Earth Sci

CM1

Universe

The Universe is composed of all time and space. It is made up of millions of stars and planets and enormous clouds [nebular clouds] of gas separated by a gigantic space.

Theory

  • A conclusion from scientific method, it has a better change yet it is still arguable.

Law

  • Agreeable for all

Prominent Theories on the Origin of the Universe 

1. Cyclical or Oscillating Universe - (15th century B.C.) “Rigveda” states that the universe came from a cosmic egg

2. Primordial universe - (5th century B.C.) Anaxogoras the cosmos came from primordial mixtures

3. Atomic Universe - (5th century B.C.) Leuccipus and Democritus that our universe came from the atom

4. Aristotelian Universe - (4th century B.C) geocentric universe

5. Stoic universe - (3rd century B.C.) Greek philosophers proposed the Stoic universe, a body interconnected to its parts

6. Heliocentric universe - (3rd century B.C.) Aristarchus (later on supported by Copernicus (1491) and proved Galileo (1621)

7. Ptolemeic universe - (2nd century A.D.) geocentric theory 2.0

8. Abrahamic universe - (6th century A.D) finite universe

9. Copernican universe - (1543) heliocentric theory 2.0

10. Cartesian vortex universe - (17th century) gravitational effects of an infinite galaxy

11. Newtonian or static universe (1687) steady state, infinite universe

12. Einsteinian universe (20th century) static, dynamically stable

13. Big Bang theory (1929)

14. Steady State universe (1948)

15. Multiverse (1983)

Origin of the Universe

Cosmology

  • It is the branch of astronomy that is the study of the structure and evolution of the universe.

Georges Lemetre

  • The proponent of Big Bang Theory

  • He stated that a very long time ago, the universe started as just a single point.

  • In 1927 he published his most famous paper, in which he applied Albert Einstein’s theory of general relativity to the entire universe. 

  • According to Lemaître’s analysis, the universe was in a state of constant expansion, having begun at a specific point in time.

The Big Bang Theory

  • It states that 13.8 billion years ago, all the matter and energy in the universe was compressed into an extremely small volume.

Edwin Hubble

        Hubble’s Observation

  • Edwin Hubble used the galactic spectra to uncover new information about our universe.

  • Hubble Space Telescope and other observatories showed that the universe is expanding at an ever-increasing rate.

Measuring Red Shift

        Hubble's law

  • Hubble found that the spectra of galaxies, except for few closest to Earth, were shifted toward the red end of the spectrum.

  • By examining the amount of red shift, he determined the speed at which the galaxies were moving away from Earth. 

  • Hubble found that the most distant galaxies showed the greatest red shift and thus were moving away from Earth the fastest

The Expanding universe

  • As the universe expanded through time, the temperature cools down.

  • Some of the matter gathered into clumps that evolved into galaxies.

  • The universe is still expanding, and the galaxies continue to move apart from one another.

Cosmic Background Radiation

  • In 1965, researches using radio telescopes detected cosmic background radiation, or low levels of energy evenly distributed throughout the universe.

  • Astronomers think that this background radiation formed shortly after the big bang.

Ripples in Space

  • Ripples are irregularities in the cosmic background radiation, which were caused by small fluctuations in the distribution of matter in the early universe.

  • The ripples may indicate the first stages in the formation of the universe’s first galaxies.

LOOPHOLE: How can you say that something happened if you were not there?

Steady-State Theory

  • This theory was developed in 1948 by Fred Hoyle, Herman Bondi, and Thomas Gold as an alternative to the Big bang.

  • The Universe is always expanding but maintaining a constant average density.

  • The Universe is infinite in extent, infinitely old and, taken as a whole, it is the same in all directions and at all times in the past and at all times in the future. In other words, the Universe doesn’t evolve or change over time.

Multiverse Theory

  • Our universe, with all its hundreds of billions of galaxies and almost countless stars, spanning tens of billions of light-years, may not be the only one. Instead, there may be an entirely different universe, distantly separated from ours and another. 

  • In principle, the other unconnected universes may have different dimensionalities, physical laws, matter and energy and topologies of space-time.

The Universe - Totality of space, time, matter and energy

Astronomers determine the structure of the universe by detecting and analyzing electromagnetic waves that come from galaxies.

The Distribution of Galaxies

  • The galaxies extend to 2 billion ly away. The Milky Way is located at the center.

  • Galaxies are not evenly distributed in space

The Galaxy

  • the “building blocks” of the universe

  • A galaxy is a large group of stars, gas, and dust bound together by gravity.

  • They come in a variety of shapes and sizes.

Milky Way Galaxy

  • It is a large barred spiral galaxy.

  • Spiral galaxies have three main component parts: the bulge, the disk, and the halo.

  • Made up of 100 billion stars. These stars form a large disk whose diameter is about 100,000 light years.

