Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: neilep on 13/05/2007 22:47:54

Title: Is An Atom A Tangible Thing I Could Touch ?
Post by: neilep on 13/05/2007 22:47:54
If it was able to " blow " an atom up to the size of an apple...what would it be like ?

hmmmmmmmmmm....I suspect that if it was an iron atom then it would be like a piece of iron yes ?...or would it ?
Title: Is An Atom A Tangible Thing I Could Touch ?
Post by: another_someone on 14/05/2007 15:07:30
Actually, I am not sure we can possibly know.

We know there will be a massive area (most of the apple) which is filled with nothing but electrons poping up here and there, but actually we do noty know what an electron looks like.  What we know about an electron is that it has a particular mass, and a particular electric field, but not what it actually looks like.  We cannot even tell where exactly the electrons are at any moment in time, only to assign probabilities to where they might be.

Within the core of the apple, there will be a minute region (maybe 1/40000th of the whole apple) in which there will be an increadably heavy nucleus.  But even this nucleus, depite the fact that we know (or at believe) that the nucleus contains protons and nuetrons (in fact, even these protons and neutrons are merely combinations of quarks), and the have certain mass, and certain forces (electric and colour force) associated with them, we do not know what they might actually look like, and still yet do not know where they are, only where they probably might be at any one moment in time.  I am not even sure (although maybe others might be able to comment) if the protons and neutrons remain distinct entities within the nucleus, or if the quarks from one proton mingle with quarks from neutrons and other protons.
Title: Is An Atom A Tangible Thing I Could Touch ?
Post by: Batroost on 14/05/2007 17:54:57
Quote
It is also that everybody has slightly different variations of cone sensitivity, with slightly different peek wavelengths for the different cones.

More or less distinct as far as the experiments I remember are concerned. There appears to be a preferred3d physical arrangement of neutrons/protons in some nuclei - people talk about shells of neutrons/protons within the nucleus in a similar way to the electron-shell model we are more familiar with from Chemistry. However, the size, shape and density of and through a nucleus appears to be very dependent on what you use to measure it.

Quote
I suspect that if it was an iron atom then it would be like a piece of iron yes ?...

I think the answer is no.
Title: Is An Atom A Tangible Thing I Could Touch ?
Post by: another_someone on 14/05/2007 18:24:48
In case anybody did not spot it - batroost has got a littel confused which thread he was replying to.

The reply is valid, but the quote he included in this thread comes from http://www.thenakedscientists.com/forum/index.php?topic=7807.msg87680#msg87680

I suspect the quote he intended was

I am not even sure (although maybe others might be able to comment) if the protons and neutrons remain distinct entities within the nucleus, or if the quarks from one proton mingle with quarks from neutrons and other protons.
Title: Is An Atom A Tangible Thing I Could Touch ?
Post by: Batroost on 14/05/2007 19:39:32
Now that is odd. I copied the quote straight from the reply screen; so I can't see how it picked-up this other one.

(I won't modify teh post - that would look even more confusing)

Another ghost in the machine...? [?]
Title: Is An Atom A Tangible Thing I Could Touch ?
Post by: neilep on 14/05/2007 20:32:06
Actually, I am not sure we can possibly know.

We know there will be a massive area (most of the apple) which is filled with nothing but electrons poping up here and there, but actually we do noty know what an electron looks like.  What we know about an electron is that it has a particular mass, and a particular electric field, but not what it actually looks like.  We cannot even tell where exactly the electrons are at any moment in time, only to assign probabilities to where they might be.

Within the core of the apple, there will be a minute region (maybe 1/40000th of the whole apple) in which there will be an increadably heavy nucleus.  But even this nucleus, depite the fact that we know (or at believe) that the nucleus contains protons and nuetrons (in fact, even these protons and neutrons are merely combinations of quarks), and the have certain mass, and certain forces (electric and colour force) associated with them, we do not know what they might actually look like, and still yet do not know where they are, only where they probably might be at any one moment in time.  I am not even sure (although maybe others might be able to comment) if the protons and neutrons remain distinct entities within the nucleus, or if the quarks from one proton mingle with quarks from neutrons and other protons.

THANK YOU GEORGE !!

