# Time dilation in a magnetic field

• Mr C Odd
No, and again this is word salad. For a rigorous approach to FTL travel, look up the Alcubierre drive. It still requires impossible things, so really just gives you a concrete reason to doubt FTL travel rather than a generic one, but it is at least mathematically consistent.Ok, perhaps I wasn't clear on the two opposing magnetic fields, what I meant by this was repelling fields, ie: two Norths facing each other.Basically I would like to know if there is any way to use magnetic fields to set up a warp field, enabling F.T.L. travel.I noticed that, when I held a finger close to my eye and focused on something further away, then moved my finger

#### Mr C Odd

Hi all.

I was wondering if time is dilated whilst traveling in a stable magnetic field that is generated by the object travelling, and if so, does this vary if you reduce or intensify the magnetic field?
Also, what happens if the object is generating two opposing magnetic fields, would orientation affect this and would time dilation still be a factor?
Lastly, has anyone done any experiments to test this?

Thanks all, I hope this exercises the old grey matter :)

It seems your question implies that you think time dilation is something that happens to an object but it is not; it is what is noted by an observer that is in a frame of reference that is moving relative to the object.

Mr C Odd
Time dilation in special relativity is a result of a choice of coordinates, so it's not affected by anything like magnetic fields.

Two opppsed magnetic fields is simply one magnetic field. Magnetic fields simply add, since electromagnetism is a linear theory.

As to experimental tests, the cosmic ray muon experiment could be argued to be one, since moving muons have a magnetic field. I'm not aware of a more specific one, but my replies are fairly trivial consequences of well tested theories.

Mr C Odd
Ok, perhaps I wasn't clear on the two opposing magnetic fields, what I meant by this was repelling fields, ie: two Norths facing each other.
Basically I would like to know if there is any way to use magnetic fields to set up a warp field, enabling F.T.L. travel.
I noticed that, when I held a finger close to my eye and focused on something further away, then moved my finger slightly into and then out of view, the blurred finger seemed to bend the image ever so slightly.
I don't know why, but it reminded me of gravitational microlensing. This in turn made me think about the properties of matter and magnetism and I wondered if we could use magnetism for long range space transport.
I looked up the speed of magnetic wave expansion and it's as near as dammit the speed of light which would mean that warp theory would collapse in on itself if magnetic fields were used as they would not be able to establish themselves externally past the speed of light.
However, what I was wondering is, if our universe is relative and we live in a galactic gravitational field, if there was some way to overcome the gravity of our situation so to speak, would any speed beyond light be purely relative to the magnetic situation?
Given that velocity increases time dilation, and that time and space are relative, would it then be possible to create your own localised gravity and negate the effects of relativity in a localised bubble, essentially a warp field?

You are off into pop-science la la land without a basis in physics, which is against the rules here on PF. This is a mainstream science forum. I suggest you read the forum rules before posting further.

Mr C Odd said:
Basically I would like to know if there is any way to use magnetic fields to set up a warp field, enabling F.T.L. travel.
No. I'm afraid pretty much everything else you wrote was word salad. You need a textbook and you need to learn the maths if you want to understand relativity.
Mr C Odd said:
Given that velocity increases time dilation, and that time and space are relative, would it then be possible to create your own localised gravity and negate the effects of relativity in a localised bubble, essentially a warp field?
No, and again this is word salad. For a rigorous approach to FTL travel, look up the Alcubierre drive. It still requires impossible things, so really just gives you a concrete reason to doubt FTL travel rather than a generic one, but it is at least mathematically consistent.

m4r35n357 and Sorcerer
Mr C Odd said:
Ok, perhaps I wasn't clear on the two opposing magnetic fields, what I meant by this was repelling fields, ie: two Norths facing each other.
Basically I would like to know if there is any way to use magnetic fields to set up a warp field, enabling F.T.L. travel.
I noticed that, when I held a finger close to my eye and focused on something further away, then moved my finger slightly into and then out of view, the blurred finger seemed to bend the image ever so slightly.
I don't know why, but it reminded me of gravitational microlensing. This in turn made me think about the properties of matter and magnetism and I wondered if we could use magnetism for long range space transport.
I looked up the speed of magnetic wave expansion and it's as near as dammit the speed of light which would mean that warp theory would collapse in on itself if magnetic fields were used as they would not be able to establish themselves externally past the speed of light.
However, what I was wondering is, if our universe is relative and we live in a galactic gravitational field, if there was some way to overcome the gravity of our situation so to speak, would any speed beyond light be purely relative to the magnetic situation?
Given that velocity increases time dilation, and that time and space are relative, would it then be possible to create your own localised gravity and negate the effects of relativity in a localised bubble, essentially a warp field?

Sorry friend, but you can’t negate relativity. The entire point of relativity is that it applies to any and every coordinate system (That was the very motivation for deriving it: Einstein didn’t believe there should be arbitrary discontinuities in the universe where one set of laws governed the universe sometimes and other times another, so he argued the laws of physics are the same for all frames of reference, and sought to find what things are invariant and which aren’t. Experiment, of course, has been consistent with the argument that the laws of physics are the same everywhere, and countless ideas we take for granted like conservation of momentum depend on that notion being true.).

Now, in whatever scifi you are writing, if your characters don’t need to return to or send signals back to their home, and as long as they don’t go near any large masses, they can go pretty much any distance in the universe in a finite time so long as they can get arbitrarily close to the speed of light relative to their starting point (that is, if special relativity is a reasonable approximation, time dilation and length contraction are all you need). But of course everyone will be long dead by the time they return.

Everything else is purely speculation and requires things that probably don’t exist like negative mass/energy (see Ibix’s post).

https://en.m.wikipedia.org/wiki/Alcubierre_drive

As several others pointed out, discussion of FTL or other pseudoscience is forbidden.