Gravity or Electromagnetism? Which will win?

You're also not consdiering mass that falls into the sun, from the decaying orbits of asteroids and/or comets, as well as any materials from outside the solar system. I'm nto 100% sure, but I believe there is a small amoutn of influx of the insterstellar medium material into the solar system...I know the solar wind prevents a lot, but I think some gets in. I'll have to check that.
 
From http://en.wikipedia.org/wiki/Sun:
Earth's fate is not clear. As a red giant, the Sun will have a maximum radius beyond the Earth's current orbit, 1 AU (1.5×1011 m), 250 times the present radius of the Sun.[28] However, by the time it is an asymptotic giant branch star, the Sun will have lost roughly 30% of its present mass due to a stellar wind, so the orbits of the planets will move outward. If it were only for this, Earth would probably be spared, but new research suggests that Earth will be swallowed by the Sun due to tidal interactions.[28]
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Additionally, the Wiki article on Solar wind claism this:
The mean velocity of these particles is about 145 km/s, which is well below the solar escape velocity of 618 km/s. However, a few of the particles will achieve energies sufficient to reach the terminal velocity of 400 km/s, allowing them to feed the solar wind.[12]
The total particles carried away from the Sun by the solar wind is about 1.3×1031 per second.[13] The total mass loss each year is about (2–3)×10-14 solar masses,[14] or 6.7 billion tons per hour. This is equivalent to losing a mass equal to the Earth every 150 million years.[15] However, only about 0.01% of the Sun's total mass has been lost through the solar wind.[16] Other stars have much stronger stellar winds that result in significantly higher mass loss rates.
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The rough calculation was within an order of magnitude. Did you use the total emissions numbers, or only those with greater than escape velocity fromt he sun? Many ejections will fall back into the Sun and never escape the solar system.
 
The Sun's energy output (3.86e33 ergs/second or 386 billion billion megawatts) is produced by nuclear fusion reactions. Each second about 700,000,000 tons of hydrogen are converted to about 695,000,000 tons of helium and 5,000,000 tons (=3.86e33 ergs) of energy in the form of gamma rays. As it travels out toward the surface, the energy is continuously absorbed and re-emitted at lower and lower temperatures so that by the time it reaches the surface, it is primarily visible light.
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http://www.nineplanets.org/sol.html
Eruptions on the Sun's surface occur often. During normal solar activity the intense heat of the corona of about 1,000,000°C (1,800,000°F) to 2,000,000°C (3,600,000°F) accelerates the plasma to escape velocity. A million tons of matter are hurled into space every second at an average speed of 400 km/s (900,000 miles/hr). Extreme speeds vary from 300 km/s (700,000 miles/hr) to 900 km/s (2 million miles/hr). In the process the plasma drags the magnetic field lines of the Sun out into space. A million tons of matter per second is huge. However, since this solar wind is spread throughout space in all directions, there are only about 6 protons per cubic centimeter when the solar wind reaches Earth. The Ulysses spacecraft and the Advanced Composition Explorer (ACE) have gathered considerable information about the solar wind. Would you like to know the solar wind conditions for the past seven days?

Solar winds are comparable to daily breezes on Earth -mild and steady. Solar flares, however, are like intense storms. The solar flares are much more powerful than solar winds, but they are localized and tend to blast material in just one direction. Flares release a quick burst of energy equivalent to 10 million volcanic eruptions or more than a billion hydrogen bombs. A coronal mass ejection (CME) is the like a hurricane- an energetic storm spread over a large area. A CME is the eruption of a huge bubble of plasma from the corona. A CME travels between 400 km/s (1 million miles per hour) and 1000 km/s (5 million miles per hour). A typical eruption can carry a billion tons of plasma, a mass equal to that of 10,000 aircraft carriers.
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http://son.nasa.gov/tass/content/solarwind.htm

Those are the figures I used.

No matter how you look at it, EM dominates gravity, in terms of how much matter is in our solar system. EM hurls far more matter out of the system, than gravity draws in. If you add in the immense amount of intergalactic wind the EM radiation prevents from falling inward, EM is far more powerful than gravity, in terms of total mass balance.

Without the solar wind, and the huge magnetic field it modifies and strengthens, we would be blasted by vast amounts of energetic plasma from other stars and the Galaxy itself.

Just as the Earth's magnetic field protects us from the solar wind and CMEs, the sun protects us from the Galactic wind.

Looking at it this way, EM beats gravity many times over. Both for protecting us from death, and in regards to the amount of mass in the Solar System.

Without EM, there could be no life on earth. Just as without gravity, we couldn't exist as well. Which is more important on a large scale? EM wins in regards to ensuring we can live on our planet. Gravity would doom us, by attracting every bit of matter right down on us. Without the protection of EM fields, especially in regards to high energy particles and CMEs, we would die.
 
robinson said:
No matter how you look at it, EM dominates gravity, in terms of how much matter is in our solar system. EM hurls far more matter out of the system, than gravity draws in.
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Almost all the matter in the solar system is already in the sun (because of gravity). So the fractional flow (that is, what fraction of stellar matter is pushed outwards due to EM interactions versus what fraction of extra-stellar matter is pulled in due to gravity) of matter is going to be radically different from the net flow of matter. Why is net flow a better way to define which interaction dominates?

If you add in the immense amount of intergalactic wind the EM radiation prevents from falling inward, EM is far more powerful than gravity, in terms of total mass balance.
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On the other hand, the sun itself has almost all the mass of the solar system, because gravity is keeping it there. Again, why is the way you define domination preferable to this alternative method? Especially since this mass loss you refer to is so small compared to the total mass.

Without the solar wind, and the huge magnetic field it modifies and strengthens, we would be blasted by vast amounts of energetic plasma from other stars and the Galaxy itself.
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And without gravity, we wouldn't be in this solar system at all. Hell, we wouldn't even be a planet. Seems a little more significant to me, to be honest. Life could exist in the oceans even without any magnetic fields to block ionizing solar and cosmic radiation, but without gravity, there's no planet at all.

