Quote:
Originally Posted by xelasnave
It is a pity that more people are not as exact as we must all benefit from more detailed correct information..I am of course assuming all that you wrote is correct but if after my research, that I will conduct to check upon all you say, I find you are not on the money I will of course be back to point out any thing that does not agree with my research and I expect at that point we can review the matter more thougherly.
I have already checked all the forks in the house and next shop will take a magnet so I test any forks I see on display..this should reduce the probability ...however certainly a search on google is called for as I expect forks would have been predominately magnetic before stainless steel came into regular use. 
Alex |
Hi Alex
A good magnet (a
reasonable size Neodymium type) will sort it out. Google... yeah maybe, but there's no substitute for experiment or self-experience in terms of learning and indeed remembering something for a long time.
With a very strong neodymium magnet you can even feel effects with copper and aluminium. Not obvious attractive effects, but a sense almost like viscous damping, like trying to stir a spoon in something thick, not quite as thick as honey, but that sort of thing when you move the object near the magnet and
vice-versa. Infact Copper and Aluminium are known as paramagnetic materials and demonstrate these less well known weak and sometimes not so weak, effects.
I once made a device to demonstrate this strange viscous damping/braking effect by using a large thick Aluminium hexagonal block. The block was solid aluminium hexagonal section about 100mm across the flats and about 150mm in length, with a 25mm hole drilled at its centre all the way through the 150mm length. I then took 2 stacked neodymium magnets and dropped them through the 150mm long 25mm diameter hole with the 150mm long hole oriented vertically. The magnets fell through VERY SLOWLY as if defying gravity (one of your favourite subjects no less
). You need to see it to really appreciate it. It is the result of the magnet falling under the influence of gravity, generating a moving magnetic field and thereby generating eddy currents in the nearby aluminium and in turn acting to dynamically brake (slow) the moving magnet, so that it falls
MUCH SLOWER than you'd expect.
I will see if I can find that Aluminium Hex Block and redo the experiment with video. It will take a while and hunt in the garage.
Best
JA