Magnets and space...
Post Reply
 
Thread Rating:
  • 0 Votes - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
11-10-2011, 10:29 PM
Magnets and space...
So I was thinking, what would happen with metal dust in space? How would it react to a magnet. If you notice in the picture, the dust will form with the magnetic field. Now if you think about it, the magnetic field isn't flat, but the dust lays that way because of gravity. If this was to be done in space would we have a type of 3d mapping of the magnetic field of magnets?

http://people.web.psi.ch/quitmann/BarMagnet_Large.jpg

"We Humans are capable of greatness." -Carl Sagan
Find all posts by this user
Like Post Quote this message in a reply
11-10-2011, 10:58 PM
RE: Magnets and space...
Have you submitted that idea here: http://www.youtube.com/spacelab?feature=inp-yo-space

If you haven't you should! It sounds interesting.

“Forget Jesus, the stars died so you could be born.” - Lawrence M. Krauss
Find all posts by this user
Like Post Quote this message in a reply
11-10-2011, 11:37 PM
RE: Magnets and space...
I think since magnetism is a vastly greater force than gravity the only difference in space would be the vacuum. That would not have much effect on the metal dust. I don't think the type of metal or the magnetic strength would make much difference. Gravity is an extremely weak force relatively speaking. Now the electromagnetic force... that's pretty hefty.

Who can turn skies back and begin again?
Find all posts by this user
Like Post Quote this message in a reply
12-10-2011, 08:52 AM
RE: Magnets and space...
(11-10-2011 11:37 PM)defacto7 Wrote:  I think since magnetism is a vastly greater force than gravity the only difference in space would be the vacuum. That would not have much effect on the metal dust. I don't think the type of metal or the magnetic strength would make much difference. Gravity is an extremely weak force relatively speaking. Now the electromagnetic force... that's pretty hefty.

I don't think you understood my OP.

I am wondering, since metal dust forms arcs around the poles of magnets if it would do the same in space, only in a 3 dimensional form. Gravity causes it to lay flat. No gravity will either cause it to take a 3 dimensional form or just form as close as possible that it can to the magnet.

And BTW Deep thought, 14-18 only. =(

"We Humans are capable of greatness." -Carl Sagan
Find all posts by this user
Like Post Quote this message in a reply
12-10-2011, 10:15 AM (This post was last modified: 12-10-2011 10:50 AM by defacto7.)
RE: Magnets and space...
(12-10-2011 08:52 AM)NotSoVacuous Wrote:  
(11-10-2011 11:37 PM)defacto7 Wrote:  I think since magnetism is a vastly greater force than gravity the only difference in space would be the vacuum. That would not have much effect on the metal dust. I don't think the type of metal or the magnetic strength would make much difference. Gravity is an extremely weak force relatively speaking. Now the electromagnetic force... that's pretty hefty.

I don't think you understood my OP.

I am wondering, since metal dust forms arcs around the poles of magnets if it would do the same in space, only in a 3 dimensional form. Gravity causes it to lay flat. No gravity will either cause it to take a 3 dimensional form or just form as close as possible that it can to the magnet.

And BTW Deep thought, 14-18 only. =(

I think the difference in gravity in space compared to the surface of the earth is negligible when comparing that to the immense difference between gravitational force and the electromagnetic force. For instance, If a guy jumps off a building, what happens when he hits the ground? Splat. Why? The electromagnetic force. Even though gravity pulls him downward at a high velocity, gravity isn't strong enough to overcome the electromagnetic force that holds atoms together. If the electromagnetic force was equal to gravity, his body would go strait though the earth and out the other side. In space gravity is basically a non-issue compared to electromagnetism. The amount of gravity that is present in the magnet and the dust is almost nothing. I think you are visualizing the effects gravity has on us as if it is the same or similar to electromagnetism. Again, gravity seems like it has a huge effect, but it's effect can only be realized by our experience on massive scales... planets, stars, and over huge distances. Electromagnetism effects the extremely tiny. There would be no effective change in our observation.

One other point. You are assuming gravity causes it to lay flat. I think not. It's the magnetism that causes it to lay flat if it's present. Gravity makes it lay flat if no magnetism is present. Those are 2 very different states.

We could ask Zatamon. He's a physicist. I'm definitely not. If I'm wrong, I'd be glad to change my view of how those forces work. I mean, gee, I'm an atheist for christ sakes. That's what I'm supposed to do... and I can't do that experiment myself.

Who can turn skies back and begin again?
Find all posts by this user
Like Post Quote this message in a reply
12-10-2011, 02:31 PM
 
RE: Magnets and space...
(12-10-2011 10:15 AM)defacto7 Wrote:  I think the difference in gravity in space compared to the surface of the earth is negligible when comparing that to the immense difference between gravitational force and the electromagnetic force.

