Fossils
A QUICK INSIGHT ON SOME UNIQUE THINGS WE CALL FOSSILS!
Foss
il
any evidence of a once-living organism, the remains or impression of a
prehistoric organism preserved in petrified form or as a mold or cast in rock
died more than10,000 yearsago
inclu
Neanderthals
What are Neanderthals?
First specimen to be recognized as a human fossil
Closest extinct human relative
Originated in Africa, but migrated north to Europe
sooner than humans
Migrated south and east during the ice age
Lived about 400,000
EVOLUTION
SPECIES IN HUMAN EVOLUTION
Lucy, the missing link between humans and apes
Turkana Boy and human similarities
Evolution of Man
LUCY
Lucy is claimed to be a missing link between humans and apes. She is
thought to be the missing link due to similar
Group 3: Sedimentary
Rock
What is Sedimentary rock?
Sedimentary rock is a type of rock that forms when particles from
other rocks or the remains of plants and animals are compacted and
cemented together.
Sedimentary rock can not be reproduced because it c
Animal Size and
Atmosphere
What are the possible causes for the larger size of
an animal in the past versus the smaller size found
today?
As of now its just speculation, but there are some theories:
Copes Theory- The theory that as animals evolve over tim
A Can of Bull Case Study
Bethany Jacobs, Mallori Mays, Kiera Cole, Desiree Hatcher, Will Shepherd
1.
A. Putting gas in your car gives it energy. Eating sugars and carbohydrates provides fuel
for your body's metabolism. These claims are also made for stimu
Part IFlu and Flu
Karen and Mary work at a grocery store. Mary is a nursing student and works part
time to pay for her living expenses. Karen has worked at the grocery for nearly 30
years, since she was 22. The two of them are talking when Karen points to
Anyone Who Had a Heart
Jen, 37 year old woman pregnant with twins at 28 weeks. Doctor tells Jen he would like her to carry the
twins out as long as she can because of her age. Jen was impregnated with a fertility procedure.
Nurse states that both babies s
direction it started in or the opposite direction and there
would be no way for it to reach any of the other possible
directions that it is allowed to point in. So instead, rather
than reversing the spin, we choose a new direction for it
at random. Then t
the spin from up to down. Thus for the Ising model, the
heat-bath algorithm can be regarded as a single-spin-flip
algorithm with an acceptance ratio which is a function of
the energy change E, just as it is in the Metropolis
algorithm, although the exact
inefficiency. We have shown then that if we are going to
simulate a Potts model with a single-spin-flip algorithm,
the algorithm that we choose should depend 4.5 Other
spin models 123 8 4 0 4 8 energy difference E 0.0 0.2
0.4 0.6 0.8 1.0 acceptance ratio
Phys. Rev. E 49, 5303. Barkema, G. T. and Newman, M. E.
J. 1997 Physica A 244, 25. Barkema, G. T. and Newman,
M. E. J. 1998a Phys. Rev. E 57, 1155. Barkema, G. T. and
Newman, M. E. J. 1998b in Monte Carlo Methods in
Chemistry, D. Ferguson, J. I. Siepmann
162, 162; Phys. Rev. Lett. 18, 1046; Phys. Rev. Lett. 19,
108. Lieb, E. H. and Wu, F. Y. 1970 in Phase Transitions
and Critical Phenomena, Vol. 1, C. Domb and J. L.
Lebowitz (eds.), Academic Press, London. Lifshitz, I. M.
and Slyozov, V. V. 1961 J. Phys.
generalizations to continuous spins are possible for all
the algorithms we discussed in Section 4.4. However, the
Metropolis algorithm and the Wolff algorithm are
probably adequate to cover most situations. 17In a
system where the energy varies quadratica
spins in the cluster, but rejected. In this case, they get
another chance to be added to the cluster on this step.)