Without EM, there could be no life on earth.
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Well, sure: chemistry is all about EM interactions. But life on earth would likely exist with or without radiation shielding from magnetic fields. Not us, but definitely life.

Gravity would doom us, by attracting every bit of matter right down on us.
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Nonsense. EM interactions are not keeping the moon from hitting the earth, and they aren't what keep most stuff from hitting us. Most stuff doesn't hit us because space is big, the earth is small, and angular momentum is generally not zero.
 
robinson said:
http://www.nineplanets.org/sol.html

http://son.nasa.gov/tass/content/solarwind.htm

Those are the figures I used.

No matter how you look at it, EM dominates gravity, in terms of how much matter is in our solar system. EM hurls far more matter out of the system, than gravity draws in. If you add in the immense amount of intergalactic wind the EM radiation prevents from falling inward, EM is far more powerful than gravity, in terms of total mass balance.

Without the solar wind, and the huge magnetic field it modifies and strengthens, we would be blasted by vast amounts of energetic plasma from other stars and the Galaxy itself.

Just as the Earth's magnetic field protects us from the solar wind and CMEs, the sun protects us from the Galactic wind.

Looking at it this way, EM beats gravity many times over. Both for protecting us from death, and in regards to the amount of mass in the Solar System.

Without EM, there could be no life on earth. Just as without gravity, we couldn't exist as well. Which is more important on a large scale? EM wins in regards to ensuring we can live on our planet. Gravity would doom us, by attracting every bit of matter right down on us. Without the protection of EM fields, especially in regards to high energy particles and CMEs, we would die.
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You are correct - EM forces on charged particles in the solar system can be stronger than the gravitational forces on those charged particles. This is well known in physics.

However you may want to calculate the different EM and gravitational forces on a mostly neutral body like the Earth. For example you will find that EM forces have no effect on the Earth's orbit. EM forces are important for keeping us alive but gravity makes sure that we have a planet to be alive on.

The conclusion is the relative strengths of EM and gravitational forces in the universe depends on the situation. You cannot say that just because gravity's fundamental constant is much less than that of EM that gravity is always weaker then EM.

Charged particles at a low mass density are dominated by EM forces.
Gravity dominates at high mass density and when there is little overall charge.
 
I think we can all agree on that. As I said, the concept of domination, or winning, is not very scientific.
 
JEROME DA GNOME said:
What exactly is a "mostly neutral body"?

:gnome:
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For simplicity, one can consider a body whose charge-to-mass ratio is many orders of magnitude smaller than the proton to be "mostly neutral". Once could even pick a particular order of magnitude limit, if one cared to.
 
Ziggurat said:
For simplicity, one can consider a body whose charge-to-mass ratio is many orders of magnitude smaller than the proton to be "mostly neutral". Once could even pick a particular order of magnitude limit, if one cared to.
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The Earth has a charge-to-mass ratio that is less than the proton?


:gnome:
 
robinson said:
Without the solar wind, and the huge magnetic field it modifies and strengthens, we would be blasted by vast amounts of energetic plasma from other stars and the Galaxy itself.

Just as the Earth's magnetic field protects us from the solar wind and CMEs, the sun protects us from the Galactic wind.

Looking at it this way, EM beats gravity many times over. Both for protecting us from death, and in regards to the amount of mass in the Solar System.

Without EM, there could be no life on earth. Just as without gravity, we couldn't exist as well. Which is more important on a large scale? EM wins in regards to ensuring we can live on our planet. Gravity would doom us, by attracting every bit of matter right down on us. Without the protection of EM fields, especially in regards to high energy particles and CMEs, we would die.
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Wow, its like there was this huge war going on - graviton were winning when you could get huge armies on the field, but when it comes to guerilla war, the ems have it. That's because they're usually fighting between themselves, and only settle down in pairs and groups. Gravitons always work together, and they're like ants - you can't get away from them, but they're individually weak.

And here come all these brainiacs, who think they can figure out who'll win, and what side they'll be on. Stupid people. Who needs 'em? Let's leave 'em with the weak force since they're so fond of it.
 
robinson said:
No matter how you look at it, EM dominates gravity, in terms of how much matter is in our solar system. EM hurls far more matter out of the system, than gravity draws in. If you add in the immense amount of intergalactic wind the EM radiation prevents from falling inward, EM is far more powerful than gravity, in terms of total mass balance.
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Let’s not forget that it is fusion driven by gravity that produces the outward pressure (and EM fields) driving such emissions from the Sun. Otherwise it would just be a big ball of hydrogen, much like Jupiter (but a lot bigger), relatively cold and dark (as compared to the sun). Isn’t “EM” suppose to draw in even greater amounts of matter into the solar system and specifically to the Sun in order to provide for a non gravitationally fusion powered but “EM” powered sun, interesting, “EM” must pull in more matter then it hurls out.


robinson said:
Without EM, there could be no life on earth. Just as without gravity, we couldn't exist as well. Which is more important on a large scale? EM wins in regards to ensuring we can live on our planet. Gravity would doom us, by attracting every bit of matter right down on us. Without the protection of EM fields, especially in regards to high energy particles and CMEs, we would die.
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Do not forget that it is specifically the “M” in “EM” that provides this protection. Earth’s global magnetic field and gravitational field are easily detectable; when you detect the Earth’s global electrical field, please let us know.
 
DeiRenDopa said:
Question for robinson: what is "Electromagnetism(EM)" (as in the OP of this thread)?

How does the "EM" in the OP relate to contemporary physics?

To what extent do you intend this thread to be a discussion that is science-based?
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Bump.

I really would like an answer to these questions robinson; would you be kind enough to oblige?
 
