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Offline geoff

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Why don't atoms melt?
« on: 13/01/2009 09:05:28 »
geoff asked the Naked Scientists:

why don't atoms melt? How can they stand the high temperatures in exploding stars? Yes, they combine to form new atoms, but why don't they melt?

What do you think?


 

Offline lightarrow

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Why don't atoms melt?
« Reply #1 on: 13/01/2009 11:35:13 »
geoff asked the Naked Scientists:

why don't atoms melt? How can they stand the high temperatures in exploding stars? Yes, they combine to form new atoms, but why don't they melt?

What do you think?
In a sense, they melt too, but it's a different concept. To melt means that atoms or molecules are not bound with directional bonds anylonger and so are free to fill the container's space, that is, the body becomes liquid. Of course an atom cannot melt, according to this definition.
However, an atom doesn't stay integer when temperature rise much, because electrons start "evaporating" out of the atom which then becomes an ion. Ions and electrons mixed together forms another state of matter called "plasma". Increasing the temp. again, even the more internal electrons leave the atom and in the end you have only nuclei + electrons separated. This happens at ~ tens/hundreds of thousands C. At even greater temp., millions of C, even nuclei begin to break into protons and neutrons. At even greater temp. (don't know how much, it's a speculation) protons and neutrons breaks into quarks...ecc.
« Last Edit: 13/01/2009 11:36:50 by lightarrow »
 

Offline yor_on

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Why don't atoms melt?
« Reply #2 on: 13/01/2009 11:46:36 »
A atom consists of a electron cloud and a nucleus.

"The nucleus occupies only a tiny fraction of the volume of an atom (the radius of the nucleus being some 10,000 to 100,000 times smaller than the radius of the atom as a whole), but it contains almost all the mass.

An idea of the extreme density of the nucleus is revealed by a simple calculation. The radius of the nucleus of hydrogen is on the order of 10−13 cm so that its volume is on the order of 10−39 cm3 (cubic centimeter); its mass is about 10−24 g (gram).

Combining these to estimate the density, we have 10−24 g/10−39 cm3 ≈ 1015 g/cm3, or about a thousand trillion times the density of matter at ordinary scales (the density of water is 1 g/cm3)."

In fusion the atoms interact to create a more massive atom.
The excess mass set free from the original atoms is released in the form of energy.
Following Einstein formula E = mc 2.

In Fission the atoms atomic nucleus split's into parts of similar mass.
As they do so they release several hundred million volts of energy.
This energy is what is used in the atomic bomb.

But none of them involves 'melting' the atom.

The nearest I can think of as 'melting' would be a Quark-gluon plasma.
http://en.wikipedia.org/wiki/Quark-gluon_plasma#How_is_this_created_in_the_lab.3F

Then again, 'Melting' is a measure of heat or temperature.
And  heat seems to have no limits?

But looked as what really happens to a atom as the temperature goes up, it is mainly 'vibrations' inside it.

So maybe the question could be.
At what temperature does the atom 'vibrate' to smithereens?
Or 'nothingness'??
 

Offline geoff

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Why don't atoms melt?
« Reply #3 on: 15/01/2009 22:44:03 »
I think you may have hit the button at what point does an atom literally vibrate so much that it shakes itself to nothingness at that point could it be said to have melted ? It would just vaporise into nothing perhaps ?
 

Offline yor_on

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Why don't atoms melt?
« Reply #4 on: 16/01/2009 15:42:23 »
A black hole?
 

Offline Vern

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Why don't atoms melt?
« Reply #5 on: 16/01/2009 16:54:00 »
Quote from: geoff
I think you may have hit the button at what point does an atom literally vibrate so much that it shakes itself to nothingness at that point could it be said to have melted ? It would just vaporise into nothing perhaps ?
Maybe nothing except the electromagnetic fields that we always find coming from particle destruction.
« Last Edit: 16/01/2009 16:55:42 by Vern »
 

Offline lightarrow

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Why don't atoms melt?
« Reply #6 on: 16/01/2009 18:03:08 »
I think you may have hit the button at what point does an atom literally vibrate so much that it shakes itself to nothingness at that point could it be said to have melted ? It would just vaporise into nothing perhaps ?
An atom of a gas, that is a free atom, vibrate around which point?
 

