What Do You Observe?

[Matheous-2]

When you strike a steel hammer on a vice or anvil and produce sparks?
Are these molecules or atoms that fly off before our eyes?
My apologies if this has been covered before (sure it has)....
Thank you.

[ToraToraTora]

yes, they are, the energy of the strike causes particles of the metal to detach and boil away.

[woofgang]

neither molecules or atoms but tiny pieces of burning iron.

[ToraToraTora]

err iron is made of atoms! of iron in fact!

[Gromit]

The heat generated by the two metals striking each other is sufficient to lossen the particles holding it as a solid, and a small fragment of metal breaks away from the main mass.

[woofgang]

My point TTT is that you can't actually see atoms or molecules with the naked eye, what you can see is a tiny fragment of iron combining with oxygen as it burns.

[Clanad]

Or… it could just be dirt or other contaminant on either the hammer or vise/anvil reacting to the sudden heat generated by compression of the air immediately surrounding the place struck.

Look, I have an excellent fire starter I take camping… never fails and all it is is a small tube inside of another tube. They fit tightly, but pull the small tube out about an inch and place a very small amount of a good kindling (I use the foamy, brownish, dried fungus one finds on fitting pine trees) on the exposed end of the small tube. Then simply smash the device against any surface… pull up on the outside tube and invariably I will find a small ember waiting to be placed on my prepared fire wood stack. The whole thing is caused by the heated air being compressed suddenly as the small tube rushes forward through the larger tube. Even works when it's wet out side...

[woofgang]

Clanad, does that kind have a name please? it sounds better than the flint and tinder kind.

[mibn2cweus]

^ fire piston ^

[Clanad]

Mine is similar to this woof:

https://www.etsy.com/listing/112818775/tisurvival-titanium-fire-piston?utm_source=google&utm_medium=cpc&utm_campaign=shopping_us_mid-accessories-other&utm_custom1=459387d6-5a0a-f469-2aa1-00004a11c700&kpid=112818775&gclid=CIX5h9LUrscCFYSPHwodXA0H7g

[Clanad]

Here's how it works:

[woofgang]

thank you Clanad and Mibn2weus

[Matheous-2]

Just to let you guys know, -I wasn't trying to light a fire!.....Only was curious as to whether I could see hot molecules flying off my hammer.....:)

[woofgang]

well yes and no, the human naked eye cant see individual molecules, but of course when you look at anything what you are seeing is millions and billions of molecules clumped together.

[Matheous-2]

Thank you woofgang -Now I'll have a look at the 'lighting a fire' technique! :)

[woofgang]

that compression jobby looks good but expensive and you need to keep the o ring greased. In the end I went for this
http://www.amazon.co.uk/gp/product/B00K7DTAN8?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

I don't hunt, shoot. fish or camp. I just like to be prepared :)

[New Judge]

Just to expand a little on what woofgang has said, the smallest object that can be resolved with the naked human eye at a distance of a metre or so is about 0.1mm. (This is not absolute: it may be anything from 0.05mm or less to 0.5mm or more depending on a number of factors – not least how “good” the particular eye is. But, as will be seen below, it does not matter too much).

Assuming that the speck you see sparking off the anvil is spherical and is as small as you can see (0.1mm diameter) it will have a volume of 4/3 x pi x (.5 cubed) which equals about 0.52 of a cubic millimetre. Made of iron this speck will have a mass (very roughly) of about 0.004 of a gram. This equates to about 0.0007 “moles” of iron. One mole of any substance contains (again, roughly) 6 times 10^23 atoms or molecules (that’s 6 followed by 23 noughts). So your speck of iron will contain (extremely roughly) 2,400 million million million atoms (that’s 24 followed by 20 noughts).

Now I may have got a decimal point in the wrong place or made a slip up along the way. I might have made a rash assumption here and there. But the point is that, whilst the sparks you see flying from the anvil are composed of atoms, the number of atoms you see are enormous. The human eye cannot detect anything smaller than specks of material containing huge numbers of atoms or molecules.

For my part I really must get out more !!!

[Matheous-2]

Thank you New Judge for an outstanding incomprehensible answer!

[Arksided]

^ lol, good to know I'm not the only dimmy in the box.

[Peter Pedant]

Ah yes New Judge
but you must have been skiving during the lessons that demonstrated that you could detect ( not see ) one atom thick ?

One was putting dusboard chalk on water and then a drop of washing up liquid 'cleared the area' and teh area was so large that by calculation the thickneww was on molecule

and secondly - Newton's Rings - the interference colours when oil settles on water - when it occurs the two levels of refection are about an atom apart
not very well explained here
http://www.scientificamerican.com/article/why-do-beautiful-bands-of/

and no I didnt find your answer incomprehensible - but then I read it through

[wildwood]

Would it not be possible to see an object smaller than 0.1mm with the naked eye when that object is glowing from the friction heat?