JEROME DA GNOME said:
The Earth has a charge-to-mass ratio that is less than the proton?
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I'm sure you have looked up the proton's charge-to-mass ratio in a standard textbook, or from the NIST (or other standards body's) website.

Just as surely you have investigated the various estimates of the Earth's mass (including stated uncertainties).

What would the charge of the Earth be (approximately) if it had the same charge-to-mass ratio as the proton?

:gnome:
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I notice that you use this symbol a lot; may I ask what you intend it to mean?
 
The Man said:
Let’s not forget that it is fusion driven by gravity that produces the outward pressure (and EM fields) driving such emissions from the Sun.
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Interesting way to look at things. I'm pretty sure EM is involved in the fusion reactions going on inside the sun. I just realized that some may view gravity, as well as the other fundamental forces, as seperate from matter. It doesn't work that way.


The Man said:
Do not forget that it is specifically the “M” in “EM” that provides this protection. Earth’s global magnetic field and gravitational field are easily detectable; when you detect the Earth’s global electrical field, please let us know.
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Electrical currents in the core create the Magnetic field. Electromagnetic fields create the currents around our planet. You have to consider the earth as a whole, not just the ground. Our EM effects extend well beyond the moons orbit.

The planet sized plasmas in our EM field are as big as the earth. Or bigger. The currents in our EM field create very energetic displays of EM radiation as well. And of course, our EM field is connected to the suns.

A very dynamic situation.
 
The Man said:
Let’s not forget that it is fusion driven by gravity that produces the outward pressure (and EM fields) driving such emissions from the Sun. Otherwise it would just be a big ball of hydrogen, much like Jupiter (but a lot bigger), relatively cold and dark (as compared to the sun).
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Fusion also involves the strong force, no? In think SF wants a part of this wrestling match ;-)

There would be no balls of hydrogen without gravity. And of course, Jupiter is a bit more complex than just that. By EM fields being driven out, do you mean the light as blackbody radiation produced by fusion (light = electromagnetic waves) or the actual magnetic field? The magnetic field is probably produced by the rotating ions in the sun (sun as plasma) but I'm not entirely sure.

The Man said:
Isn’t “EM” suppose to draw in even greater amounts of matter into the solar system and specifically to the Sun in order to provide for a non gravitationally fusion powered but “EM” powered sun, interesting, “EM” must pull in more matter then it hurls out.
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Who huh what? I think I missed what was being talked about on the other thread...
 
robinson said:
Interesting way to look at things. I'm pretty sure EM is involved in the fusion reactions going on inside the sun. I just realized that some may view gravity, as well as the other fundamental forces, as seperate from matter. It doesn't work that way.
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Fusion is just a collision, it has to do with the kinetic energy of the particles, so that, when they collide, they can overcome the electrostatic potential barrier and the nuclear forces take over.

Gravity gives pressure in the core of a star, and this pressure increases the temperature of the gas, increasing the kinetic velocity of the particles. At the same time the increased density of particles increases the collision frequency of the particles and fusion may start.

So, sure there is some E involved, in the repulsive force that needs to be overcome, there is no B involved.

Naturally gravity is created by mass, the electric force is created by charge, the magnetic force is created by currents (or magnetic moments) etc. etc. However, you can have a field and then have a test particle in that field.

robinson said:
Electrical currents in the core create the Magnetic field. Electromagnetic fields create the currents around our planet. You have to consider the earth as a whole, not just the ground. Our EM effects extend well beyond the moons orbit.
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Indeed, in the core of the Earth there is convection, which creates in a dynamo way the magnetic field that we have. There are stray magnetic loops, which are sheared and folded through the convective flow in the iron-sulphur core.
Now, the Earth's magnetic field reaches out to the magnetopause and down the tail. The influence of the Earth in the solar wind is limited to the region inside the bow shock. The moon is most of the time outside the influence region of the Earth, i.e. outside the magnetopause and the bow shock. Only, when traversing on the night side does the moon get into contact with the Earth's magnetic field.
So, only downstream of the Earth, along the tail, is there a region where the magnetic field extends beyond the orbit of the moon.

robinson said:
The planet sized plasmas in our EM field are as big as the earth. Or bigger. The currents in our EM field create very energetic displays of EM radiation as well. And of course, our EM field is connected to the suns.
A very dynamic situation.
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I have no idea what this means. I would hope that planet sized things would be as big as the Earth, but that as a beside.

You seem, as so many electrodynamical non-initiated to put some magical quality to "our EM field," where you first have to explain what that is!

Currents in our EM field? what does that all mean? Do you mean currents in the Earth's magnetosphere, or what?

And NO there is no direct connection between the Earth and the Sun, apart from the fact that the solar wind comes from the Sun (with magnetic field) and hits the Earth. But I guess you are hinting at the ridiculous THEMIS press release, where they were talking about bezillion ampere currents flowing from the Sun to the Earth. That whole press release was rubbish, it was not the first time that such a thing has been observed (although it was the first time for THEMIS) etc. etc. This has been brought down several times already on BAUT.

So, before anything, you need to explain yourself a whole lot better than you have done before.

Also, the premise of your OP is wrong, because you consider a CME to be one object. Although it is one structure, it is not a gravitationally bound body, like e.g. a moon, so you cannot say that gravity will grab it, and the magnetic field will keep it away. That is way to simplistic.
 
tusenfem said:
Currents in our EM field? what does that all mean? Do you mean currents in the Earth's magnetosphere, or what?
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Do some homework. The EM field of the earth is vast and complex, with many startling discoveries still being made.

tusenfem said:
And NO there is no direct connection between the Earth and the Sun, apart from the fact that the solar wind comes from the Sun (with magnetic field) and hits the Earth.
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Now you are showing your ignorance. That is the old view before THEMIS, and I don't think you are going to sell anyone on it.

tusenfem said:
Also, the premise of your OP is wrong, because you consider a CME to be one object. Although it is one structure, it is not a gravitationally bound body, like e.g. a moon, so you cannot say that gravity will grab it, and the magnetic field will keep it away. That is way to simplistic.
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I didn't say any of those thing, you did.

