thursday: How does
field interact with Higgs bosons to give us mass as we know it?
How could a Higgs Boson be created, and how
does it fit into the standard model?
the Higgs Field
is to the Higgs boson as the Electromagnetic Field is to the Photon
(aka the Electromagnetic Boson)
the Higgs boson is not massless whereas the photon is)
Field does not
interact with the Higgs Boson to give particles mass; the Higgs field
(or boson) interacts with EACH particle (electron, neutrino, ...) to
give it mass
what is dark matter?
if we knew,
we would have given away the Nobel Prize for that discovery!!
(we haven't! if only you had included a proposal for such with
your college app! or, perhaps, something to do for miniterm next
already answered in class or the text
How do protons change into
neutrons, that is, when they exchange say a pion, do they lose
the quark compositions of p/n/p answers the
question: p -->
n + p+
(uud --> udd + ud)
n --> p
(udd --> uud
(here, an underline indicates an
If quarks are not conserved, how do they change and
create new particles?
we have seen
a number of
examples in class of non-conservation of quarks:
1) for example, quarks and antiquarks can be created (or destroyed) in
question above for p/n transformation examples);
2) in addition, a quark species can change into a different kind of
quark by interacting with electrons/positions or
also discussed during the presentation of evidence for quarks, gluons,
and color: ne
+ u --> e+
+ d )
more about resonances in particles?
is to know is in our textbook. really.
to complicated questions
If we understand the physical laws
governing particles, why can't we predict chemical reactions starting
from the interactions of the particles without learning chemistry laws?
essentially the same reason
that knowing the laws of physics cannot predict the angle of scattering
of an alpha particle impinging on a nucleus....
there are things that we cannot know
(instantaneously) on the atomic
scale about a sample of particles that contains an Avogadro's number of
particles (or even a trillionth of that number)
instead, when we do have a sufficient
number of particles and we know
the statistical rules that apply to them (e.g.,
Maxwell-Boltzmann, Fermi-Dirac, Bose-Einstein), we can then define
macroscopic variables (such as temperature and pressure) that measure
ensemble averages of physics properties possessed by individual
particles (such as kinetic energy and momentum) in order to make sense
of the situation....
the closer we are to dealing with
individual particles, the more we
have to use individual properties such as momentum, kinetic energy, and
the farther we are away from
dealing with a few particles, the
more useful are the macroscopic properties such as temperature,
pressure, and volume
For a given nuclear reaction, each
combination of products has some probability of occurring.
How can we
determine the probability for a particular combination?
now that we
have an idea of what the wavefunction means...
the probability of a particular combination happening is the product of
the wavefunction of the initial state with the wavefunction of the
final state (times the interaction strength) integrated over all
easy to say, perhaps not so easy to calculate...
The end of chapter 15 talked a little bit about string theory,
but I really want to know why string theory was created.
How would string theory help us or be beneficial to making new
discoveries in physics?
Would proving string theory change our understanding of physics
I would really like to know whether string theory is viable or would it
improve on our current theories.
The hope (by
string theorists) is that string theory is a viable path to quantum
gravity (a unified theory of quantum mechanics and gravity) and/or a
grand unified theory of forces (including gravity). By modeling
particles as strings (as opposed to points), the hope is that many of
the infinities (due to a divide by zero as one approaches a point
particle) will disappear.
string theory is unable to make any prediction that is testable by any
(There are many string theories and they do make
predictions, just not testable ones.)
Until it is able to produce a testable prediction, it
belongs to the fields of philsophy and religion.
theorist would NOT give such an answer, however. But he/she would
about material not really directly relevant to the course,
covered in other courses, miniterms, etc,
or that require a significant
background in other fields of physics
in quantum physics
How does quantum entanglement work?
quantum miniterm 2009
how can light behave as a particle and wave?
textbook, chapters 3 - 6
but please, NEVER say that particles behave like waves...
What evidence is there for dark matter?
Astrophysics course spent approximately 1 week on the quite substantial
and varied evidence for dark matter:
microlensing and macrolensing of background objects;
the flatness of spiral-galaxy rotation curves at large distances from
the trapping of hot intergalactic gas in clusters of galaxies
available in any decent astronomy textbook
when we were discussing Black
Holes, you told us that Einstein's Theories of General and Special
Relativity did not apply to
black holes because they predicted acceleration either up or down from
the black hole (and thus our discussion on quantum gravity, string
theory, etc). I was curious if that, with our knowledge of
Special Relativity from
Modern Physics, you could explain why Einstein's theories incorrectly
Or in other words, what part of
Einstein's theories about black holes is wrong?
sorry, but I
never said any such thing! Not only do Einstein's General and
Special Relativity theories make any number of predictions about the
behavior of matter, space, and time in the observable region around a
black hole or any other compact massive object, the predictions are all
borne out correctly (!!) by current observations! We spent days
discussing both the predictions and the observations that indeed agreed!
What I did say is that General Relativity is unable to make a
prediction for future behavior about a point particle that encounters a
point singularity. General Relativity is therefore incomplete in
(sigh.... did i really become a teacher so that students could take
things i say and re-quote them blatantly out of context???)