Cosmology Slides. Iroquois Myth The heavens were around for a lot longer than the Earth, according to a creation myth told by the Iroquois people of North.

Cosmology Slides

Iroquois Myth

• The heavens were around for a lot longer than the Earth, according to a creation myth told by the Iroquois people of North America. One of the heavenly inhabitants, the Great Spirit, punished his daughter for becoming pregnant by throwing her through a hole formed when he ripped up a giant tree. To keep her from perishing, though, he ordered the Great Turtle to dive down into the water, bring up some mud and wait for the daughter to land on its back. When she landed, she gathered up the mud and created the Earth as an island carried on the Great Turtle's back.http://www.brighthub.com/science/space/articles/11499.aspx

Genesis – The Bible

• In the beginning God created the heavens and the earth.2 Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters.

• 3 And God said, "Let there be light," and there was light. 4 God saw that the light was good, and he separated the light from the darkness. 5 God called the light "day," and the darkness he called "night." And there was evening, and there was morning--the first day.

Other Creation Myths

• In ancient Greece, In the beginning there was an empty darkness. The only thing in this void was Nyx, a bird with black wings. With the wind she laid a golden egg and for ages she sat upon this egg. Finally life began to stir in the egg and out of it rose Eros, the god of love. One half of the shell rose into the air and became the sky and the other became the Earth. Eros named the sky Uranus and the Earth he named Gaia. Then Eros made them fall in love. .

• The ancient Babylonians' view of the universe was detailed in the Enuma Elish, a creation myth inscribed on a series of seven clay tablets. In the story, a battle among the gods leads Marduk, the god of spring, to kill Tiamat, goddess of the sea. He splits her body in two, and one half becomes the Earth, the other, the sky. The slain Tiamat's saliva becomes the rain.

http://www.cs.williams.edu/~lindsey/myths/myths_16.html

Flat Earth

http://4.bp.blogspot.com/_x0tbqXdMlkc/TU-VuLfkVAI/AAAAAAAAAGQ/7SkmfXEsN3U/s1600/flat_earth-edit.jpg

http://2.bp.blogspot.com/-sCIpfNH9Fw8/TpNwd_CQ6AI/AAAAAAAAACk/dwexLhz2rhg/s1600/falling-off-flat-earth.jpg

Cosmological Principle

• Seen on a sufficiently large scale, the universe looks the same for all observers.

• The universe is the same whoever you are and wherever you are.

• two testable structural consequences of the cosmological principle are homogeneity and isotropy. – Homogeneity : the same in all locations: “the gravy is

smooth if you ignore the lumps”. Galaxies violate the cosmological principle

– Isotropy: the same in all directions. Get the same results no matter where you look.

• Allows Universe to be treated as a whole, with average energy densities, speeds, pressures, temperatures – Allows science to work

http://en.wikipedia.org/wiki/Cosmological_principle

Olber’s Paradox

• http://en.wikipedia.org/wiki/Olbers%27_paradox#History

The paradox is that a static, infinitely old universe with an infinite number of stars distributed in an infinitely large space would be bright rather than dark.

Quantifying Olber’s Paradox

Animation of Olber’s Paradox

http://en.wikipedia.org/wiki/File:Olber%27s_Paradox_-_All_Points.gif

Einstein’s Field Equations

• http://en.wikipedia.org/wiki/Einstein_field_equations#Mathematical_form

the Ricci curvature tensor – curvature of space – related to amount of mass in the universe

the scalar curvature also related to the curvature of space

the stress–energy tensor . describes the density and flux of energy and momentum in spacetime, generalizing the stress tensor of Newtonian physics. It is an attribute of matter, radiation, and non-gravitational force fields. The stress-energy tensor is the source of the gravitational field in the Einstein field equations of general relativity, just as mass is the source of such a field in Newtonian gravity.

The metric tensor - defines notions such as distance, volume, curvature, angle, future and past.

The Cosmological Constant – put in by Einstein as a modification of his original theory of general relativity to achieve a stationary universe. Einstein abandoned the concept after the observation of the Hubble redshift indicated that the universe might not be stationary, as he had based his theory on the idea that the universe is unchanging.[1]

Hubble Diagram

Difference in types of redshift

CMB

http://en.wikipedia.org/wiki/File:Firas_spectrum.jpg

Other forms of Wiens Law

Stellar Parallax

• http://en.wikipedia.org/wiki/File:Stellarparallax2.svg

Extragalactic Distance Measures

• http://en.wikipedia.org/wiki/Cosmic_distance_ladder#Main_sequence_fitting

Rotation Curve of Spiral Galaxy

• http://en.wikipedia.org/wiki/Galaxy_rotation_problem#History_and_description_of_the_problem

Dark Matter Halos

• http://www.nasa.gov/mission_pages/hubble/science/dark-matter-core.html

Expected Dark Matter Halo in Milky way

• http://news.nationalgeographic.com/news/2012/04/120419-dark-matter-sun-missing-stars-milky-way-space-science/

Einstein’s Field Equations

• http://en.wikipedia.org/wiki/Einstein_field_equations#Mathematical_form

the Ricci curvature tensor – curvature of space – related to amount of mass in the universe

the scalar curvature also related to the curvature of space

the stress–energy tensor . describes the density and flux of energy and momentum in spacetime, generalizing the stress tensor of Newtonian physics. It is an attribute of matter, radiation, and non-gravitational force fields. The stress-energy tensor is the source of the gravitational field in the Einstein field equations of general relativity, just as mass is the source of such a field in Newtonian gravity.

The metric tensor - defines notions such as distance, volume, curvature, angle, future and past.

The Cosmological Constant – put in by Einstein as a modification of his original theory of general relativity to achieve a stationary universe. Einstein abandoned the concept after the observation of the Hubble redshift indicated that the universe might not be stationary, as he had based his theory on the idea that the universe is unchanging.[1]

Curvature of Space

• http://preposterousuniverse.com/writings/encyc/

The circle represents very roughly the region favored by current observations of distant supernovae, the cosmic microwave background, and the dynamics of galaxies.