Offline yor_on

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Why don't atoms melt?
« Reply #7 on: 16/01/2009 19:15:54 »
I think you may have hit the button at what point does an atom literally vibrate so much that it shakes itself to nothingness at that point could it be said to have melted ? It would just vaporise into nothing perhaps ?
An atom of a gas, that is a free atom, vibrate around which point?

Lightarrow

Do you see vibration as being a 'force' shaking a single atom uniformly?
Or as something 'dissolving' it from all 'points' by vibrations?
If there only was one atom?

I haven't thought about this.
It's a nice question:)
 
In a gas the molecules consisting of atoms will move faster and faster until the atoms all become 'free', as I see it.
Would you agree to that?

And let us say that even when they are 'free' they still will receive energy from some 'cosmic happening':)

Will then the electron cloud be what is responsible for the atoms breakdown.
Steered by the electromagnetic force.

But inside that we have the nucleus, governed by the weak and the strong force.
Will the nucleus vibrate too?

It should, shouldn't it?
« Last Edit: 16/01/2009 19:26:37 by yor_on »
 

Offline Soul Surfer

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Why don't atoms melt?
« Reply #8 on: 17/01/2009 09:13:20 »
There is some wrong thinking in here.

quote   "at what point does an atom literally vibrate so much that it shakes itself to nothingness "

In all materials particles interact and temperature is a measure of the mean energy of the particles as they interact.  This vibration is not a property of the molecule atom or particle itself it is a measure of the intensity and frequency of its collisions between other particles. In between collisions particles just travel in straight lines.  So an atom can never "shake itself to pieces" although it might easily be damaged by the collision with another atom.

This is why particle accelerator collisions are a measure of the properties of matter at high temperatures.

There are already some good explanations in this topic of the general processes of ionisation and nuclear and even baryon disintegration as temperatures rise from normal temperature to the extremes of supernovae neutron stars and the first microseconds of the big bang itself so I will not go into these in detail.

However there is one important fact that must be remembered there are important conservation laws that must be maintained in the interactions.  Energy and angular momentum are fundamental but most interactions also conserve baryon and lepton numbers these imply the number of mass carrying particles like protons and electrons are also maintained so things do not in general get destroyed to pure energy and nothing else.  What happens cannot produce nothingness.

There is one big failing in our experimentation at high energies that is we cannot measure interactions over large assemblages of particles at high energies only single interactions.  Many of the interesting properties of solids and liquids come from the interections of atoms and molecules on a large scale.  The only way to understand this will be to learn from behaviours at temperatures we can control and extend this to large assemblages of particles at high energies.

So to come back to the original question atoms do "melt" at high temperatures if by "melt"  you mean break down into simpler components which react independently.   As the temperature and density rises  atoms can become states of matter known as  plasma, (ordinary star material) neutronium (neutron star material)  quarkonium  (quark star material)  This latter state is currently hypothetical and as yet unobserved but seems quite likely.

« Last Edit: 17/01/2009 09:28:00 by Soul Surfer »
 

Offline yor_on

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Why don't atoms melt?
« Reply #9 on: 17/01/2009 10:45:22 »
Thanks Soulsurfer, but i'm still not sure how a single atom 'breaks down'.
Radiation for example, that 'ghostly' entity that transfers energy from a hotter object to a cooler?
Then we are talking about photons transferring energy to that atom, right?

I thought it was mainly the electron-cloud that would vibrate if you just would have one atom?
And that the nucleus would need much more energy to 'split' (vibrate/move apart, melt?)
So how do one single atom 'melt' or 'vibrate' under 'the influence' (of to much energy:)?
To my knowledge it is the movement of the particle that represent its 'heat/energy'?

But this question is new to me:)

 

Offline lightarrow

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Why don't atoms melt?
« Reply #10 on: 17/01/2009 14:58:10 »
An atom of a gas, that is a free atom, vibrate around which point?
Lightarrow

Do you see vibration as being a 'force' shaking a single atom uniformly?
Vibration means periodic motion around a point.

Quote
Or as something 'dissolving' it from all 'points' by vibrations?
If there only was one atom?
???

Quote
In a gas the molecules consisting of atoms will move faster and faster until the atoms all become 'free', as I see it.
Would you agree to that?
Are you talking about molecular thermal decomposition into atoms?

