Gravitation vs Magnetic and Electric Field

In summary, there is a magnetic and electric field around every planet and the sun, which vary with a factor of r^-3 due to the dipole action they produce. These forces are not the cause of the elliptical orbit of the planets around the sun, as gravity results from mass, not charge, and varies with a factor of 1/r^2. The Sun's magnetic field does not decrease as r^-3, but rather gets entrapped in solar wind and transported away with a smaller decrease. However, magnetic forces are strong enough to influence the elliptical nature of the orbit. On a larger scale, the gravitational force completely predominates over the other fundamental interactions. Therefore, the cause of the elliptical orbit of the planets
  • #1
Philosophaie
462
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There is a Magnetic and Electric Field around every planet and the sun due to the dipole action they produce. They vary with a factor of r^-3. Are these forces the stuff that gives gravitational forces its name or is there more to it?
 
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  • #2
Gravity results from mass, not charge, and varies with a factor 1/r2, not 1/r3. The Moon and Mars have almost no magnetic field but still have a gravitational field.
 
  • #3
Worse: the Sun's magnetic field does not decrease as r^-3. This has long been a puzzle. A common explanation now is that flux gets entrapped in Solar wind and transported away with a smaller decrease.
 
  • #4
Magnetic forces are strong enough to influence the elliptical nature of the orbit though.
 
  • #5
The orbit of what? Neither JPL (DE40x series of ephemerides) nor the St. Petersburg Institute of Applied Astronomy's (EPM200x series ephemerides) model electromagnetic interactions amongst the sun and planets.
 
  • #6
Then there are many fields that effect our Universe. One, gravitational field. Two, Magnetic and Electric, and then "Dark Energy" which we won't go into now. The Magnetic and Electric Fields are "out" as a cause for the elliptical orbit of the planets. What is the cause of the elliptical orbit of the planets around the sun?
 
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  • #7
Philosophaie said:
What is the cause of the elliptical orbit of the planets around the sun?
Gravity.
 
  • #8
I know now gravity is much much greater of a force than Magnetic and Electric Field. I heard that the Sun flips its Magnetic Field during the course of a year. Does that disrupt things?
 
  • #9
Philosophaie said:
I know now gravity is much much greater of a force than Magnetic and Electric Field. I heard that the Sun flips its Magnetic Field during the course of a year. Does that disrupt things?
Actually, gravity is by far the weakest of the four fundamental interactions. Two protons, for example, will fly away from one another because the electrostatic repulsive force between a pair of protons is more than 1036 times stronger than the gravitational attractive force between a pair of protons. Electromagnetism in turn is much, much weaker than the strong force at short distances. Think about it this way: the strong force is powerful enough to hold protons together at extremely short distances.

We don't have to account for the strong force at anything but subatomic levels because the particles that mediate the strong force aren't stable; the strong force simply dies out. The electrostatic force similarly dies out at largish distances because most reasonable sized conglomerations of matter are electrically neutral. The only thing that is left on planetary scale and larger are the gravitational force and multipole electromagnetic forces (e.g., Earth's electromagnetic field).

The multipole electromagnetic fields are pretty dang weak. Think about it this way: Watch a compass needle. It doesn't snap into alignment with the Earth's magnetic field. It slowly meanders into alignment. The Earth's magnetic field averages 0.5 gauss on the Earth's surface. In comparison, the field of a small bar magnet at the boundaries of the magnet is about 100 gauss. It gets worse than that: the multipole fields drop as the inverse cube of distance. On planetary scales and larger, the gravitational force completely predominates the other fundamental interactions.
 
  • #10
Philosophaie said:
I know now gravity is much much greater of a force than Magnetic and Electric Field.

D H said:
Actually, gravity is by far the weakest of the four fundamental interactions. Two protons, for example, will fly away from one another because the electrostatic repulsive force between a pair of protons is more than 1036 times stronger than the gravitational attractive force between a pair of protons.

but at Wilczek once put it, this is really because, measured in natural units, the protons' masses are extremely tiny (compared to the Planck mass) while the protons' charge are just a single order of magnitude away from the Planck charge. that's how i would compare apples-to-apples.

