Another gravity question

A

Adam

§Þ@ç€ MØnk€¥
Registered Senior Member
Basically, do gravitational forces from different massive objects combine?

A star ahs a certain amount of gravity. But as I understand it, a galaxy has stronger gravity that justt he maximum individual component.

Let the lines below indicate the strength of gravity wells.

Star:
*------>

Two stars:
*------>
*------>

Galaxy:
*------------------------------------------------------------------>

See what I'm asking? How exactly is the gravity well of a galaxy stronger than the strongest component? Or isn't it stronger at all?
 
Gravitational forces add together. The gravitational pull of a galaxy is equal to the sum of the the gravitational pulls of all the stars in the galaxy.
 
Buy those thick College Physics textbook by Giancoli (latest edition), it's a very good book for conceptualizing and learning about the basics of physics.

There are good problems on that site. I suggest you buy the book and run through anything you don't know. Or just take a course :D
 
Thanks. I assumed gravitational forces add together, since that whole mass thing n all. But how? Is the way it happens understood at all?
 
Yes, it's well understood.

Every bit of matter in the universe attracts every other bit of matter, with a force which is proportional to the product of the masses and inversely proportional to the square of the distance between the bits. (Sir Isaac Newton)
 
I'm ok with all that. But how do the forces of gravity from different masses combine? With charge, for example, we're talking about simple balance between positive and negative. The same concept applies for up and down, spin, et cetera. What's going on with the combination of gravity forces? Is it, again, balance or equilibrium like we see in the other forces? If so, how? What is the mechanism involved? Can you explain the mechanism in a way similar to how we explain charge and spin and such?
 
Gravitational forces are vectors (just like every other force).

To find the net gravitational force on an object, we add up the gravitational force vectors from all the masses attracting the object. In the addition process, we must take into account not only the magnitudes of the forces, but also their directions (i.e. we do a vector addition).
 
Adamski:
But how do the forces of gravity from different masses combine?
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Gravity is the "warping" of spacetime that an object causes. This "warping" gives rise to force, and this force "pulls" on another object. When there are more masses, the "warping" is more extreme and thus stronger.
 
Grrr. What I am after is the mechanism for how it happens. Like with otehr thigns we have gluons and colour bonds or whatever. What is the method by which gravity/mass combines?
 
Not sure what you're after, exactly.

Perhaps gravitons (if they exist). Perhaps the gravitational field.

????
 
Okay, I've been looking at gravitons on the web. Yep, that's what I'm after. Something that isn't known to exist. That sucks.
 
Perhaps Thed may answer this, I am learning more about the Big Bang and more about the Plasma Theory.

But the Big Bang hypothesizes that there is another dimension. Time is the 4th dimension, and a 5th dimension contains a super massive object known as a Higgs Boson which exists in subnuclear dimensions. The Higgs Boson and mass in our dimension interact with one another to cause gravity. Gravity is most likely an interaction of energy.

"In sum, the Higgs boson is a critical ingredient to complete our current understanding of the Standard Model, the theoretical edifice of particle physics. Different types of Higgs bosons, if they exist, may lead us into new realms of physics beyond the Standard Model."
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They need this to exist to support the Big Bang Theory.

Try some of these interesting links.

What exactly is the Higgs boson? Have physicists proved that it really exists?

How does the Higgs boson affect string theory?

One Step Closer to the God Particle

Big Bang's Non-inflatable Dimensions

A Short One on the Higgs

Here's an interesting question: if the Higgs mechanism determines the mass of particles, and the Higgs boson is an intermediary for this mechanism, what give the Higgs its finite and (potentially) predictable mass? I've heard some answers: the Higgs mass is predictable due to the symmetry of the standard model (this requires some knowledge of group theory to fully understand); yet, in the context of this same answer, I was told that the Higgs mechanism is that which breaks the symmetry of the Standard Model (the symmetry needs to be broken, because according to the math we find that the masses of the Z and W bosons have no place in the SM (it predicts zero mass for these bosons --- well, actually, the SM predicts zero mass for everything)).

Supersymmetry tries to tackle the problem of the Higgs' mass being finite arising from practically nowhere, but it is mighty suspicious to me. True, some people have had luck with mathematical tricks (Gell-Mann introduced QCD as a mathematical trick, but it was eventually shown to be correct when quarks were found) but until we can show that all mathematical curiosities have viable representations in the physical world, one need not to accept postulations as definite (or even strongly suggestive) answers.
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Also, you should get Giancoli's Physics book, it explains basically everything you need about Physics in general, to work, force, thermadynamics, and so on. It has nice diagrams, the problems show you mathematically how it all fits and it's 1000+ pages. :)
 
Hi Adam,

I understand the need to categorize and classify, but is that really enough? Like, we have "photons". Yes, it has a name, but what is it?

A particle and a wave, say some. But that's ridiculous; the two concepts are logically incompatible. Which in reality means that it isn't both -- it's neither! So, sometimes it manifests itself as a wave, sometimes as a particle -- but what is it really? Aside from a name, nobody knows...

Some say it's an "energy packet". Whoopty-doo, but what the heck is "energy" then? Ability to do work? What's that, a packet of ability to do work? That sometimes acts like a wave and sometimes like a particle? Bleh...

Nah, all we're doing is playing games. Giving names to things doesn't help any when what we really want is to understand the thing behind the name.

