Science > Physics > Particles light years apart really feel each other's gravitational force?
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Science > Physics |
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"" |
| Date: |
30 May 2006 08:23:19 PM |
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Particles light years apart really feel each other's gravitational force? |
I was thinking about how no particles are actually free, and therefore
always have quantized characteristics, because of tiny gravitational
forces from far away masses. But then I thought, when a force becomes
so amazingly small, even nature must assume it to be zero. But then I
realized that apparently nature basically has infinite precesion, never
dropping even the smallest numbers, because this is how objects such as
the sun and earth apparently gravitationally attract each other.
Normally, we just consider the total mass of the sun and earth to
calculate the gravitational force, but actually this total
gravitational force acting on the earth lets say I believe is the sum
of all the individual sun particles attracting all the individual earth
particles. For example, we could calculate the gravitational force
acting on the earth by calculating the gravitational force of a single
sun molecule acting on the whole earth, and do the same for all the
other sun molecules (taking account of their position) and sum them all
up. I just find it amazing that individual molecules are actually
feeling each other over an unamaginably large distance (say between
galaxies!) with unamaginably small force. Because there are an
unamaginably large number of molecules, the total force can be decent
to very large. I'm right about this ain't I?
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| User: "CWatters" |
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| Title: Re: Particles light years apart really feel each other's gravitational force? |
31 May 2006 04:49:47 AM |
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<sunabrujj15@mail.com> wrote in message
news:1149038599.659460.87600@c74g2000cwc.googlegroups.com...
up. I just find it amazing that individual molecules are actually
feeling each other over an unamaginably large distance (say between
galaxies!) with unamaginably small force.
More impressive than that...
Imagine each star is surrounded by a sphere. The area of the sphere is
4pr^2 right. Now most of the light emitted by the star passes through that
area. Now imagine the sphere has a radius equal to the distance between the
earth. That's a big sphere and the area is huge...yet there is still enough
light passing through that fraction represented by the area of your eye for
you to see it.
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| User: "" |
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| Title: Re: Particles light years apart really feel each other's gravitational force? |
31 May 2006 09:37:31 AM |
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CWatters wrote:
More impressive than that...
Imagine each star is surrounded by a sphere. The area of the sphere is
4pr^2 right. Now most of the light emitted by the star passes through that
area. Now imagine the sphere has a radius equal to the distance between the
earth. That's a big sphere and the area is huge...yet there is still enough
light passing through that fraction represented by the area of your eye for
you to see it.
Cwatters,
Although it is impressive that a photon released by a molecule on the
sun may eventually hit a molecule on the earth, it's not as impressive
as the gravitational field of a molecule on the sun influencing a
molecule on the earth. This is because 1: the photon from a molecule
just goes off in a focused single direction, wheras the gravitational
field from a molecule must go out in all directions, leading to the
1/distance^2 drop off (which as you mentioned is also how the light
intensity drops off for considering all the photons from all the
molecules together, but here I'm just thinking about individual
molecules) and 2: the numerical value for the photon energy is decent,
wheras the numerical value for the gravitational force between two
molecules even right next to each other is tiny, and 3: the photon
emitted by a sun molecule only influences a single molecule (on the
earth say) upon impact, but the gravitational field from a sun molecule
actually influences every other molecule in the universe (or so it
seems). Just emagine, every elemental particle with mass in the
universe has always felt the existance of every other elemental
particle with mass in the universe!
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| User: "Helmut Wabnig" |
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| Title: Re: Particles light years apart really feel each other's gravitational force? |
31 May 2006 02:43:35 AM |
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On 30 May 2006 18:23:19 -0700, "sunabrujj15@mail.com"
<sunabrujj15@mail.com> wrote:
I was thinking about how no particles are actually free, and therefore
always have quantized characteristics, because of tiny gravitational
forces from far away masses. But then I thought, when a force becomes
so amazingly small, even nature must assume it to be zero. But then I
realized that apparently nature basically has infinite precesion, never
dropping even the smallest numbers, because this is how objects such as
the sun and earth apparently gravitationally attract each other.
Normally, we just consider the total mass of the sun and earth to
calculate the gravitational force, but actually this total
gravitational force acting on the earth lets say I believe is the sum
of all the individual sun particles attracting all the individual earth
particles. For example, we could calculate the gravitational force
acting on the earth by calculating the gravitational force of a single
sun molecule acting on the whole earth, and do the same for all the
other sun molecules (taking account of their position) and sum them all
up. I just find it amazing that individual molecules are actually
feeling each other over an unamaginably large distance (say between
galaxies!) with unamaginably small force. Because there are an
unamaginably large number of molecules, the total force can be decent
to very large. I'm right about this ain't I?
sure you'r right.
:-)
w.
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