Similarity beetwen magnetic and gravitational field

Click For Summary

Discussion Overview

The discussion explores the analogy between magnetic fields and gravitational fields, particularly in terms of their effects on objects. Participants examine whether magnetic fields can accelerate ferromagnetic objects in a manner similar to how gravitational fields can affect material objects, including spacecraft.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • Some participants suggest that magnetic fields act on ferromagnetic objects similarly to how gravitational fields act on material objects, proposing that magnetic fields can be used to accelerate these objects.
  • Others argue that the analogy between magnetic and gravitational fields is not straightforward, noting that the gravitational field is more familiar and that electric fields could serve as a better analogy.
  • A participant questions the dynamics of a ball bearing passing near a magnet, suggesting that the magnet will attract the ball and modify its speed and trajectory.
  • Another participant confirms that the trajectory of the ball bearing will indeed be modified and mentions that the magnet will also be pulled towards the ball bearing, although it is statically attached to the Earth.
  • One participant introduces the idea that the perception of magnetic attraction can be misleading, as the mass of the objects involved can influence the apparent direction of attraction.
  • There is a discussion about the concept of magnetic induction, where the ball bearing becomes slightly magnetized as it passes a magnet, affecting its trajectory and speed.
  • Participants express uncertainty about how the increase in kinetic energy occurs in the context of magnetic potential energy and its relationship to gravitational potential energy.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the analogy between magnetic and gravitational fields. Multiple competing views remain regarding the nature of magnetic attraction and the implications of magnetic fields on ferromagnetic objects.

Contextual Notes

Participants highlight the complexity of the analogy, noting that assumptions about the behavior of magnetic fields and gravitational fields may not hold universally. The discussion reflects a range of interpretations and uncertainties regarding the underlying physics.

atc
Messages
3
Reaction score
0
Hello everybody!

I was read in a web page that magnetic field act over the ferromagnetic objects in the same way gravitational field act over any material object, mean magnetic field is a potential field energy as gravitational field. (http://van.physics.uiuc.edu/qa/listing.php?id=432")
As you know, a gravitational field of a planet can be used to accelerate a spaceship which passes near by this field and have a certain speed that alow the motion of the ship to be changed by gravitation but also prevent the ship to fall to the planet. This action give an amount of energy to the ship, increasing its speed.
Now, because magnetic field behave on ferromagnetic materials similar as gravitational field on any material objects, mean is possible to use magnetic field to accelerate ferromagnetic objects, in the same way a gravitational field does with ships?
 
Last edited by a moderator:
Physics news on Phys.org
atc said:
Hello everybody!

I was read in a web page that magnetic field act over the ferromagnetic objects in the same way gravitational field act over any material object, mean magnetic field is a potential field energy as gravitational field. (http://van.physics.uiuc.edu/qa/listing.php?id=432")
As you know, a gravitational field of a planet can be used to accelerate a spaceship which passes near by this field and have a certain speed that alow the motion of the ship to be changed by gravitation but also prevent the ship to fall to the planet. This action give an amount of energy to the ship, increasing its speed.
Now, because magnetic field behave on ferromagnetic materials similar as gravitational field on any material objects, mean is possible to use magnetic field to accelerate ferromagnetic objects, in the same way a gravitational field does with ships?

Er... you did not understand the analogy. This person answering the question could have easily used an electric field example just equally well. In this case, the gravitational field was used because it is more familiar. But it doesn't mean that such analogy should be implied to mean that they can be identically described (seen any magnetic monopole lately?).

Zz.
 
Last edited by a moderator:
ZapperZ said:
Er... you did not understand the analogy. This person answering the question could have easily used an electric field example just equally well. In this case, the gravitational field was used because it is more familiar. But it doesn't mean that such analogy should be implied to mean that they can be identically described (seen any magnetic monopole lately?).

Zz.

OK.
So what's happen then if, let say, a ball bearing having a speed enough high to pas near a magnet placed on a flat table, but not to stick on the magnet?
The magnet will attract the ball and modify its speed and trajectory, isn't it?
 
Yes, of course, the trajectory of the speeding ball bearing will be modified.

Keep in mind though, that this event also pulls the magnet towards the ball bearing in-flight. Perhaps not much to mention since the magnet is statically attached to what eventually is the earth.

Also, given your scenario, there is a magnetic induction imposed upon the ball bearing as it fly's past a close, static magnet. Thus the ball bearing itself becomes slightly magnetized, affecting the speed and altered trajectory by that virtue as well.
 
Perhaps this is not relevant here, but I have come across a great deal of misunderstanding regarding magnetic attraction within the general public.

A magnet does NOT exclusively pull towards itself, say, a steel disk. To verify this, one simply needs to have the mass of the steel disk GREATER than that of the magnet, and it will appear as if the massive steel disk is pulling the magnet towards the steel.

In reality, what's happening is that the magnetic field entagles both objects and seeks a collapse to a lesser separation of the collective center-of-mass. The aspect of inertia provides an illusion as to what is being "attracted", whether it's the magnet or the steel disk. The greater(or static) mass wins the illusion of being "attractive.

Just some thoughts...
 
pallidin said:
Keep in mind though, that this event also pulls the magnet towards the ball bearing in-flight. Perhaps not much to mention since the magnet is statically attached to what eventually is the earth.

Indeed. Your point is: the magnet act over the ball bearing, changing its trajectory and speed and kinetic energy, but also the ball act over the Earth through magnet, changing its speed, trajectory and so kinetic energy (respecting proportions, of course)?
So, returning to my initial question (can a magnet act similar to a gravitational field, regarding potential energy), this mean, we have an increase of kinetic energy of ball bearing and magnet (or Earth), and the ball continues its trajecory away from the magnet, mean its magnetic potential energy increase (http://van.physics.uiuc.edu/qa/listing.php?id=411"), but also its kinetic energy has been increased. I stil don't understand how this come!

pallidin said:
Also, given your scenario, there is a magnetic induction imposed upon the ball bearing as it fly's past a close, static magnet. Thus the ball bearing itself becomes slightly magnetized, affecting the speed and altered trajectory by that virtue as well.

Well, yes, but the question remain the same.
 
Last edited by a moderator:

Similar threads

  • · Replies 7 ·
Replies
7
Views
13K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 27 ·
Replies
27
Views
4K
  • · Replies 43 ·
2
Replies
43
Views
5K
  • · Replies 35 ·
2
Replies
35
Views
3K
  • · Replies 5 ·
Replies
5
Views
5K
  • · Replies 22 ·
Replies
22
Views
3K
Replies
10
Views
4K