Yet another Physics question
Discussion
The universe is made up of protons, neutrons and electrons. (and quarks whatever they are). The elctrons circle the nucleus and the protons and neutron stick together in the middle nucleus. What's the space made up of that the electron travels through? What fills the space between the protons and neutrons if they're cylindrical like the pics show?
atoms are mostly empty space. The is nothing between the nucleus and the electrons. The atoms have a sort of spherical force field around them, caused by the electrons that mean you can't push an atom through an atom (because like charge repel eachother - so electrons repel electrons). This is why you can't push your head through a wall.
OK - good question! This makes my brain itch and it's my job!
The space between the orbital of an electron and its nucleus is filled with 'space' - exactly the same stuff as you find when you leave the Earth's atmosphere. And there's a lot of it; if you magnified a hydrogen atom so that the proton (nucleus) was the size of a football, the electron would be a 2mm ball bearing orbiting a mile away.
The nucleus of an atom is made up of protons and neutrons which are, in turn, each made up of three quarks. Nuclear quarks come in two 'flavours' - 'up' and 'down'. Up-quarks have a charge of +1/3 and Down-quarks a charge of -2/3. Protons are made of only Ups (1/3+1/3+1/3= a charge of +1) and neutrons are made of two Ups and a Down (1/3+1/3-2/3= a charge of 0).
The nucleus is held together by the neutrons insulating the protons from each other and stopping them repelling electrically, whilst the quarks that they are made of exchange the Strong Nuclear Force in the form of Gluons that 'stick' the whole thing together.
The protons and neutrons are best not thought of as solid 'balls', they behave more like the bubbles in a foam with no 'space' between them...
You can wake up now!
>> Edited by MGBGT on Wednesday 22 February 20:24
The space between the orbital of an electron and its nucleus is filled with 'space' - exactly the same stuff as you find when you leave the Earth's atmosphere. And there's a lot of it; if you magnified a hydrogen atom so that the proton (nucleus) was the size of a football, the electron would be a 2mm ball bearing orbiting a mile away.
The nucleus of an atom is made up of protons and neutrons which are, in turn, each made up of three quarks. Nuclear quarks come in two 'flavours' - 'up' and 'down'. Up-quarks have a charge of +1/3 and Down-quarks a charge of -2/3. Protons are made of only Ups (1/3+1/3+1/3= a charge of +1) and neutrons are made of two Ups and a Down (1/3+1/3-2/3= a charge of 0).
The nucleus is held together by the neutrons insulating the protons from each other and stopping them repelling electrically, whilst the quarks that they are made of exchange the Strong Nuclear Force in the form of Gluons that 'stick' the whole thing together.
The protons and neutrons are best not thought of as solid 'balls', they behave more like the bubbles in a foam with no 'space' between them...
You can wake up now!
>> Edited by MGBGT on Wednesday 22 February 20:24
MGBGT said:
The space between the orbital of an electron and its nucleus is filled with 'space' - exactly the same stuff as you find when you leave the Earth's atmosphere. And there's a lot of it; if you magnified a hydrogen atom so that the proton (nucleus) was the size of a football, the electron would be a 2mm ball bearing orbiting a mile away.
I guess this is the bit I was wondering about, it's hard to imagine what space is, from your explanation it's simply "nothing". I guess without this magic ingredient(nothing) the whole place would be a hell of a lot denser, it's just hard to imagine "nothing".
Thanks for all the info, I for one found it quite interesting
The 'space' has dimensions and it is host to the apposing and attractive forces that balance to hold the components together. These energies fill the 'space' and if anything enters the 'space' it will be influenced by the energy. You could therefore argue that the space isn't empty; it is in fact full of energy. Ultimately it's all energy but that's another debate.
tvrbob said:
The 'space' has dimensions and it is host to the apposing and attractive forces that balance to hold the components together. These energies fill the 'space' and if anything enters the 'space' it will be influenced by the energy. You could therefore argue that the space isn't empty; it is in fact full of energy. Ultimately it's all energy but that's another debate.
seconded
(Not quite right to say the forces balance and this stops the electrons falling in to the nucleus, or the atom is balanced by these forces. The thing that stops the electrons all falling in to the nucleus ... well actually a statement of a rule which simply says the electrons won't all fall into the nucleus ... is the Pauli Exclusion Principle ... http://en.wikipedia.org/wiki/Pauli_ex ... another odd feature of quantum mechanics)
>> Edited by ATG on Thursday 23 February 11:07
>> Edited by ATG on Thursday 23 February 11:07
ATG said:So is Pauli Exclusion the opposing force? If so it is a balance of forces that maintains the separation and thereby the 'space'.
