Deck 13: Interstellar Travel and the Fermi Paradox

Question 1

Nuclear fusion is the process by which

A) electrons are rearranged inside an atom, releasing energy
B) a number of smaller nuclei combine to form a larger nucleus with the release of energy
C) an electron is ejected from the nucleus of an atom, releasing energy
D) large nuclei break up into smaller nuclei with the release of energy

Answer 1

a number of smaller nuclei combine to form a larger nucleus with the release of energy

Question 2

The maximum terminal velocity we could accelerate a chemical rocket to (assuming using 100 stages!) is approximately

A) 50 % of the speed of light
B) 0.001 % of the speed of light
C) 0.1 % of the speed of light
D) 10 % of the speed of light

Answer 2

0.1 % of the speed of light

Question 3

What kind of message from Earth was carried by the Pioneer probes?

A) a gold-coated copper record
B) a plaque
C) a DVD
D) a VHS tape

Answer 3

a plaque

Question 4

Traveling at their current speeds, how long will it take the Pioneer and Voyager probes to reach the nearest stars?

A) at least 100,000 years
B) several billion years
C) around 4.4 years
D) about a 1,000 years

Question 5

What kind of message from Earth was carried by the Voyager probes?

A) a gold-coated copper record
B) a plaque
C) a DVD
D) a VHS tape

Question 6

In order to get large payloads into space using chemical rockets,

A) multiple rocket stages are necessary
B) extremely large single-staged rockets must be used
C) very lightweight rockets
D) rockets must be launched from the tops of tall mountains

Question 7

Which of the following is not a difficulty associated with interstellar travel?

A) the large distances between the stars
B) the speed of light being the fastest possible speed we can travel
C) the enormous amount of energy required to accelerate any ship to high speed
D) all three of the above are difficulties

Question 8

What mass ratio is required to launch a rocket from the surface of Mars (escape velocity = 5.0 km/s) if its engines produce an exhaust velocity of 3.0 km/s?

A) 1.8
B) 5.3
C) 6.9
D) 7.4

Question 9

The rocket equation relates the final velocity of a chemical rocket to

A) the mass of its payload
B) the velocity of its exhaust gases and the ratio of the mass of the rocket with all its fuel to the mass of the rocket after all its fuel has been consumed
C) the escape velocity of the Earth
D) the velocity of its exhaust gases and mass of the rocket before launch

Question 10

During the nuclear fission of uranium, what percentage of the original mass of the uranium is converted into energy?

A) 0.7%
B) 0.07%
C) 70%
D) 100%

Question 11

According to Einstein's Special Theory of Relativity, it is not possible to travel

A) faster than 75 % of the speed of light
B) slower than 1 % of the speed of light
C) faster than 90 % of the speed of light
D) at or faster than the speed of light

Question 12

Nuclear fission is the process by which

A) a number of smaller nuclei combine to form a larger nucleus with the release of energy
B) electrons are rearranged inside an atom, releasing energy
C) an electron is ejected from the nucleus of an atom, releasing energy
D) large nuclei break up into smaller nuclei with the release of energy

Question 13

In the nuclear fusion of four hydrogen nuclei to form a helium nucleus, the resultant helium nucleus

A) is more massive than the four hydrogen nuclei, the missing mass being converted into energy
B) is radioactive, generating energy by ejected electrons from beta decay
C) is less massive than the four hydrogen nuclei, the missing mass being converted into energy
D) has exactly the same mass as the four hydrogen nuclei, the energy being generated by the helium nucleus rearranging itself by emitting a gamma ray

Question 14

Approximately what mass ratio is required for a rocket to leave the Earth's gravity?

A) 60
B) 99
C) 25
D) 39

Question 15

The Earth's escape velocity is defined to be the

A) minimum orbital speed for the Moon to escape from the Earth's gravity
B) minimum orbital speed for the Earth to escape from the Sun's gravity
C) minimum velocity required for an object to escape the Earth's gravity
D) velocity that objects are pulled toward the Earth's surface by gravity

Question 16

The energy required to accelerate a ship the mass of an ocean liner to a cruising speed of 10% of the speed of light is approximately

A) one million times the Earth's current annual energy usage
B) one hundred times the Earth's current annual energy usage
C) equal to the Earth's current annual energy usage
D) ten times the Earth's current annual energy usage

Question 17

The energy required to accelerate an interstellar spaceship depends on

A) its mass only
B) its final velocity only
C) the type of fuel it uses
D) its mass and final velocity

Question 18

Chemical rockets work on which basic physical principle?

