Geol Midterm 3, 19-22

Front 1

nebular hypothesis

Back 1

is the most widely accepted model in the field of cosmogony to explain the formation and evolution of the Solar System. It suggests that the Solar System formed from nebulous material

Front 2

Supernova / Black Holes Limits (compared to our sun)

Back 2

• 2-8 * Sun’s mass: Type 1 supernova (trigger runaway nuclear reaction, often by adding
materials from nearby stars or nebula)
• 8-15 * Sun’s mass: Type II supernova (internal collapse drives out gravity wave that pushes
out light materials. Core becomes neutron or black hole
• 20-30 * Solar mass – just forms black hole

Front 3

Evidence for black holes:

Back 3

Regions where size and speed of rotation tells us that huge masses
must be there.
• Very common in centers of galaxies.
– Regions where energy shooting out in columns perpendicular to
rotating massive regions
– Supernovaes that turn into dark regions.
• Collapsed massive stars
– Quantum particle behavior at event horizons (future discussion)

Front 4

Quasars

Back 4

We now think that these objects are probably mega-Black Holes,
that have the mass from many collapsed stars.
• There are two types of Quasars, those that are active and giving
off enormous amounts of (x, gamma) radiation, and those that
are quiescent. Why?
• We also have detected a Quasar at the center of our own galaxy.
Can we use it to study fundamental physics?

Front 5

Virtual Particles

Back 5

We believe that information about the four
fundamental forces in the Universe are carried by
massless particles called Bosons.
• The Bosons are:
– Photon - electromagnetic force
– Graviton - gravity force
– Gluon - strong force
– W/Z (three particles including the Higgs Boson) - weak force
• Wherever in the universe these forces exist, we think
the Bosons (and their anti-particles) are constantly
being formed as pairs. They normally recombine and
annihilate each other very quickly.

Front 6

Dark Matter - I

Back 6

The amount of lensing visible cannot
be accounted for by the visible mass of
the stars/galaxies present. It is
presumed that another invisible form
of matter must also be present - dark
matter.

Front 7

‘Spacecraft Behaving Badly’

Back 7

Pioneer 10 and Pioneer 11 are spacecraft that were
launched in the early 1970’s to study the outer Solar
System.
• The spacecraft have now ceased operating, but their inertia
is slowly carrying them out of our Solar System.
• The problem is that their speed and trajectories are not
matching what computer calculations say they should be -
this is termed the Pioneer anomaly.
• The Pioneer anomaly has been evident since the 1980s,
continues today, and it causes the spacecraft to move
slower out of the Solar System than expected.
• This means there is some other force acting on them
separate from their own inertia and gravity.

Front 8

Dark Energy

Back 8

• Dark energy is presumed to be a form of energy
that has ‘strong negative pressure’. That is, it
wants to increase the volume of the Universe and
acts against gravity.
• Dark energy is presumed to permeate all of the
Universe in approximately uniform concentration.
• It is not known how to fit the idea of dark energy
into our current view of matter/energy. But, one
possibility is that it is a consequence, at the
quantum scale, for any increase in the local
volume of space.

Front 9

What is the universe made of?

Back 9

4% normal matter,

21% dark matter

74% dark energy

Front 10

What is the core problem with the astronomy paradigm?

Back 10

Another way to say this is need to combine 4
fundamental forces:
– Gravity, electromagnetism, weak and strong forces

Front 11

What is the mathematical field of Chaos theory?

Back 11

Dynamical Systems

Front 12

Broad definition of Chaos:

Back 12

A field of study in mathematics, physics, and
philosophy studying the behavior of dynamical
systems that are highly sensitive to initial
conditions.
– Small differences in initial conditions yield widely
diverging outcomes for chaotic systems,
– systems are deterministic, meaning that their future
behavior is fully determined by their initial conditions,
with no random elements involved.
– But long-term prediction is in general impossible. Why?