Quote
And let us say that even when they are 'free' they still will receive energy from some 'cosmic happening':)
???

Quote
Will then the electron cloud be what is responsible for the atoms breakdown.
Steered by the electromagnetic force.
Let's make an example: you shoot a bullet to a peach and it breaks down to many pieces. Would you say that the peach' pulp is responsible for the peach brakdown?

Quote
But inside that we have the nucleus, governed by the weak and the strong force.
Will the nucleus vibrate too?
Yes.
 

Offline yor_on

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Why don't atoms melt?
« Reply #11 on: 17/01/2009 15:48:25 »
I 'think Ill start with this :)
"As for atomic vibrations, I have posited that heat is the manifestation of the outermost electrons' vibrations, which is microkinetic energy that might be called also "micromomentum."

Buildings and cells possess material walls. Not so atoms, whose boundary, which I call "microevent horizon", is defined by the gravity and inertia fields--and perhaps also or mainly, by the electromagnetic field--of the nucleons. 

When atoms are in the ionized state when exposed to intense heating, the outermost electrons' vibrations in this plasma are the depositories of heat. The ionized atoms, even single-electron hydrogen, retain their boundaries. "

http://www.journaloftheoretics.com/Articles/3-3/commentary3-3.html

I'm not sure how you see "Vibration means periodic motion around a point."?
like a stone thrown into a pond with the vibrations moving as waves?
Anyway, that was one of the things I was curious on:)

And how it was thought that those vibrations interacted with that atom.
As a whole, or like when something 'solid' is made to explode by its inner interactions.

Also I thought of that electron cloud as the first and primary exchange mechanism of heat into vibrations.

Lightarrow, "molecular thermal decomposition into atoms"?
Does that mean a chemical reaction of a gas 'unbounding' molecules into atoms by heat?

I was thinking of it in terms of  kinetic reactions when heated molecules collided, splitting them into their constituents (Atoms).
But both descriptions seems to fit to me?

Hope that made it somewhat clearer.


« Last Edit: 17/01/2009 15:50:42 by yor_on »
 

Offline lightarrow

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Why don't atoms melt?
« Reply #12 on: 17/01/2009 19:42:28 »
I 'think Ill start with this :)
"As for atomic vibrations, I have posited that heat is the manifestation of the outermost electrons' vibrations, which is microkinetic energy that might be called also "micromomentum."
No.
1. Heat is not something that a body have, but it's energy transferred from a hotter to a colder body; heat exists only during this transfer.
2. When you heat a body you increase its internal energy, both potential and kinetic.
3. Kinetic energy only is related to the body's temperature.
4. A single atom's temperature doesn't exist because it cannot be defined.
5. Kinetic energy of an atom or molecule has nothing to do with electrons.
6. When the electron clouds "vibrate" they releas energy in the form of EM radiation.

Quote
I'm not sure how you see "Vibration means periodic motion around a point."?
like a stone thrown into a pond with the vibrations moving as waves?
Anyway, that was one of the things I was curious on:)
Like a mass attached to a fixed spring: give it a knock and it will oscillate.

Quote
Lightarrow, "molecular thermal decomposition into atoms"?
Does that mean a chemical reaction of a gas 'unbounding' molecules into atoms by heat?
Yes. Heat water enough and the molecules will start to broke into hydrogen and oxygen atoms.

Quote
I was thinking of it in terms of  kinetic reactions when heated molecules collided, splitting them into their constituents (Atoms).
But both descriptions seems to fit to me?
It's exactly the same I wrote  :)
 

Offline yor_on

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Why don't atoms melt?
« Reply #13 on: 17/01/2009 22:49:03 »
Why do you do this to me Lightarrow?
Just when I started to get a grip on it ::))

What does this mean?
"4. A single atom's temperature doesn't exist because it cannot be defined."
Then it shouldn't be able 'break down' either, should it?

Are you saying that only a 'quark gluon soup' will 'break down' atoms.
And that photons can't do that to a single atom.

As for number five. I thought that the kinetic force was transfered from atom to atom via their electron-clouds, ah, possibly so that is, maybe, or perhaps, maybe not? :)

SO???

I saw it as particles when described as a gas:)
But in my question about photons and a single atom I'm not sure how to see it?