Electromagnetism in turn is much, much weaker than the strong force at short distances. Think about it this way: the strong force is powerful enough to hold protons together at extremely short distances.

We don't have to account for the strong force at anything but subatomic levels because the particles that mediate the strong force aren't stable; the strong force simply dies out. The electrostatic force similarly dies out at largish distances because most reasonable sized conglomerations of matter are electrically neutral. The only thing that is left on planetary scale and larger are the gravitational force and multipole electromagnetic forces (e.g., Earth's electromagnetic field).

The multipole electromagnetic fields are pretty dang weak. Think about it this way: Watch a compass needle. It doesn't snap into alignment with the Earth's magnetic field. It slowly meanders into alignment. The Earth's magnetic field averages 0.5 gauss on the Earth's surface. In comparison, the field of a small bar magnet at the boundaries of the magnet is about 100 gauss. It gets worse than that: the multipole fields drop as the inverse cube of distance. On planetary scales and larger, the gravitational force completely predominates the other fundamental interactions.

i think this illustrates why, on the grand scale, there is only gravity left in the contest of forces of orbits and such. unlike E&M, for gravity like-signed "charges" attract, there seems to be only positive masses around doing celestial mechanics. even though, if you were measuring things in kg and coulombs, the E&M force is so much stronger than gravity, celestial bodies are pretty much neutral in electric charge. the superposition of what the charged particles do to each other in the stars and planets pretty much cancel out because of the equal numbers of protons and electrons in them. though there aren't net EM forces between them, but since we're all positive mass, there is gravity left.
 
  • #11
So... does it mean that it makes no difference for Earth's magnetic field if gravity is decreasing? Is it staying the same or will it disapear?

what is exact relationship between gravity and magnetic field?
 
  • #12
The magnetic field is caused by an electric current doing loops somewhere inside the Earth.

Gravity depends on the mass of Earth.

If you can understand what mechanism causes the two different phenomenon it becomes apparent that the two don't directly affect each other. Mass and gravity of an object is not involved anywhere in the equations that describe magnetic force and field, you see that decreasing mass/gravity won't affect magnetism in any direct way.

This isn't to say that there is no indirect relationship. It is easy to imagine that decreasing the mass/gravity could possibly affect the amount of current or size the path that the current inside the Earth is traveling. This would, in turn, affect the mag field.
 
  • #13
I thought so, but i wasn't sure. It's all because Earth's magnetic filed is not fully explained yet. I'm not studying physics so had small problem. Thx anyway. Sorry if you found my question stupid ;D lol
 
  • #14
A good explanation on how does gravity cause the elliptical orbits around the sun.
[crackpot link deleted]
 
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1. What is the difference between gravitation and magnetic and electric fields?

Gravitation is a natural phenomenon by which all objects with mass are brought towards one another, while magnetic and electric fields are forces that act on charged particles. Gravitation is a fundamental force of nature that is always attractive, while magnetic and electric fields can be either attractive or repulsive depending on the charges involved.

2. How do gravitation and magnetic and electric fields affect matter?

Gravitation and magnetic and electric fields can both cause matter to move and interact with other matter. Gravitation is responsible for the motion of planets and other celestial bodies, while magnetic and electric fields can cause charged particles to move and can be harnessed to produce electricity.

3. Are gravitation and magnetic and electric fields related?

While both gravitation and magnetic and electric fields can affect matter, they are fundamentally different forces. Gravitation is a result of the curvature of space-time caused by mass, while magnetic and electric fields are caused by the interaction of charged particles. However, both can be described and calculated using the laws of physics and mathematics.

4. Can gravitation and magnetic and electric fields cancel each other out?

No, gravitation and magnetic and electric fields cannot cancel each other out. They are independent forces that act on matter simultaneously. However, the effects of one force may be stronger than the other, leading to a net force on an object.

5. What are some real-life applications of gravitation and magnetic and electric fields?

Gravitation plays a crucial role in the motion of celestial bodies and is also harnessed in technologies such as satellites and space travel. Magnetic and electric fields are used in a variety of applications, including generators, motors, and medical imaging technologies like MRI machines.

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