## Gravitational Mass

Things that don't belong anywhere else. (Check first).

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Shoofle
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### Gravitational Mass

How would it work that an object would have a high inertial mass but low gravitational? I can't imagine it. Or the other way around. But it can be imagined? Interesting. How does that work?

"Yo mama's so lupine, she barks, moans, whines, woofs, yelps, whimpers, growls, and snarls, but what really excites naturalists and laypersons alike is her howl."

I wish I could find A Portrait of Yo Mama as a Young Man. It's definitely one of the funniest books I've read. I think I know where it is, too...[/i]

davean
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Well, I guess that our feeling for that illusion could come from something like drag.

Shoofle
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In that case the resistance to movement is not the inertial resistance of the dragee but the resistance of, for example, the air particles being pushed ahead of it, and the resistance to compression of those air particles. There's no drag in space! Everything works better in space!!

xkcd
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I don't see what the problem is -- just imagine something that acts like it has no gravity (easy -- we don't notice the gravity FROM most things) and doesn't react to gravity (weightless). So a chair that just floats around the room, but still takes force to push on. Like how things are in space.

Matt
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What's the background here; is there something reported to have these properties in a situation where most things don't float around?
Hi. I'm from Massachusetts.

davean
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Matt wrote:What's the background here; is there something reported to have these properties in a situation where most things don't float around?

Last edited by davean on Tue Apr 18, 2006 4:02 am UTC, edited 1 time in total.

Matt
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davean wrote:Not you mama, she fat.

Your mama is so fat she broke her leg and hot bloody fat came out. Some of it even got on the mayor!
Hi. I'm from Massachusetts.

Ikarus
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I guess it should read "her attraction goes up as the cube of the inverse distance", because that's how the gravitational potential looks like in our world.

Hawknc
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Wow, blast from the past.

i
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hmmm.... this seems to be an old thread...

*scrubbing bubbles*. I'm gonna respond anyway.

You could look at the issue from a mathematical point of view. Take the equation for the force of gravity and the equation for accelleration. Then increase or decrease the gravitational coefficient.

This change will effect the equation for gravity without effecting the equation for accelleration.

ps. I suppose if you ever found a way to derive one equation from the other, you would become a very famous person.

40010Mike
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### Re: Gravitational Mass

But, as an Asimov-addict, I wanted to steer those who enjoyed reading this comic (as much as I did) towards some slick sci-fi that took on a similar issue.

Take the ponderance made by the hat and change it to read "One could imagine an extremely large object with [zero] resistance to force and no gravity...but this is never observed."

The short story is titled "Super-Neutron" and can be found in the short story collection The Early Asimov, or Eleven Years of Trying.

22/7
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### Re: Gravitational Mass

Hawknc wrote:Wow, blast from the past.
Totally not a hypothetical...

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tendays
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### Re: Gravitational Mass

There's nothing wrong in necroing an underexploited but potentially cool thread, is there?

You get a similar effect if you look at an object in a medium with high density (but low viscosity, so doesn't create too much friction).
It will both get less attracted by other objects, and will attract other objects less (Archimedes). However its resistance to motion will stay the same. If the density of that object is lower than the mediums, you get an object seems to have a negative gravitational mass but positive inertial mass (think bubbles).

Now let the people who actually know something about physics yell at the nonsense I just spouted (IOW, IANAP)
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