "

[timo]

Because the do? Drop a piece of paper from a height of 2 m and stop the time. Then do the same with your laptop . Pieces of papers and laptops falling down is much more common than metal balls that are later melted into a single ball.

[swansont]

Way back when, things were reasoned out, rather than empirically tested. People had certain notions, they made sense at the time (possibly they were true for a few cases), and were accepted as being true. Nobody bothered to test to see if the "truths" actually applied universally.

[Naturalist]

I think it also has something to do with people back then giving Aristotle so much authority. 500 years ago, you would be considered a fool by your friends if your words contradicted that of the Aristotle. I think some of Aristotle's views were similar to that of the Bible, which many people still today place at the peak of all authority, the Bible is considered the ultimate truth, and to question assertions from it means to lack intelligence. Thanks to many scientists and also some religious people who defended the fruitfulness of real science, away from authoritarianism, things are much different.

 

Galileo Galilee discovered more than just the fact of friction, but he discovered the importance of experiment, and I think this is one reason he is considered a father to modern science.

[Reaper]

Way back when, things were reasoned out....

 

 

That's debatable and depends on the era of time. I remember that way back when, they were debating over how many angels could fit on the head of a pin.

[Naturalist]

I guess your going to have to forgive the ignorance I may have, but in " ... it depends on the era of time." I don't understand what you mean by "era of time". What do you mean by "era of Time"?

[Reaper]

I guess your going to have to forgive the ignorance I may have, but in " ... it depends on the era of time." I don't understand what you mean by "era of time". What do you mean by "era of Time"?

 

 

Sorry, should have been more clear. I meant an era/place in time in human history.

[foodchain]

What puzzles me, is why is it that people in the past assumed that a heavy object would fall at a faster rate that a light object ????

 

I could have say five small metal balls, each weighing one pound, and one ball that weighs 5 pounds.

 

If I drop them all at the same time, they will all hit the ground at the same time.

 

If I squeezed all of the five balls into a black box, and placed the 5 pound ball into another black box, then we would have 2 black boxes that each weigh 5 pounds plus the weight of the box. If I then dropped both of these black boxes, once again, both will hit the ground at the same time. Makes sense !

 

If I melt these 5 balls down and make one 5 pound ball out of them, once again if I drop this 5 pound ball it will still hit the ground after that very same specific time period that it took previously when that ball was still in its previous form of being 5 separate balls.

 

And so that question arises " Why is it that people in the past assumed that a heavy object would fall at a faster rate that a light object ???? "

 

 

Probably because there existed no system for the regular attempt to obtain anything empirical about the world around them, not to mention if even such words existed or what form such notions such as empirical even came in regards to human thought. Today it seems a much simpler notion, but even while science was starting to come alive its not as if people new about atoms, or germs, or air basically in regards to what it does. Today we have for instance force diagrams, dictionaries, technical manuals, high speed super computers, space travel, greatly extended lifetimes is probably another one. I mean if we could not beat back in any way illness or disease, find a regular way to cultivate food, what that would mean for humanity.

 

So basically why I think people probably thought a heavier object would fall on earth faster then a lighter one, probably because a feather typically wont fall from the sky to the ground as fast as say a rock giving the concept of the atmosphere even, it might have been living on seeing is believing without understanding exactly what was being observed. I mean it does work physically, if I jump from a plane and deploy a parachute I will not reach the ground at that same time as the rock will that was thrown from the plane.

[Naturalist]

That's debatable and depends on the era of time. I remember that way back when, they were debating over how many angels could fit on the head of a pin.

 

Are you serious? Who really asked that question, and what made them think angels were so small? I'm reading this book "Microbe Hunters" that describes the history of microbes, from Leeuwenhoek to Pasteur. It's amazing how everyone blamed diseases on evil spirits until the full discovery microbes and their relationship with humans. I don't know of this part is true, but the author speaks of a group of scientists known as the Invisible Society and how they tested out an experiment that involved "unicorn dust" and a spider. Back then, they believed that placing a spider in a circle of "unicorn dust" (whatever that was, but they made sure they had the substance everyone was talking about) would make paralyze the spider within the circle. You can guess what happened. Of course, it didn't work. (well, even if it would have worked, or would have trapped the spider, there would probably be a physical explanation to it.)

 

Anyway, Leeuwenhoek legacy was born and this so called Invisible Society was born just a while after Galileo Galilee's discoveries.

[Reaper]

Are you serious? Who really asked that question, and what made them think angels were so small?

 

It's not really attributed to any one person, but it was a topic that was literally fiercely debated among priests, scholars, and other intellectuals of the Catholic Church during the middle ages. St. Thomas Aquinas was one of them. It was more of a question about the nature of spirituality, as far as I understand it. Regardless, it was pretty irrational and not really reasonable. The subject was eventually dropped simply because there was no way they could apply reason or logic to the argument. Basically, there was no way to prove anything and it was based on individual opinion.

 

 

I don't know of this part is true, but the author speaks of a group of scientists known as the Invisible Society and how they tested out an experiment that involved "unicorn dust" and a spider. Back then, they believed that placing a spider in a circle of "unicorn dust" (whatever that was, but they made sure they had the substance everyone was talking about) would make paralyze the spider within the circle. You can guess what happened. Of course, it didn't work. (well, even if it would have worked, or would have trapped the spider, there would probably be a physical explanation to it.)

 

Unicorn dust? This I gotta see.

[FastTrack]

Thanks for some interesting responses, folks.

 

I waited a bit before I too responded.

 

History says that once I do respond, my responses tend to vanish over night, and so please read this response quickly before ....

[BenTheMan]

Way back when, things were reasoned out, rather than empirically tested. People had certain notions, they made sense at the time (possibly they were true for a few cases), and were accepted as being true.