Take a look at the site of Wikipedia's the Earths Magnetic Field article.

defacto is absolutely right: the force of gravity compared to the force of electromagnetic forces is completely negligible (the ratio is 2.4x10^(-43)). Gravity does not enter the picture at all.

Yes, you would have a 3D version of the image posted in the OP.



(12-10-2011 08:52 AM)NotSoVacuous Wrote:  I am wondering, since metal dust forms arcs around the poles of magnets if it would do the same in space, only in a 3 dimensional form. Gravity causes it to lay flat. No gravity will either cause it to take a 3 dimensional form or just form as close as possible that it can to the magnet.

Metal dust forms arcs around a bar magnet because the metal dust particles are magnetized into tiny magnetic dipoles that line up in the direction of the magnetic force field's B vector, thus visualizing the magnetic forces around the bar magnet. That image is what lead Faraday to his revolutionary concept of "Fields".

The Earth's magnetic field is not influenced by the presence, or absence, of metal dust around it at all. It is still the 3D version of what the OP image showed. However, the metal dust eventually will fall down onto the ground (speed depending on the size of the particles) due to gravitational forces. The Earth's magnetic field is affected by the solar wind, as you saw it on the Wikipedia article.
Quote this message in a reply
[+] 1 user Likes Zatamon's post
12-10-2011, 07:11 PM
RE: Magnets and space...
I'd like to differ.. NSV's idea is good because while electromagnetism is a much stronger force - tracing field lines with iron filings would be more possible in space with gravity out of the picture. Magnetism is such a short range force. The field strength decreases at an accelerated exponential rate depending on distance.

Gravity quickly trumps the em field strength after a tiny distance.

“Forget Jesus, the stars died so you could be born.” - Lawrence M. Krauss
Find all posts by this user
Like Post Quote this message in a reply
12-10-2011, 08:11 PM
 
RE: Magnets and space...
(12-10-2011 07:11 PM)DeepThought Wrote:  I'd like to differ.. NSV's idea is good because while electromagnetism is a much stronger force - tracing field lines with iron filings would be more possible in space with gravity out of the picture. Magnetism is such a short range force. The field strength decreases at an accelerated exponential rate depending on distance.

Gravity quickly trumps the em field strength after a tiny distance.

Both forces are inversely proportionate to the square of distance (see Newton's gravitational formula and the Biot-Savart law for magnetic force).
Quote this message in a reply
12-10-2011, 09:54 PM (This post was last modified: 12-10-2011 10:14 PM by DeepThought.)
RE: Magnets and space...
(12-10-2011 08:11 PM)Zatamon Wrote:  Both forces are inversely proportionate to the square of distance (see Newton's gravitational formula and the Biot-Savart law for magnetic force).

Actually... This is the formula you want for finding force exerted between 2 magnets or between a magnet and a chunk of iron.

http://en.wikipedia.org/wiki/Force_betwe...etic_force

Have a play around here: http://www.kjmagnetics.com/calculator.asp

It changes by more than the inverse square law like I was saying...



Magnetism is really a complex field all on it's own. Most of it goes over my head. I know it's a short range force when compared with gravity. Also things like magnetic permeability of a substance comes into play. Magnets can be wrapped in iron with only one of the poles exposed (as they are in loud speakers). That changes the shape of the magnetic field significantly. Calculating forces in different locations while taking all that into account is beyond most people.

“Forget Jesus, the stars died so you could be born.” - Lawrence M. Krauss
Find all posts by this user
Like Post Quote this message in a reply
12-10-2011, 10:40 PM
 
RE: Magnets and space...
(12-10-2011 09:54 PM)DeepThought Wrote:  Magnetism is really a complex field all on it's own. Most of it goes over my head. I know it's a short range force when compared with gravity.

You are right about this when you consider specialized geometrical configurations, using the assumptions in the article you linked to.

Quote:Calculating forces in different locations while taking all that into account is beyond most people.

That is why I used the general formula first discovered by Biot/Savart and Ampere independently.

Ampère’s force law states that the force acting between two infinitesimal current elements ds and ds’ at distance ‘r’ from each other depends on the currents i and i’ flowing through them and on three angles of their mutual (3-dimensional) orientation according to the following formula:

df = i * i’ * ds *ds’/r2 * (sina*sinb*cosc - ½ cosa*cosb )

In the special case when the two current segments are parallel (a=90; b=90; c=0)
The force law takes the simple form of:

df = i * i’ * ds *ds’/r2

In either case, I don't quite understand what gravity and magnetism have to do with each other, as presented in the OP. Gravity is an attractive force that acts on the mass of the hypothetical metal particles in space. The magnetic field of Earth, on the other hand turns the metal particles into tiny magnetic dipoles and rotates them to align with the magnetic field lines.

So what was the point again?
Quote this message in a reply
[+] 1 user Likes Zatamon's post
Post Reply
Forum Jump: