Lesson 1: Origin & Structure of the Earth, the Universe and the Solar System Flashcards
Learn about the Origin and Structure of the Earth, the Universe, and the Solar System. Go back to how it began and explore deeper to the cosmos.
“Ordinary” matter consisting of protons, electrons, and neutrons that comprises atoms, planets, stars, galaxies, and other bodies.
Baryonic Matter
Matter that has gravity but does not emit light.
dark matter
A source of anti-gravity; a force that counteracts gravity and causes the universe to expand.
dark energy
An early stage in the formation of a star resulting from the gravitational collapse of gases
Protostar
A nuclear fusion reaction responsible for the energy produced by stars
Thermonuclear Reaction
Stars that fuse Hydrogen atoms to form Helium atoms in their cores; outward pressure resulting from nuclear fusion is balanced by gravitational forces.
Main Sequence Stars
A large unimaginable expanse of gas, stars, dust clouds, and consists of planets and galaxies.
Universe
The structure of the universe is composed of:
a) 63.4% - dark energy; 27% - dark matter; 9.6% - Baryonic Matter
b) 71% - dark energy; 24.4% - dark matter; 4.6% - Baryonic Matter
c) 60% - dark energy; 20% - dark matter; 20% - baryonic matter
d) 71.4% - dark energy; 24% - dark matter; 4.6% - Baryonic Matter
d) 71.4% - dark energy; 24%- dark matter; 4.6% - Baryonic Matter
What are the three most abundant elements in the universe?
a) Hydrogen, Helium, Beryllium
b) Hydrogen, Helium, Lithium
c) Hydrogen, Lithium, Beryllium
d) Hydrogen, Aluminum, Iron
b) Hydrogen, Helium, Lithium
the building block of galaxies and is born out of clouds of gas and dust in galaxies
Stars
the hot core of a future star as thermonuclear reactions set in
Protostar
It is the contraction of an astronomical object due to the influence of its own gravity. It is a fundamental mechanism for structure formation in the universe.
Gravitational Collapse
These are like furnaces where elements are synthesized or combined/fused together. Most stars such as the sun belong to the so called “main sequence stars”. In the cores of such stars, hydrogen atoms are fused through thermonuclear reactions to make helium atoms.
Stellar Interiors
A star’s energy comes from combining light elements into heavier elements by fusion, also called ________
Nuclear Burning or Nucleosynthesis
What are the four main kinds of galaxies?
Elliptical, Spiral, Irregular, and Barred Spiral
Based on recent data, how old is the universe?
Around 13.8 billion years old
The diameter of the universe is possibly infinite but should be at least ______________
91 billion light years
It is the distance light can travel in a year; a unit of length used to measure astronomical distance
Light Years
What is approximately the density of the universe?
- 5 x 10^-31 g/cm^3 (according to resource book)
9. 9 x 10^-30 g/cm^3 (according to wmap.gsfc.nasa.gov)
It is a cluster of billions of stars and clusters of galaxies to form super clusters.
Galaxies
It is the currently accepted theory of the origin and evolution of the universe. It postulates that 12 to 14 billion years ago, the portion of the universe we can see today was only a few millimetres across. It has since expanded from this hot dense state into the vast and much cooler cosmos we currently inhabit.
The Big Bang Theory
The Big Bang Theory rests on what two main principles?
Theory of General Relativity & the Cosmological Principle
__________ assumes that the universe is homogeneous and isotropic.
The Cosmological Principle
___________ generalizes Isaac Newton’s theory of gravity; describes gravity no longer as a gravitational “field” but rather it is supposed to be a distortion of space and time itself.
Theory of General Relativity
define isotropic
uniformity in all orientations; not varying in magnitude according to the direction of measurement
define homogeneous
properties are same on every point
Ancient Egyptians believed in many gods and myths which narrate that:
a. the world was spewed by a serpent and gave birth to the stars
b. the world arose from an infinite sea at the first rising of the sun
c. the God Isis created the world from a big mold of mud and formed with it the sky and the seas
d. the Egyptians believed no myth about how the world formed
b. the world arose from an infinite sea at the first rising of the sun
The ______________ tell the story of a creator God _______ who, alone in a dark and water-covered earth, felt an intense stomach pain and then vomited the stars, sun and moon.
