Big Bang Theory

Question 1

What is the space hierarchy?

Answer 1

UNIVERSE - GALAXIES - SOLAR SYSTEMS - PLANETS - dwarf planets, moon, asteroid, meteor, space debris

Question 2

What is a Heliocentric solar system?

Answer 2

Sun (Sol) is at the centre, Sun is orbited by 8 planets, There are 5 dwarf planets. EARTH IS IN THE SOLAR SYSTEM IN MILKY WAY - GALAXY

Question 3

What makes a planet?

Answer 3

-Orbits the host star
-Be mostly round
-Be big enough that its gravity cleared away all other objects of similar size near its orbit around the sun

Question 4

How are moons and natural satellites classified?

Answer 4

Objects are classified as moons if they orbit a planet, rather than the sun. They are also known as natural satellites.

Question 5

What is the relationship between stars, solar systems, galaxies and universe?

Answer 5

There are millions of stars in a galaxy, including our star, the Sun, which is part of the Milky Way Galaxy. The Sun is surrounded by celestial bodies such as planets and moons that orbit it, forming the solar system with the Sun at its center. Each star in a galaxy may have its own solar system with orbiting planets and moons, contributing to the vastness of galaxies in the universe. HEIRARCHY - STAR - SS - GALAXY AND UNIVERSE

Question 6

What is the universe?

Answer 6

The universe is everything. It includes all of space, and all the matter and energy that space contains. It contains EVERYTHING!

Question 7

What is a galaxy?

Answer 7

Galaxies are concentrations of stars, gas, dust, and dark matter held together by gravity.

Question 8

What are the three main categories of galaxies?

Answer 8

There are three major categories of shapes: elliptical, spiral and irregular.
(PPT 6.1)

Question 9

What galaxy type is the milky way?

Answer 9

Our galaxy is known as the Milky Way and it is a spiral galaxy

Question 10

How many galaxies are there and what do they contain in the middle?

Answer 10

The Milky Way is but one of billions of galaxies in the observable universe — all of them, including our own, are thought to have supermassive black holes at their centers
A black hole is an area of such immense gravity that nothing – not even light – can escape from it.

Question 11

What are constellations?

Answer 11

Patterns of stars in the sky that are used for navigation, storytelling, and astronomical organization, helping to divide the sky into regions for easier identification.

Question 12

What are the current constellations?

Answer 12

Astronomers divide the sky into 88 current official constellations to map and identify stars and celestial objects. AREA IN THE SKY

Question 13

What is a dwarf planet?

Answer 13

A dwarf planet is a celestial body that orbits the Sun, is nearly spherical in shape, but lacks the gravitational force to clear smaller objects from its orbital path, meaning debris and other objects share its orbit.

Question 14

What is AU (astronomical unit)?

Answer 14

AU is a standardized unit for distance in space, it is the distance from the earth to the sun. 1AU = 150MIL or 149.6mil meters (ASK ABOUT PARALLAX)

Question 15

What is a light year and how do we calculate distances with it?

Answer 15

A light-year is the distance light travels in one year, not a measure of time. It equals approximately
9.5 * 10^12 km (9.5 trillion kilometers). The speed of light is constant, 300,000km/s

Question 16

What happens at the birth of a star?

Answer 16

All stars begin as collection of dust and gas called a nebula. When the dust and gas is dense enough gravity takes over and the gas and dust collapses, forming a cloud. This dense cloud is now called a protostar. The temperature of a protostar is not high enough for any reactions to occur, but with the increasing pressure, there is an increase in temperature.
Once they are high enough….nuclear fusion occurs!

Question 17

What is nuclear fusion?

Answer 17

Nuclear fusion is where 2 isotopes of hydrogen (deuterium and tritium) combine to form Helium, along with the release of a neutron and energy (in the form of immense amounts of heat and light).

Question 18

What is apparent magnitude?

Answer 18

Brightness of a star as seen from earth, Scale ranges from -30 (brightest) to +30 (dimmest).

Question 19

What is absolute magnitude?

