Astro Sfa 105 Ch 17 Beginning Of Time

Front 1

What is the term given to the single moment in time, when all things cam into being?

Back 1

Big Bang

Front 2

T or F
We can see back to the very beginning of time.

Back 2

False

Front 3

Light from distant galaxies shows us what the universe looked like when it was _________ years old.

Back 3

1-2 Billion years old

Front 4

T or F
The universe is filled with a faint glow of radiation that appears to be the remnant heat of the Big Bang.

Back 4

True

Front 5

How old was the universe when it became transparent to light?

Back 5

@ 380,000 years old

Front 6

T or F
Light could pass freely through the universe when it was younger than 380,000 years old.

Back 6

False,
Light could not pass freely through the universe before it was 380,000 years old.

Front 7

T or F
The universe is cooling and becoming less dense as it expands.

Back 7

True

Front 8

T or F
The universe must have been hotter and denser in the past.

Back 8

True

Front 9

T or F
The universe was so hot in its first few seconds that photons could transform themselves into matter, and vice versa.

Back 9

True

Front 10

T or F
Reactions that create and destroy matter occur regularly in the universe.

Back 10

FALSE,
Reactions that create and destroy matter are now relatively rare in the universe.

Front 11

What is the term for the laboratory controlled collision of two photons with a total energy greater than twice the mass-energy of an electron?

Back 11

creation of an electron-antielectron pair

Front 12

What is produced during the creation of an electron-anti-electron pair?

Back 12

2 particles:
1. neg. charged electron; and
2. pos. charged antielectron

Front 13

T or F
An electron is a particle of matter.

Back 13

True

Front 14

T or F
An antielectron is a particle of matter.

Back 14

False,
An antielectron is a particle of ANTIMATTER

Front 15

What happens when an electron and an antielectron collide?

Back 15

They ANNIHILATE each other totally, transforming all their mass-energy back ito photon energy

Front 16

Can reactions produce or destroy any particle-antiparticle pair?

Back 16

Yes

Front 17

Cite another example of the products that can be created in a particle-antiparticle collision?

Back 17

protons and antiprotons

Front 18

What was the early universe filled with?

Back 18

Hot dense blend of:
1. photons
2. matter
3. antimatter

Front 19

List the 4 distinct forces that govern the universe:

Back 19

1. gravity
2. electromagnetism
3. strong force
4. weak force

Front 20

What force provides the glue that holds planets, stars, and galaxies together?

Back 20

Gravity

Front 21

What is the dominant force between particles in atoms and molecules?

Back 21

Electromagnetism

Front 22

T or F
Gravity is stronger than electromangetism on small scales?

Back 22

False
Electromagnetism is stronger than gravity

Front 23

What is electromagnetism dependent on?

Back 23

The electrical charge of a particle instead of its mass

Front 24

What force is responsible for all chemical and biological reactions?

Back 24

Electromagnetism

Front 25

T or F
On large scales, electromagnetism is stronger than gravity.

Back 25

FALSE<
On large scales,
gravity is stronger than electromagnetism.

Front 26

With distance, what happens to gravity and electromagnetism?

Back 26

They become weaker with distance.

Front 27

T or F
Less mass means more gravity.

Back 27

FALSE
MORE mass means more gravity

Front 28

What forces operate only over extremely short distances, making them important within atomic nuclei but not on larger scales?

Back 28

1. strong forces
2. weak forces

Front 29

What force binds atomic nuclei together?

Back 29

Strong force

Front 30

What force plays a crucial role in nuclear reactions such as fission or fusion?

Back 30

Weak force

Front 31

What force is the only force besides gravity that affects weakly interacting particles such as neutrinos or WIMPs?

Back 31

Weak force

Front 32

T or F
Scientists now believe that at the high temps that prevailed in the early universe, the four forces were not so distinct as they are today.

Back 32

True

Front 33

What is the term used to describe the merging together of electromagnetic and weak forces when they lose their seperate identies under conditions of very high temps or energy?

Back 33

Electroweak Force

Front 34

At very high temps what does the electroweak force merge with to form grandunified theories forces?

Back 34

Strong forces

Front 35

What 2 forces can merge together at high temps to form granunified theories forces?

Back 35

Electroweak forces and strong forces

Front 36

What are GUTs?

Back 36

Grandunified theories

Front 37

What is the GUT force?

Back 37

Grandunified theories which are electroweak forces + strong forces

Front 38

T or F
Some scientists believe that at high energies the GUT force and gravity merge into a single "super force"

Back 38

True

Front 39

List the 3 names for theories that link all 4 forces of the universe?

Back 39

1. supersymmetry
2. superstrings
3. supergravity

Front 40

What is the term for time periods of the universe that are distinguished by major change in physical conditions as the universe cooled?

