By 1900 chemistry was falling nicely into place the elements had been identified
The qualitative and quantitative aspects of chemical reactions were well understood
Atomic structure was completely unknown It was known that atomic structure was composed
of positive charges and negative charges. It was thought that the positive charges
were clustered together in some way. they really did not know.
In 1900 physics was dominated a series of articles that was published in 1687 in Latin
The author was Sir Isaac Newton and the title was Principia
Newtonian physics is all about things that can be seen and things that can be understood
Things like gravity and leverage and friction and gravitational attraction and things that can be seen
like the forces when you swing something around.
Atomic structure and quantum mechanics can never be understood on this level
You cannot understand atomic structure in the same way ....
you have to embrace atomic structure with your heart and soul.
It is a different type of learning.
1900 ..... Earnest Rutherford was at the University of Manchester
Rutherford's area of expertise was radioactivity this came right out of the work of
Madam and Pierre Curie in France
Rutherford...his expertise was the alpha particle.
The alpha particle is given off from the radioactive decay of uranium, radium and polonium.
Rutherford went to two of his graduate students, Marsden and Geiger and proposed an experiment
The experiment was to shoot alpha particles through a piece of gold foil.
The experiment was pretty simple....take a piece of lead
drill a small hole deep into the lead and put a piece of polonium at the bottom of the hole.
The result of this was a gun that shot alpha particles in a pretty specific way.
The alpha particles were shot at piece of gold foil. it was expected that the alpha particles would
kind of mush through the gold foil in the same way bullet would go through a bag of sand.
The results were completely unexpected. the alpha particles went right through the gold foil!
They did not seem to hit anything.
Once in a great while, an alpha particle would hit something and the results were dramatic.
The angles of deflection were significant....
to the point that sometimes the alpha particles would bounce straight back.
Rutherford's expertise was with the alpha particle.
From his knowledge of radioactive decay and the alpha particle
he came to the conclusion that if the gold atom is the size of the planet earth
The positive charges are all together in one place at the center, 200 feet in diameter
and he , furthermore, coined the phrase "nucleus"
so , the age of atomic discovery really began with this discovery.
The ... understanding, ....learning, I think, for all of us is experiential and visual.
that is never going to work for quantum mechanics and atomic structure
it is a different type of learning
You need to embrace this with your heart and your soul
you need to wrap yourself around this... and maybe the weirdest thing about it that
you quickly come to love it
I was not a smart kid. But I was curious and I had an active mind.
I think that children understand what energy is. Energy is like things falling
things moving and like flames, like watching your mom cook breakfast
driving a car, things falling and hitting the ground,
maybe noise would be in the category of energy
so...you plug this thing into the wall and the energy just goes
right through the wires! I mean, was I the only ten year old in the world
that thought that was weird.
I mean, the wires don't even move.