Why do objects stay together?

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OK - atom-atom interactions tend to be different from molecule-molecule interactions and molecule-atom interactions.
Well, I guess that that makes it more complicated. Anyways, if all molecules can be cooled down to a solid, then my point can still be made.


That's right - when an atoms stay close to other atoms we say the atoms are "bonded" to each other. Some effort is required to separate them.
There are different ways that atoms may become bonded to each other.

You will notice, though, that a structure like a bridge may not be made out of a single slab of a substance - two solids may be joined by drilling holes through them and fitting a third solid through the hole ... those two solids are now bound by the third one.
Yes, a bridge can be built in many ways, but I was not trying to change the topic to how people make bridges when I wrote that analogy. I was just trying to make it clear how the substance was placed. I am confused about the fact that every single substance has the ability to become solid (or at least nearly every single substance), so every single substance must somehow bond its atoms/molecules when it is cooled and/or pressurized. I don't understand how this is possible without some sort of "universal" bond.


What I am trying to get you to realize is the variety of possible bonds.

In previous replies you have been jumping around material types and bond types and getting confused: the confusion comes from the changes in types. A description for one will not apply to another. i.e. you talked about sharing electrons for eg ... but that's not the only way to bind two atoms.
I am not getting confused. Like I said, I understand what has been written. It is just that everything I am writing turns out to be more complicated than I meant it to be. This is why I was writing about the bridge scenario, yet you still tell me of the other complications that I am trying to avoid. Yes, I understand that there are many types of materials all with different types of bonds. Yes, I also understand that the variety of bonds is large. But, this is not my point.


Define "true solid". What would a "false solid" be like?
Nevermind about that.


You didn't look up "solid helium" did you?
I just looked it up and found out that helium at absolute zero at pressures under 1 atm are still non-solid. Is this what you wanted me to know?


No - and you do not appear to be understanding me.
I don't care how far you got in school - I need to know where you want me to pitch the replies.
What do you mean when you say, "pitch the replies"? Also, what do you mean by education level if not the classes I have taken?
 

Drakkith

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Yes, a bridge can be built in many ways, but I was not trying to change the topic to how people make bridges when I wrote that analogy. I was just trying to make it clear how the substance was placed. I am confused about the fact that every single substance has the ability to become solid (or at least nearly every single substance), so every single substance must somehow bond its atoms/molecules when it is cooled and/or pressurized. I don't understand how this is possible without some sort of "universal" bond.
This 'universal' bond is simply the electrostatic/electromagnetic interaction between charged particles forming one of the different types of possible bonds. To quote wiki:

Since opposite charges attract via a simple electromagnetic force, the negatively charged electrons that are orbiting the nucleus and the positively charged protons in the nucleus attract each other. An electron positioned between two nuclei will be attracted to both of them, and the nuclei will be attracted toward electrons in this position. This attraction constitutes the chemical bond. Due to the matter wave nature of electrons and their smaller mass, they must occupy a much larger amount of volume compared with the nuclei, and this volume occupied by the electrons keeps the atomic nuclei relatively far apart, as compared with the size of the nuclei themselves. This phenomenon limits the distance between nuclei and atoms in a bond.

If you cool a material into a solid in a rectangular prism shape, and then you place it spanning a length like a bridge, then the particles won't just fall like a fluid into the river. I want to know why that is. The atom of the substance at the bottom has some force acting upon it to balance out the force of gravity. I thought that I was being told that that force came from the bonds that it had with other forces. If this isn't the case with all substances, then what is holding those atoms up? I'm just wondering what force could hold those atoms in place for every known substance in the Universe, because, like you said, you can turn anything into a solid by cooling it down or pressurizing it (or a solid-like state at least).
To simplify it a great deal, when you cool an object down, you reduce the kinetic energy and momentum of the atoms and the subatomic particles that compose them. When you reduce their energy, it requires a smaller amount of force to hold them in place. Once you remove enough energy the atoms are unable to break away from the attractive force they are experience to and from the other atoms around them. It is at this point that they become solid. This attraction between them that locks them into place is the bond.

Note that the behavior of subatomic particles is very non-intuitive, so any full explanation of atomic/molecular bonds will be incomplete if you don't understand quantum mechanics.
 
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Simon Bridge

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As Drakkith says, the "universal" bond you are interested in is some instance of the electromagnetic interaction.
There are four fundamental forces and the theory that there is a single interaction-mechanism that explains all of them is called "grand unification". We don't have that one just at the moment so we have to content ourselves with variations.

An EM bond is just one manifestation of the EM interaction - the force that separates bound atoms can be electromagnetic as well. So it is not a universal bonding force... which is why it is called an interaction instead.

A consequence of the electromagnetic interaction may be that an electron gets shared between two ions - bringing them closer together, or it may be that one atom grabs an electron off the other and the two atoms are drawn together without sharing the electron (a bit like how my bag of candy can attract children without me having to share it ;) ).

I have been trying to get you to appreciate that this fundamental interaction manifests in different ways depending on the details - like the scale and complexity of the situation. The interaction between two ions is different from the interaction between molecules - and bulk materials behave differently again.

If you look up "cellular automata" you will see how excruciatingly simple interactions can lead to extremely complex results.

It is a big complicated Universe that gets messily fascinating very fast.
 
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To simplify it a great deal, when you cool an object down, you reduce the kinetic energy and momentum of the atoms and the subatomic particles that compose them. When you reduce their energy, it requires a smaller amount of force to hold them in place. Once you remove enough energy the atoms are unable to break away from the attractive force they are experience to and from the other atoms around them. It is at this point that they become solid. This attraction between them that locks them into place is the bond.
Ah, I see now. It is the electromagnetic force that bonds the atoms. But what happens when they get pressured? Do they simply get closer together, increasing the strength of the electromagnetic bonding force?

There are four fundamental forces and the theory that there is a single interaction-mechanism that explains all of them is called "grand unification". We don't have that one just at the moment so we have to content ourselves with variations.
I know what the four fundamental forces are: Strong force, which holds together the nuclei of atoms; weak force, which is what causes beta decay and positron emission in atoms; the electromagnetic force, which is the force that causes magnetism and electricity; and gravity, the weakest of all forces.

An EM bond is just one manifestation of the EM interaction - the force that separates bound atoms can be electromagnetic as well. So it is not a universal bonding force... which is why it is called an interaction instead.
I know; the electromagnetic force is what causes two alike charges to repel.

A consequence of the electromagnetic interaction may be that an electron gets shared between two ions - bringing them closer together, or it may be that one atom grabs an electron off the other and the two atoms are drawn together without sharing the electron (a bit like how my bag of candy can attract children without me having to share it ;) ).
Yes, I know about covalent and ionic bonds.

If you look up "cellular automata" you will see how excruciatingly simple interactions can lead to extremely complex results.
Actually, I already know what cellular automata are. I especially enjoy the Game of Life, but I enjoy seeing cellular automata related to the Prisoner's Dilemma, Rock, Paper, Scissors, and the Snowdrift game. They are all fun to watch and see what happens for various starting situations. What especially intrigues me is how a simple R-pentomino can evolve into such a chaotic pattern.
 

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