The Universe

Question 1

The Universe

How old is the universe?

(I.e. how long ago was the Big Bang)?

Answer 1

13.8 billion years

Question 2

The Universe

What is the diameter of the visible universe (as of 2020)?

Answer 2

93 billion light-years

Question 3

The Universe

How long after the Big Bang (13.8 billion years ago) did the first stars begin to form?

Answer 3

400 million years

Question 4

The Universe

Just after the Big Bang, the universe was an expanding ‘soup’ of what?

Answer 4

Subatomic particles

(e.g. quarks and leptons)

Question 5

The Universe

Stars form as cooling condensations of what (under the influence of dark matter)?

Answer 5

Hydrogen, helium, and lithium

Question 6

The Universe

If stars are condensations of hydrogen, helium, and lithium, from where do we get the heavier elements?

Answer 6

Star cores, collapsing stars, supernovae

(compressed/formed via pressure and heat; then, seeded out to the universe when the stars die)

Question 7

The Universe

What is the theory of the ‘heat death of the universe?’

Answer 7

The end of the universe: continual expansion for trillions of years as the expanding elements’ temperature approaches absolute zero

Question 8

The Universe

The initial ‘state’ of the universe lasted a tiny fraction of a second at which point all matter was condensed into a tiny point. This moment is called what?

Answer 8

The Planck Epoch

Question 9

The Universe

The initial “glow” of the Big Bang can be seen throughout space today observed as what?

Answer 9

Cosmic microwave background radiation

Question 10

The Universe

True/False.

The expansion of the universe is decelerating.

Answer 10

False.

The expansion of the universe is accelerating.

Question 11

The Universe

What is causing the acceleration of the universe expansion?

Answer 11

Dark energy

Question 12

The Universe

Is there more matter or antimatter in the universe (or are they equal?)?

Answer 12

Matter

(If they were equal, they would just cancel one another out into photons.)

Question 13

The Universe

From where does the cosmic microwave background radiation we observe in the universe come?

Answer 13

The initial “glow” of the Big Bang

Question 14

The Universe

Name three fundamental physical constants which are highly ‘fine-tuned’ to our universe being able to form matter.

Answer 14

The speed of light;

the Planck constant;

the elementary charge

Question 15

The Universe

Protons and neutrons are made up of what smaller particles?

Answer 15

Quarks

Question 16

The Universe

What is the closest spiral galaxy to ours?

Answer 16

The Andromeda galaxy

(which is currently hurtling towards us)

Question 17

The Universe

What is the closest star/planetary system to ours?

Answer 17

Alpha-Centauri

Question 18

The Universe

What is at the center of the Milky Way galaxy?

Answer 18

A supermassive black hole

(Sagittarius A)

Question 19

The Universe

In order from closest to furthest from the sun, name the four terrestrial planets of our solar system.

Answer 19

Mercury; Venus; Earth; Mars

Question 20

The Universe

In order from closest to furthest from the sun, name the two gas giants of our solar system.

Answer 20

Jupiter; Saturn

Question 21

The Universe

In order from closest to furthest from the sun, name the two ice giants of our solar system.

Answer 21

Uranus; Neptune

Question 22

The Universe

True/False.

The planetary paths of our solar system all lie in a nearly flat disc called the ecliptic.

Answer 22

True.

Question 23

The Universe

Why did our solar system (and many like it) form with its planets in a fairly flat plane?

Answer 23

Young stars often form with protoplanetery disks (circumstellar disks) of gas and dust

(these are a form of _accretion disc_)

Question 24

The Universe

The asteroid belt within our solar system is found where?