Back 40

Eras

Front 41

What is the name of the era that represents the first
-43
10 second in the history of the universe?

Back 41

Planck Time

Front 42

What was the temp of the universe when it was
-43
10 second old?

Back 42

32
10 K

Front 43

What is the name for the period of time refers to all times prior to the Planck time?

Back 43

Planck era.

Front 44

What forces operated in the universe during the Planck era?

Back 44

One, superforce

Front 45

When did the Planck era end?

Back 45

When the temp dropped below
32
10 K.

Front 46

What happened to the force(s) that operated in the universe when the Planck era ended?

Back 46

Gravity became distinct, and
GUT forces remained merged

Front 47

What is the name of the era that followed the Planck era?

Back 47

GUT era

Front 48

Why is the GUT era so named?

Back 48

GUT force is a unified force representing the merger of the strong, weak, and electromagnetic forces.

Front 49

How long did the GUT era last, temperature wise?

Back 49

Until the universe's temp dropped below

29
10 K

Front 50

When did the universe reach

29
10 K?

Back 50

When the universe was

-38
10 seconds old.

Front 51

How long did the GUT era last?

Back 51

less than a trillion-trillion-trillionth second.

Front 52

Theoretically speaking, what happened with the "freezing out" of strong and electroweak forces at the of the GUT era?

Back 52

Release of enormous amount of energy.......
sudden and dramatic expansion of the universe

Front 53

What is the term used to describe the sudden and dramatic expansion of the universe?

Back 53

Inflation

Front 54

What forces operated at the end of the GUT era?

Back 54

1. gravity
2. strong force
3. electroweak force.

Front 55

What era followed the GUT era?

Back 55

Electroweak Era

Front 56

What 2 forces were still merged during the electroweak era?

Back 56

1. electromagnetic force
2. weak force

Front 57

When did radiation begin to fill all of space?

Back 57

Since the Planck era

Front 58

T or F
Intense radiation filling space spontaneously produced mattera dn antimatter particles.

Back 58

True

Front 59

How old was the universe when its temperature dropped to

15
10 K?

Back 59

When the universe was

-10
10 second old

Front 60

At what temperature is it thought that electromagnetic and weak forces "freeze out" of electroweak forces?

Back 60

15
10 K.

Front 61

What is the name for the particles thought to have pervaded the universe when it was hotter than
15
10 K?

Back 61

Weak bosons

Front 62

What are the 2 types of particles that make up the Weak bosons?

Back 62

W bosons
Z bosons

Front 63

T or F
We have direct experimental evidence concerning the conditions in the universe at the end of the electroweak era.

Back 63

True

Front 64

What is the name for the era that followed the Electroweak era?

Back 64

Particle era

Front 65

Why is the Particle era so named?

Back 65

Because of the role of subatomic particles, and
total number of particles was roughly = total number of photons

Front 66

What particles do we no longer find freely existing in the universe today, but were created by photons?

Back 66

Quarks

Front 67

What are the building blocks of protons and neutrons?

Back 67

Quarks

Front 68

When did the particle era end?

Back 68

When the universe was 0.001 sec.
(1 millisecond)

Front 69

WE conclude that for every 1 billion antiprotons in the early universe, how many protons were there?

Back 69

1 billion + 1 proton

Front 70

What was the result of 1 billion protons and 1 billion antiprotons annihilating each other?

Back 70

1 proton was left

Front 71

T or F
It is thought that some of the protons and neutrons left over from when the universe was 0.001 sec are the very ones that make up our bodies.

Back 71

True

Front 72

What era followed the Particle era?

Back 72

Era of Nucleosynthesis

Front 73

Why was the era of nucleosynthesis so named?

Back 73

It was during the period of time when protons and neutrons were merging into heavier nuclei but temps remained to high, so that the forming nuclei broke apart as fast as they formed.

Front 74

When was most of the helium in the universe made?

Back 74

During the first 5 minutes

Front 75

When did the era of nucleosynthesis end?

Back 75

When the universe was @ 5 minutes old

Front 76

When did the era of nucleosynthesis end?

Back 76

When the universe was 5 minuites old and 9
10 K.

Front 77

What % of the universe was made up of ordinary matter (baryonic) at the end of the era of nucleosynthesis?

Back 77

75%

Front 78

What is the name for hydrogen with a neutron?

Back 78

Deuterium.

Front 79

Describe the universe at the end of the era of nucleosynthesis?

Back 79

A very hot plasma of hydrogen nuclei, helium nuclei, and electrons.

Front 80

How long did the era following the era of nuceosynthesis last?

Back 80

380,000 years

Front 81

What era followed the era of nucleosynthesis?

