Is Gravity Really the Weakest Force in the Universe?

In summary, physicists often mention that gravity is a weak force compared to the other fundamental forces, and its mechanism of action is different. However, it is still possible to compare the relative strength of different forces, even if they are mediated by different mechanisms. The concept of gravity propagating in extra dimensions is not necessary to explain its weakness, as the forces are what they are regardless of our models. Additionally, the fact that our models for gravity differ from those for other forces does not necessarily mean that they are fundamentally different.
  • #1
FredrikJ
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All physicists I've heard discussing gravity to the public always mentions that it's a very weak force compared to the other forces and that no one knows why. One possible reason could be that the gravitational force is propagating in other dimensions.
As far as I know gravity works in a completely different way compared to the other forces. The other forces use carrier particles but gravity works by curving the fabric of space and time.
Aren't we comparing apples and oranges when we are comparing the strength of gravity to the strength of the other fundamental forces?
 
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  • #2
FredrikJ said:
Aren't we comparing apples and oranges when we are comparing the strength of gravity to the strength of the other fundamental forces?
I feel that it is not really for me to answer this question (others here have the actual knowledge to do so), but I would think that one can still compare the relative strength of different fundamental forces, even though these forces may be mediated by different mechanisms. In other words, I don't think this is a matter of comparing apples and oranges. Is this correct?
 
  • #3
See e.g.
http://www.huffingtonpost.com/victor-stenger/myths-of-physics-2-gravit_b_5718233.html

I'd say the comparison is not that bad. In theory we can measure e.g. the electric force between a proton and a neutron in a Hydrogen-atom, and do the same for gravity. Doing the math with it gives a huge difference. between the two. Of course, in GR gravity is merely an 'inertial force', but that shouldn't be a problem. Somebody on a spinning disc can also compare the centrifugal force he/she is measuring with the gravitational force she is undergoing, do the corresponding math and compare the two.
 
  • #4
Of course you can compare the forces but since the mechanisms behind the forces are completely different I don’t understand why we need an answer to why the gravitational force is so much weaker than the other fundamental forces. If the gravitational force were in the same order of magnitude as the electromagnetic force in strength I think it would be an incredible coincidence.
If there was a graviton, carrying the force the same way as photons do with the electromagnetic force, I would have understood the concept of finding out what causes the forces to be so different in strength but since those forces work in a completely different way I don’t understand why we need an additional explanation, like gravity propagating in extra dimensions.
 
  • #5
First, the forces are what they are, irrespective of our models. An airplane is faster than a snail, even though they are totally different objects moving in totally different ways. Yes, gravity can break your leg, but it takes a whole planet to do it. That's pretty weak.

Second, the fact that our best mathematical models of gravity don't look anything like our best mathematical models of other forces may or may not be telling us there are fundamentally different. The map is not the territory.
 
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  • #6
Vanadium 50 said:
Yes, gravity can break your leg, but it takes a whole planet to do it. That's pretty weak.
That's the most vivid demonstration of the weakness of gravity I ever seen. :smile:
 
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Is gravity really that weak?

Yes, compared to other fundamental forces like electromagnetism and the strong and weak nuclear forces, gravity is considered to be the weakest force. However, on a macroscopic scale, gravity is still a dominant force in the universe, as it governs the motion of planets, stars, and galaxies.

Why is gravity considered to be weak?

Gravity is considered to be weak because it has the smallest magnitude compared to the other fundamental forces. For example, the force of gravity between two objects is about 10^-38 times weaker than the force of electromagnetism between the same two objects.

How is gravity measured and quantified?

Gravity is measured using a unit called Newtons (N). It is quantified by the mass of the objects and the distance between them. The more massive an object is, the stronger its gravitational force, and the closer two objects are, the stronger their gravitational force.

Can gravity be made stronger or weaker?

No, gravity cannot be made stronger or weaker. It is a fundamental force of nature that cannot be manipulated or controlled. However, its effects can be altered by changing the mass and distance of objects.

Is there a limit to how weak or strong gravity can be?

Yes, there is a limit to how weak or strong gravity can be. This is determined by the mass and distance of the objects involved. For example, the gravitational force between two objects becomes negligible when they are at a great distance from each other or have very little mass.

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