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Author Topic: What causes patterns to appear on metal foil surfaces?  (Read 1603 times)

Offline metalinterest

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Hi,
   I saw this form on some aluminum foil, any ideas what would cause this?
« Last Edit: 28/12/2012 15:07:32 by chris »


 

Offline Boogie

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Re: Physics - Odd effect on metal?
« Reply #1 on: 30/11/2012 16:34:47 »
Are you saying that the effect occured on it's own? One day it was nice and smooth and the next day you saw that? Perhaps expanding and contracting of the aluminum foil during temperature shifts caused it?

Do you have a cat? Are you certain someone/something didn't disturb it?

If it came that way, it may have occured during fabrication or handling.

 

Offline metalinterest

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Re: Physics - Odd effect on metal?
« Reply #2 on: 01/12/2012 05:20:05 »
Hi,
 thanks for the reply, well it was placed on a bed, over a wooden floor on a concrete foundation, it was perfectly flat and even, and I watched it form in about just under two seconds right under my eyes. there is no heat source or anything within a meter around it, just me looking at it, and no I don't have any special powers :p Can you speculate on the safety of something like this, as I would expect it only occur if there was heat like from a conduction cooker or some other high energy source like microwaves or high powered radio or even from light it would take a fair amount of power to generate the heat needed to turn a flat piece of aluminum foil to look like that so quick. The light in the room which it was not under is about 1.5m away from it (energy saving bulb), no power lines unless they are in the foundation. I assume the effect of distortion would be caused by heat generated in the metal? Any other ideas?
 

Offline RD

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Re: Physics - Odd effect on metal?
« Reply #3 on: 01/12/2012 06:15:38 »
The light in the room which it was not under is about 1.5m away from it (energy saving bulb), no power lines unless they are in the foundation. I assume the effect of distortion would be caused by heat generated in the metal? Any other ideas?

The quality and direction of lighting can make wrinkles more or less visible, (that's how portrait photographers flattered people before photoshop).

"silver" foil sheets are used in photography to "fill" shadows, your foil by its very reflective nature has an inbuilt "fill" making the shadows caused by creases less obvious. 

http://www.amazon.co.uk/Ex-Pro-Photographic-Light-Reflector-Collapsible/dp/B000RGPUKM

Wrinkles visibility would also change depending on your position with respect to the light source, they may become more/less obvious when viewed from a different angles. 

i.e. the wrinkles could have been there all the time, you just suddenly noticed them because you changed your viewpoint , or their lighting changed, (e.g. changing the position of your body suddenly obstructed or exposed the light source).
« Last Edit: 01/12/2012 06:19:20 by RD »
 

The Naked Scientists Forum

Re: Physics - Odd effect on metal?
« Reply #3 on: 01/12/2012 06:15:38 »

 

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