A) Kepler's first law of planetary motion
B) Einstein's special theory of relativity
C) Newton's third law of motion
D) the law of conservation of energy

Question 19

Which is the most common type of spacecraft propulsion used today?

A) solar sails
B) nuclear rockets
C) ion engines
D) chemical rockets

Question 20

The mass ratio of a rocket is defined to be the

A) mass of the empty rocket without fuel divided by the mass of the payload
B) mass of the fully fueled rocket divided by the mass of the rocket after the fuel is burned
C) mass of the rocket after the fuel is burned divided by the mass of the fully fueled rocket
D) mass of the fuel in the rocket divided by the mass of the rocket payload

Question 21

A solar sail could conceivably be accelerated out into space using

A) light reflected from the Earth
B) starlight from the Milky Way
C) a giant wind machine constructed in orbit around the Earth
D) a powerful laser on Earth

Question 22

Which type of spacecraft does not need to carry any fuel?

A) nuclear rockets
B) ion engines
C) solar sails
D) chemical rockets

Question 23

An antihydrogen atom would consist of

A) a proton and a positron
B) a proton and an antielectron
C) an antiproton and a positron
D) an antiproton and an antielectron

Question 24

During the nuclear fusion of hydrogen to helium in the core of our Sun, what percentage of the original mass of the hydrogen is converted into energy?

A) 0.7%
B) 0.07%
C) 70%
D) 100%

Question 25

Compared to a chemical rocket, an ion engine has a

A) smaller thrust but can be operated for a longer time period
B) smaller thrust and can only be operated for a shorter time period
C) larger thrust and can be operated for a longer time period
D) larger thrust but can only be operated for a shorter time period

Question 26

When an electron collides with a positron the two particles

A) fuse to form a heavier particle
B) bounce off each other
C) are destroyed, producing a pair of high-energy gamma rays
D) are destroyed, producing another pair of particles

Question 27

The observed slowing down of time predicted by Einstein's Special Theory of Relativity for an object traveling close to the speed of light is referred to as

A) time dilation
B) time expansion
C) a time warp
D) time contraction

Question 28

Which kind of interstellar spacecraft would require the crew to be placed in suspended animation, perhaps for thousands of years?

A) solar sail
B) interstellar ark
C) matter-antimatter rocket
D) nuclear rocket

Question 29

The Project Daedalus starship designed by the British Interplanetary Society in the 1970s was propelled by

A) chemical rockets
B) nuclear fusion reactors
C) nuclear fission reactors
D) the annihilation of matter and antimatter

Question 30

Consider a spacecraft that travels round-trip to the zeta reticuli star system (distance 39.5 light-years) at 99% of the speed of light. If the round-trip travel time as measured from Earth is 79.8 years, how much time would pass for passengers on the spacecraft?

A) 39.9 years
B) 79.8 years
C) 22.6 years
D) 11.3 years

Question 31

The Luyten 726-8 binary system is approximately 9 light-years away. If we send a spacecraft to visit this system traveling at 90% of the speed of light, how long will a one-way trip take as measured from the Earth?

A) it's impossible to tell unless we know the spacecraft's method of propulsion
B) more than 10 years
C) 10 years
D) less than 10 years

Question 32

The ultimate speed of a solar-sail-propelled spacecraft is limited by the

A) low energy photons that the Sun produces
B) gravitational force of the Sun
C) fact that the intensity of sunlight falls off rapidly with distance
D) mass of the spacecraft

Question 33

Bert and Ernie are two friends of the same age. Bert visits a nearby star system on a spaceship that travels close to the speed of light while Ernie stays at home. Which of the following will be true on Bert's return to Earth?

