Universe and the Solar System

Baryonic matter - "ordinary" matter consisting of protons, electrons, and

neutrons that comprises atoms, planets, stars, galaxies, and other bodies.

Dark matter - matter that has gravity but does not emit light.

Dark Energy - a source of anti-gravity; a force that counteracts gravity and

causes the universe to expand.

Protostar- an early stage in the formation of a star resulting from the

gravitational collapse of gases.

Thermonuclear reaction - a nuclear fusion reaction responsible for the energy

produced by stars.

Main Sequence Stars - stars that fuse hydrogen atoms to form helium atoms in

their cores; outward pressure resulting from nuclear fusion is balanced by

gravitational forces

light years - the distance light can travel in a year; a unit of length used to

measure astronomical distance.

Hydrogen and Helium as the most abundant elements in the universe. Having

the lowest mass, these are the first elements to be formed in the Big Bang

Model of the Origin of the Universe.

A star's energy comes from combining light elements into heavier elements by

fusion, or “nucler burning” (nucleosynthesis).

Structure, Composition, and Age

The universe as we currently know it comprises all space and time, and all

matter & energy in it.

It is made of :

1) 4.6% baryonic matter (“ordinary” matter consisting of protons,

electrons, and neutrons: atoms, planets, stars, galaxies, nebulae, and

other bodies)

2) 24% cold dark matter (matter that has gravity but does not emit light)

3) 71.4% dark energy (a source of antigravity)

Dark matter can explain what may be holding galaxies together for the reason

that the low total mass is insufficient for gravity alone to do so while dark energy

can explain the observed accelerating expansion of the universe.

Hydrogen, helium, and lithium are the three most abundant elements.

Stars - the building block of galaxies born out of clouds of gas and dust in

galaxies.

I. Instabilities within the clouds eventually results into gravitational collapse,

rotation, heating up, and transformation to a protostar.

Protostar-the core of a future star as thermonuclear reactions set in.

Stellar interiors are like furnaces where elements are synthesized or

combined/fused together.

Sun -belong to the so-called “main sequence stars.”

main sequence stars- Star that fuses hydrogen atoms to form helium atoms in

their core.

A galaxy is a cluster of billions of stars and clusters of galaxies form

superclusters. In between the clusters is practically empty space.

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Universe and the Solar System

Baryonic matter - "ordinary" matter consisting of protons, electrons, and neutrons that comprises atoms, planets, stars, galaxies, and other bodies. Dark matter - matter that has gravity but does not emit light. Dark Energy - a source of anti-gravity; a force that counteracts gravity and causes the universe to expand. Protostar - an early stage in the formation of a star resulting from the gravitational collapse of gases. Thermonuclear reaction - a nuclear fusion reaction responsible for the energy produced by stars. Main Sequence Stars - stars that fuse hydrogen atoms to form helium atoms in their cores; outward pressure resulting from nuclear fusion is balanced by gravitational forces light years - the distance light can travel in a year; a unit of length used to measure astronomical distance. Hydrogen and Helium as the most abundant elements in the universe. Having the lowest mass, these are the first elements to be formed in the Big Bang Model of the Origin of the Universe. A star's energy comes from combining light elements into heavier elements by fusion, or “nucler burning” (nucleosynthesis). Structure, Composition, and Age The universe as we currently know it comprises all space and time, and all matter & energy in it. It is made of :

4.6% baryonic matter (“ordinary” matter consisting of protons, electrons, and neutrons: atoms, planets, stars, galaxies, nebulae, and other bodies)
24% cold dark matter (matter that has gravity but does not emit light)
71.4% dark energy (a source of antigravity) Dark matter can explain what may be holding galaxies together for the reason that the low total mass is insufficient for gravity alone to do so while dark energy can explain the observed accelerating expansion of the universe. Hydrogen, helium, and lithium are the three most abundant elements. Stars - the building block of galaxies born out of clouds of gas and dust in galaxies. I. Instabilities within the clouds eventually results into gravitational collapse, rotation, heating up, and transformation to a protostar. Protostar -the core of a future star as thermonuclear reactions set in. Stellar interiors are like furnaces where elements are synthesized or combined/fused together. Sun -belong to the so-called “main sequence stars.” main sequence stars- Star that fuses hydrogen atoms to form helium atoms in their core. A galaxy is a cluster of billions of stars and clusters of galaxies form superclusters. In between the clusters is practically empty space.

