When people say:
"When you sit in a chair like I'm sitting in this chair right now"
"I'm actually hovering over this chair"
"but actually my butt is hovering above the chair by this
just tiny tiny amout" "because of the electrons of my body"
"because the electrons of my butt" "are repelling the electrons of this chair"
"it's not us actually touching the subatomic material of the object"
Is that really true? Does it mean that MC Hammer has just been singing about physics all along?
"Can't touch this !!"
Alas, this doesn't take into account the fact that the universe is quantum mechanical
For example, you probably know that electrons behave like spread-out waves
and from chemistry, you probably also know
that it's perfectly fine for two negatively charged electrons
to share the same energy level of an atom or a molecule
as long as they have their intrinsic spins oriented in opposite directions
So, even though electrons repel each other
their wave packets can overlap.
For example, check out this image of a ring of iron atoms
sitting on a surface of copper.
see the overlap of the spread out electrons? Now, would you call that touching?
If you look at a dictionnary, touch is usually defined
as physical contact. Well, contact is defined as
touching physically. Not much help.
But most of people have this intuitive idea that
touch is something like two solid objects
so close together there is no space between them.
The trouble is this doesn't have anything to do with overlapping
waves which, as we know, are how electrons actually behave.
So, it seems that touch is a word that may just be
incapable of describing the actual universe as we understand it today.
Either that, or we should change our notion of touch
to mean interaction at short distance which is really what happens
between electrons when you sit on a chair.
But, regardless of whether or not we ever actually touch anything
I think that when we talk about the electromagnetic repulsion
of your butt and your chair, what we are really trying to say is
Hey! Remember how cool it is that we are made of atoms and molecules
and that other people made of atoms and molecules
were clever enough to figure that out.
Now, that is touching.
This episode of Minute Physics is supported by audible.com
The leading provider of audio books across all types of litterature
including fiction, non-fiction and periodicals
I highly recommend 'Surely you're joking, Mr. Feynman'
A hilarious and fascinating autobiography
of the amazing man and physicist Richard Feynman
and you can download this audiobook or another of your choice for free
Again, thanks to Audible for making it possible for me
to keep producing Minute Physics and for giving you a free audiobook