Assuming absolute zero were a possibility:?

[Lithium381]

Would we be able to make matter cease to exist? Seems logical that if something reached absolute zero, there would not be any energy, and since energy is matter and/or vice versa. Also, even closer to absolute zero, would there be enough momentum/energy in the electrons to keep a field up? That they would not fall into the nucleus? If they did.....would they just cancel eachother out, ceasing to "exist" in any form that i can think of...:-\ Any thoughts?

 

[uart]

Originally posted by: Lithium381
Any thoughts?

Yep, here's a thought. Thermal energy is not the only form of energy that the matter contains.

 

[Rainsford]

AFAIK, absolute zero would mean no movement of the atoms themselves, not sure about the subatomic particles. So that would mean that assuming you could reach absolute zero, the matter would still be there, but there would be no way to "see" it without raising its temp above absolute zero because with no movement, I don't think there would be any way to interact with it.

Keep in mind that I'm no physics professor, but I did stay at a Holiday Inn Express last night

 

[sao123]

Well, If you were able to reach a state of absolute zero, that would be the state where there is zero kinetic energy available. Potential energy could be stored, but is useless until released.
Now since, temperature is a measure of the velocity of the vibration or movement of the atom itself. If the atom stops moving totally...hmm.

Well heres my own thought/question about conservation of energy/momentum? Could the super fast velocity of the electron in its orbit be part of the driving force behind atom vibration(temperature?) Think about it, put a mass on a string and spin it about you...if the mass is large enough or fast enough, it will cause you to wobble about, even maybe step back and forth. could this also be happening on the (sub)-atomic level?
If so, for an atom to stop moving totally (absolute zero), then the electron would also have to stop orbiting. It would be sucked in & collide with the nucleas. However, theoretically: protons and electrons dont annihalate each other the way matter/antimatter do. I do imagine there is some process which would allow a proton and electron to fuse and produce a neutron?

However, I agree with Rainsford...if this were to happen... as soon as a light photon hit the event and then reflected as light which you could see, the absolute zero state would be voided, because some of the energy from the phton would be absorbed.

But...IANANEONP (I am not a NASA engineer or nuclear physicist.)

 

[drag]

Here's what I know about this.

The lowest the temperate gets anywere in the universe is 3 degrees above kalvin.

There is only one place known to science were it gets colder, and that's in labritories here on Earth.

We can get a few fractions of a degree above kalvin, thru a couple of different technics.

The first one, is to get it simply as cold as you can get it using refriguation technics,

The second one is to use a magnetic feild to trap the atoms you want to get very cold.

Then you fire lasers at them, the photons collide with atoms moving towards the light, slowing them down. Other ones shoot off from the light taking lots of the energy with them.

Then once you get as cold as you get (remember thermal energy is the shuffling and moving that the atoms do) using the cooling lasers, you gradually lower the magnetic feild. The atoms bounce against each other, say (for example) you have 2 atoms hit one atom, the energy from the 2 atoms shoot the 1 atom off faster, while they slow down. So the atoms that manage to break out the magnetic feild take the kinetic energy with them, the ones remaining get slower/colder.

Using these technics you can get those atoms down to a few billionths of a degree above absolute zero. (To me that freaking insane to have something that cold.)

Once the atoms reach a certian point, they simply collaspe on one another, they lost enough energy that they are no longer repelled by one's another movement and they collaspe into a into a kind of super-atom.

This is called Bose-Einstein condensation.

here is were I learned about it. It's a funny website, but reminds me that unless you are unable to explain complicated subjects to a small child so that they can understand it, you don't truly understand the issues yourself

So if you were to get something down to absolute zero, all molecular structure would probably break down. Absolute zero= NO ENERGY whatsoever. NO light, no movement, no nothing. (I suppose you could argue that something can contain potential energy because we are all moving in space and we could smack into something, but that's kinda to academic for me to care about.) Gravitational force wouldn't exist because all the atoms would collaspe on each other filling up the vast spaces imbetween the nucleases and the various rings of electrons. 99.99999...% of a atom is empty space, normally. Or something like that.

Of course this gives me instant thoughts about the original big bang, were the entire universe would fit on the head of a pin. (or whatever).

