- #1
physicsnoob12
- 15
- 0
is it true that you are never actually touching something? i keep hearing that this is true but why is it that we can feel the texture of things?
NobodySpecial said:i think the point is that two pieces of matter never touch - the force you feel is the electrostatic repulsion from the charges in the material
physicsnoob12 said:is it true that you are never actually touching something? i keep hearing that this is true but why is it that we can feel the texture of things?
Vanadium 50 said:But there is also the fact that chemical bonds form between the two objects touching. If they are connected, how can one say they are not touching? And we're right back arguing about semantics.
This is not true.jfy4 said:Chemical bonds are the constant exchange of photons between charged particles.
DaveC426913 said:This is not true.
physicsnoob12 said:is it true that you are never actually touching something? i keep hearing that this is true but why is it that we can feel the texture of things?
but why is it that we can feel the texture of things?
DaveC426913 said:At the atomic level, physical objects do not have clear, hard boundaries.
jfy4 said:Please tell me what really happens then... Because I was under the strong impression that it was...
Calrik said:Well yes and no obviously. Touch is a biological sensation it has pretty much nothing to do with physics which is about something beyond biological concerns. Essentially this isn't a physics question it's merely a question of psychology and biology.
Nothing touches in physics either, it just influences another field or particle. The term touch is entirely inappropriate to any science but biology.
jfy4 said:Please tell me what really happens then... Because I was under the strong impression that it was...
alxm said:I am certain that nowhere, jfy4's imagination, has a chemical bond ever been defined as "the constant exchange of photons between charged particles". It's a ridiculous remark that says absolutely nothing other than "electrons repel"
...
Explain yourself, jfy4.
alxm said:The electromagnetic force is mediated by photons. That says nothing at all about chemical bonding, because electrons on two atoms near each other (as well as within the atoms) will exchange photons and experience repulsion completely regardless of whether or not they're bonding.
DaveC426913 said:His question is equally applicable if he were asking how a ruler could touch a rock. No biology involved.
He did. He asked about touching. A ruler can touch a rock. This a general case of touching. In the absence of specificity, any answer that can apply is valid.Calrik said:Exactly, but then he did not ask that
Attempts to claim that there's no logic here won't work. We won't fall for this kind of verbal smoke and mirrors.Calrik said:"If a tree falls in the woods and no one is around to hear it what colour is it?"
DaveC426913 said:He did. He asked about touching. A ruler can touch a rock. This a general case of touching. In the absence of specificity, any answer that can apply is valid.
But an answer that attempts to exclude valid answers because it imposes its own assumption is not a valid answer, such as your introduction of a narrow definition of 'touching' as being a limited to the senses.Attempts to claim that there's no logic here won't work. We won't fall for this kind of verbal smoke and mirrors.
His question makes perfect sense as-is. I don't see where you're missing it.Calrik said:Ok your not getting the point not sure if that is my problem or yours. Basically to ask a pertinent question you need to ask a pertinent question about something that is defined or at least knowable experimentally.
DaveC426913 said:His question makes perfect sense as-is. I don't see where you're missing it.
Certainly, there are interesting facets to the question, such as yours, but the central question is simply:
Is it true that two things are never really touching?
That question can be answered independently of all the facets.
I disagree the question made any sense you don't. So?physicsnoob12 said:is it true that you are never actually touching something? i keep hearing that this is true but why is it that we can feel the texture of things?
cbetanco said:Aren't chemical bonds an electromagnetic phenomena? Doesn't it have to due with how electrons in the outer shells of the atoms interact? The only way I know of two electrons interacting is through the exchange of virtual photons, but maybe I am missing something...
Neutron star - the lightweight little brother of a BH - where the force is enough to crush the electrons and the protons together till they're all just neutrons shoulder-to-shoulder.Nick666 said:Maybe the only place where stuff touches other stuff is at the center of a black hole .
jfy4 said:As for others who have objected, please teach me! if it is not that way, i'd love to here a more correct view.
DaveC426913 said:I realize I do not actually have an answer. I too am hoping an expert in the field will weigh in.
jfy4 said:I am open to learning new information. But QED is is fairly clear in its explanation of electromagnetic phenomena. To be frank, I do not believe to be wrong in this matter,
DaveC426913 said:I am certainly willing to be corrected. Can you show a reference where it says that chemical bonds are the constant exchange of photons between charged particles.
Are these virtual photons?
I do.jfy4 said:I'm not even sure anyone needs to be corrected,
alxm said:The electromagnetic force is mediated by photons. That says nothing at all about chemical bonding, because electrons on two atoms near each other (as well as within the atoms) will exchange photons and experience repulsion completely regardless of whether or not they're bonding. Knowing that the electromagnetic force is mediated by photons does nothing to explain chemical bonding. You don't even remotely need QED to explain chemical bonding; a 'classical' Coulomb gauge with instantaneous attraction/repulsion works fine.
Saying that chemical bonding is because of electromagnetic repulsion/attraction is like saying a turbulent vortex in a stream forms because water has viscosity. It's an inherently dynamical effect. On top of that, electrostatic forces are not sufficient to explain chemical bonding or any electronic properties, even when you take into account dynamics, since the Pauli principle and exchange energy plays a quite important role.
I am certain that nowhere, jfy4's imagination, has a chemical bond ever been defined as "the constant exchange of photons between charged particles". It's a ridiculous remark that says absolutely nothing other than "electrons repel". In what ways would "electrons repel" describe what a chemical bond is? And more relevantly, in what way does it explain why some atoms will form a bond, and others do not. They all have electrons around them, don't they? So why will two neutral hydrogen atoms form a bond, but not two neutral helium atoms? Explain yourself, jfy4.
jfy4 said:Fair enough, You can explain bonds with classical e&m. But, QED is The fundamental mechanics for e&m, not classical, and as such, classical e&m is completely contained in QED. Hence, you can never go wrong by using the correct method in describing a phenomenon, even when a more naive approach will suffice...
As far as how bonds work in a more qualitative manner, you can ask any chemist and they will tell you that the fundamental importance in bonding atoms and molecules is the relationship between charges of atoms and the electrodynamics of the system. Which, fortunately, is completely explained by QED, and the pivot of QED is the QED vertex, which is the emission, and absorption of photons. I hope this helps put you at ease about how bonds work and the importance of fundamental physics in other areas of science.
Not quite. At the level at which "you are never actually touching something" there's no 'you'.physicsnoob12 said:is it true that you are never actually touching something?
Because at the level at which "we can feel the texture of things" there is a 'you'('we'), and that 'you'('we') is properly described as "actually touching something".physicsnoob12 said:i keep hearing that this is true but why is it that we can feel the texture of things?