# Naked Science Forum

## Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: JMLCarter on 30/03/2011 01:08:21

Title: How much energy holds nucleons together?
Post by: JMLCarter on 30/03/2011 01:08:21
2) One day early man discovered fire (then, they say, he played with it).
3) But the energy density of molecular bonds (as released by fire) is dwarfed by that of nuclear bonds.
1) Perhaps we can also say of pre-fire days that kinetic energy (i.e. interactions between stable molecules) was dwarfed in terms of energy density by fire.

So, extrapolating, suppose we could access the next level down, inter-quark forces within nucleons.

How much energy are we talking about in these inter-quark bonds?
Is there a "binding energy" curve for the different nucleons according to their quark composition?
Why aren't we already building nucleon reactors?
Title: Re: How much energy holds nucleons together?
Post by: yor_on on 30/03/2011 02:16:30
If Einstein is correct it should come down to 'energy'. And if we found a way to use that energy for macroscopic machinery? Here's one example.

"Energy of one kilogram of mass:

E = M * c^2
E = 1*(3*10^8)^2 = 9*10^16 J

Assume that your house consumes 500KWH monthly where 1 KWH = 3600,000 Joules.

years = 9*10^16/(12*500*3.6*10^6) = 4,166,666 years

So rounding it up --> You could drive your house on one kg invariant mass for about 4 million years."

Wouldn't that be nice?
Title: Re: How much energy holds nucleons together?
Post by: lightarrow on 30/03/2011 19:48:29

2) One day early man discovered fire (then, they say, he played with it).
3) But the energy density of molecular bonds (as released by fire) is dwarfed by that of nuclear bonds.
1) Perhaps we can also say of pre-fire days that kinetic energy (i.e. interactions between stable molecules) was dwarfed in terms of energy density by fire.

So, extrapolating, suppose we could access the next level down, inter-quark forces within nucleons.

How much energy are we talking about in these inter-quark bonds?
Is there a "binding energy" curve for the different nucleons according to their quark composition?
Why aren't we already building nucleon reactors?

Because we are already doing it  [:)].
Nuclear reactors are exactly this. Nuclear force is infact the force between quarks (which acts inside a nucleon or between 2 different nucleons).

http://en.wikipedia.org/wiki/Strong_interaction
Title: Re: How much energy holds nucleons together?
Post by: CPT ArkAngel on 31/03/2011 00:08:10
Nuclear force is between protons and neutrons (nucleons). Strong Interaction is between quarks inside nucleons and other hadrons. Nuclear force is seen as a residual of the Strong Interaction. The average binding energy of nuclear force is about 1 to 9 MeV, depending on the number of nucleons in a specific atom. The binding energy of Strong Force is unknown due to quarks confinement, but it is certainly higher than the mass-energy of pions (135 to 140 MeV). The Strong Force is 137 times the Electromagnetic Force, but it has a range of about 10^-15 m, contrary to electromagnetic force, which is infinite.

http://en.wikipedia.org/wiki/File:Binding_energy_curve_-_common_isotopes.svg

http://hyperphysics.phy-astr.gsu.edu/hbase/forces/couple.html#c2

http://hyperphysics.phy-astr.gsu.edu/hbase/particles/quark.html#c6
Title: Re: How much energy holds nucleons together?
Post by: JMLCarter on 31/03/2011 21:22:40
Thanks CPT it's interesting just to know there is (easily) an order of magnitude higher energy in bonds at the quark level within a nucleon (than at the nuclear level).

For this to kind of energy to be accessed we are most likely talking about using some kind of high energy radiation to split nucleons. Note: This does not occur in a nuclear reactor; in a particle accelerator, certainly but not in a way that returns more energy than it releases. The freed quarks would need to have enough energy to break other nucleons - I would be interested to know if the energy sums would add up as they do for nuclear fission (not that the world isn't dangerous enough already).
Title: Re: How much energy holds nucleons together?
Post by: Soul Surfer on 31/03/2011 23:56:59
JMLCarter:  You are now starting to realise the importance of thermodynamics in energy sources.  If a system has already achieved a stable state it is not possible to extract energy from it.  Things burn in a fire because when they oxidise energy is released.  Uranium ractors generate energy because uranium nuclei contain more energy than two approximately half size nuclei when they split.  Hydrogen can be fused to helium to release energy and this is is the source of energy of most stars and a possible source of future energy for mankind.  subnuclear particles have already reached their final state and can never offer a source of energy.  Antimatter is almost non existent in our universe now but it provided a vast source of energy in the past.  There is however one source of potential infinite energy that people are considering tapping into but no one has found a way of doing it yet.  That is the quantum mechanical vacuum energy as seen in the Casimir effect.
Title: Re: How much energy holds nucleons together?
Post by: JMLCarter on 01/04/2011 20:48:31
I can see it is a theoretical impossibility to extract energy from systems that are already in their lowest energy configuration; but not that stability has much to do with it. Hydrogren is stable, yet a fissile energy source. Perhaps there is more to the application of thermodynamics to energy sources than you yet realise?