 

[Soulkeeper]

it would shake physics, chemistry, and science in general to it's core


hahahaha

 

[f95toli]

Your first problem is that you have to define temperature which is not easy in this case.
The simplest case is a simple (non-interacting) gas, here the kinetic energy of each atom is simply equall to 3/2*kb*T where kb is Boltzmanns constant, zero temperature would then mean that the atoms are not moving at all, nothing really strange would happen. This is the "traditional" way of thinking of temperature.

The other. perhaps more modern, way of thinking of temperature is to say that at zero temperature all everything is in its ground state, this does NOT mean that nothing is moving but simply that there are no available states with lower energy.

In for example the a metal things become more complicated when you reduce the temperature below about 1 K, now the temperature of the free electrons in the metal and the temperature of the phonons (lattice vibrations) can start to differ.

In a normal low-temperature lab you cat get down to about 20 mK using standard equipment, in most cases a a dilution fridge. If you need to get lower than that you need specialized equipment.

 

[UptheMiddle]

What about the electron portion of his question? Would temperature impact rotation about the nucleus? Personally, I don't think so. That would imply that on the other end of the spectrum (as things heat up), electrons would be flying out of orbit which probably wouldn't be a fun time in an uncontrolled environment.

Just thinking out loud, does anybody know what causes expansion/contraction with fluxuations in temperature (on an atomic level)? Something to do with higher/lower kinetic energies causing the atoms to repel/attract....oh man, its too late to be thinking like this!!! lol....

 

[f95toli]

If the electron is "orbiting" (remember that the description of an atom as a "solar system" is just a clssical model and not really correct) the nucleus in its ground state (the lowest "orbit") I think you could say it is already at 0 K.

 

[NerdOfTheNorth]

Originally posted by: sao123

Well heres my own thought/question about conservation of energy/momentum? Could the super fast velocity of the electron in its orbit be part of the driving force behind atom vibration(temperature?) Think about it, put a mass on a string and spin it about you...if the mass is large enough or fast enough, it will cause you to wobble about, even maybe step back and forth. could this also be happening on the (sub)-atomic level?

I don't think so, considering that the mass of an electron is far less than the mass of a proton or neutron and that there should be about twice as many particles in the neucleus as in orbit. So if you have 20 boulders in a pile and tie them to 10 pebbles then swing the pebbles around they probably won't affect the pile of boulders. At least, that's my thinking...

Originally posted by: UptheMiddle

Just thinking out loud, does anybody know what causes expansion/contraction with fluxuations in temperature (on an atomic level)? Something to do with higher/lower kinetic energies causing the atoms to repel/attract....oh man, its too late to be thinking like this!!! lol....

As far as I know, it's like this. The higher the temperature, the greater the velocity of the atoms. The greater the velocity of the atoms, the more commonly they collide. The more commonly the atoms collide, the farther away from each other they are bounced. The farther away they are bounced, the lesser the density of the substance in question. Now, since the Law of Conservation of Matter should cause the total mass of the substance to remain the same and the density is decreasing, the volume must increase to compensate. And thus, the substance expands.

 

[sao123]

I don't think so, considering that the mass of an electron is far less than the mass of a proton or neutron and that there should be about twice as many particles in the neucleus as in orbit. So if you have 20 boulders in a pile and tie them to 10 pebbles then swing the pebbles around they probably won't affect the pile of boulders. At least, that's my thinking...

You thinking is correct until you take into account F=MA. Remember, the velocity of those electrons are as close to C as you can physically get. Because of the tight orbit the radial acceleration of the particle probably approaches infinity.
As small as the mass of the electron is, I think the A value will compensate heavily.

 

[NerdOfTheNorth]

mmm... that could very well be true. So you say that the velocity of the electrons is relatively close to C. How close are we talking here?

 

[sao123]

According to the Bohr Hydrogen Model:
The velocity of the electron is 2.18769 x 10^6 m/s and C is 2.99792 x 108 m/s.
so I would estimate the unexcited speed of an electron is C/100. Which is still very relatively close to C.

The mass of a proton is 1.67262158(13) × 10-27 kg
The mass of an electron is 9.10938188(72) × 10-31 kg,
The mass of a neutron is 1.67492716(13) × 10-27 k
A difference of 1:10000


I am currently working on the calculations, for the radial acceleration of the electron.
but when F=MeAe = MpAp, There is definately going to be a radial acceleration exerted on the nucleas of the atom.

