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Old 11-09-2014, 08:48 PM   #61 (permalink)
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Thanks LeTheVerte, I missed that. I don't always carefully read freshstarts posts.

Here is the first sentence in a Wikipedia article called "Newton's law of universal gravitation". (It was the easiest thing to point to).

"Newton's law of universal gravitation states that any two bodies in the universe attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them."

Gravity is not something that comes into existence when an object reaches a certain size. If it does, I would like to see the reference for that.
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Old 11-09-2014, 09:01 PM   #62 (permalink)
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Notation is simple, and the concepts are nothing more than application of two things, F=Gm1m2/r^2, and F=ma. Newton's equations. A is the acceleration due to gravity. G is a constant, a scalar, a number, equal to 6.67 x 10-11 Nm2/kg2. Gravity is a vector field having magnitude and direction; its magnitude is F is the force due to gravity, and direction is along the line joining the two masses. I was clear on the use of f for force, and G for this constant. No confusion in my stuff at all.

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Hence (all things being equal) a bowling ball will move more quickly towards another object (regardless of that other objects size) than a feather, because of it's greater mass and resulting greater inertia.
You seem to have mixed inertia in your understanding of gravity, force, acceleration, and so on. Inertia is a law of motion, not a quantity. This is also Newton, and you can learn about it by looking at his First Law of Motion. He has a couple more of these laws. Saying that something moves faster because of greater inertia doesn't seem to scan for me.

I'm still curious about your assertion that objects fall at the same rate is an approximation. How so? Why do you think that? And an approximation to what? What is the real answer?

Again, wikipedia is correct of course. What seems to be missing here is an understanding of what is said there. You used words to say exactly what I did in the first sentence of this post. Maybe careful reading would be a help.
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Old 11-09-2014, 09:02 PM   #63 (permalink)
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It's Heavy, Man...

An accessible discussion on this...

'For many of you out there, this little factoid might not be surprise — as unusual science facts go, this one is pretty well-known in popular culture by now. It turns out that as long as air resistance isn’t a major problem, EEVERYthing on planet Earth not already on the floor will fall at the same speed, if dropped from the same height. Things that are really really light, such as feathers, pieces of paper, my scientific credentials — these things get hung up in the air and DO fall slower than heavier things. But anything big enough that air resistance doesn’t matter (basically anything bigger than a golf ball) will fall exactly at the same rate.'

I'm gonna go have some Ice Cream now...

'Why Heavier Things Don't Fall Faster' ~ Timeblimp.com

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Old 11-09-2014, 09:08 PM   #64 (permalink)
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Originally Posted by MesaMan View Post
I'm gonna go have some Ice Cream now...
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Tutti Frutti?
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Old 11-09-2014, 09:16 PM   #65 (permalink)
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Originally Posted by freshstart57 View Post
Tutti Frutti?
Not that there's anything wrong with that.
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Old 11-09-2014, 09:27 PM   #66 (permalink)
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Choc. Although I do like Little Richard...
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Old 11-09-2014, 09:34 PM   #67 (permalink)
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As interesting as this thread may be for some of our members, it's not really recovery related.

The Newcomers forum is about newcomers, and recovery.

As we do with all such threads, after a while we move them to the Cafe - carry on

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Old 11-09-2014, 10:58 PM   #68 (permalink)
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I'll make one more attempt freshstart. I am referring to gravitational field (little g) NOT to gravitational constant (big G). I'll use a visual to make my point.

Here is the video of the hammer and feather dropped on the moon. Hammer vs Feather - Physics on the Moon - YouTube

Notice the RATE at which both fall. Now look at the RATE that which both fall in the OP's video clip. Slower on the moon right? Whys that? BECAUSE THERE IS LESS GRAVITY THERE. And WHY is there less gravity? BECAUSE THE MOON HAS LESS MASS than the earth. This is the effect of gravitational field! Little g. This is what I'm talking about, little g, NOT big G.

The gravitational force between two objects is directly proportional to the product of their masses, and the greater the force the greater the acceleration.

Here is your thought experiment. You take two different spaceships and go to two equally remote parts of the universe. That is, places equally remote from all gravitational influences. You have two bowling balls in one spot and two feathers in the other. You place the two bowling balls exactly 1 inch from each other and stabilize both, so they are perfectly still. You do exactly the same thing with the two feathers in the other equally remote part of the universe and at exactly the same time. Which pair of objects will bump into its twin first? The two bowling balls or the two feathers? (here's a hint, think little g).

AGAIN, from the initial example, the difference in time between bowling ball and a feather hitting the earth in a vacuum (or in the moons vacuum) is EXTREMLY tiny, but if you understand the principle involved you understand that the bowling ball wins the race, even if its only by the width of an atom, simply because it has more mass.

I can't make it any simpler, and with that I give up (unless you can cite the reference for that magic number that mass needs to attain before it begins to produce gravity. I would be very interested in knowing that. ).
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Old 11-09-2014, 11:43 PM   #69 (permalink)
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I found this little video which uses an interesting method explain gravity in terms of Einstein's theory of relativity. Gravity Visualized - YouTube
It's kind of a fun demonstration.
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God does not care about our mathematical difficulties. He integrates empirically.
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