Magnetic weapons

[Ann Feuerbach]

Thank you Jim for your kind praise. Believe it or not, I was condemed by my PHD supervisor for not writing "academic" enough. I think that means big words and complicated sentence structures! However, my Russian friends said they like it because they can actually read/translate it easily. I always thought that the was the point of academic writing. Obviously I am not of the elitest academic type. I have so much more to add for the book that could not be put in the PhD
As to archaeomagnetism testing. I believe that the process involves carefully measuring the angle of declination as well as intensity and direction before it is removed from the ground, and then again in a special chamber to eliminate outside forces. I do not recall off hand how much the objects make up is involved.

[Mare Rosu]

OK ALL
I said I was winding down on my part of this thread started by JENS, and after reading
Ann and RIVKIN input on this magnetic stuff I should have stopped last week! Do all you follow their exchange? Man that is some heavy stuff. Anyway I said I would do as FEARN suggested and acquire a magnetic knife holder and zap a carbon blade.
I used a Case butcher knife, as was in contact with the magnetic holder for approximately five minutes, the pictures show that the blade did take magnetic profile with three pols.
I also took a picture of the Mysore dagger with four compasses on the blade to show you that it has the four changes all at the same time.
Gene

[Jim McDougall]

Hi Ann,
That is exactly what is great! You are able to discuss material that is typically pretty involved and technical and integrate fascinating historical data, which makes it possible to understand
The original course of this thread was to try to discover how extensively lodestone was involved in the wootz in blades. In some of the material we discovered it seems that it inadvertantly occurred in the raw material from Hyderabad, which remained in certain janbiyya blades found in Arabia.

The ensuing discussion here has been fascinating, and I think I've learned more than in any science class I ever took! ( as far as I can remember...the little red schoolhouse ya know!!

Gene,
You better not bail out on us here!!! You have been doing an incredible job of scientific experimentation, I think the first of this type I can recall. What you are doing presents some excellent hands on perspective for some of the somewhat complex ideas that have come up. Thank you for following through on this !!! Outstanding work!

All the best,
Jim

[Jens Nordlunde]

Gene, you are doing excellent with the compasses – tell me did you empty the shop ?
Allow me just one question, when you show the blade with the compasses, it seems as if the magnetism north-south is farther away from each other than the magnets on the knife holder – is that so?

Jens

[Mare Rosu]

JENS
You are very astute MR. JENS
I failed to take a picture of the knife on the magnetic holder at the tip end.
I placed the knife on the holder in two different places that is why you see two areas of magnetic fields and not just the one, both times were approximately five minutes each time with the tip end placement being the last one.
I thing the Case knife picture was different in that the knife profile came out very well while on the Mysore dagger just the magnetic fields are shown.
You ask about the compasses, yes I had to go to two different stores to get them, I tried to get all of them to be the same but could not find four just alike.
One other thing JENS, is that if you look closely at the Mysore dagger with the four compasses on the blade you will see that the tip end compasses is pointing North not South. I do not know why that happened as I did not notice it myself until I posted the pictures, another mystery on the never ending quest for information on Magnetic Weapons!
JIM
I thank you for your comments and will of course stay around as this thread is now becoming a college course for the uninformed (me).
With folks like you and ANN, as well as RIVKIN and I must also add
FEARN for his input/suggestions ( I think he is getting all of his "smarts" from his mother! ) it is hard not to learn from all of this. I also think it is a very interesting subject and not well understood. I do "blame" all of this on JENS, why cant he just read an not ask all of these hard questions?
Gene

[Ann Feuerbach]

This is all such great stuff. It will take me awhile to absorb it all and figure out what it all means! I got someone lined up with homemade ingots any suggestions of how to test them? RIVKIN could you suggest any suitable methods?

[Jens Nordlunde]

Gene, you really had me laugh aloud, I guess that you did not get a discount price, since you had to buy them in two different stores – if you ‘only’ buy two or three compasses a one store, it is harder to discuss the price – although I think a camel dealer would have .

Ann, would it be possible for you to show a picture of one of the ingots?
If it looks like I think, it is like round bread, being thinker in the middle. Would that not make a difference when trying to make them magnetic? Also, if the ingot is round, how would the magnetism be at the ‘sides’? Would it not be different if it is longish ?

Jens

[Rivkin]

Originally Posted by Ann Feuerbach

This is all such great stuff. It will take me awhile to absorb it all and figure out what it all means! I got someone lined up with homemade ingots any suggestions of how to test them? RIVKIN could you suggest any suitable methods?

The problems I see is that:
1. The magnetization depends on two unknown factors - how non-uniform the steel is and what kind of fields the sample was exposed to. Lighting, wielding machines and subways all produce significant fields, capable of magnetizing pieces of iron.

So at least two different experiments should be condacted, unless you are interested in non-uniformities alone. Then the reasonable thing is to ask a steel metallurgist, but I think they actually measure permeability - they take not very large field, apply it to the sample and see what kind of magnetization is produced - it's supposed to be uniform if for example you apply the field along the easy axis (parallel to the sword?), but only if the sample itself is uniform.

Another way is to use X_Ray scattering or conductance or chemical tests - I think all these techniques are been used in the steel industry.

another interesting thing would be to try to achieve the true ground state in the sample by heating it up and cooling it down in the absence of external fields, with probably some random ac fields being applied to the body.

Concerning shape-dependent demag factors, there are programs like rkmag and oomf that allow one to simulate the magnetizations, so you should get the approximate picture of what kind of state you should have.

2. To Mare Rosu:

Thanx for the pictures,
The thing I would consider to be interesting is a conductance test. I don't think it can fire up with a simple resistometer, but it can be that if you place probes at about 5mm from each other on the dagger and move them alongside the dagger's surface that you will be able to see a significant change in the resistance along some set of points, which is possibly can be connected to the changes in the metall itself.

The problem is that not all steels are ferromagnetic, but they are all conductors, so unlike magnetism, you should not see a lot of difference.

P.S. I'm not a steel guy and not an experimentalist, so I really should not give any advices.

Sincerely yours,

K.Rivkin