Eroding Metal with very small forces

[kolleamm]

Consider we have an iron piece. If we could somehow tap on the iron with our finger for a very long long time, I mean millions of years, would it ever be able to make a dent?

 

[mfb]

Yes. Assuming your finger stays healthy and regenerates to keep tapping. Every tap pushes some iron atoms to the side.

You might want to do that in a water and oxygen-free environment, otherwise it will rust way before you see any effect from tapping.

 

[pixel]

Rocks in streams are smooth because the flowing water gradually wears them away.

 

[kolleamm]

True but I remember reading something about iron being able to resist infinite cycles of deformation if they are small enough. It was on the topic of elastic limit.

 

[mfb]

Infinite for all practical purposes, not actually infinite.
On extremely long timescales, the iron will sublimate atom by atom if nothing else destroys it before.

 

[kolleamm]

Thanks for the answer. That makes sense.