How else do they transfer the energy?
I'm getting confused.
It's ok though.

Been there before:)
« Last Edit: 17/01/2009 22:57:19 by yor_on »
 

Offline geoff

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Why don't atoms melt?
« Reply #14 on: 17/01/2009 22:52:48 »
Boy Oh Boy dont you guys go deep .
Its Just a thought but if atoms take so much energy to strip the electrons off,then is it possible that the only place here that this could happen could be in a black hole .
Imagine the scene as atoms approach the energies released strip the electrons ,the nucleus falls in and joins the rest in the middle ,the electrons join in a cloud around it so you have one gigantic atom with heaven only knows how many levels of electron orbits  all held together by the combined forces of all the absorbed matter .
Now if that Lot went bang ,would we get a new universe?

By the way thanks for every ones input it very interesting to read so many different views and for a Lay man to get a deeper insight thanks every one but don,t stop.
 

Offline lightarrow

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Why don't atoms melt?
« Reply #15 on: 18/01/2009 11:07:43 »
Why do you do this to me Lightarrow?
Just when I started to get a grip on it ::))
Because you are a nice person and I want you to learn something more... :)

Quote
What does this mean?
"4. A single atom's temperature doesn't exist because it cannot be defined."
Then it shouldn't be able 'break down' either, should it?
Temperature is a statistical concept and that can only be applied to a specific ensemble of particles (that is, where kinetic energies are statistically distributed in a specific way). If you have a particle moving even at 200,000 km/s, it doesn't break against a wall which is travelling along it at the same speed.

Quote
Are you saying that only a 'quark gluon soup' will 'break down' atoms.
And that photons can't do that to a single atom.
???

Quote
As for number five. I thought that the kinetic force was transfered from atom to atom via their electron-clouds, ah, possibly so that is, maybe, or perhaps, maybe not? :)
Then a plasma and so the Sun shouldn't have a temperature at all...
Kinetic energy is transferred through molecular/atomic/particles collisions; if you had a gas of protons, e.g., it would be the same.

Quote
I saw it as particles when described as a gas:)
But in my question about photons and a single atom I'm not sure how to see it?
What do you mean?
« Last Edit: 18/01/2009 11:10:35 by lightarrow »
 

Offline yor_on

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Why don't atoms melt?
« Reply #16 on: 18/01/2009 12:51:20 »
I wrote "Are you saying that only a 'quark gluon soup' will 'break down' atoms.
And that photons can't do that to a single atom."

Well, I was wondering in what way radiation (photons) might 'break down' a atom.
shouldn't it be able to?

I understand what you say about temperature being a statistical concept .
But as soon we have photons interacting with a atom it will be a 'real' concept again, right?

Am I right in assuming that this reasoning goes back to that nothing can be seen as having any values without having any 'interaction' and subsequent, or, 'observation'.

So one could then say that first there are something called 'interaction' which then c(w)ould be anything happening between two frames of reference in spacetime.
And most importantly, with or without anyone observing.
Would that then fulfill the 'statistical demand'?

Then we have the 'Observer' who at times (all times?) seems to interact with what (s)he is 'observing'.
That makes two different definitions for an interaction, doesn't it?

The first one would be 'objective' in that it doesn't need any 'observation' to do 'its thing/interact':)
The other one, if there is any truth to 'observing' changes the outcome of a experiment, would then be a highly subjective matter.

In the first case HUP shouldn't be a problem.
That is, if we don't define 'interactions' themselves as 'observers'.
Do we?

In the second case though, HUP is well and breathing:)
That is if you define HUP otherwise than , observed or unobserved always seen as valid.
If I choose to see HUP as valid, only, when observing.

But then, it seems to me that 'time' can bear no influence on us changing that experiment by 'observing'.
As we could allow an 'outcome' (experimenting) but still wait a year before 'observing' that outcome.
Which should mean that our 'observing' would be valid as having effects 'outside/freed' of times arrow?
As our 'observation' then would 'fall out' as an specified outcome first one year later.

--

Also it is so that all observations made follows lights speed :)
We are always observing already 'done' phenomena.
How can that be?
If we by observing change them.

----

I wasn't specifically thinking of a plasma Lightarrow when I wrote this, but you are correct that a plasma transfers/creates heat via particle collisions in a ionized gas.