What I said, was:

The sun every now and then ejects a whole bunch of plasma. A CME. And it accelerates towards us. Really really fast.

That isn't a premise. It is a description of an event that occurs regularly.

A few billion tons of plasma has just been ejected from the sun. It is heading towards us at 2000 kilometers per second. It isn't photons, it is plasma. The fourth state of matter. And not only is it fast, and heavy, due to the velocity of the mass, it has a huge mass.

See? More description.

Because it is heading towards us, our gravity is increasing the speed, because gravity does that to mass. It is going to hit us, and really hard.

What is more important? Our planet is a neutral body, according to Sol, and our 3,000,000,000 Tons of matter heading towards us is neutral.

Again, a description of an event. There is no premise, there are questions.
 
The point, which I think was too subtle, was about objects in our local solar system. Sol claimed they are all neutral, and gravity is what matters most. I consider both objects in the example, point out that EM is far more important than gravity in this case, and explain why.

If it was only gravity involved, we would get hammered by the mass of the CME. As well as suffering all kinds of other damage. That isn't a small amount of mass heading our way.

And this happens a lot.

If the earth was neutral, we would be doomed! Doomed I say!

Considering just the ground, one might say the earth is neutral, but that is dumb. The electric currents in the core create a huge magnetic field. You might consider a giant electromagnet "neutral", but that avoids reality, in which the magnetic field doesn't matter or something.

This relates to the larger issues of course.
 
robinson said:
The point, which I think was too subtle, was about objects in our local solar system. Sol claimed they are all neutral, and gravity is what matters most.
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Don't misquote me, please.

If the earth was neutral, we would be doomed! Doomed I say!
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The earth IS almost neutral - how many times do you have to be told that? That doesn't prevent it from having a magnetic field. Did you think refrigerator magnets, or electromagnets for that matter, have a net charge?

Considering just the ground, one might say the earth is neutral, but that is dumb. The electric currents in the core create a huge magnetic field. You might consider a giant electromagnet "neutral", but that avoids reality, in which the magnetic field doesn't matter or something.
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"Dumb". I see.

So electrodynamics and Maxwell's equations are "dumb"? Words with precise technical meanings are "dumb"? But please, don't let reality or the laws of physics stand in the way of your idiotic and ignorant polemics.
 
robinson said:
tusenfem said:
Currents in our EM field? what does that all mean? Do you mean currents in the Earth's magnetosphere, or what?
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Do some homework. The EM field of the earth is vast and complex, with many startling discoveries still being made.
And NO there is no direct connection between the Earth and the Sun, apart from the fact that the solar wind comes from the Sun (with magnetic field) and hits the Earth.
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Now you are showing your ignorance. That is the old view before THEMIS, and I don't think you are going to sell anyone on it.

[...]
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{DRD pulls up a chair, opens a new bottle of fine Italian wine, and prepares to watch robinson make a gigantic fool of himself (once again) ...}

r baby, I think tusenfem has revealed enough about himself, even here in the JREF Forum, for you to have discovered for yourself how many papers he has had published on things like planetary magnetospheres, the subject of his PhD thesis, his involvement in in situ solar system plasma research (solar wind, etc) through space probes, etc, etc, etc. Expect a woppin'.

To other readers: what are the odds that r will offer an apology? or admit to ignorance?
 
robinson said:
Interesting way to look at things. I'm pretty sure EM is involved in the fusion reactions going on inside the sun. .
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Absolutely, but those “EM” forces acting to keep the particles separate is overcome by the compression and kinetic energy resulting from gravity, so in that opposition, gravity wins, as tusenfem points out.


tusenfem said:
Fusion is just a collision, it has to do with the kinetic energy of the particles, so that, when they collide, they can overcome the electrostatic potential barrier and the nuclear forces take over.

Gravity gives pressure in the core of a star, and this pressure increases the temperature of the gas, increasing the kinetic velocity of the particles. At the same time the increased density of particles increases the collision frequency of the particles and fusion may start.
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robinson said:
I just realized that some may view gravity, as well as the other fundamental forces, as separate from matter. It doesn't work that way.
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Well I do not know what you mean by “separate from matter” or who you think might hold that point of view. You’re going to need some more straw.


robinson said:
Electrical currents in the core create the Magnetic field. Electromagnetic fields create the currents around our planet. You have to consider the earth as a whole, not just the ground. Our EM effects extend well beyond the moons orbit.
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Sure, moving charged particles creating a magnetic field and magnetic fields moving charged particles. Electrical fields can also move charged particles and result from specially the separation and not just the movement of charged particles, but charged particles are not always moving as a result of an electrical field, particularly when those currents do not result in a net gain or loss of energy in those charged particles (know a force free currents).

Another driving force for charged particles can be purely kinetic as in convection (as tusenfem also pointed out) and again does not result from an electrical field.


tusenfem said:
Indeed, in the core of the Earth there is convection, which creates in a dynamo way the magnetic field that we have. There are stray magnetic loops, which are sheared and folded through the convective flow in the iron-sulphur core.
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If charged particles become separated (positive from negative) an electrical field is the result but may not by the cause. As in the case of a generator where kinetic energy (armature rotation) and magnetic fields are used to generate an electrical potential or electrical field that did not exist before.
 
robinson said:
You might consider a giant electromagnet "neutral", but that avoids reality, in which the magnetic field doesn't matter or something.
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You apparently do not know the difference between charge and current.
 
NoisyAstronomer said:
Fusion also involves the strong force, no? In think SF wants a part of this wrestling match ;-) .
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True, but it is only after effects of gravity have overcome the repulsion of the charged particles that “SF” has a chance to pin them onto the fusion mat, it is a tag team match, but “G” kicks the crap out of “EM” before “SF” is tagged into the ring.