Back 81

Era of Nuclei

Front 82

T or F
Fully ionized nuclei moved independently of electrons during the era of nuclei.

Back 82

True

Front 83

What happened when a nucleus captured an electron to form a complete atom during the era of nuclei?

Back 83

A photon quickly ionized it.

Front 84

When did the era of nuclei end?

Back 84

When the universe was 380,000 years old and 3,000 K temp.

Front 85

When did the universe become transparent?

Back 85

At the end of the era of nuclei.

Front 86

What followed the era of nuclei?

Back 86

Era of Atoms

Front 87

What is the term for the period of time when the universe consisted of a mixture of neutral atoms and plasm along with a large number of photons?

Back 87

Era of Atoms

Front 88

How long did the era of atoms last?

Back 88

Until the universe was @ 1 billion years old.

Front 89

What era followed the era of atoms?

Back 89

Era of Galaxies

Front 90

What era continues today?

Back 90

Era of Galaxies

Front 91

List the eras in chronological order starting from the very first:

Back 91

1. Planck Era
2. GUT Era
3. Electroweak Era
4. Particle Era
5. Era of Nucleosynthesis
6. Era of Nuclei
7. Era of Atoms
8. Era of Galaxies

Front 92

How many eras have occured during the life of the universe?

Back 92

8 including the one we are in now, the Era of Galaxies.

Front 93

What is the term for the photons arriving at Earth directly fronm the end of the era of nuclei when the universe was about 380,000 years old?

Back 93

Cosmic microwave background

Front 94

Who discovered the cosmic microwave background?

Back 94

Penzias and Wilson

Front 95

What are we observing when we observe the cosmic microwave background?

Back 95

A time when the universe was only 380,000 years old.

Front 96

T or F
When we observe the cosmic microwave background, we are seeing light from the most distant regions of the observable universe, only 380,000 light-years from our cosmological horizon.

Back 96

True

Front 97

T or F
When we observe cosmic microwave background, we are essentially seeing light from only 380,000 light years from our cosmological horizon

Back 97

True

Front 98

T or F
The cosmic microwave background has a perfect thermal radiation spectrum with a peak of 2.73 K.

Back 98

True

Front 99

What was COBE?

Back 99

The Cosmic Background Explorer, a NASA satellite launched in the 1990s, that mapped the temp of the cosmic microwave background in all directions,.

Front 100

T or F
The cosmic microwave background temperature varies slightly from one place to another by a few parts in 100,00

Back 100

True

Front 101

T or F
Neutrons are slightly more massive than protons.

Back 101

True

Front 102

What shut off nuclear fusion before the universe could produce elements much heavier than helium?

Back 102

Rapid cooling, and
Expansion of the early universe

Front 103

Do we know where structure comes from?

Back 103

No, but it could be because of inflation

Front 104

Do we know why the large scale universe is so uniform?

Back 104

No. But it could be because of inflation

Front 105

Do we know why the density of the universe close to critical density?

Back 105

No.bUT it could be because of inflation

Front 106

T or F
Einstein's general theory of relativity tell us that gravity can curve the structure of spacetime.

Back 106

True

Front 107

What are the 3 categories of shape that scientists think that the universe is in:

Back 107

1. spherical or closed
2. flat - or critical
3. saddle-shaped or open

Front 108

What is a closed shape?

Back 108

Spherical

Front 109

What is a critical shape?

Back 109

flat

Front 110

What is an open shape?

Back 110

saddle-shaped

Front 111

What would be the shape of the universe of the matter density of the universe were precisely equal to the critical density?

Back 111

Flat

Front 112

Based on an analysis of the temp observed in the cosmic microwave background, what is theorized about the shape of the universe?

Back 112

That the overall geometry is flat, implying that the total mass-energy of the universe must be equivalent to the critical density.

Front 113

Based on an analysis of the temp observed in the cosmic microwave background, what is theorized about the total measurements of the masses of the universe?

Back 113

Total matter density = 26% critical density;
Extraordinary dark matter = 22% critical density

Front 114

What 2 theorized characteristics of the universe imply the existence of a repulsive "dark energy" that currently accelerates the expansion?

Back 114

1. flat geometry
2. matter density lower than critical density

Front 115

What is the essence of the idea of Olbers' paradox?

Back 115

Either:
1. the number of stars is finite, or
2. the universe changes in a way that prevents us from seeing an infinite number of them.

Front 116

T or F
Kepler believed that the universe had a finite numbers of stars because he thought it had to be finite in space, with some kind of dark wall surrounding everthing.

Back 116

True

Front 117

T or F
Galaxies fill all of space more or less uniformly.

Back 117

True

Front 118

At what age are we seeing the universe by observing the cosmic microwave background?

Back 118

380,000 years old.