 

[f95toli]

I assume you are aware that the Bohr hydrogen model was just a first attempt to understand the atom. You need to use quantum mechanics to understand the atom, the "velocity of the electron" as is "travels around the nucleus" is a meaningless concept.

 

[sao123]

Double post... n/m.

 

[sao123]

I understand that the velocity means little...
But remember..temperature is a measure of the kinetic energy an atom has. This kinetic energy exists not in net displacement but in a back & forth vibration.

The fact remains that because the electron does not travel in a straight line, there must be an acceleration on the electron at all times.
(which the approximate velocity of an electron can be used to calculate)
This outward acceleration must be balanced F = MA = MA, and the force is significant enough to cause the nucleas to "wobble", essentially moving the entire atom.

All I am saying is that this high speed orbit by multiple electrons around the nucleas is possibly an explaination for the atomic vibration which we call temperature.

 

[f95toli]

First of all, temperature is NOT simply a measure of the atomic "vibration" and the temperature of matter is not in any way related to the motion of the electrons that are bound to a atoms (it IS related to the temperature of the FREE electrons, which .
"Temperature" in solid state physics is just a thermodynamic quantity which basically tells you the shape of the distribution functions, it also tells you the amount of collective lattice vibrations (phonons).

And no, there is no (classical) "force" on the electron, the Bohr model can not explain why the forces are "balanced", it assumes that the electrons can only be in certain discrete "orbits" and based on that assumption you can calculate a few properties of hydrogen. However, it was known from the start that the model is just a "toy", if you want to calculate things like angulat momentum you need quantum mechanics. You also need to introduce concepts which has no classical analogue such as spin and the Pauli principle.

You are trying to describe an atom using classical physics, this simply does not work.

 

[sao123]

In response to #1 by Lithium....
I suggest you research Bose-Einstein condensation and its relationship to absolute zero.
It doesnt work in all circumstances...but at least part of the time, the answer to your question is sorta yes - sorta no
The matter is never destroyed, but the atoms cease to exist in the form we know them.


In response to f95...its all theory anyway.
explain this...as I was taught...in college level chemistry
In a group of atoms there is always a whole range of speeds, some fast some slow, but there is one average of them all. Temperature is describing the average & the range of speeds of the bunch of atoms together. It is a function of the distribution of the kinetic energy of a group of atoms. Correct or not?

 

[drag]

I know that photons have enough mass to move objects by their impact. So electrons must have a impact on the Atom's movement, no matter how small. So if you were to reach absolute zero were no movement = no energy, then electrons would have to be accounted for. What do the electrons do in a Bose-Einstein super-atom? Do they just collaspe allong with the rest of the atom?

I would figure that a zero energy molecule would be completely chemicaly and electrically inert.

What would be interesting to see is how gravity is affected in all this. It could help to illustrate the role in gravity in relation to tempurate, light, and electricity.

The reason that I figure that all structure would collaspe is that if you were to get a zero tempurature desk (for instance) you would still have gravity affecting the desk. The molecules would still be attracted to each other. Then they would move towards each other and then that wouldn't be zero-tempurature would it? They would bang against each other and create some sort of tempurature reading, no matter how small.

Molecular structure would have to be destroyed as part of the cooling proccess.

 

[f95toli]

Sao123: Yes it is correct as long as you are talking about a gas with "ball-like" non-interacting atoms.

 

[NerdOfTheNorth]

Originally posted by: drag
I know that photons have enough mass to move objects by their impact.

Forgive my limited understanding of Physics, but it was my knowledge that when anything travels at C, its mass is multiplyed by infinity. Thus, if light (photons) had mass, that mass would become infinite and some very weird things would start to happen. I haven't noticed the solar system collapsing in towards my flashlight, for example. Also, light is energy, not matter, and it was to my knowledge that energy, as a rule has no mass. Someone explain where I went wrong, please.

 

[sao123]

NerdoftheNorth...
Light is only a photon when it interacts with another piece of matter. While it is traveling through a void medium, it is a wave.
At this point of interaction...usually a collision (reflection, refraction, etc) with a group of atoms, Light is no longer moving at C. It has to slow down during the interaction. At this point I believe photons have some infinately small mass. But it isnt zero.

