High School How does force transfer through an object microscopically?

[Remain]

I heard that you can never really touch anything. I also heard from an article that the reason why your butt doesn't fall through your chair is due to forces.

Here is a short excerpt:
"Cracking like lightning through the void, all the specks of electrons and the specks of nuclei are constantly interacting through a force called electromagnetism. Each interaction is carried out through the jolting exchange of particles of pure energy called photons (which is really just a nubbins of light). Each photon swapped equals a little push or a pull — a force — exerted across the emptiness. That's really what's keeping the stuff we call your butt from drifting through the stuff we call your chair."
http://www.npr.org/sections/13.7/2015/04/07/398008378/why-doesn-t-your-butt-fall-through-the-chair

So when I apply a force to an object, how exactly is the force transferred from my hand to the atoms that make up the object? Like what atomically in my hand carries the energy to be transferred? Is it photons? If so how does it know how much energy to transfer?

 

[Drakkith]

I heard that you can never really touch anything. I also heard from an article that the reason why your butt doesn't fall through your chair is due to forces.

At the atomic level, the interaction of short-range forces between neutral atoms is essentially what "touching" means.

Here is a short excerpt:
"Cracking like lightning through the void, all the specks of electrons and the specks of nuclei are constantly interacting through a force called electromagnetism. Each interaction is carried out through the jolting exchange of particles of pure energy called photons (which is really just a nubbins of light). Each photon swapped equals a little push or a pull — a force — exerted across the emptiness. That's really what's keeping the stuff we call your butt from drifting through the stuff we call your chair."

This is extremely misleading. The photons the article refers to are virtual photons, which are nothing but a particular way of describing the interaction between particles, specifically that it is the result of the exchange of force-carrier particles. But this isn't an exchange like two people throwing a ball back and forth is. Virtual photons are not released by one particle to travel through space to be "caught" by the other. In fact, this "exchange" happens instantly, without the virtual photons even moving between the two particles at all. Sounds crazy, right? This is one reason why many scientists view virtual particles are simply being nothing but an artifact of the math and the particular way in which interactions are modeled.

So when I apply a force to an object, how exactly is the force transferred from my hand to the atoms that make up the object? Like what atomically in my hand carries the energy to be transferred? Is it photons? If so how does it know how much energy to transfer?

As far as I know, that depends entirely on how you model the interaction. Classically, the interaction is a smooth, continuous process without any discrete jumps or jolts. In quantum physics, this mostly remains the same except when emitting and absorbing real photons. Virtual photons still cause smooth, continuous interactions, though they can also lead to other effects that aren't predicted by classical mechanics.

In the end, regardless of how we model it, the result is that forces are transferred between the atoms in your body in some manner. Currently we choose to model this as being the result of an exchange of virtual photons, as it is a convenient way of modeling the interactions since it requires very little change to the way that we model real particles in quantum physics. It is entirely possible that there is another way of describing and modeling this, but it may require a somewhat more complicated description or one that isn't as easily merged with existing quantum physics.

 

[Remain]

Thank you so much sir! :)

 

[hilbert2]

In quantum chemistry, they draw these Van der Waals potential energy curves that show how trying to put two atoms too close to each other requires a large amount of energy

In continuum mechanics, which doesn't consider the microscopic nature of matter, quantities such as bulk modulus are used for describing how easy/difficult it is to compress some material to smaller volume.