NoisyAstronomer said:
There would be no balls of hydrogen without gravity. And of course, Jupiter is a bit more complex than just that. By EM fields being driven out, do you mean the light as blackbody radiation produced by fusion (light = electromagnetic waves) or the actual magnetic field? The magnetic field is probably produced by the rotating ions in the sun (sun as plasma) but I'm not entirely sure.
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Again true, but this discussion is not about if there was no gravity, but which might dominate under which circumstances. So if gravity could not overcome the repulsion of charged particles there would be no fusion in the Sun, but gravity would still make it a big (and yes more complex) ball of hydrogen.

You may not be sure, but you are still correct, it is a similar convection dynamo effect as produces the Earth’s magnetic field. “EM fields being driven out”? I am not sure how you got that from what I said, so I will clarify.

The Man said:
“Let’s not forget that it is fusion driven by gravity that produces the outward pressure (and EM fields) driving such emissions from the Sun.”
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(bolding added) So it is “EM” fields created by gravity powered fusion helping to drive the emissions and not “EM fields being driven out”.


NoisyAstronomer said:
Who huh what? I think I missed what was being talked about on the other thread.
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Well, that would not have been hard to do, an externally “EM” powered Sun is one of the alternatives presented and discussed on that thread. That would require significant highly energized particles to be entering the solar system and specifically the sun to provide that power.
 
sol invictus said:
Don't misquote me, please.
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I always provide a link when I quote somebody, so interested parties can see the entire context.

sol invictus said:
You failed to understand the point. Both gravity and plasma can in principle be "scaled". That is, we know what the laws of physics are and so we can deduce what the situation will be when we scale everything up in size. One of the immediate and obvious consequences is that gravity is much stronger than electromagnetism (for large objects which are uncharged on average).
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I hope we all agree that "stronger" is relative, as my example should make clear. If everything was a solid neutral body, then gravity would be all there is. Obviously most of the Universe is plasma, which may be "neutral" from the point of view, that if we add the charges up we get a balanced or neutral charge. But in reality, plasmas carry magnetic fields with them, and they move, so they are not neutral in regards to what happens. Like the earth is not neutral in regards to what happens when massive amounts of MASS slams into it. Because the Mass isn't really neutral. Moving ionized particles create, well, you know. If they slam into each other, they also create all kinds of EM radiation as well.

sol invictus said:
The earth IS almost neutral - how many times do you have to be told that? That doesn't prevent it from having a magnetic field. Did you think refrigerator magnets, or electromagnets for that matter, have a net charge?.
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You keep talking about "net charge". Nobody thinks the earth or moon or sun are attracted to each other because of EM. OK maybe Jerome, but nobody really is saying that, except maybe him. I don't want to even give that idea more than a passing chuckle. Maybe a guffaw.

Of course the earth, as well as most non-plasma matter is neutral. That is how things are. Otherwise there would be electric currents and lightning everywhere, a terrible situation.

sol invictus said:
So electrodynamics and Maxwell's equations are "dumb"? Words with precise technical meanings are "dumb"? But please, don't let reality or the laws of physics stand in the way of your idiotic and ignorant polemics.
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You said that, not me. Yes, precise definitions are used to avoid misunderstanding stuff. Saying something is neutral, in regards to charge, seems to mean something. I'm not sure what you want to get across.

In regards to gravity VS Electromagnetism, (forget about that strong force, it isn't even in the picture), some things, some very large things, are dominated by EM, not gravity.

Like the magnetic field of the sun. And the solar wind, and the galactic wind, and somewhere way out there, I don't think anybody is 100% sure yet, the solar wind (and Magnetic field) meets the Galactic wind (and it's magnetic field), and stuff happens. If gravity has little or no effect on the plasma streaming out of the sun, near the sun, it has almost no effect on it way out there, where mysterious things are happening.

Maybe. Best theories I have read say gravity is not a player there. But the radio energy coming from the heliopause says there is energy being released and transmuted and other interesting stuff. Shock waves, and mingling of magnetic fields and who knows what.

Is the boundary out there, with it's shock waves and radio energies and maybe teardrop shape, is that a large thing? It might extend to our nearest neighbor, we know it is at least halfway there.

That is a big thing. A magnetic plasma "thing" that is so big it is hard to imagine. Is it neutral? No net charge? Possibly so.

So gravity must dominate it's structure. Because according to Sol, big things are neutral, so only gravity matters.

Wait, let me quote you.

"One of the immediate and obvious consequences is that gravity is much stronger than electromagnetism (for large objects which are uncharged on average)."
-Sol
 
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robinson said:
I always provide a link when I quote somebody, so interested parties can see the entire context.
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Except when you don't.

You keep talking about "net charge". Nobody thinks the earth or moon or sun are attracted to each other because of EM. OK maybe Jerome, but nobody really is saying that, except maybe him.
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Except Zeuzzz and BAC.

I don't want to even give that idea more than a passing chuckle. Maybe a guffaw.
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Really? So why did you lift a quote of mine from a thread demonstrating how stupid that is and start a new thread about it?

Wait, don't tell me.... because you're a troll?
 
robinson said:
Do some homework. The EM field of the earth is vast and complex, with many startling discoveries still being made.
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Do my homework???????? Sorry old chap, but magnetospheric physics IS MY JOB, I work with data from Cluster, DoubleStar, Themis, Venus Express, Galileo, ......
see www geocities com/DrMartinV

But i see that you do not explain yourself, what DO YOU MEAN WITH Currents in our EM field? what does that all mean? Do you mean currents in the Earth's magnetosphere, or what? If you want to discuss something, you first have to explain clearly what you mean you want discussed.

robinson said:
Now you are showing your ignorance. That is the old view before THEMIS, and I don't think you are going to sell anyone on it.
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Now that is not "the old view before THEMIS. That press release was a bunch of garbage, written by a press agent that had as little knowledge of space plasma physics as you do.

robinson said:
I didn't say any of those thing, you did.

