Why atoms? All that binding energy--why is it bound up?

This is one of those “Oh crap, I don’t have the faintest clue about anything” moments: particle “stuff,” as thead after thread reminds us, is either all energy (if you want to look at it that way), or huge amounts of different kinds of binding energy working as/among other stuff.

Way back when, when the Universe was deciding what to do with its loads and loads of energy, why/how did it (“agency” as figure of speech) go to all the trouble to “use it” forcing together in physical proximity particles that don’t want to be in physical proximity with each other?

I’m not sure which of my umpty-ump different misconceptions of the way things work this question underlies, but probably a lot of them.

So be gentle with me.

I don’t think there’s any scientific answer to your question. “Why does stuff exist?” is, like most “why” questions, in the realm of philosophy.

NM

Part of the answer is that your premise isn’t really correct: almost none of the energy in the Big Bang ended up going into matter. Our universe is made from the scraps.

Among the losses:

  • Neutrinos created in nuclear reactions flying off to who-knows-where
  • Photons, too.
  • Matter and antimatter were created in almost equal parts (within one part in tens of millions). Matter “won”, though we wouldn’t have known the difference; the universe would work perfectly well if it were made from antimatter instead. No one knows why they weren’t created in exactly equal parts. At any rate, all but a tiny amount annihilated and we got the remainder.
  • Dark matter. Who knows what this stuff is? But it’s there and it dominates the matter in the universe.
  • Good old expansion. The stuff was tightly packed before and now it’s not. The energy is still there, of course, by virtue of stuff being widely separated. But that’s the opposite of what you’re arguing.
  • Dark energy? Maybe not a function of the Big Bang; it seems to be an artifact of physical law. But who knows.

Furthermore, the matter we did get wasn’t tightly bound right away. Remember that almost all visible matter is hydrogen. Gravity had to do its thing and create some stars before we really got a decent quantity of heavy elements.

I believe the answer you’re looking for is 42.

Dr., thank you very much. I’m sort of feeling it.

So all the energy in all the mass in the universe, if hey-presto Mc[sup]2[/sup]-ed, would still give a (measurable?) smidgen…

How is [del]babby[/del] proton made?

  • off to look up early Universe history *

Why don’t particles want to be in close proximity?

As I understand it, the strong nuclear force is the greatest force of “attraction” in the universe, by a wide margin.

It would seem the universe chose to make particles really like each other.

This is starting to get beyond my knowledge level, but the handwaving answer is that the nuclear forces are such that below a certain temperature, the quarks–the components of protons, neutrons, and other particles–can’t exist in a free state. They just really want to snap together into a particle. If you take a proton and try to extract a quark, you have to pump so much energy into it that you end up producing a quark-antiquark pair and get a new particle out of it. We have protons because the quarks can’t exist any other way.

Early in the Big Bang, everything was so hot that this wasn’t a problem. You just had a hot soup called a Quark-Gluon plasma (we can recreate this in particle accelerators, BTW). The universe had to expand and cool a bit before the energy condensed into normal matter.

Why are the laws set up such that quarks behave this way? Well, that’s getting into philosophical questions like Chronos mentioned. The anthropic principle answer is that you need energy to condense into matter, because otherwise you don’t get elements, which means you don’t get chemicals, which means you don’t evolve life that can contemplate the laws of the universe.

The strong nuclear force drops off in power quickly. By the time an atom gets to be uranium-sized, the electromagnetic repulsion of all those protons is starting to get stronger than the strong nuclear force. And by the time you get to the outside of an atom, all those negatively charged electrons keep atoms apart even though they’re mostly empty air.

If it helps, think of a magnet on Earth. At certain distances, the magnet is stronger than gravity and can hold something off the ground. But you don’t have to move very far away from the magnet before gravity becomes the dominant force again.

There are at least three reasons that that’s a very unfortunate choice of phrasing.

The space inside an atom is actually mostly empty nougat.

Atoms are not mostly empty air, of course. Maybe empty space, but not air.

Even “empty space” is not entirely correct, though. It would be more accurate to say that the space outside an atom’s nucleus is filled with the quantum fields that represent the atom’s electron(s).

Yeah, guilty as charged on that one. :o

Sorta. The strong nuclear force is more accurately called the residual strong force, or residual color force.

It’s residual because the force holding nucleons (protons and neutrons) together is actually the leftover component from differences in the color force from individual quarks.

When you are far from a nucleon, the strong force adds up to zero. But because nucleons are not point particles, and the three quarks they’re composed of are physically separated, when you get very close, you can start seeing forces from one of the quarks dominate, and its these small differences that cause nucleons to stick together.

In fact the color force itself does not reduce with distance. This is why free quarks don’t exist–it takes so much energy to separate them that you’ll just generate more quark/antiquark pairs if you try. You can only get them so far apart.

The residual strong force is a similar effect to how atoms appear neutral when you’re far away, but appear charged when you’re close. Same deal with magnets. The difference is that instead of a single type of charge (+/- or N/S), you have three (red/antired, blue/antiblue, and green/antigreen. Of course these aren’t in any way “real” colors).

I’m disliking the ‘colour’ concept as an explanation that will be one layer,
eg Newtonian, quantum mechanics, color, then something else…

It will blur into that something else … and the original question is, what is that something else ?

If the binding energy might be places there as photons, and must be released as photons, is the binding energy’s mass therefore a collection of photons, do they exist in their in some way, so its potential energy, its actually photons in there ? Can a quark be constructed from photons ?

My response is more along this line. That’s the way the universe “is” because that’s the way we understand it to be, insofar as we understand it at all. There seems to be of course some correspondence between how the universe IS and how we understand it to be, but my suspicion has come to be that the efforts to align those two show us more about how the mind works than about how the universe works.

A cop out, I know. But that has always made me feel a little better about pursuing a career in the life sciences rather than the physical sciences.

I just hope that we never find out that it was one of those incidents where God said, “hold my beer and watch this y’all”. Of course that leads to the question of where did god come from.

Is this to say that “residual strong force” is to “color force” as “Van der Waals force” is to “electromagnetic force”? (My daughter is taking SAT this morning :slight_smile: )

I guess you’re saying that the “strong force” is a fictitious force. If so, that goes a long way toward saying how weak “strong force” is compared with “color force”.

Yep! Aside from the fact that three are three types of charges instead of one, it’s a fairly similar phenomenon.

Because the electromagnetic force is so strong, particles tend to move around until things are macroscopically neutral. But close up, you frequently have a dipole–something that’s positive on one end and negative on the other. Pairs of dipoles attract each other since the + and - on each end can line up.

With the color force, quarks arrange themselves into “colorless” matter. A color and its anticolor in a pair are colorless. A red-green-blue triplet is also colorless, as is antired-antigreen-antiblue. There’s some evidence that you can get combinations of these as well, such as a “pentaquark” with both an RGB triple and color-anticolor pair.

Regardless, as with EM, when you get really close it no longer appears neutral. And as you say, the residual force is much weaker than the force itself. The “real” strong force is astonishingly strong–about 10,000 newtons between two quarks. That’s literally a metric ton of force. The residual strong force is “only” about 100 N, IIRC.

Not exactly. But there have been efforts to unify electromagnetism (which is itself a unification of electronic and magnetic force), the weak nuclear force, and the color force. The first two have been unified in an “electroweak” force theory. All three have not yet been combined successfully, although many attempts have been made, called “Grand Unified Theories”, or GUTs.

The main problem is that you can only observe this unification at very high energies; higher than we can produce in particle accelerators. Some of the other predictions they make, like proton decay, have not yet been observed.

Physicists are still trying, though. And they’d like to get gravity in there, too.