F95.
I believe this theory is partially correct for liquids and solids too, this is, I thought, the current model for heat conduction through a material, or from 1 material touching another. The atomic collisions spreads out to anything it touches. Speeding up or slowing down adjacent atoms/molecules.


Drag,
I was thinking exactly the same.

Molecular structure would have to be destroyed as part of the cooling proccess

Even stronger than that...atomic structure ceases to exist in this case.
With no electron field to repel the atoms apart or hold the molecules together, all the nucleases of surrounding atoms collapse into 1 large nucleas.
The electrons in the BEC actually go into the lowest energy state concievable...Total collapse into the nucleas.

With all the matter in a lump and no structure, So densly packed...but what about the no energy region?
Because the universe likes to be in balance, I imagine this thing could become an intense energy sucker, sorta sounds similar to the matter making up black holes? I wonder if theres a correlation here.

 

[Matthias99]

NerdoftheNorth...
Light is only a photon when it interacts with another piece of matter. While it is traveling through a void medium, it is a wave.
At this point of interaction...usually a collision (reflection, refraction, etc) with a group of atoms, Light is no longer moving at C. It has to slow down during the interaction. At this point I believe photons have some infinately small mass. But it isnt zero.

As I am not a physics person myself, I'm also a little fuzzy on this. However, my understanding is that light always travels at C. In situations where light seems to move more "slowly" (ie, in a material with a high IOR), it's really just being reflected or absorbed/retransmitted many times over. The photons move at C when travelling between molecules of the substance in question, but it takes a few picoseconds (or whatever) for an atom to absorb and retransmit a photon, making it seem to move more slowly.

However, in terms of light exerting force on something: when a photon gets absorbed/retransmitted/reflected off of an object, obviously some energy has to be expended to change its direction (since by Newton's First Law the photons should keep going in a straight line unless some force affects them). By Newton's Third Law, the photons bouncing off the object must create a small impulse on the object being hit by the photons.

Photons do not appear to have any rest mass, but they're also apparently incapable of ever truly being at rest. Beyond that I just get confused, as I haven't studied quantum mechanics.

 

[f95toli]

Sao123: No, this theory is strictly speaking not correct in solids. You have to use a much more sublte theory if you want to define the temperature of a solid in this way. It is more complicated than just saying that it is only related to the motion of the individual atoms.

Your misstake is that you are assuming that "temperature" is a well definied concep but it is not. In most situations temperature is just a way to describe the energy distribution of a ensemble of particles or states, you can NOT talk about the temperature of a single particle. Things get even more complicated in solids because then you can have many different temperatures depending on which ensemble you are studying. The temperature of the electron gas will not be the same as that of the lattice at low temperatures (there is neat "trick" you can use called "electron cooling" which uses this fact to cool only the electron gas, not the lattice).

And your description of the BEC is wrong, nothing happens to the electron states in the atom when the gas becomes a BEC.

I should point out something before this discussion continues: I know this field faily well and work with low temperatures on a daily basis since I study quantum mechanical phenomena in solids (mostly in superconductors), I do enjoy explaining things but in this case it is difficult to describe what I mean without resorting to math or fairly advanced physics.
If someone is interested I could propably recommend a book or two on the subject.

 

[drag]

I beleive that he ment to say that BEYOND BEC is were the collaspe of the electon states would occur.


Anyways I always beleived that the concept of zero degrees kelvin = absolute zero = zero energy.


Now no matter how cold it's impossible to stop all movement. It's just not possible. You have HUP and all that quantum stuff, which part of it dictats that it's impossible to reach no movement or any oscillation. Plus it's against all the laws of thermodynamics.

It's not realy hard to explain why you can't reach zero movement.

So absolute zero is as impossible to reach as it is to reach infinate tempurature. You can get closer and closer to zero, with in fractions of it, then with in fractions of that, then within fractions of that etc etc, but it's like trying to find the end of PI. Just like you could pile up all the energy in the universe, but you couldn't ever reach infinate energy.

But there has to be something powering electrons, right? Something that compels them to orbit, something to get them to spin around and rattle around between atoms.

Now do you suppose that like BEC you could reach another lower level of energy state even lower then that were these things begin to break down? Something were even hydrogen begins to act more like a liquid then a gas?

So if absolutely no energy is not possible, can you possibly reduce it to a point were there might as well be no energy?