What I said, was:

The sun every now and then ejects a whole bunch of plasma. A CME. And it accelerates towards us. Really really fast.

That isn't a premise. It is a description of an event that occurs regularly.

A few billion tons of plasma has just been ejected from the sun. It is heading towards us at 2000 kilometers per second. It isn't photons, it is plasma. The fourth state of matter. And not only is it fast, and heavy, due to the velocity of the mass, it has a huge mass.

See? More description.

Because it is heading towards us, our gravity is increasing the speed, because gravity does that to mass. It is going to hit us, and really hard.

What is more important? Our planet is a neutral body, according to Sol, and our 3,000,000,000 Tons of matter heading towards us is neutral.

Again, a description of an event. There is no premise, there are questions.
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Our Earths is basically neutral (due to all kinds of processes perfect neutrality is naturally not possible). If there would be a great charge imbalance with respect to the sun, then through the electrons and ions of the solar wind this imbalance would be negated in a very short time.

All the particles of the CME will be pulled on by gravity, and when it hits we notice it in the magnetic field data and in the aurora etc. However, when the CME hits it is not like there is an impact like a big asteroid. It is all single particles that hit the magnetosphere and put their momentum "into the magnetic field". So, the whole premise of the OP is badly put, because you seem to think that a CME is one massive object, whereas it consists of plasma and magnetic fields, and nothing solid.
 
sol invictus said:
You keep talking about "net charge". Nobody thinks the earth or moon or sun are attracted to each other because of EM. OK maybe Jerome, but nobody really is saying that, except maybe him.
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Except Zeuzzz and BAC.
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Nonsense Sol. I've probably done the calculation to show how weak electrostatic/magnetostatic forces between large mass bodies of planetary/solar size are more times than you on this forum.

And saying that the Earth is completely neutral is misleading. You can work out using lightning and the conductivity of the atmosphere the surface of the Earth is 250,000 to 400,000 Volts negatively charged in repsect to the ionosphere, giving rise to an electric field (a vertical electric field at the surface, pointing down, that averages 117 N/C), but the atmosphere has roughly equal and opposite charge, so the Earth when considered from this particular point is as a whole roughly neutral.

By using Alfevns technique of considering the entire electric current system, basically a circuit analysis type arroach, this value can be worked out easily. Such an approach has proved very sucessful for modelling mercurys complex birkeland current system, and was the same approach Alfven used to deduce the properties of the heliospheric current circuit, his current disruption models, and many other phenomena.

The electrical Environment of the Earth's Atmosphere: A Review
The study of the electrical environment of the Earth’s atmosphere has rapidly advanced during the past century. Great strides have been made towards the understanding of lightning and thunderstorms and in relating them to the global electric circuit. The electromagnetic fields and currents connect different parts of the Earth’s environment, and any type of perturbation in one region affects another region. Starting from the traditional views in which the electrodynamics of one region has been studied in isolation from the neighboring regions, the modern theory of the global electrical circuit has been discussed briefly. Interconnection and electrodynamic coupling of various regions of the Earth’s environment can be easily studied by using the global electric circuit model.[....]

The global atmospheric electric circuitThe study of the global atmospheric electric circuit has advanced dramatically in the past 50 years. Large advances have been made in the areas of lightning and thunderstorm research, as related to the global circuit. We now have satellites looking down on the Earth continuously, supplying information on the temporal and spatial variability of lightning and thunderstorms. Thunderstorms are electric current generators, which drive electric currents up through the conducting atmosphere. They maintain the ionosphere at a potential of ~+250 kV with respect to the Earth's surface. The global electric circuit is completed by currents ~2pA/m2 flowing through the fair weather atmosphere, remote from thunderstorms, and by transient currents due to negative cloud-to-ground lightning discharges. The time constant of the circuit, ~>2min, demonstrates that thunderstorms must occur continually to maintain the fair weather electric field. New discoveries have been made in the field of sprites, elves and blue jets, which may have a direct impact on the global circuit. [....]
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http://www.madsci.org/posts/archives/2000-10/972662284.Es.r.html
The solid Earth has a negative charge of about a half million coulombs. The atmosphere has a roughly equal and opposite charge, so that the Earth as a whole is roughly neutral. The charge difference produces a "fair weather electric field" in the lower atmosphere averaging about 6 volts per meter -- however, this field varies strongly with altitude, and is nearly 100 volts per meter at ground level. The total voltage difference between the ground charge and the atmosphere's charge (which exists roughly 30-50 km up) is about 300,000 volts. A simple calculation shows that the total energy stored in the fair weather electric field is 150 billion joules.

Since air isn't a perfect insulator, electrons leak from ground to air constantly, trying to reduce the charge difference to zero. This current amounts to 2000 amps. [....]
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http://www.ava.fmi.fi/~tjt/fairw.html
The thundercloud charge centres, accumulating tens of coulombs of electricity, are discharged mainly by lightning: cloud flashes (most abundant) cause mutual neutralization of the centres; the lower centre is also discharged to the ground - by negative ground flashes - and charges up the earth (the positive centre is discharged similarly, but by a smaller amount). An excess charge will be left in the upper positive centre, and it leaks by conduction to the surrounding air, about one ampere per thunderstrom cell. Because of the exponentially increasing conductivity, most of this leak current is guided to the ionosphere, where it is distributed over the globe and charges the upper atmosphere to a potential of about 300,000 V with respect to the ground. This "ionospheric potential" maintains the so-called fair-weather current, whose density is about 2 pA/m2 (picoamperes per square metre). According to Ohm's law, the fair-weather current density and the electric conductivity are associated with a downward electric field, about 100 V/m near the ground. The number of simultaneously active thunder cells ("thunderstorms") over the globe is about 1000-2000, so the whole circuit carries a current of about 1000 amperes.