This step is repeated as many times as necessary until
there are no spins left in the cluster whose neighbours
have not been considered for
one in which all the spins are lined up pointing in the
same direction. However, that direction can equally well
be any of the allowed directions of the spins. The system
therefore has one degree of freedomrotation of all the
spins by the same amountwhich
dimensionality of the spins and that of the lattice are
independent. We can put Heisenberg spins on a
twodimensional lattice for instance.) Heisenberg spins
can be represented either as three-component vectors
with s 2 s 2 x + s 2 y + s 2 z = 1, or by two
high temperatures where the probabilities of occurrence
of the states of any particular spin become increasingly
independent of the states of the spins neighbours, there
is less and less difference between the performance of
the two algorithms, and we hav
of the Ising model gives us the continuous spin models, in
which the spins on the lattice have a continuous range of
values, rather than a discrete spectrum like the Ising and
Potts models. The two most widely studied such models
are the XY model and the
and Landau, D. P. 1991 Phys. Rev. B 44, 5081. Ferrenberg,
A. M., Landau, D. P. and Wong, Y. J. 1992 Phys. Rev. Lett.
69, 3382. Ferrenberg, A. M. and Swendsen, R. H. 1988
Phys. Rev. Lett. 61, 2635. Ferrenberg, A. M. and
Swendsen, R. H. 1989 Phys. Rev. Lett
Chem. Phys. 57, 4009. Rieger, H. 1995 Phys. Rev. B 52,
6659. Rubinstein, M. 1987 Phys. Rev. Lett. 59, 1946. Rys,
F. 1963 Helv. Phys. Acta 36, 537. Saleur, H. 1991 Nucl.
Phys. B 360, 219. Schrage, L. 1979 ACM Trans. Math.
Software 5, 132. Schulke, L. and Z
University Press. Blote, H. W. J and Swendsen, R. H. 1979
Phys. Rev. B 20, 2077. Booth, T. L. 1971 Digital Networks
and Computer Systems, Wiley, New 131 132 References
York. Bortz, A. B., Kalos, M. H. and Lebowitz, J. L. 1975 J.
Comp. Phys. 17, 10. Breema
Viovy, J.-L. 1994 Biopolymers 25, 431. Hukushima, K. and
Nemoto, K. 1996 J. Phys. Soc. Japan 65, 1604.
Jayaprakash, C. and Saam, W. F. 1984 Phys. Rev. B 30,
3916. Kalos, M. H. and Whitlock, P. A. 1986 Monte Carlo
Methods, Volume 1: Basics, Wiley, New York
These are the only states in which the spin makes a
contribution to the Hamiltonian. In all the other states it
makes no contribution to the Hamiltonian. Thus,
evaluating the Boltzmann factors eEn appearing in
Equation (4.40) requires us to calculate the
concentrate on the XY/Heisenberg class of models as
examples of how Monte Carlo algorithms can be
constructed for continuous spin models. The first thing
we notice about these continuous spin models is that
they have a continuous spectrum of possible stat
exponent of z = 0.60 0.02 for the algorithm in the q = 3
case in two dimensionsa considerable improvement
over the z = 2.2 of the Metropolis algorithm. As before,
the single-spin-flip algorithms come into their own well
away from the critical point becaus
fact it cannot be answered within the realm of the
classical systems we are studying here. Only by studying
quantum mechanical systems and then taking their
classical limit can the question be answered properly.
However, for the purposes of Monte Carlo si
square lattice at low temperature simulated using the
heat-bath and Metropolis algorithms. In this case, the
heat-bath algorithm takes about 200 sweeps of the lattice
to come to equilibrium, by contrast with the Metropolis
algorithm which takes about 20 0
lower mean acceptance ratio, because with larger
changes in spin direction moves can have a larger energy
cost. As we mentioned, no one has, to our knowledge,
investigated in any detail the question of how best to
compromise between these two casesall the
choice for large q Potts models. Before we move on, here
is one more question about the heat-bath algorithm:
what does the algorithm look like for the normal Ising
model? The answer is easy enough to work out. In the
Ising case the algorithm would involve