My thinking was that every 'vibration' between atoms, no matter:) in what state they might be (as long as they still are atoms), have to have a velocity.

Even if that 'force' (particles/photons/waves) propagating, seen geometrically, might be 'crescent shaped' and so spread out in several directions when propagating I thought you could treat each interaction of it with another atom as a single photon/electron/? with a decided velocity, interacting with the electron cloud firstly.

But that would hinge on, for example, if photons propagating in space time.
If they are more of 'probabilities' then I'm not sure why they need a 'motion' at all.
Then it seems more to hinge on what the 'weakest' points of an atom might be?
If you see how i mean here:)


Yes, it's quite nice with a forum that still have some humor and civility left.
Much better than those forums 'pounding' their opinions upon each other:)

--------

Geoff?

What did you mean by "Its Just a thought but if atoms take so much energy to strip the electrons off,then is it possible that the only place here that this could happen could be in a black hole ."

A light bulb does this every time you turn the switch:)
And that's why they stop working after a while.

You meant to strip all electrons of a atom?
http://www.thenakedscientists.com/forum/index.php?topic=18074

I did like your Atom:)

« Last Edit: 18/01/2009 14:10:17 by yor_on »
 

Offline lightarrow

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Why don't atoms melt?
« Reply #17 on: 18/01/2009 16:36:28 »
I wrote "Are you saying that only a 'quark gluon soup' will 'break down' atoms.
And that photons can't do that to a single atom."

Well, I was wondering in what way radiation (photons) might 'break down' a atom.
shouldn't it be able to?
In many different ways, also depending on the radiation's wavelenght.

Quote
I understand what you say about temperature being a statistical concept .
But as soon we have photons interacting with a atom it will be a 'real' concept again, right?
Am I right in assuming that this reasoning goes back to that nothing can be seen as having any values without having any 'interaction' and subsequent, or, 'observation'.
So one could then say that first there are something called 'interaction' which then c(w)ould be anything happening between two frames of reference in spacetime.
And most importantly, with or without anyone observing.
Would that then fulfill the 'statistical demand'?
Then we have the 'Observer' who at times (all times?) seems to interact with what (s)he is 'observing'.
That makes two different definitions for an interaction, doesn't it?
The first one would be 'objective' in that it doesn't need any 'observation' to do 'its thing/interact':)
The other one, if there is any truth to 'observing' changes the outcome of a experiment, would then be a highly subjective matter.
In the first case HUP shouldn't be a problem.
That is, if we don't define 'interactions' themselves as 'observers'.
Do we?
In the second case though, HUP is well and breathing:)
That is if you define HUP otherwise than , observed or unobserved always seen as valid.
If I choose to see HUP as valid, only, when observing.
But then, it seems to me that 'time' can bear no influence on us changing that experiment by 'observing'.
As we could allow an 'outcome' (experimenting) but still wait a year before 'observing' that outcome.
Which should mean that our 'observing' would be valid as having effects 'outside/freed' of times arrow?
As our 'observation' then would 'fall out' as an specified outcome first one year later.
Also it is so that all observations made follows lights speed :)
We are always observing already 'done' phenomena.
How can that be?
If we by observing change them.
I wasn't specifically thinking of a plasma Lightarrow when I wrote this, but you are correct that a plasma transfers/creates heat via particle collisions in a ionized gas.
My thinking was that every 'vibration' between atoms, no matter:) in what state they might be (as long as they still are atoms), have to have a velocity.
Even if that 'force' (particles/photons/waves) propagating, seen geometrically, might be 'crescent shaped' and so spread out in several directions when propagating I thought you could treat each interaction of it with another atom as a single photon/electron/? with a decided velocity, interacting with the electron cloud firstly.
But that would hinge on, for example, if photons propagating in space time.
If they are more of 'probabilities' then I'm not sure why they need a 'motion' at all.
Then it seems more to hinge on what the 'weakest' points of an atom might be?
If you see how i mean here:)
Don't know what you are saying, sorry. Please, try to express just one precise concept at a time.
 

Offline yor_on

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Why don't atoms melt?
« Reply #18 on: 18/01/2009 17:58:49 »
Sort of got carried away here :)
 

Offline yor_on

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Why don't atoms melt?
« Reply #19 on: 18/01/2009 22:50:54 »
Ok, I'll try to break it down.