So... "gravitons". "Gravitational waves". "Space-time". It's all bullshit. What is space? A Cartesian coordinate system? Or is that just another name?
 
Adam,

I'm ok with all that. But how do the forces of gravity from different masses combine? With charge, for example, we're talking about simple balance between positive and negative. The same concept applies for up and down, spin, et cetera. What's going on with the combination of gravity forces? Is it, again, balance or equilibrium like we see in the other forces? If so, how? What is the mechanism involved? Can you explain the mechanism in a way similar to how we explain charge and spin and such?
Click to expand...

I think I know what you are talking about...
Imagine a blanket held straight in the air. If you put balls on it, the blanket will bend to accomodate the balls. Depending on the weight, the mass of the ball, it will bend a lot or not.

If you are talking in the sobatomic level, I guess there's no gravity. In the subatomic level there are other forces, but no gravity. Gravity only makes difference in the macrocosmic world. However, if gravitons exists, I believe gravity is the strongest force in the universe... instead of the strong nuclear force...

If gravitons exist they are probably quarks and it will be pretty hard to detact them...
 
overdoze,

I like that... :D
Did you ever learn Taoism? :D

You made me remember that I would post about this subject... thanks... :);)
 
*Xev quietly thanks Cthulhu for the vodka, or else this would be impossible*

Nelson, kindly keep your pseudoscience out of physics and math.

If you are talking in the sobatomic level, I guess there's no gravity. In the subatomic level there are other forces, but no gravity.
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It is a very, very weak force but it exists.

However, if gravitons exists, I believe gravity is the strongest force in the universe... instead of the strong nuclear force...
Click to expand...

Strongest force? What are you talking about?

If gravitons exist they are probably quarks and it will be pretty hard to detact them...
Click to expand...

Umm, Nelson dear, gravitons and quarks are different things.

Chosen:
Giancoli is indeed an excellent textbook for beginning physics! I have his fifth edition sitting right next to me.

However...

They need this to exist to support the Big Bang Theory.
Click to expand...

No, the Higgs is not necessary to support the big bang theory - it is presumed to be necessary to complete the standard model.

Simular things, but different.

Also, the Higgs need not be outside our current four (well, actually 11 or 24 - but we won't get into Kaluza-Klein) dimensions.

As for gravity being an interaction of energy, you're right. Remember that E=mc^2, and that mass rather "causes" the gravitational force.

Nice post. If you ever want a beginning paper on the Higgs, I've got one from a few semesters ago.

Adam: Gravitons. Yep, we have yet to detect such. According to the standard model, they should exist.....absence of evidence is not evidence of absence, of course, but I do wonder how this affects the validity of the SM.

But my explanation - does it not work? Could you clarify the question?
 
Xev,

Nelson, kindly keep your pseudoscience out of physics and math.
Click to expand...

...?
Which pseudoscience...?

It is a very, very weak force but it exists.
Click to expand...

Do you really concider... let's say... 0,00000000000001 of force...?:bugeye:

Strongest force? What are you talking about?
Click to expand...

I think I made myself sufficiently clear...

Umm, Nelson dear, gravitons and quarks are different things.
Click to expand...

Gravitons are types of quark...
Have you ever study this...? :eek:
 
Nelson:
...?
Which pseudoscience...?
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Daoism. I do not think this is the appropriate forum for it.

Do you really concider... let's say... 0,00000000000001 of force...?
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.0000000001 of what force? Gravity?

Yes, it's a bloody force! It is a very weak force sub-atomically.

I think I made myself sufficiently clear...
Click to expand...

There IS NO STRONGEST FORCE! They all apply over different levels.

Gravitons are types of quark...
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They are a hypothetical type of sub-atomic particle. Not a type of quark.
Quarks:
http://www2.slac.stanford.edu/vvc/theory/quarks.html
Here, this should help:
Gravitons:
http://research.spinweb.com/glossary/terms/gravitons.htm


Have you ever study this...? :eek:
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Well, let's see, I've only studied informally for four years, and I've only studied physics at college level for four semesters......

Looks like you do indeed have somthing to be embarassed about. :rolleyes:

Now Nelson, if your ego can't stand being corrected on science, I'd advise you to stick to religion and parapsychology. I'm being as gentle about this as I can, but I do not appreciate having my credentials questioned simply because you cannot stand being wrong.

We're all wrong at times, Nelson. The best thing to do is to accept it with dignity and grace and try to learn.
 
Xev,

Daoism. I do not think this is the appropriate forum for it.
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I was just comparing what overdoze said with Taoism...

Yes, it's a bloody force! It is a very weak force sub-atomically.
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That's what I'm talikng about...

There IS NO STRONGEST FORCE! They all apply over different levels.
Click to expand...

Only because they apply to different levels it doesn't mean we can't compare them...:bugeye:

They are a hypothetical type of sub-atomic particle. Not a type of quark.
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Ok... then...
BURN THE BOOKS I READ!!!!!:rolleyes:
:D:D:D:D:D

Now Nelson, if your ego can't stand being corrected on science, I'd advise you to stick to religion and parapsychology. I'm being as gentle about this as I can, but I do not appreciate having my credentials questioned simply because you cannot stand being wrong.
Click to expand...

Ok... then all the books I read on the subject are wrong and MUST be burnt...:bugeye: :eek:
 
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