 

This is an important point. One would hope that humanity has progressed since the scientific revolution, but...

 

http://www.scienceforums.net/forum/showthread.php?t=28145

http://www.scienceforums.net/forum/showthread.php?t=28150

http://www.scienceforums.net/forum/showthread.php?t=28230

http://www.scienceforums.net/forum/showthread.php?t=28231

 

There are other examples of this that one can see everyday. Everytime you see someone online selling a book that uses ``the power of positive thought'', magic crystals, intelligent design and tinfoil hats, it is a bonafide affront to science.

[John Cuthber]

Just a quick point. Galileo knew he didn't need to do the experiment because he could work out what the outcome would be.

He imagined 2 items tied together and dropped. First of all, lets assume Aristotle was right. The light object falls and the heavy one overtakes it pulling on the string. The heavy object falls but is slowed down because the light one is holding it back.

Overall the combined object of the 2 balls and the string is clearly heavier than any of its components and it has to fall faster than any of them would do on its own.

So the big ball is falling slower than it would (on its own) because the small one is holding it back, but faster than it would fall because it's now part of the combined object. That's a contradiction so the assumption (ie Aristotle's view) must have been wrong.

Galileo only did the experiment to demonstrate this to people who couldn't understand the argument.

[BenTheMan]

No thought experiment can ever replace a real experiment. The real experiment HAD to be preforemed, otherwise Galileo was just waving his hands as Aristotle did.

 

See the above post for links to copious handwaving.

[abskebabs]

See the above post for links to copious handwaving.

Think I'll pass. I don't really want to "take sides" in this seeming tribal warfare going on, but I can't seem to finish reading those threads even when I try really hard.

[Sisyphus]

No thought experiment can ever replace a real experiment. The real experiment HAD to be preforemed, otherwise Galileo was just waving his hands as Aristotle did.

 

See the above post for links to copious handwaving.

 

Although Galileo did perform a lot of experiments, he wasn't strictly an empiricist. The methods of "science" as we know it really began with Francis Bacon and Rene Descartes, and slowly evolved and gained respect over the following centuries. Galileo performed experiments to prove his points to skeptics (it was the Aristotleans who demanded he prove his wild claims with demonstrations, actually), and he did change his views as the result of such experiments, but experiment was not a rule he followed. He had more trust in logic and mathematics than empirical results.

 

Also, enough of the Aristotle bashing. His theories were based on observation, just not necessarily controlled experiment (a la Francis Bacon) and mathematization and quantification (a la Galileo). The problem was not with Aristotle, but with those who dogmatized his ideas.

[BenTheMan]

I'm not bashing Aristotle at all... I am bashing the people who think it is still ok to walk around in robes and sandals, wearing laurels in their hair, and waxing poetic about the ``deeper truth'' of quantum theory, and ``explanations'' of Nature, as opposed to ``descriptions''.

 

And to be clear, I wear sandals as often as I can, and laurels when I'm in the mood

[rbouchard47]

"If I drop them all at the same time, they will all hit the ground at the same time."

Five, separate, 1lb balls will not drop faster than one 5lb ball

Will they?

[iNow]

My understanding is that, if you control for friction, they all land at the same time.

 

 

The reason that a piece of paper falls more slowly than something like a ball is because of the effect of the air it has to "push out of it's way" on the way down. ... I think.

[alan2here]

So the polystyrene ball hits the ground the same time as the lead one of the same size?

 

I thought it was that the big lead ball and the small lead ball hit the ground at the same time?

[Spyman]

Without air friction they will all hit the ground at the same time.

 

Movie of a drop on the Moon: http://en.wikipedia.org/wiki/Image:Apollo_15_feather_and_hammer_drop.ogg

 

Apollo 15 Commander Dave Scott demonstrates that the mass of an object does not affect the time it takes to fall, using a hammer and a feather on the Moon.

[MrMongoose]

Generally lighter materials are weaker so have more damage on their surface, greater roughness and more air resistance (or maybe theyre made into more intircate structures to give strength,- lets say made into a feather by god- which also tends to mean more air resistance.

 

The weight seems fairly intuitive though.. hold a light object in one hand and a heavy object in the other and the heavier one shows greater intention to go towards the ground. you don't even need to drop it to realise that means it'll drop faster.

 

Please don't tell me I'm wrong.. I was just typing through the fingers of an ancient.

 

What on earth is this big box of light in front of me?!?!?!

[insane_alien]

but remove the air resistance and they drop at the same rate. reality is under no such restraints as 'intuitiveness'.

[Mr Skeptic]

but remove the air resistance and they drop at the same rate. reality is under no such restraints as 'intuitiveness'.

 

I prefer "Intuitiveness has no restraints such as reality." If nature doesn't make sense to us, does that mean that our intuition is wrong, or that nature is unintuitive? My thought is that if something doesn't make sense, then you probably don't understand it well enough.

[MrMongoose]

but remove the air resistance and they drop at the same rate. reality is under no such restraints as 'intuitiveness'.

 

Well, yes its easy to counter the answer to a question with an answer to a different question that wasn't asked. The fact is that ancient humans generally exist within the Earth's atmosphere.

 

I'm sure if you asked them "So, what would happen if I dropped two things on the Moon" they'd be more likely to say "Drop things on the Moon? Theres nothing higher than the Moon.. Its just a picture God painted on the sky" rather than "I'd guess that the Moon is a sphere orbitting the earth with a negligible atmopshere, and that things would be no different were I to stand there"

 

I did afterall give the disclaimer that I was answering the question knowing what a 1st century skullery maid knows rather than newtonian physics. Its pretty easy to know the answer with the hindsight of giants' shoulders.