1. I wrote "Are you saying that only a 'quark gluon soup' will 'break down' atoms.
And that photons can't do that to a single atom.
Well, I was wondering in what way radiation (photons) might 'break down' a atom.
shouldn't it be able to? "
--------

2. " I understand what you say about temperature being a statistical concept .
But as soon we have photons interacting with a atom it will be a 'real' concept again, right? " (that is, a 'working again' concept)

That was in answer to your statement "Temperature is a statistical concept and that can only be applied to a specific ensemble of particles (that is, where kinetic energies are statistically distributed in a specific way)."

---------

3. What then followed was just me wondering where that definition might have originated.

I wrote "Am I right in assuming that this reasoning goes back to that nothing can be seen as having any values without having any 'interaction' and subsequent, or, 'observation'."

And from there the rest came as by itself:)

It circles around HUP (Heisenberg uncertainty principle).
And how we might define it (and time).

Hope that made it somewhat easier to unwind:)



« Last Edit: 18/01/2009 22:54:01 by yor_on »
 

Offline lightarrow

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Why don't atoms melt?
« Reply #20 on: 19/01/2009 00:28:44 »
Ok, I'll try to break it down.

1. I wrote "Are you saying that only a 'quark gluon soup' will 'break down' atoms.
And that photons can't do that to a single atom.
Well, I was wondering in what way radiation (photons) might 'break down' a atom.
shouldn't it be able to? "
About 'quark gluon soup' I don't think physicists knows a lot more than the bare name, and you want to discuss the effects on an atom? Optimist!  :)
Photons can break down an atom by:
a) giving it enough energy to expel electrons through electromagnetic interaction;
b) kick off electrons through Compton scattering (higher energies);
c) collide with nuclei breaking them apart (even higher energies)
... don't know (even higher energies);

Quote
2. " I understand what you say about temperature being a statistical concept .
But as soon we have photons interacting with a atom it will be a 'real' concept again, right? " (that is, a 'working again' concept)
Can you make a specific example of what you want to say? For example (don't know): "Given a single free atom in space....interacting in this way...with a photon...is it possible to say that the atom's temperature is varied?" or anything else, but very specific, please.

Quote
3. What then followed was just me wondering where that definition might have originated.
You mean the definition of temperature? It comes from thermodynamics, which consider macroscopic, not microscopic, objects. Temperature is defined as the Average kinetic energy of the particles when they are in thermal equilibrium, that is when they have already exchanged their energies in a way that depends on the system considered, for example for an atomic gas the distribution of their velocities must be a Maxwellian. Do you find a simple way to extrapolate from this the concept of temperature for a few or, worse, for a single particle?

Quote
I wrote "Am I right in assuming that this reasoning goes back to that nothing can be seen as having any values without having any 'interaction' and subsequent, or, 'observation'."
This has "half" to do with the concept of temperature; half because it doesn't consider the fact that temperature is defined for macroscopic objects only.
« Last Edit: 19/01/2009 00:31:30 by lightarrow »
 

Offline yor_on

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Why don't atoms melt?
« Reply #21 on: 19/01/2009 16:37:46 »
Ok, I'll try to break it down.

1. I wrote "Are you saying that only a 'quark gluon soup' will 'break down' atoms.
And that photons can't do that to a single atom.
Well, I was wondering in what way radiation (photons) might 'break down' a atom.
shouldn't it be able to? "
About 'quark gluon soup' I don't think physicists knows a lot more than the bare name, and you want to discuss the effects on an atom? Optimist!  :)
Photons can break down an atom by:
a) giving it enough energy to expel electrons through electromagnetic interaction;
b) kick off electrons through Compton scattering (higher energies);
c) collide with nuclei breaking them apart (even higher energies)
... don't know (even higher energies);

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2. " I understand what you say about temperature being a statistical concept .
But as soon we have photons interacting with a atom it will be a 'real' concept again, right? " (that is, a 'working again' concept)
Can you make a specific example of what you want to say? For example (don't know): "Given a single free atom in space....interacting in this way...with a photon...is it possible to say that the atom's temperature is varied?" or anything else, but very specific, please.

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3. What then followed was just me wondering where that definition might have originated.