Answer 19

The absolute magnitude of a star is a measure of its actual brightness (intrinsic luminosity) as if it were placed at a standard distance of 10 parsecs (32.6 light-years) from Earth. It does not depend on the star’s actual distance from Earth. Absolute magnitude is used along with a star’s temperature to determine its classification, where red stars are cooler and blue/white stars are hotter.

Question 20

What is the star spectra (spectrum)?

Answer 20

The star spectra is the light from a star split into its different colors (spectrum). The dark lines in the spectrum show the specific wavelengths of light absorbed by the elements in the star’s atmosphere. By analyzing these lines, scientists can determine the star’s composition.

Question 21

What is red shift (relation to star spectra)?

Answer 21

For stars, redshift occurs when the star is moving away from the observer, causing its light to shift toward the red end of the spectrum (longer wavelengths, lower frequencies). This shift in spectral lines helps astronomers measure the star’s motion and distance relative to Earth.

Question 22

What is blue shift (relation to star spectra)?

Answer 22

For stars, blueshift occurs when the star is moving toward the observer, causing its light to shift toward the blue end of the spectrum (shorter wavelengths, higher frequencies). This shift in spectral lines helps astronomers measure the star’s motion relative to Earth.

Question 23

What is the doppler effect?

Answer 23

The Doppler Effect is the change in the frequency and wavelength of light caused by the motion of a star or galaxy relative to the observer. When the object moves toward the observer, the light waves are compressed (shorter wavelength, higher frequency), causing a blueshift. When the object moves away, the light waves are stretched (longer wavelength, lower frequency), causing a redshift. This effect helps astronomers study the motion and distance of stars and galaxies.

Question 24

What is Hubble’s Law?

Answer 24

In 1929, Edwin Hubble discovered that most galaxies are moving away from Earth. He observed that the farther a galaxy is, the greater its redshift and the faster it is moving away. This relationship proved that the universe is expanding and became the basis of Hubble’s Law.

Question 25

What is the expanding universe theory and how is it supported?

Answer 25

Scientists explain the movement of most objects away from each other in the universe through the expansion of space. As empty space increases, it stretches the distance between objects, similar to how the surface of a balloon stretches as it is inflated. The farther apart two objects are, the more space there is between them, and the faster they appear to move apart.

Question 26

What is a Herzsprung - Russell diagram - hr diagram?

Answer 26

The Hertzsprung–Russell diagram, or HR diagram, is a scatter plot of stars showing the relationship between the stars’ absolute magnitudes or luminosities versus their stellar classifications or effective temperatures. Y AXIS - ABSOLUTE, X - NORMALLY TEMP ON SURFACE

Question 27

What is luminosity?

Answer 27

Luminosity is an absolute measure of radiated electromagnetic power (light), the radiant power emitted by a light-emitting object. In astronomy, values for luminosity are often given in the terms of the luminosity of the Sun, L⊙

Question 28

What is the death of the star?

Answer 28

The death of a star refers to the final stages of its life cycle after it has used up its nuclear fuel. Stars undergo radical changes during their lifetime, which depend on their mass. Massive stars live only a few million years, while smaller stars can last for trillions of years. The size and color of a star indicate its mass, stage of life, and how it will eventually die. For example, an average star like the Sun ends as a white dwarf, while massive stars explode as supernovae and become neutron stars or black holes.

Question 29

What are the 2 main theories for the universe’s existence?

Answer 29

Big bang theory (BBT) and Steady state theory (SST)

Question 30

What is the similarity in both?

Answer 30

They both support the theory that the universe is expanding.

Question 31

What is the Big bang theory (BBT)?

Answer 31

The universe began around 15 billion years ago with the Big Bang, originating from a single point called a singularity. As the universe expanded, tiny particles like positrons and electrons collided, creating light energy, and later formed protons and neutrons. Hydrogen, Helium, and Lithium emerged, and as the universe cooled to about 3000°C, these elements captured electrons, forming the first atoms and allowing light to escape. Gravity pulled these elements together, igniting nuclear fusion and creating the first stars. Surrounding clouds of matter cooled and clumped, forming the first planets. Over time, galaxies formed in regions where gravity was stronger, pulling matter together.

Question 32

What is the steady state theory (SST)?