I. This organization of matter in the universe suggests that it is indeed clumpy at a certain scale. But at a large scale, it appears homogeneous and isotropic. II. Isotropic - having physical properties that are the same when measured in different directions Based on recent data, the universe is 13.8 billion years old. The diameter of the universe is possibly infinite but should be at least 91 billion light-years ( light-year = 9.4607 × 1012 km). Its density is 4.5 x 10-31 g/cm3. I. Two ways by which astronomers estimate the age of the universe :

by estimating the age of the looking oldest stars
by measuring the rate of expansion of the universe and extrapolating back to the Big Bang. Expanding Universe In 1929, Edwin Hubble announced his significant discovery of the “redshift” interpretation that galaxies are moving away from each other, hence as evidence for an expanding universe, just as predicted by Einstein’s Theory of General Relativity. He observed that spectral lines of starlight made to pass through a prism are shifted toward the red part of the electromagnetic spectrum , i.e., toward the band of lower frequency; thus, the inference that the star or galaxy must be moving away from us. Red shift – A change in frequency of the position of the line. Doppler effect - change in frequency and wavelength the further the galaxy the faster it moves AWAY. Cosmic Microwave Background There is a pervasive cosmic microwave background (CMB) radiation in the universe. Its accidental discovery in 1964 by Arno Penzias and Robert Woodrow Wilson earned them the physics Nobel Prize in 1978. It can be observed as a strikingly uniform faint glow in the microwave band coming from all directions-blackbody radiation with an average temperature of about 2.7 degrees above absolute zero. Non-scientific Thought
Ancient Egyptians believed in many gods and myths which narrate that the world arose from an infinite sea at the first rising of the sun.
The Kuba people of Central Africa tell the story of a creator god Mbombo (or Bumba) who, alone in a dark and water-covered Earth, felt an intense stomach pain and then vomited the stars, sun, and moon.

From time zero (13.8 billion years ago) until 10-43 second later, all matter and energy in the universe existed as a hot, dense, tiny state (fig. 7). It then underwent extremely rapid, exponential inflation until 10-32 second later after which and until 10 seconds from time zero, conditions allowed the existence of only quarks, hadrons, and leptons.
Then, Big Bang nucleosynthesis took place and produced protons, neutrons, atomic nuclei, and then hydrogen, helium, and lithium until 20 minutes after time zero when sufficient cooling did not allow further nucleosynthesis. • From then on until 380,000 years, the cooling universe entered a matter-dominated period when photons decoupled from matter and light could travel freely as still observed today in the form of cosmic microwave background radiation.
As the universe continued to cool down, matter collected into clouds giving rise to only stars after 380,000 years and eventually galaxies would form after 100 million years from time zero during which, through nucleosynthesis in stars, carbon and elements heavier than carbon were produced.
From 9.8 billion years until the present, the universe became dark-energy dominated and underwent accelerating expansion. At about 9.8 billion years after the big bang, the solar system was formed. It was previously thought that the gravity would eventually stop the expansion and end the universe with a “Big Crunch” and perhaps to generate another “bang”. the universe would expand forever leading to the “Big Chill” or “Big Freeze ” since it cools during expansion. The recent observation of accelerating expansion suggests that the universe will expand exponentially forever. SOLAR SYSTEM The Solar System refers to the extraterrestrial place where the Sun and the Earth belongs to. As of present, there are currently 8 known planets found in the Solar System. different components of the solar system: our stars, the Sun, Mercury, Venus, Earth, Mars, Jupiter, Saturn Uranus and Neptune, Pluto, dozens of moons and millions of asteroids, comets and meteoroid. The solar system is located in the Milky Way galaxy- a huge disc- and spiral- shaped aggregation of about at least 100 billion stars and other bodies. Age of Solar System is at 4.6 billion years old based on radioactive dating of meteorites (Solar System is much younger than the Universe. This galaxy is about 100 million light years across. The solar system revolves around the galactic center once in about 240 million years The Milky Way is part of the so- called Local Group of galaxies , which in turn is part of the Virgo supercluster of galaxies Large Scale Features of the Solar System

