(unit 1 chp1) origin & formation of the universe

the understanding of the origin, evolution and structure of of the universe.

cosmology

reveals that ancient Indians believed that the universe had an origin and pondered about how and where the world and everything in it began.

The Hymn of Creation in the Rigveda

What was the first thing that existed based on the Hymn of Creation in the Rigveda?

Darkness

What was the second thing that existed based on the Hymn of Creation in the Rigveda?

Desire

they believed that the cosmos has always existed.

ancient Greeks

beliefs of ancient Greeks

• the cosmos was neither created nor is it perishable

• it was timeless and infinite in extent.

• the universe has a center 

He first proposed that Earth was not the center of the universe, but a central fire around which the sun, moon, the planets, and other celestial objects revolved uniformly.

Philolaus (470-385 B.C.)

He supported the idea of Philolaus but suggested that the central fire was the sun.

Aristarchus (310-230 B.C.)

He proposed the Heliocentric model of the universe.

Aristarchus

He proposed the center of the cosmos is Earth.

Aristotle

Aristotle’s geocentric cosmology dominated all studies and speculations about the arrangement of the cosmos until

16th Century

popularized and advanced the geocentric model

Claudius Ptolemy

heavenly bodies revolved around a stationary Earth placed at the center of the universe.

Geocentric model

designed the Ptolemaic model

Claudius Ptolemy

Ptolemy’s design even tried to explain the planetary and solar motions through different paths known as:

• epicycle

• deferent

• eccentric

the planetary and solar motions through different paths known as epicycle, deferent and eccentric. A dominant model of the universe until the scientific revolution in the 16th century.

Ptolemaic model

During these centuries, the western worldview the dominated the world of science projected a history that directed toward progress.

17th and 18th century

Who proposed the Big Bang Theory?

Georges Lemaitre

Who proposed the general relativity?

Albert Einstein

He believed that the universe was a finite and static four-dimensional closed sphere. The universe was homogeneous, where matter spread smoothly throughout space.

Albert Einstein

• the most accepted theory today

• the universe is approximately 13.7 billion years old.

• cosmologists who supported this theory divided the history of the universe into a series of eras or time periods.

Big Bang Theory

Eras of the Big Bang Theory

1. The Planck Era

2. The Grand Unified Theory (GUT) Era

3. Electroweak Era

4. Particle Era

5. The Era of Nucleosynthesis

6. Era of Nuclei

7. Era of Atoms and Galaxies

Enumerate the pieces of evidence in testing earlier theories:

1. Mass Distribution

2. Angular Momentum Distribution

3. Shape and alignment of orbits

4. Chemical Composition

the mass of the system is not evenly distributed. Most of the mass is concentrated in the sun.

Mass Distribution

or the tendency to rotate is concentrated more among the planets instead of the sun.

Angular momentum distribution

the planets moved in nearly circular orbits that nearly align with the equator of the sun in the same direction.

Shape and Alignment of Orbits

the planets and the sun have similar chemical compositions, although varying in proportions.

Chemical composition

CMBR

Cosmic Microwave Background Radiation

who accidentally proved the CMBR

Arno Penzias and Robert Wilson

this is the afterglow of the Big Bang Theory

(CMBR) Cosmic Microwave Background Radiation

theory of cosmos

Hubble

This shocked a nearby interstellar system and triggered the collapse of a solar nebula.

supernova

pancake-shpaed circumstellar disk of dust and gas known as the?

protoplanetary disk

particles in the protoplanetary disk started to collide and form ___, which led go a series of formations of planets in the solar system.

planetesimals

the planetesimals were also assimilating other materials in yheir surroundings. this is known as

accretion

terrestrial planets

• mercury

• venus

• earth

• mars

the icy planetesimals have a gravitational force stronv enough to capture the abundant hydrogen and helium gases within the solar nebula. this process is called?

nebular capture

large jovian planets

• jupiter

• saturn

• neptune

• uranus

the outermost layer of a terrestrial planet. it is composed of igneous, metamorphic, and sedimentary rocks.

crust

two types of crust

• continental

• oceanic

is composed primarily of basalt, diabase, and gabbro.

oceanic crust

is mostly composed if rocks less dense than the other type of crust, it includes granitez silicates, and aluminum.

continental crust

the section comprising the crust and the upper portion of the mantle, covering a depth of about 100 km

lithosphere

the rock shell surrounding the outer core of other planets.

mantle

thickest layer of Earth

mantle

extends from the crust to a depth of about 410 km and is often described to comprise two regions: the lithosphere and the asthenosphere.

upper mantle

is the section beneath the lithosphere that reaches to a depth of around 410 km

asthenosphere

these plates are said to float above the asthenosphere

lithospheric plates

this portion is hotter and denser than the upper mantle, but its rock composition is more solid due to the intense pressure.

lower mantle

is where rocks undergo significant transformations and become denser.

transition zone

the central layer of the planet, divided into inner and outer portions

Core

is composed mostly of metals, particularly solid iron and nickel. this portion is solid.

inner core

the inner core is surrounded by the liquid iron, which has a thickness of 2,270 km. this portion is liquid.

outer core

the relative measure of the increase in Earth's interior heat and pressure.

geothermal gradient