David wrote:
It is said that since the energy of a bound system is lower
than that of an unbound one, its mass is lower as well.
This being the explanation why when a proton and neutron
merge, it has to release energy in the form of nuclear
binding energy. Can anyone tell me what concept in physics
does this belong to? I mean.. When two people copulate,
they are binded. But they don't lose any mass and

your example is wrong IE
not relevant to what happens in binding of nucleid
in binding of nucleid they are 'squeezed closer to each other
and therefore there is no room to some of its peripheral
orbitals therefore they have to be shot out
in order of squeezing them closer you need energy
IE pressing them closer needs outside energy
and as a result those peripheral orbitals pop out
and here is a tricky situation
you might expect that the output energy from that process
will be exactly the same as the impute energy
but
here comes a surprise:!!!
not necessary at all you cant know in advance
if it will be more or less than the input energy!!
for instance in fusion
the output energy is (surprisingly) bigger than the input energy!
how come??
it is because some peripheral orbitals were sot out
yet there mass equivalent energy was bigger than the
impute energy!!
it is metaphorically as if you had energy sored in
bottle and all you needed is some trigger
to open the seal of the bottle
or another metaphor
a mass located on a high cliff
you need only Little push in order to let it fall
and release a lot of energy
so you cant know in advance while you invest energy in a process
if it will be 'endothermic' or exothermic'
(unless you have previous experience!!)
in-the nuclear processes that of existing particles
while the connection is already done
we forget about th energy that *was* invested in it
and we start only from the 'connected situation'
so we can know that in order to separate those
combined particles we have always to invest energy
first in order to separate them geometrically
and second
there is a need to 'heal the wound' by addition of matter
and matter is mass in motion IE energy.

that answer of mine was just of hand
so i might not be wrong here and there
so please correct me if wrong!!

TIA
Y.Porat
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