Neglecting how it is done or the energy costs of doing it for a minute, a replacement of an UP quark in a proton with a DOWN quark to make a neutron must either release or require some energy.

How much energy?
Title: Re: How much energy holds nucleons together?
Post by: lightarrow on 01/04/2011 20:55:56
I can see it is a theoretical impossibility to extract energy from systems that are already in their lowest energy configuration; but not that stability has much to do with it. Hydrogren is stable, yet a fissile energy source. Perhaps there is more to the application of thermodynamics to energy sources than you yet realise?

Neglecting how it is done or the energy costs of doing it for a minute, a replacement of an UP quark in a proton with a DOWN quark to make a neutron must either release or require some energy.

How much energy is the first question, and then we might next think about the energy cost of firing quarks into the proton or neutron to achieve it.
You can't do that because isoleted quarks cannot exist (it is just theorized they exist at incredible high energies).
Title: Re: How much energy holds nucleons together?
Post by: JMLCarter on 01/04/2011 21:37:33
Even in particle accelerators we have not yet seen isolated quarks?

That's a pretty high energy threshold. Or is there some other reason?
Title: Re: How much energy holds nucleons together?
Post by: syhprum on 01/04/2011 22:11:49
It is suggested that the very largest supernova are powered by a matter/antimatter process.

http://www.physorg.com/news/2011-04-keck-telescope-images-super-luminous-supernova.html

"The final category includes the most massive progenitor stars, those more than 100 solar masses. In this case, “the current state of the art predicts that they make matter and antimatter, electron-positron pairs, because they are so hot,” Wheeler said. “That process destabilizes the whole star and it contracts, ignites the thermonuclear fuel, and then explodes, blowing the whole star up.”
Title: Re: How much energy holds nucleons together?
Post by: JMLCarter on 01/04/2011 22:37:10
Is that about creating electron/positrons from energy, rather than just observing them. It's not so hard to detect existing electrons.

Have we not smashed up a nucleon and detected isolated quarks?
Title: Nucleon Energy vs Nuclear Energy
Post by: Soul Surfer on 02/04/2011 10:44:18
JML Carter Firstly going back to your post of 1st april hydrogen is not a fission source of energy but a fusion one (maybe that was aimed at an april fool!)

The electron positron supernova exists because the temperature inside the star gets so hot that the thermal radiation supporting the pressure of the layers above gets so hot that electron positron pairs can be created as the photons interact with other matter instead of just more photons.  This creation of matter suddenly saps the energy in the centre and starts a collapse which runs away as things get hotter.

Isolated quarks have not and are unlikely ever to be detected because they cannot be separated by more than about the size of a proton  10^-15 meter  without the energy of separation creating another quark antiquark pair and this happens in about the length of time it takes light to travel that distance,  that is about 3x10^-24 second uncertainty forbids "seeing" things at this level of detail.  The effects have to be inferred by the statistical outcomes.  This is in some ways the inverse process of the creation of electron positron pairs by high energy gamma rays interacting with matter.

You can visualise the process in the LHC where to protons collide.   just two of the three quarks in each of the protons collide, hit each other and stop dead on the spot(approximately) while the other two carry on in opposite directions drawing out a complex string of quark pairs all of which go in different directions as the lose energy and decay to stable particles so one collision produces a whole cascade of particles in different directions all of which have to be measured for energy and direction and related back to the original collision to work out what actually happened
Title: How much energy holds nucleons together?
Post by: lightarrow on 02/04/2011 13:57:11
Even in particle accelerators we have not yet seen isolated quarks?
No. It's called "confinement": 2 quarks are bounded by a force which increases with distance, as in the case of a spring.

Quote
That's a pretty high energy threshold. Or is there some other reason?
Apart the confinement, I am not aware of other reasons. It's theorized that at immense energies the confinement should break up, but we can't achieve those energies for the moment.
Title: How much energy holds nucleons together?
Post by: JMLCarter on 02/04/2011 14:25:13
"carry on in opposite directions drawing out a complex string of quark pairs all of which go in different directions as the lose energy and decay to stable particles"