Much of the mass of the Solar System is concentrated at the center (Sun) while angular momentum is held by the outer planets. Orbits of the planets elliptical and are on the same plane. All planets revolve around the sun. The periods of revolution of the planets increase with increasing distance from the Sun; the innermost planet moves fastest, the outermost, the slowest; All planets are located at regular intervals from the Sun Small scale features of the Solar System Most planets rotate prograde

Prograde - counterclockwise when viewed from above the Earth's North Pole. Inner terrestrial planets are made of materials with high melting points such as silicates, iron , and nickel. They rotate slower, have thin or no atmosphere, higher densities, and lower contents of volatiles - hydrogen, helium, and noble gases. The outer four planets - Jupiter, Saturn, Uranus and Neptune are called "gas giants" because of the dominance of gases and their larger size. They rotate faster, have thick atmosphere, lower densities, and fluid interiors rich in hydrogen, helium and ices (water, ammonia, methane) Theories on the formation of the solar system Nebular hypothesis According to this theory, the Sun and all the planets of our Solar System began as a giant cloud of molecular gas and dust. This nebular theory failed to account for the distribution of angular momentum in the solar system. In the 1700s Emanuel Swedenborg, Immanuel Kant, and Pierre-Simon Laplace independently thought of a rotating gaseous cloud that cools and contracts in the middle to form the sun and the rest into a disc that become the planets. Encounter hypothesis In this scenario, a rogue star passes close to the Sun about 5 billion years ago. Material, in the form of hot gas, is tidally stripped from the Sun and the rogue star. This material fragments into smaller lumps which form the planets. Otto Schmidt’s accretion theory proposed that the Sun passed through a dense interstellar cloud and emerged with a dusty, gaseous envelope that eventually became the planets. Protoplanet Hypotheses

Geosphere Largest of the four spheres Layers:

Crust – the earth thin and rocky outer skin. Two types of crust:

Oceanic crust –usually found beneath oceans and large bodies of water and is made up of basaltic rocks.
Oceanic crust – thinner compared to oceanic crust, dominated by granatic rocks.

Mantle – compromise more Than 82% of the earth’s total volume. Upper mantle : is further divided to “stiff” lithosphere(Stiff portion of the upper

mantle) and “plastic” Asthenosphere ( weaker layer beneath the

lithosphere) Lower mantle: rigid portion of the mantle because of pressure buildup.

Core – deepest portion of the Earth. Outer core: liquid portion of the core, movement of the iron is generating the Earth’s magnetic field. Inner core: solid portion of the earth. Atmosphere The atmosphere is the thin gaseous layer that envelopes the lithosphere. Provides the exchange of gases we need for respiration and also protects us from the ultraviolet radiation coming from the sun. composed of:
78% nitrogen (N)
21% oxygen (O2)
0.9% argon and trace amount of other gases. One of the most important processes by which the heat on the Earth's surface is redistributed is through - atmospheric circulation. Layers of atmosphere: Troposphere lowest layer closest to the earth. Densest layer of the atmosphere. Stratosphere where the ozone layer is found Mesosphere acts as layer for meteors to burn Thermosphere the density of gas molecule is very low compared to troposphere. Lithosphere includes the rocks of the crust and mantle, the metallic liquid outer core, and the solid metallic inner core. the Plate Tectonics is an important process shaping the surface of the Earth. The primary driving mechanism is the Earth's internal heat, such as that in mantle convection. Biosphere the set of all life forms on Earth.

It covers all ecosystems—from the soil to the rainforest, from mangroves to coral reefs, and from the plankton-rich ocean surface to the deep sea. Sunlight is not necessary for life. Hydrosphere About 70% of the Earth is covered with liquid water (hydrosphere) and much of it is in the form of ocean water (Figure 3). Only 3% of Earth's water is fresh: two-thirds are in the form of ice, and the remaining one-third is present in streams, lakes, and groundwater Heat is absorbed and redistributed on the surface of the Earth through ocean circulation. Hypsographic curve is a graphical representation of the proportion of land at various elevations (meters above or below sea level)

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Universe and the Solar System

mantle) and “plastic” Asthenosphere ( weaker layer beneath the