NOTE: Other forms of galaxies could be in elliptical and irregular forms, which means the galaxy has no definitive shape or symmetry.






Solar System

  • It is about 25,000 light years away from the center of our galaxy

  • It formed about 4.5 billion years ago, when a massive interstellar cloud of gas and dust collapsed on itself.

  • Giving rise to the star that anchors our solar system—that big ball of warmth known as the sun.

  • The Sun was formed about 4.57 billion years 

  • The Earth formed about 4.54 billion years ago.

Models of the Solar System

  • Geocentric Model (Geocentrism)

  • The earth is at the center of the universe.

  •  Every other celestial body rotates around the earth.

  • Greeks were strong supporters of this theory, especially the great philosophers Aristotle and Ptolemy.

  • Aristotle and Ptolemy were the proponents of the Geocentric Theory.

  • Heliocentric Model (Heliocentrism)

  • The sun is at the center of the universe.

  • Nicolas Copernicus, who supported and was the proponent of Heliocentric Theory. 

  • Aristarchus of Samos who proposed the theory first in 3rd century BC but was not taken seriously because of the influence of the Aristotelian view of the universe and lack of proof of the theory at that time.

       Copernican theory can be summarized as follows:

  1. The motion of the celestial bodies is uniform, eternal, and circular or compounded of several circles.

  2. The center of the cosmos is the Sun.

  3. Around the Sun, in the order of Mercury, Venus, Earth and Moon, Mars, Jupiter, and Saturn move in their own orbits and the stars are fixed in the sky.

  4. The earth has three motions: daily rotation, annual revolution, and annual tilting off its axis.

  5. The retrograde motion or the backward motion of the planets is as explained by the Earth’s motion.

  6. The distance from the Earth to the Sun is small compared to the distance to the stars.

Planets in the Solar System

Mercury-Venus-Earth-Mars-Jupiter-Saturn-Uranus-Neptune

Classifications of Planets

  • Terrestrial planets 

  • MVEM

  • Solid and rocky planet

  • Jovian planets 

  • JSUN  

  • Gaseous planets

  • the gas giants and ice giants

Moons in the Solar System

  • 150 moons orbit planets in our solar system. Among the planets.

  • known as natural satellites

  • Mercury and Venus are moon-free

  • Mars has two small moons called Phobos and Deimos

  • Earth’s moon is called Luna

  • Jupiter have 79 moons including Io, Europa, Ganymede, and Callisto.

  • Saturn have 62

  • Uranus have 27

  • Neptune have 14 moons

  • Pluto has five moons, one of which is so close to Pluto in size that some astronomers argue Pluto and this moon, Charon, are a binary system.

Atmosphere of the Planets

  • Mercury does not have an atmosphere at all. Instead, scientists refer to its extremely thin covering of oxygen, hydrogen, sodium, helium, and potassium as an exosphere.

  • Venus and Mars are mostly carbon dioxide.

  • The thick atmospheres of Jupiter, Saturn, Uranus, and Neptune are made primarily of hydrogen and helium

        Earth’s Atmosphere

  • Earth is the only planet in the solar system known to harbor life. 

  • Earth has a molten nickel-iron core, which gave rise to an extensive magnetic field.

  • Earth’s is composed mainly of nitrogen and oxygen—key for sustaining life.

  • It serve as our shields from harmful radiation coming from the Sun.

Earth: A Habitable Planet 

Factors that make a planet habitable (TAEN)

  • Temperature influences how quickly atoms and molecules move

  • Atmosphere

  • Energy

  • Nutrients used to build and maintain an organism’s body

NOTE: Earth is the only place, confirmed to host life and is the only one known for sure to have liquid water in the surface. 

The following reasons why planet earth is unique: 

  • It has liquid water. 

  • Plate Tectonics 

  • It has atmosphere that shelters it from the worst of the sun’s rays.



  • Earth is the only planet in the solar system that has a large amount of liquid water. About 70% of the surface of the Earth is covered by liquid or frozen water. 

  • Earth is sometimes called “blue planet.” or “blue marble”. 

  • It is habitable because it has the right distance from the sun. It is kept warm by an insulating atmosphere, and it has the right chemical ingredients for life including water and carbon.

  • It can provide water, oxygen, useful biological products for human, and has suitable weather and climate.

Earth, Venus, and Mars similarities:

  • Terrestrial planets have solid rocks and silicates. 

  • These 3 planets have an atmosphere. 

  • They all almost have the same time of rotation. 

  • Earth and Mars both have water. 

  • They all have carbon dioxide. 

  • All have landforms. 

Earth, Venus, and Mars differences: 

  • Venus has no water. 

  • Venus does not have oxygen while Mars has a very little amount of oxygen.

  • Earth has life forms.