Understanding the Weakness of Gravity and its Role in the Universe

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SUMMARY

The discussion clarifies that gravity, while considered the weakest of the four fundamental forces, is still powerful enough to hold planets, stars, and galaxies together due to their significant mass. Participants highlighted that gravity's attraction is counteracted daily by other forces, such as electromagnetism, which can be stronger in certain contexts. The conversation emphasized the importance of understanding the relative strengths of these forces, particularly through practical examples like magnets and nuclear forces.

PREREQUISITES
  • Understanding of the four fundamental forces: gravity, electromagnetism, strong nuclear, and weak nuclear.
  • Basic knowledge of mass and its relationship to gravitational force.
  • Familiarity with practical demonstrations of forces, such as magnets.
  • Concept of resultant forces from multiple weaker forces.
NEXT STEPS
  • Research the comparative strengths of fundamental forces in physics.
  • Explore the role of mass in gravitational attraction using Newton's law of universal gravitation.
  • Investigate practical applications of electromagnetism, such as MRI machines and neodymium magnets.
  • Study the concept of resultant forces and how they apply to various physical systems.
USEFUL FOR

Students of physics, educators explaining fundamental forces, and anyone interested in the dynamics of celestial bodies and the universe's structure.

Samia qureshi
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If gravity is a weak force , then
How it holds planets , stars and galaxies together ?
let me know if i am right..?
Gravity only attracts there is no negative version of the force to push things apart and while gravity is powerful enough to hold galaxies together, it is so weak that you overcome it every day when pick up ball you are counteracting the force of gravity from all of earth.
 
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Answering the title: Yes.

It's weak in the context of the four fundamental forces: gravity, electromagnetism, "strong nuclear, weak nuclear", the last two of which are just forces which keep atoms together.

The key to understanding: Playing with magnets, you can easily see how electromagnetism can be stronger than gravity, while being 10000x smaller than the Earth. And of course, the nuclear forces are minuscule and of course resist gravity.

(Look up videos of MRI machines or neodymium magnets, then imagine how strong a magnet the size of the Earth would be)
 
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means only gravity is responsible for the holding of stars planets together ?
 
Samia qureshi said:
means only gravity is responsible for the holding of stars planets together ?
The sum of many weak forces = a strong resultant force!
 
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Samia qureshi said:
means only gravity is responsible for the holding of stars planets together ?

They have a lot of mass so the force is large enough to hold them together.
 
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Thank you now its clear to me :smile:
 

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