For the Physics Guru's...

I was having an interesting conversation with a friend of mine. He was watching a Discovery Channel special on Physics, particles and all that jazz.

So he had an interesting question:

If you have 2 pennies, and hold them 2 inches apart, they're 2" apart.
So when they touch, what is the distance?

Some say zero. I said if you take it further, they're still not touching as they cant share the same space, so there would be an distance between them at the atomic level.

SO- 2 objects touching. What is the distance between them??

Twice the distance of the orbits of the electons furthest from the center of the atoms of each object.

Edited........

Make that the sum of two distances of the electrons from the center ot atoms. The objects may have different atomic structures.

It depends on whether or not any of the particles in one of the 2 pennies are 'entangled' with any of the particles in the other one, in which case there would be no distance between them as they would always be 'touching' regardless of where they are in space

I suspect that they actually overlap a bit together a bit.

Think about if you took two things with a rough surface, such as two pieces of extremely coarse sandpaper.

\/\/\/\/\/\/\/\/\/\/\/\/

./\/\/\/\/\/\/\/\/\/\/

Push those rough surfaces above together and the points of the top one will go down into the spaces in the bottom one, and vice versa.



This article has some bearing on the subject:
http://en.wikipedia.org/wiki/Cold_welding

Prepare the surfaces properly, touch them together properly, and the objects might well join into one.

And we're wondering why the forums are being closed down...

I seriously doubt the presence of too many cordial discussions about physics has much to do with it.

I don't see this as a difficult question, just an unspecific one. When you said that the two coins were two inches apart, I assumed you meant that their centers were two inches apart. If that is what you meant, then when they are brought together so their edges touch, they are still (coin 1 radius) plus (coin two radius) apart.

If they are stacked touching one another, they are (1/2 coin 1 thickness) plus (1/2 coin two thickness) apart.

No?

Since nobody actually knows what a particle is, it isn't possible to say how far apart the pennies are when, at the macro level, they are touching. At the molecular level, the pennie's edges will be fuzzy and not well defined, so they may tend tend to merge slightly. They may also tend to repel each other, due to the charges in the outer particles of the molecules - the electrons. Also, since particles are unlikely to be discreet points, it isn't possible to say where one particle ends and another one begins, so it isn't possible to give an accurate answer to your question, Sue.

What question was that?

How far apart the pennies are when touching each other.

ETA:
Ooops. It was Tod lol

Haha.........that would be a logical mistake to make. Suezanne does often pose some mind bending questions.

It's a good thing in my opinion too.

Nothing in this universe ever touches anything else.. it all is an illusion of the electromagnetic and nuclear forces attracting and repelling.

So the closest the 2 pennies can come together is 2 times the radius of the electromagnetic field of a single molecule of the penny's material composition.

So there is no such thing as a material object...........it's all energy.

Isn't that what quantum physics is all about?

Not even neutronium?

Almost all of any object is space, but the space is filled with forces. Two in the nucleus of each atom and one significant force filling the space in and around each atom (gravity is negligable). Atoms are made of particles which may or may not be clumps of energy but nobody knows, so nobody knows the answer to your statement, Peggy.

When you knock on a door, it's the forces that stop your knuckes on the surface of the door and not discreet lumps of solid stuff

Particles such as neutron and protons are composed of even smaller and smaller particles with their own forces. There was a couple hundred diff ones last time I checked. But they all have a "force" which when that force collides with another force sends out yet another particle surrounded by it's own force to do it's bidding.

Gravitational attraction can make things super dense to the point of becoming a black hole. But as once believed that nothing escapes a black hole, not even light, that theory is not accepted anymores. There is still a massless radiation being emitted from a black hole with a "force" of it's own.

Ohhh.. It's the old "it's turtles all the way down" defense!

LMAO!!!

Some believe in the holy grail of one single particle and one single force... the Grand Unified Theory. Does God want us to know that much about His inner workings? Will that lead us to the Almighty Himself? We'll see... lol

But surely that particle is just another face of that force - one and the same things

Pfff. Physicists. You're all a bunch of bloody philosophers.

Engineers can answer the question.

The pennies are one penny diameter apart when they are touching, measuring from their centers of mass.

But, but, but.............what if they are put on their edge? Then it's the thickness of a single penny? This is getting too complicated. Too many theories.............I want facts.

since there are no perfectly flat surfaces, sue's answer is about s close as you get.

So from one of the Mad Max flicks:

"No matter where you are, there you are." is the only real fact in anything?

Who'd thought a Mel Gibson B grade flick would contain the secrete of where anything is.

/me pokes Peggy and whispers "Buckaroo Banzai".