(Not quite right to say the forces balance and this stops the electrons falling in to the nucleus, or the atom is balanced by these forces. The thing that stops the electrons all falling in to the nucleus ... well actually a statement of a rule which simply says the electrons won't all fall into the nucleus ... is the Pauli Exclusion Principle ... http://en.wikipedia.org/wiki/Pauli_ex ... another odd feature of quantum mechanics)
No, it's not a force. It's a statement of a fundamental Quantum Mechanics rule ... in the same way that you can state a rule in classical Physice like "objects with mass attract each other, and we'll call that attraction Gravity". It's not an explanation, it's a statement of an observed behaviour.
There are two parts to atomic structure in Quantum Mechanics:
One of the features of QM is that physical properties like position and velocity in some circumstances become "quantised"; e.g. a physical property is only allowed to take one of a set of discreet values and is excluded from any intermediate values. Atoms are examples of quantised systems. The energy of the electron with respect to the nucleus is only allowed to take one value from a set of discreet states. In classical Physics this energy would be the combination of the potential and kinetic energy associated with an orbit. It is a bit like the quantisation says "satellites can't orbit at whatever height they like, they have to orbit at either 75km or 100km or 110km or 115km, etc."
The second feature of QM is that certain types of particles (known as fermions and including protons, neutrons and electrons) are not allowed to exist in the same quantum state as each other. This is a statement of the Pauli Exclusion principle. In classical Physics we are used to the idea that two physical objects can't be put in the same place; e.g. you can only put one egg in an egg cup, there is no room for a second egg in the cup, the second egg can't somehow coexist in the same space that is occupied by the first egg. The Pauli exclusion principle is similar to that. A quantum state is the total collection of physical properties that describe an object. For an electron in an atom it turns out there are three relevant physical properties; the electron's intrinsic angular momentum known as "spin" which can only take the values +1/2 and -1/2, the primary quantum number which is pretty much the energy level associated with an orbit, and the harmonic angular momentum number which beats the shit out of me. What this means is that the state of an electron in an atom can be uniquely defined by three numbers and the values those numbers can take is quantised, e.g. they are only allowed to take values like (+1/2, 1, 1) and (-1/2, 1, 1) and (+1/2, 2, 1) ... states like (-0.4, .3 , .2) just don't exist. Pauli exclusion says that only one electron can occupy each quantum state. This means only one electron can occupy the state (+1/2, 1, 1). If you add another electron to the atom it must occupy a different state. As a result there are onl;y a certain number of spaces available at each allowed "orbital distance" away from the nucleus. Once all the spaces are filled with electrons, further electrons must occupy states at greater distances from the nucleus. This is what is determining the size of atoms. It is treated as a fundamental property of nature, not the result of a balance of forces or someother more fundamental mechanism.
There are two parts to atomic structure in Quantum Mechanics:
One of the features of QM is that physical properties like position and velocity in some circumstances become "quantised"; e.g. a physical property is only allowed to take one of a set of discreet values and is excluded from any intermediate values. Atoms are examples of quantised systems. The energy of the electron with respect to the nucleus is only allowed to take one value from a set of discreet states. In classical Physics this energy would be the combination of the potential and kinetic energy associated with an orbit. It is a bit like the quantisation says "satellites can't orbit at whatever height they like, they have to orbit at either 75km or 100km or 110km or 115km, etc."
The second feature of QM is that certain types of particles (known as fermions and including protons, neutrons and electrons) are not allowed to exist in the same quantum state as each other. This is a statement of the Pauli Exclusion principle. In classical Physics we are used to the idea that two physical objects can't be put in the same place; e.g. you can only put one egg in an egg cup, there is no room for a second egg in the cup, the second egg can't somehow coexist in the same space that is occupied by the first egg. The Pauli exclusion principle is similar to that. A quantum state is the total collection of physical properties that describe an object. For an electron in an atom it turns out there are three relevant physical properties; the electron's intrinsic angular momentum known as "spin" which can only take the values +1/2 and -1/2, the primary quantum number which is pretty much the energy level associated with an orbit, and the harmonic angular momentum number which beats the shit out of me. What this means is that the state of an electron in an atom can be uniquely defined by three numbers and the values those numbers can take is quantised, e.g. they are only allowed to take values like (+1/2, 1, 1) and (-1/2, 1, 1) and (+1/2, 2, 1) ... states like (-0.4, .3 , .2) just don't exist. Pauli exclusion says that only one electron can occupy each quantum state. This means only one electron can occupy the state (+1/2, 1, 1). If you add another electron to the atom it must occupy a different state. As a result there are onl;y a certain number of spaces available at each allowed "orbital distance" away from the nucleus. Once all the spaces are filled with electrons, further electrons must occupy states at greater distances from the nucleus. This is what is determining the size of atoms. It is treated as a fundamental property of nature, not the result of a balance of forces or someother more fundamental mechanism.
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