Why does not the (fair-weather) atmospheric electric field cause a shock of 200 V to a standing human? Because the human is grounded in practice; the poorly conducting air cannot charge up a grounded object. Below a thundercloud, where the ground-level electric field may be tens of kV/m, the situation is different - but then the threat comes from a lightning strike. [.....]
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http://courses.eas.ualberta.ca/eas202/Lecture20/lightning/
At any moment there are about 2000 thuderstorms takingplace on the Earth. In total these are responsible for transferring negative charge down to the ground at 1800A. At this rate the groud should gain -1.6x108 C per day. If this gain in charge was not balanced by an eqivalent loss the ground would soon become so charged that lightning strikes would not be possible due to repulsion. [...]
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THE MODEL OF THE NONSTATIONARY ELECTRIC FIELD IN THE LOWER
ATMOSPHERE




Its really not a simple as saying the Earth is completely neutral. Or any other body for that matter. A lot of other things have to be considered. The values above do not consider the electric field produced when gravity sepates the electrons from the nuclei of their atoms (due primarily to their different masses), creating a radial field of electric dipoles withing the Earth, which has been deduced to charge the sun at ~100 coulombs. I wonder what value of charge they would get for the sun if they deduced it from a circuit analysis type approach like is done with the Earth? I guess its hard to measure the lightning and circuits on the sun when the surface is many magnitudes brighter than the currents and lightning itself :)
 
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Robinson, you seem to have some confusion over the nature of electromagmetism. Electricity and magnetism aren't the same things. A magnetic field can be induced with electrical current in a wire, sufficient but not necessarily: a magnet also does so with no electrical current. Similarly a magnet can cause current to move in a wire, but it is not the only way - batteries use no magentic principles to create current. There are magnetic fields, and there are electrostatic fields, and they are not at all the same things. Only in some cases does a phenomenon have aspects of both, and they always (I think) require periodic movement - a frequency.

Think about the complications of those thoughts before you so cavalierly call upon EM to face off against other forces.
 
shadron said:
Robinson, you seem to have some confusion over the nature of electromagmetism[sic]. Electricity and magnetism aren't the same things.
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One of the problems with electromagnetism is that it is difficult to reconcile with classical mechanics, but it is compatible with special relativity. According to Maxwell's equations, the speed of light in a vacuum is a universal constant, dependent only on the electrical permittivity and magnetic permeability of free space. This violates Galilean invariance, a long-standing cornerstone of classical mechanics.

One way to reconcile the two theories is to imagine a luminiferous aether through which the light propagates. But we know there is no aether. Einstein created special relativity, which replaces classical kinematics with a new theory of kinematics that is compatible with classical electromagnetism.

Relativity theory shows that in moving frames of reference a magnetic field transforms to a field with a nonzero electric component, as well as electricity always having a magnetic component, thus firmly showing that they are two sides of the same coin, and thus the term "electromagnetism".

By looking at reality through the theory of special relativity, we have formulas for how electromagnetic objects, in particular the electric and magnetic fields, are altered under a Lorentz transformation from one inertial frame of reference to another.

It also shows that an electric force in one frame of reference may be a magnetic force in another and vice-versa, and likewise that certain laws of magnetism can be "derived" from corresponding laws of electricity and vice-versa.

This also allows a notation for the laws of electromagnetism, namely the "manifestly covariant" tensor form.

The covariant formulation of classical electromagnetism makes it simple to prove that the laws of classical electromagnetism take the same form in any inertial coordinate system, and also provide a way to translate the fields and forces from one frame to another.

Now go argue with somebody else about electromagnetism.
 
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robinson:

shadron is still correct. Although they are closely related, electricity and megnetism are NOT the same thing; they are differnet aspects fo the same force, but not the same thing.

I'm reminded of the tale about three blind men trying to describe an elephant:

Man 1 (at the tail): An elephant is like a rope!

Man 2 (at the nose): No, it's like a snake!

Man 3 (in the middle): No, it's like a rhino!

The elephant is like an elephant. Parts of it may be like a rope, and parts like snake, and parts like a rhino, but the tail is not like the trunk, and these are not like the middle. The same holds true for electromagnetism.

You'd do well to learn humility when arguing with experts (which, to make clear, I am not). Reading a few web pages does not make you proficient. it woudl also help to provide your sources (wikipedia it appears, in this case:covariance, Electromagnetism), especially when many of your statements are very closely direct quotes from those pages.

It's your posts like this that I find highly ironic, especially considering the quote in your sig line.
 
Do you even know what the electromagnetic field is? As currently defined?

Did you know that electromagnetism led Einstein to create the theory of special relativity?

According to modern physics, the photon is responsible for electromagnetic phenomena. It is the carrier of electromagnetic radiation. That light, as well as any other radiation, as well as any kind of magnetism, is part of electromagnetism?

Which is why the topic title says EM, not electricity, not mage=netism, not light, but Electromagnetism. A fundamental force of the Universe.

Before EM, I am humble.
 
robinson said:
One of the problems with electromagnetism is that it is difficult to reconcile with classical mechanics, but it is compatible with special relativity. According to Maxwell's equations, the speed of light in a vacuum is a universal constant, dependent only on the electrical permittivity and magnetic permeability of free space. This violates Galilean invariance, a long-standing cornerstone of classical mechanics.

One way to reconcile the two theories is to imagine a luminiferous aether through which the light propagates. But we know there is no aether. Einstein created special relativity, which replaces classical kinematics with a new theory of kinematics that is compatible with classical electromagnetism.

Relativity theory shows that in moving frames of reference a magnetic field transforms to a field with a nonzero electric component, as well as electricity always having a magnetic component, thus firmly showing that they are two sides of the same coin, and thus the term "electromagnetism".