Answer 24

Between Mars and Jupiter

Question 25

# The Universe What is the Kuiper belt?

Answer 25

A massive, massive ring of asteroids surrounding our solar system ## Footnote *(It is just outide Neptune's orbit; it is 20x wider than the asteroid belt and 100x mrore massive.)*

Question 26

# The Universe What is the oort cloud?

Answer 26

A massive, massive cloud of icy structures which surround our solar system and represent the limits of the sun's gravitational influence

Question 27

# The Universe The ________ \_\_\_\_\_\_\_\_s (in the context of the Fermi Paradox) are a series of potential barriers that may explain why we have not identified life in the universe.

Answer 27

The **_great_** **_filter_**s (in the context of the Fermi Paradox) are a series of potential barriers that may explain why we have not identified life in the universe. ## Footnote *(I.e., at least one of the steps listed in the attached image must be incredibly unlikely to actually occur.)*

Question 28

# The Universe What kind of star is our sun?

Answer 28

A white dwarf

Question 29

# The Universe How long from now will our star turn into a red giant, rendering the earth uninhabitable?

Answer 29

5 billion years

Question 30

# The Universe What does it mean if something is redshifted relative to us?

Answer 30

We are moving away from one another in space

Question 31

# The Universe What does it mean if something is blueshifted relative to us?

Answer 31

We are moving toward one another in space

Question 32

# The Universe **True/False**. In a section of the vacuum of space, there is no 'true' vacuum as some level of energy is almost always present (this leads to the rise of virtual particles, even for a short time).

Answer 32

**True**. * (Note 1: Space is a vacuum, not a* **_void_***!)* * (Note 2: Not to mention the effects of dark matter/energy.)*

Question 33

# The Universe The _____________ is a group of principles attempting to determine how statistically probable our observations of the universe are, ***given that we could only exist in a particular type of universe to start with***. (I.e. is our universe 'fine-tuned' for telological reasons, or do we as carbon-based creatures see it as 'fine-tuned' simply because we exist and this is the only way we could exist?)

Answer 33

The **_anthropic principle_** is a group of principles attempting to determine how statistically probable our observations of the universe are, ***given that we could only exist in a particular type of universe to start with***​. (I.e. is our universe 'fine-tuned' for telological reasons, or do we as carbon-based creatures see it as 'fine-tuned' simply because we exist and this is the only way we could exist?)

Question 34

# The Universe What is the name of the equation put together to give a rough range (based off a number of conjectural estimates) of how many active, communicative civilizations are extant in the Milky Way galaxy?

Answer 34

The **Drake Equation**

Question 35

# The Universe Name some of the factors represented in the Drake equation (which attempts to identify *N*, the number of active, communicative civilizations within the Milky Way galaxy)?

Answer 35

*N* = the average **rate of star formation** \* the fraction of **those stars that have planets** \* the average number of **planets that can potentially support life** (per star that has planets) \* the fraction of **those** **that** **develop life at some point** \* the fraction of **those that develop intelligent civilizations** \* the fraction of **those that develop a technology that releases detectable signs of their existence into space** \* the **length of time** for which such civilizations **release detectable signals** into space

Question 36

# The Universe What is the Fermi paradox?

Answer 36

The contradiction between the **lack of evidence** and the **high probability** **estimates** for **_existence of extraterrestrial civilizations_**

Question 37

# The Universe What is Kepler's first law of planetary motion?

Answer 37

The orbit of any planet is an ellipse with the sun at one of the ellipse foci

Question 38

# The Universe **True/False**. Planetary motion is near circular in regards to the sun, with the sun at the center of the circular route.

Answer 38

**False**. Planetary motion is elliptical in regards to the sun, with the sun at one of the two foci of the ellipse.

Question 39

# The Universe Kepler's second law of planetary motion is that basically that a line between the sun and the planet sweeps an equal area of space in equal amounts of time. ## Footnote **What does this mean in practical effect?**

Answer 39

The planets must speed up when they are near the sun

Question 40

# The Universe What is Kepler's third law of planetary motion?

Answer 40

A planet's orbital time squared is equal to its average distance from the sun cubed **P**_OrbitalTime**² = A**_{DistanceToSun}**³**