Front 13

Discreteness

Back 13

Most processes acting in the world today are continuous
– i.e., always active.
• But we normally measure such systems only at discrete
times.
• We thus have incomplete knowledge of what is
happening with systems between measurements.
– Not an issue if deterministic, linear processes.
– But is an issue if system can make sudden changes
• Some systems are not continuous - just a series of
events.
– E.g: earthquakes, radioactive decay, electron tunneling

Front 14

Nonlinearly?

Back 14

Nonlinearly in mathematics means that future values of
a process depend on past values of the same process;
• This also can be referred to as feedback;
• Positive feedback means that, if a process goes in one
direction, nonlinear feedback makes it go that way even
faster/farther;
• Negative feedback means that, if a process goes in one
direction, nonlinear feedback tries to make it go the
other way.

Front 15

How did Lorentz study chaotic systems?

Back 15

Weather models

Front 16

What is the main problem with dynamical systems?

Back 16

Problem is that very small changes in input
parameters may create great variability in
behavior;

Front 17

Argue: Simple systems behave in simple ways

Back 17

No, simple systems may evolve into
complex, chaotic systems

Front 18

Argue: Complex behavior implies complex causes

Back 18

No, complex systems have underlying
simple order and thus simple causes

Front 19

Argue: Different systems behave differently

Back 19

No, there is a shared universality of chaotic
system behavior

Front 20

What is an attractor?

Back 20

An attractor is a set to which a
dynamical system evolves after a
long enough time. That is, points
that get close enough to the
attractor remain close even if
slightly disturbed.

Front 21

Who studied variability?

Back 21

Benoit Mandelbrot 1924

Front 22

What are the two patterns of variability?

Back 22

» spatial patterns - length of coastlines (example later)
» temporal patterns - cotton prices (example later)

Front 23

Self-Similarity:

Back 23

It has a fine structure at arbitrarily small scales.
– It is too irregular to be easily described in traditional
Euclidean geometric language.
– It is self-similar (at least approximately).
– It has a Fractal dimension which is
greater than its topological dimension.
– It has a simple and recursive definition.

Front 24

Examples of fluid flow:

Back 24

EXAMPLES:
» atmospheric circulation
» ocean circulation
» streams/rivers
» magmatism
» mantle convection- plate tectonics
» outer core convection - Earth’s magnetic field

Front 25

Benoit's two effects which are not accountable with linear systems analysis:

Back 25

» Noah effect = sudden discontinuous changes can occur
» Joseph effect = persistence of a value can occur for a while, yet suddenly change afterwards

Front 26

What is science?

Back 26

• Model of Universe: A unified group of theories that
describe or explain the natural universe around us.
• Process: An approach of problem solving or method of
attainment of knowledge about natural world.

Front 27

Components of science?

Back 27

The universe

Imperfect model of universe

Doing science

Imperfect scientists

Front 28

Paradigm shift? Who?

Back 28

Thomas Kuhn 1962

Front 29

Explain paradigms of science:

Back 29

Front 30

What does the timeline look like for those paradigms?

Back 30

Front 31

Evidence for Great Flood:

Back 31

• Evidence for Black Sea
Flood
– Ancient shorelines 400 ft
below sea level.
– Evidence of waves & fossils,
wind & plants along old
shorelines.
– Fossils give ages of 7500 b.p.
– Evidence of change in water

-----

•Ice sheet melts fills lake.
•Ice withdraws and land rises.
•Water drains elsewhere & lake
begins to dry up (10,000 to
5600 B.C.).
•Sea level rising up to Bosporus
Straits as oceans fill.
•At 5600 B.C. 350 ft above
nearby Black Sea lake level.
•Breaks through and rapidly
fills lake.
from fresh to seawater.

Front 32

When did science become legally outlined?

Back 32

Front 33

Normal star evolution:

Back 33

Normal Stars:
• Form from gas nebula by gravitational attraction
• As gas heats up and pressure from contraction
reaches a special point, H+H combine to form He
(fusion)
• Heat and pressure balance gravitational forces and
star is stable
• When H fuel is gone star contracts to white dwarf
(can’t collapse more due to Pauli Exclusion
Principle - can’t normally squeeze electrons into
nucleus)