WOW !!..There is a lot we do not know and our knowledge is then based on sound theory determined by observation and speculation eh ?


Presumably one day we will be able to magnify down to that particular level and see what's gong on.
Thank you George
Title: Is An Atom A Tangible Thing I Could Touch ?
Post by: another_someone on 14/05/2007 21:26:03
Presumably one day we will be able to magnify down to that particular level and see what's gong on.

What do you mean by 'see' what is going on.

The atom is much smaller than the wavelength of light, so we will never be able to 'see' with light.

The closest we can get to 'seeing' an atom is using a scanning electron microscope.

The problem we have is that ultimately (and this goes back to what I was saying in one of the other threads) everything we know about the world basically comes down to everything we know about electrostatic forces, and infer from that as to what might be behind it.  So too with the atom, all we really know, and maybe all we might ever know, is what is happening to the electrostatic forces in an atom - so we can see those forces, but can only ever speculate about the particles that might create those forces.  For all we know, there are no particles at all, merely forces (although those forces carry momentum, so if there are no particles as such, we need somehow to explain that momentum - note to sophiecentaur - I did not say inertia [:)]).
Title: Is An Atom A Tangible Thing I Could Touch ?
Post by: Bored chemist on 14/05/2007 21:42:50
The silvery colour of iron is due to electrons moving in bands in the solid. A single atom, on its own, wouldn't look like iron (and it wouldn't stick to a magnet either).

Title: Is An Atom A Tangible Thing I Could Touch ?
Post by: Batroost on 15/05/2007 17:59:22
Quote
The atom is much smaller than the wavelength of light, so we will never be able to 'see' with light.

Not necessarily. There are some new optics being investigated with materials that have a negative refractive index. In theory (and I think in a few very recent experminets) this allows you to resolve detail at a scale that is smaller than the wavelength of light you are using!

I think this is going to become a very interesting field over the next few years...
Title: Is An Atom A Tangible Thing I Could Touch ?
Post by: another_someone on 15/05/2007 18:17:07
There are some new optics being investigated with materials that have a negative refractive index. In theory (and I think in a few very recent experminets) this allows you to resolve detail at a scale that is smaller than the wavelength of light you are using!

I think this is going to become a very interesting field over the next few years...

I think it is interesting, but from what I recollect, the original expectation was that they could indeed exceed the diffraction limits, but that later indications were that maybe they hit the same limit by a different route.

Not exactly sure (not even sure that anybody else is sure).

Problem is, if we do find a way of breaking the diffraction limit - will this undermine anything in quantum physics?
Title: Is An Atom A Tangible Thing I Could Touch ?
Post by: that mad man on 15/05/2007 18:53:54
Has anyone seen a picture of that STM that can pickup, move and place individual atoms?

The inventor has created a small atomic picture or logo thing.

But, if they cant be seen then how do they know they have moved them and how can they take a picture?

Sorry but I'm a bit confused now!
Title: Is An Atom A Tangible Thing I Could Touch ?
Post by: another_someone on 15/05/2007 19:06:17
Has anyone seen a picture of that STM that can pickup, move and place individual atoms?

The inventor has created a small atomic picture or logo thing.

But, if they cant be seen then how do they know they have moved them and how can they take a picture?

Sorry but I'm a bit confused now!


The problem is, what do you mean by "can't be seen"?

They can be seen by another STM (I think the logo was IBM - he was employed by IBM).

What an STM does is measure the electric field around an atom.  All light does is interact with the electric fields around an atom.  They may do it differently, but they are basically doing the same thing.
Title: Is An Atom A Tangible Thing I Could Touch ?
Post by: Bored chemist on 15/05/2007 19:09:13
That Mad MAn,
Is this the image you mean?
http://www.ieee-virtual-museum.org/collection/event.php?id=3457012&lid=1
Title: Is An Atom A Tangible Thing I Could Touch ?
Post by: that mad man on 15/05/2007 19:22:00
Cheers BC, To be honest, no!

It was something similar though so I guess he did a few.

Hope this is not off topic but, what interested me about it was the possibility of fabricating circuits at an atomic level. God, I'd love to make a transistor this way!

Bee