What causes magnetic repulsion and attraction?

[Prashan Shan]

is magnetic repulsion and attraction is due to the bending of curvature of spacetime?

 

[mrnike992]

No. The bending curvature of spacetime causes gravitational attractive forces. The force of magnetic attraction and repulsion is attributed to one of the other four fundamental forces, the electromagnetic force.

 

[Prashan Shan]

No. The bending curvature of spacetime causes gravitational attractive forces. The force of magnetic attraction and repulsion is attributed to one of the other four fundamental forces, the electromagnetic force.

thank you for replying. I saw on internet that magnetic lines are curved due to the bending of space time.

 

[mrnike992]

Well, electromagnetic waves follow the curve of spacetime, but this does not provide the forces of magnetic attraction/repulsion.

 

[PeterDonis]

magnetic lines are curved due to the bending of space time.

This is true, but it's not what produces magnetic forces. Magnetic forces are present even where the curvature of spacetime is negligible.

 

[Prashan Shan]

This is true, but it's not what produces magnetic forces. Magnetic forces are present even where the curvature of spacetime is negligible.

then, can a strong enough magnetic field bent space time?

 

[mrnike992]

Not directly, no.

 

[PeterDonis]

can a strong enough magnetic field bent space time?

Not directly, no.

Actually, yes, it can. Magnetic fields contain energy, and energy produces spacetime curvature. But "strong enough" turns out to be very, very, very strong indeed; to produce the same spacetime curvature as the mass of the Earth does, you would need a magnetic field of about 10 million Tesla throughout an entire volume of space equal to the Earth's volume.

 

[Prashan Shan]

Actually, yes, it can. Magnetic fields contain energy, and energy produces spacetime curvature. But "strong enough" turns out to be very, very, very strong indeed; to produce the same spacetime curvature as the mass of the Earth does, you would need a magnetic field of about 10 million Tesla throughout an entire volume of space equal to the Earth's volume.

ho much energy is required to bend space over a very small area.

 

[mrnike992]

Actually, yes, it can. Magnetic fields contain energy, and energy produces spacetime curvature. But "strong enough" turns out to be very, very, very strong indeed; to produce the same spacetime curvature as the mass of the Earth does, you would need a magnetic field of about 10 million Tesla throughout an entire volume of space equal to the Earth's volume.

Ah, I see. That makes sense. Then nothing does not bend spacetime.

 

[PeterDonis]

ho much energy is required to bend space over a very small area.

It's spacetime, not space, and how much energy is required depends on how much you want to bend spacetime, and over how small an area. In general it takes a lot of energy to cause measurable spacetime curvature; that's why we associate spacetime curvature, i.e., gravity, with large masses, since rest mass is the most concentrated form of energy we know. But even then, as you can see, it takes a lot of mass--the size of a planet--to produce significant spacetime curvature.

 

[Prashan Shan]

It's spacetime, not space, and how much energy is required depends on how much you want to bend spacetime, and over how small an area. In general it takes a lot of energy to cause measurable spacetime curvature; that's why we associate spacetime curvature, i.e., gravity, with large masses, since rest mass is the most concentrated form of energy we know. But even then, as you can see, it takes a lot of mass--the size of a planet--to produce significant spacetime curvature.

i asked this question because,,
when a magnet dropped into a copper tube it produces induced current which opposes the further motion of the magnet and produces a time dilation effect (the magnet seems to move slowly) right?
but i thought that it is due to real time dilation which is caused due to the bending of space time around the magnet. it may seem silly.

yes more energy is required to bend space time with magnet but what if space time is really bent when one magnetic field crosses another magnetic field.sorry for my bad english.

 

[mrnike992]

That's not time dilation. That's simply magnetic force working in the opposite direction of gravitational forces, resulting in a smaller magnitude of acceleration.

 

[PeterDonis]

what if space time is really bent when one magnetic field crosses another magnetic field.

As I said before, spacetime curvature is caused by the energy in a magnetic field (just as by any other kind of energy). Whether one magnetic field is crossing another is irrelevant; it's the energy in the fields that matters.