Answer 32

The universe has no beginning and no end.
The space between galaxies remains constant because as the universe expands there is a continuous creation of new stars and galaxies to replace the old and unobservable ones

Question 33

What are the key differences between big bang theory and steady state theory (BBT VS SST)?

Answer 33

The Big Bang Theory suggests the universe has a finite beginning and evolves over time, while the Steady State Theory proposes the universe has always existed in a constant, unchanging state, with continuous creation of new matter balancing its expansion.

Question 34

What are the 4 evidences for BBT?

Answer 34

‘red shift’, ‘einsteins eqn’, ‘cosmic microwave background radiation’ and ‘the elements present’

Question 35

What is the supporting evidence of ‘the red shift’ mean?

Answer 35

The discovery of the red shift of light provides evidence for an expanding universe, which supports the BBT.

Question 36

What is the supporting evidence of ‘the elements’ mean?

Answer 36

The vast amounts of hydrogen and helium in the Universe supports the BBT.
Steady State Theory (SST) suggests that Helium is only made via the Nuclear fusion in stars, but with 8.7% of atoms in the Universe being Helium, which is much more than can be produced by stars, this disproves SST. The high percentage of Helium atoms can be explained by the big bang theory

Question 37

What is the supporting evidence of ‘the Cosmic Microwave Background Radiation’ mean?

Answer 37

CMB is faint heat radiation left over from the Big Bang. It proves the universe was once hot and dense, as predicted by the Big Bang Theory. Over time, the universe cooled as it expanded, leaving radiation near absolute zero (-270°C). The discovery of CMB supports the Big Bang by confirming the universe’s cooling and expansion over billions of years.

Question 38

What is the supporting evidence of ‘einstein’s equation’ mean?

Answer 38

A flaw in the Big Bang Theory was the question of how matter could come from nothing. Einstein’s equation,
𝐸
=
𝑚
𝑐
2
E=mc
2
, showed that energy can be converted into matter, and vice versa, providing a scientific basis for the creation of matter after the Big Bang. This made the theory more plausible.

Question 39

What is the James Webb telescope?

Answer 39

The James Webb Space Telescope is an advanced infrared observatory telescope. Its powerful capabilities allow it to explore the universe’s history, including galaxy and planet formation, and may indirectly provide evidence of dark matter.

Question 40

What is the importance of the International space station (ISS)?

Answer 40

The primary purpose of the ISS was to provide space laboratories for studying the effects of gravity in space. It also provides the opportunity to investigate the effect of a space environment on humans.

Question 41

What is a black hole?

Answer 41

A black hole is a region in space where the pulling force of gravity is so strong that light is not able to escape. The strong gravity occurs because matter has been pressed into a tiny space. This compression can take place at the end of a star’s life. Some black holes are a result of dying stars.
Because no light can escape, black holes are invisible.

Question 42

How are stellar black holes formed (death of star)?

Answer 42

Stellar black holes form when the centre of a very massive star collapses in upon itself.

Question 43

What is dark matter?

Answer 43

Dark matter is an invisible form of matter that makes up most of the universe and is detected only through its gravitational effects.

Question 44

What are the 2 hydrogen isotopes that are involved in nuclear fusion?

Answer 44

Deuterium (Hydrogen-2) and Tritium (Hydrogen-3)

Question 45

Name the normal (average-mass) star life cycle timeline.

Answer 45

Stellular nebula, main sequence, Dying star - red giant, planetary nebula, white dwarf, black dwarf

Question 46

Name the supermassive star life cycle timeline.

Answer 46

Stellar nebula, massive main sequence, red supergiant, supernova, neutron star of black hole

Question 47

What are the 2 main types of stars?

Answer 47

Average-mass stars (normal) end as white dwarfs. (up to 8xmass of sun)
Massive stars end as either neutron stars or black holes after a supernova explosion. (>8x mass of sun)

Question 48

What is the parallax effect?

Answer 48

The parallax effect is the apparent shift in the position of a nearby object compared to distant objects when viewed from different angles. In astronomy, it’s used to measure the distance to stars by observing them from different points in Earth’s orbit around the Sun.

thumb - close 1 eye than other distance is diff but same yk:

Scientists measure a star’s distance using this parallax angle,