Kuba people of Central Africa; Mbombo (or Bumba)
In India, there is the narrative that Gods sacrificed ________, the primal man whose head, feet, eyes, and mind became the sky, earth, sun, and moon respectively.
Purusha
It is an alternative theory of the origin of the universe, first put forward by Sir James Jean in about 1920 then revised by Bondi and Gould in 1948, then it as further developed by Fred Hoyle to deal with problems that had arisen in connection with alternative big bang hypothesis.
Steady State Model
It is a view that the universe is always expanding but maintaining a constant average density, matter being continuously created to form new stars and galaxies at the same rate that old ones become unobservable as a consequence of their increasing distance and velocity of recession.
Steady State Model
This theory maintains that new matter is created as the universe expands thereby maintaining its density.
Steady State Model
A hypothetical scenario for the ultimate fate of the universe, in which the expansion of the universe eventually reverses and the universe recollapses, ultimately causing the cosmic scale factor to reach zero, an event potentially followed by the reformation of the unvierse.
Big Crunch
It can be observed as a strikingly uniform faint glow in the microwave bond coming from all directions - black body radiation with an average temperature of about 2.7 degrees above absolute zero. This was accidentally discovered by Arno Penzias and Robert Woodrow Willson in 1964.
Cosmic Microwave Background Radiation
What is the temperature absolute zero?
-273.15 degrees C / -459.67 degrees F
The universe is expanding for a time and then to its contradiction due to gravity.
Oscillating Theory
What tests has the Big Bang Theory withstood for it to become the broadly accepted theory of how the universe began?
1) The Red Shift
2) It proves the abundance of hydrogen, helium, and lithium.
3) The uniformly pervasive cosmic microwave background radiation
It explains the peculiarities of the orbit of Mercury and the bending of light by the sun.
Theory of General Relativity
What are the main theories on how the universe will meet its end?
The Big Crunch / The Big Rip / The Big Freeze or The Big Chill
Nucleosynthesis requires very high temperature. What is the minimum temperature for H fusion?
5 x 10^6 degrees Celcius
What would be the fate of the universe if the density of the universe is lower than the critical density?
There wouldn’t be enough gravitational force to stop or reverse the expansion — the universe would expand to the “Big Chill or the Big Freeze” since it cools down during the expansion.
What would be the fate of the universe if the density of the universe is greater than the critical density?
Gravity would eventually stop the expansion of the universe and end with a “Big Crunch” and perhaps to generate into another “bang”.
Which of the following would scientists say true about most galaxies?
a) They are moving away from each other.
b) They spread evenly throughout space.
c) They consist only of stars.
d) They are held together by electromagnetism.
a) They are moving away from each other.
Globular clusters in our galaxy ___________.
a) are concentrated in the galactic nucleus.
b) are spherically distributed about the galactic center.
c) are present only in our galaxy.
d) are concentrated in spiral arms.
a) are concentrated in the galactic nucleus.
The expansions of the universe was discovered by observing that all galaxies are moving away from us. Who made this discovery?
a) Albert Einstein
b) Johannes Kepler
c) Edwin Hubble
d) Both a & c
c) Edwin Hubble.
In 1929, Edwin Hubble announced that he had measured the speed of galaxies at different distances, and had discovered that the farther they were, the faster they were receding.
Which of the following would scientists say is true about matter in the universe?
a) Matter in the universe started out very uniform and has gotten less uniform with time.
b) The first elements formed in the universe were primarily hydrogen and helium.
c) All the present structure in the universe was formed in the Big Bang.
d) None of the above.
b) The first elements formed in the universe were primarily hydrogen and helium.