By looking at reality through the theory of special relativity, we have formulas for how electromagnetic objects, in particular the electric and magnetic fields, are altered under a Lorentz transformation from one inertial frame of reference to another.

It also shows that an electric force in one frame of reference may be a magnetic force in another and vice-versa, and likewise that certain laws of magnetism can be "derived" from corresponding laws of electricity and vice-versa.

This also allows a notation for the laws of electromagnetism, namely the "manifestly covariant" tensor form.

The covariant formulation of classical electromagnetism makes it simple to prove that the laws of classical electromagnetism take the same form in any inertial coordinate system, and also provide a way to translate the fields and forces from one frame to another.

Now go argue with somebody else about electromagnetism.
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Uh, huh. Well, you can sure talk the talk, robinson, far enough to snow me. Why then do you say things like this?

Considering just the ground, one might say the earth is neutral, but that is dumb. The electric currents in the core create a huge magnetic field. You might consider a giant electromagnet "neutral", but that avoids reality, in which the magnetic field doesn't matter or something.
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It's dumb to say the earth is electrically neutral, because it has a magnetic field?
 
robinson said:
One of the problems with electromagnetism is that it is difficult to reconcile with classical mechanics, but it is compatible with special relativity. According to Maxwell's equations, the speed of light in a vacuum is a universal constant, dependent only on the electrical permittivity and magnetic permeability of free space. This violates Galilean invariance, a long-standing cornerstone of classical mechanics.

One way to reconcile the two theories is to imagine a luminiferous aether through which the light propagates. But we know there is no aether. Einstein created special relativity, which replaces classical kinematics with a new theory of kinematics that is compatible with classical electromagnetism.

Relativity theory shows that in moving frames of reference a magnetic field transforms to a field with a nonzero electric component, as well as electricity always having a magnetic component, thus firmly showing that they are two sides of the same coin, and thus the term "electromagnetism".

By looking at reality through the theory of special relativity, we have formulas for how electromagnetic objects, in particular the electric and magnetic fields, are altered under a Lorentz transformation from one inertial frame of reference to another.

It also shows that an electric force in one frame of reference may be a magnetic force in another and vice-versa, and likewise that certain laws of magnetism can be "derived" from corresponding laws of electricity and vice-versa.

This also allows a notation for the laws of electromagnetism, namely the "manifestly covariant" tensor form.

The covariant formulation of classical electromagnetism makes it simple to prove that the laws of classical electromagnetism take the same form in any inertial coordinate system, and also provide a way to translate the fields and forces from one frame to another.

Now go argue with somebody else about electromagnetism.
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You seem to have missed some key points, robinson, particularly charge invariance, that charge remains the same regardless of your reference frame. As well as the distinction between the two constituents of an electrical vector field, that results.

http://en.wikipedia.org/wiki/Charge_invariance


http://en.wikipedia.org/wiki/Moving_magnet_and_conductor_problem

In addition to consistency, it would be nice to consolidate the descriptions so they appear to be frame-independent. A clue to a framework-independent description is the observation that magnetic fields in one reference frame become electric fields in another frame. Likewise, the solenoidal portion of electric fields (the portion that is not originated by electric charges) becomes a magnetic field in another frame: that is, the solenoidal electric fields and magnetic fields are aspects of the same thing.[2] That means the paradox of different descriptions may be only semantic. A description that uses scalar and vector potentials φ and A instead of B and E avoids the semantical trap. A Lorentz-invariant four vector Aα = (φ / c0, A ) replaces E and B[3] and provides a frame-independent description (albeit less visceral than the E– B–description). [4] An alternative unification of descriptions is to think of the physical entity as the electromagnetic field tensor, as described later on. This tensor contains both E and B fields as components, and has the same form in all frames of reference.
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Referances and notes

2. There are two constituents of electric field: a solenoidal field (or incompressible field) and a conservative field (or irrotational field). The first is transformable to a magnetic field by changing the frame of reference, the second originates in electric charge, and transforms always into an electric field, albeit of different magnitude. .
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http://en.wikipedia.org/wiki/Solenoidal_field

http://en.wikipedia.org/wiki/Conservative_field

It would be better if you try to read and understand references you use, instead of just paraphrasing them.
 
The Man said:
True, but it is only after effects of gravity have overcome the repulsion of the charged particles that “SF” has a chance to pin them onto the fusion mat, it is a tag team match, but “G” kicks the crap out of “EM” before “SF” is tagged into the ring.
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Teehee. Best description ever.

The Man said:
Again true, but this discussion is not about if there was no gravity, but which might dominate under which circumstances. So if gravity could not overcome the repulsion of charged particles there would be no fusion in the Sun, but gravity would still make it a big (and yes more complex) ball of hydrogen.
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Hmmm. I know this isn't what the discussion is about, but indeed gravity first acts on neutral atmoic hydrogen to make stars, it is only in the hot, pressurized interior does hydrogen ionize and the EM force become important. Then again, EM forces hold atoms together in the first place. Ack! I think the whole thing of asking "which is more important" is just trivial. But asking which is stronger in certain circumstances can be talked about. It's just complicated.

The Man said:
You may not be sure, but you are still correct, it is a similar convection dynamo effect as produces the Earth’s magnetic field. “EM fields being driven out”? I am not sure how you got that from what I said, so I will clarify

(bolding added) So it is “EM” fields created by gravity powered fusion helping to drive the emissions and not “EM fields being driven out”.
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Again, I'm still not sure whether we're talking about electric and magnetic fields or light.

The Man said:
Well, that would not have been hard to do, an externally “EM” powered Sun is one of the alternatives presented and discussed on that thread. That would require significant highly energized particles to be entering the solar system and specifically the sun to provide that power.
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Hmmm... I may have heard of that before.
 
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