You mean the definition of temperature? It comes from thermodynamics, which consider macroscopic, not microscopic, objects. Temperature is defined as the Average kinetic energy of the particles when they are in thermal equilibrium, that is when they have already exchanged their energies in a way that depends on the system considered, for example for an atomic gas the distribution of their velocities must be a Maxwellian. Do you find a simple way to extrapolate from this the concept of temperature for a few or, worse, for a single particle?

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I wrote "Am I right in assuming that this reasoning goes back to that nothing can be seen as having any values without having any 'interaction' and subsequent, or, 'observation'."
This has "half" to do with the concept of temperature; half because it doesn't consider the fact that temperature is defined for macroscopic objects only.

Thanks Lightarrow, I can see why you balked at my question(s):)
So temperature is a concept for macroscopic objects.

Can one define what happens as 'temperature' when one isolate a atom and then 'shoot' photons on it with a laser?

Reading what you wrote I started to look for it on the net.
I must admit that until now I've never wondered about what the properties/interactions of just one atom might be though.
http://www.sciencecentric.com/news/article.php?q=08041422
But they define it as a molecule?

Why?
It is one atom and photon(s) interacting?

To be a molecule they must treat the photons as particles it seems to me?
((My kind of scientists::))

Yes SC, a joke, a most harmless joke...
( Now seen to most bravely running for cover, while swearing to itself that never more lend itself to be expressed at a physics forum :)

And it seems very reasonable to see temperature as a macroscopic object/expression.
And not expect the same behavior at a quantum level:)

Depressingly little do I know:)
But most happily so::))

-------

This article is interesting too.

If one read to the end where it state that " researchers could poke atomic-sized holes in the membrane and use the system to study how single atoms or ions pass through the opening."
"This could serve as sort of an artificial analog of an ion channel in biology," McEuen said -- or as a way to measure the properties of an atom by observing its effect on the membrane. "You're tying a macroscopic system to the properties of a single atom," he said, "and that gives opportunities for all kinds of single atom sensors."

http://www.sciencedaily.com/releases/2008/09/080922122519.htm
« Last Edit: 19/01/2009 16:59:11 by yor_on »
 

Offline lightarrow

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Why don't atoms melt?
« Reply #22 on: 19/01/2009 18:14:39 »

Thanks Lightarrow, I can see why you balked at my question(s):)
So temperature is a concept for macroscopic objects.

Can one define what happens as 'temperature' when one isolate a atom and then 'shoot' photons on it with a laser?
Temperature cannot be defined; you can define the atom's mass, momentum, energy (kinetic or else) but not its temperature. We have also discussed it a little here:
http://www.thenakedscientists.com/forum/index.php?topic=16205.0

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Reading what you wrote I started to look for it on the net.
I must admit that until now I've never wondered about what the properties/interactions of just one atom might be though.
http://www.sciencecentric.com/news/article.php?q=08041422
But they define it as a molecule?

Why?
It is one atom and photon(s) interacting?

To be a molecule they must treat the photons as particles it seems to me?
((My kind of scientists::))
It's a new kind of quantum system (we know only the most simple ones), called "molecule" to mean a sort of "aggregate" among the atom and the photons. I had never known about it before, very interesting!
Photons can never be treated as waves only or as particles only and this is another example; you need QED to treat this system.
 

Offline geoff

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Why don't atoms melt?
« Reply #23 on: 20/01/2009 19:59:44 »
yor-el
hi in reply to your liking the idea of a light bulb stripping electrons ,it fairly easy with low energy levels .in my understanding every layer of electrons in an atom is held by an electrostatic attraction that equates to electron volts the more layers the higher the voltage ,suppose a black hole could thoought of as one single atom with all mass that falls into it dividing into nuclei and electrons ,how many shells of electrons w(c)ould there be apply e=mcsquared thatb is a lot of energy at what point would the attractions break down and it be striped  of its layers ,I dont think I would want to be near by .
its one atom that will not be affected by HUP indeed it might affect the observer.
that was what I was thinking
 

Offline geoff

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Why don't atoms melt?
« Reply #24 on: 20/01/2009 20:02:25 »
sorry yor-on
yor el
if I remember right was supermans father.
Geoff
 

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Why don't atoms melt?
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