Heard a really strange tale today and I'm wondering what the scientific explanation is...

[1949threepence]

In the early hours of 27th May this year, this area, along with many others in the South and Midlands, experienced some violent electrical storms. I can attest to this fact as I was woken up by one at about 3am. There was another one the following afternoon, not quite as bad. Somebody told me that lightning had struck the shed next door, incinerating it immediately, and certainly there was a fair amount of cloud to ground type lightning. 

This is where it gets interesting - the couple whose neighbour's shed was struck, tell me that they had some coins on the kitchen working surface, and it was the next day, when the lady put a piece of cutlery close to them, that she noticed some of the coins stuck to it. They had become actual magnets, and her husband placed some on the side of the fridge, as they acted like fridge magnets. Over the course of the following week, the effect weakened, and they've now reverted back to non magnets. 

The obvious inference is that the temporary magnetism is in some way directly attributable to the close lightning stroke which burned next door's shed.

Any scientific explanation to this phenomenon? I'm at a loss. I certainly don't think they've made it up. 

Another obvious question. Why did it just affect the coins and not the cutlery or any other metals in the house? 

              

Edited June 10, 2018 by 1949threepence

[DrLarry]

mmmmm  if you pass Iron (and a lot of coins have steel centres I think these days) through an electrical current back and forth you can disrupt the normal alignment of the Iron atoms in the lattice which does make the iron bar magnetised you can I believe re-enforce this phenomena by angling the bar at 23.3333 degrees which is the axial angle around which the earth magnetic poles align, although that is a variable angle as the poles wander.  Is this temporary yes I think it might well be it might be that the lightening acting as an electrical charge might create a temporary field ...this is essentially the same process that makes and electromagnet. Most steel (and some other metal)  objects have a low level of magnetic field around them this would attract the lightning if it was close by.  I would say then it is possible if the lightning was that close.  Perhaps you could ask your neighbour if you can collect some of the nails from the shed and see if they are magnetised. 

[will1976]

I'd hazard a guess they was pennies and two pennies and it has something to do with them being copper clad steel as to why only those coins was affected but how I have no idea

[DrLarry]

the coins maybe were more exposed the other cutlery may have been in a drawer surrounded by wood which would have dampened the field  as wood is a bad conductor of electrical charge (unless it is damp) The lightning if it did "blow up" the shed was mostly likely trying to touch ground with something metallic do they have an iron washing line stand close by?

Edited June 10, 2018 by DrLarry

[DrLarry]

10 minutes ago, will1976 said:

I'd hazard a guess they was pennies and two pennies and it has something to do with them being copper clad steel as to why only those coins was affected but how I have no idea

yes most are copper clad steel cores these days 

[DrLarry]

same thing happens in igneous rocks containing iron, as they freeze out of the magma they align themselves with the position of the magnetic field its a fossil record of the magnetic field.  

[Rob]

Just as a magnet moving in a coil will produce electricity (called a power station) and current will flow, so an electrical discharge (current flow) will induce magnetism in a ferrous object. It works both ways.

[DrLarry]

the other thing also is that whilst the coins are light enough to exhibit their strength if the cutlery was affected in some way it would be more difficult to "prove" to yourself that they showed magnetic qualities, the knife is too heavy to stick to the fridge the penny has a large surface area relative to the weight.  

Did it not cause a fire when it hit the shed?  

[1949threepence]

7 hours ago, DrLarry said:

the other thing also is that whilst the coins are light enough to exhibit their strength if the cutlery was affected in some way it would be more difficult to "prove" to yourself that they showed magnetic qualities, the knife is too heavy to stick to the fridge the penny has a large surface area relative to the weight.  

Did it not cause a fire when it hit the shed?  

That is true, although obviously the piece of cutlery which first attracted their attention to what happened, was clearly not itself magnetic, as two magnets repel rather than attract.

Yes, the shed was incinerated. There is nothing left of it. Burnt part of the fence down as well. But the house was unaffected as the shed is someway up the garden. It appears lightning isn't always attracted to the highest point.

Thanks for the explanations gents - very interesting and enlightening (no pun intended)  

   .      

[Rob]

2 hours ago, 1949threepence said:

That is true, although obviously the piece of cutlery which first attracted their attention to what happened, was clearly not itself magnetic, as two magnets repel rather than attract.

Yes, the shed was incinerated. There is nothing left of it. Burnt part of the fence down as well. But the house was unaffected as the shed is someway up the garden. It appears lightning isn't always attracted to the highest point.

Thanks for the explanations gents - very interesting and enlightening (no pun intended)  

   .      

Opposite poles attract, like poles repel

[Gary D]

The cutlery is stainless steel, not all steels can be magnetised, austenitic stainless is non magnetic.

[1949threepence]

1 hour ago, Gary D said:

The cutlery is stainless steel, not all steels can be magnetised, austenitic stainless is non magnetic.

Another useful bit of info. Thanks Gary.

[Peter]

I'm surprised the shed got hit and not the TV Ariel or the roof of the house.  

[1949threepence]

10 hours ago, Peter said:

I'm surprised the shed got hit and not the TV Ariel or the roof of the house.  

So was I. But I did a bit of research and it would appear that lightning doesn't always take the highest and easiest path to Earth. Hence why people get struck in the street walking along, while the tops of nearby houses remain unaffected. In fact it can strike just about anything. 

explanatory link    

[blakeyboy]

Hmm...if the steel core of the coins is  'soft' magnetic material, like mild steel,

the the induced magnetism will indeed slowly reduce.

To create the effect, you would need a powerful magnetic field that doesn't change polarity.

Indeed, how to de-magnetise something is to use a coil powered off ac mains which reverses 100 times a second,

and slowly draw it away. ( Remember the 'wand' that the old tv engineer used when your tube tv screen went funny colours?)

Magnetising ( or what magnet manufacturers call 'charging' or 'energising') can indeed be achieved using a single 

high-level pulse of DC current, like what a capacitive discharge will produce, or, in this case, a lightning 'strike'.

I put 'strike' in parentheses, since the big high current ( million + amps) discharge goes UP.

The high voltage 'leader' comes slowly down, finding a path, ionising a channel of air, and the ground discharges to the cloud.

Persistence of vision makes us see this as a downward 'stroke'.

Lightening rods etc spray electrons up to the cloud, discharging the cloud, and can actually make a big upward discharge more unlikely.

 

I'm selling my magnet collection. Special Offer:

Buy a North pole, and get a South pole free!!!