A) Ernie will be younger than Bert
B) Ernie will be older than Bert
C) Bert and Ernie will still be the same age
D) Ernie will not have been born

Question 34

Particles of matter and antimatter have the

A) same charge and mass
B) same charge but different mass
C) different charge and mass
D) same mass but opposite charge

Question 35

The antimatter equivalent of an electron is called

A) a positron
B) an antielectron
C) a posielectron
D) a cation electron

Question 36

In order for a solar sail spacecraft to be accelerated to speeds high enough to accomplish interstellar travel in a reasonable amount of time, it would need to be started

A) from a lunar orbit where the gravity is weaker
B) close to Earth using mirrors on the surface to reflect sunlight onto the sails
C) far from the Sun so Jupiter could be used to help it on its way using a gravitational assist
D) close to the Sun where the radiation pressure is higher

Question 37

What is the name of the research program at the Los Alamos Science Laboratory that started to develop a design for an interstellar ship propelled by small hydrogen-bombs?

A) Project Blue Book
B) Project Orion
C) The Alan Parsons Project
D) Project Rover

Question 38

The antimatter equivalent of a proton is called

A) a positron
B) an antiproton
C) a negiproton
D) an anion proton

Question 39

What is the name of the research program in the 1950s that started to develop nuclear fission reactors that could be flown in rockets?

A) Project Blue Book
B) Project Orion
C) The Alan Parsons Project
D) Project Rover

Question 40

The maximum terminal velocity we could accelerate a nuclear rocket to is approximately

A) 50 % of the speed of light
B) 0.001 % of the speed of light
C) 0.1 % of the speed of light
D) 10 % of the speed of light

Question 41

The main practical problem associated with building an interstellar ramjet is

A) making the ship large enough to scoop up enough hydrogen fuel given that the density of hydrogen in space is so low
B) producing enough thrust to accelerate the spacecraft to a high enough speed
C) separating the matter and antimatter fuels from each other
D) receiving enough photon energy to propel the craft

Question 42

Given how many times intelligent civilizations could have appeared over the universe's history, it is most likely that if other civilizations exist, they will

A) be slightly less advanced than us
B) be much less advanced than us
C) have about the same level of technology as us
D) be much more advanced than us

Question 43

A possible design of a "warp drive" might involve

A) generating a shortcut between two distant parts of the universe through a black hole
B) placing a movable massive object like a black hole in front of a spacecraft and using its gravity to shorten the spatial distances in front of the rocket
C) using the annihilation of matter and antimatter to accelerate a spacecraft close to the speed of light
D) generating a shortcut between two distant parts of the universe through hyperspace

Question 44

Von Neumann machines are hypothetical

A) self-replicating probes sent out to explore the galaxy by an advanced civilization
B) devices capable of creating wormholes
C) devices capable of time travel
D) spacecraft capable of traveling faster than the speed of light

Question 45

A wormhole is a

A) passageway to a parallel universe through a black hole
B) shortcut between two distant parts of the universe through hyperspace
C) shortcut between two distant parts of the universe through a black hole
D) way of traveling faster than the speed of light

Question 46

In Einstein's General Theory of Relativity, spacetime is

A) one dimensional
B) two dimensional
C) four dimensional
D) three dimensional

Question 47

How is the "Fermi Paradox" normally stated?

A) Why are we here?
B) Who are we?
C) Where are we?
D) Where is everybody?

Question 48

Einstein's General Theory of Relativity tells us that a photon traveling close to a massive object will

A) travel in a straight line past the object
B) follow the curvature of spacetime around the object
C) be reflected by the object
D) be absorbed by the object

Question 49

In principle, we could accelerate a matter-antimatter rocket to approximately

A) 90 % of the speed of light
B) 50 % of the speed of light
C) 30 % of the speed of light
D) 100 % of the speed of light

Question 50

Which kind of spacecraft collects its fuel during its passage?

A) interstellar ark
B) matter-antimatter rocket
C) solar sail
D) interstellar ramjet

Question 51

Which of the following is not a solution to the Fermi Paradox?

A) no one is interested or able to communicate
B) we are unable to detect their communications
C) we are not interested in communicating
D) no one is out there

Question 52

The idea that other civilizations are aware of our existence but have deliberately chosen to hide from us is referred to as the

A) zoo hypothesis
B) conspiracy hypothesis
C) sentinel hypothesis
D) UFO hypothesis

Question 53

Which of the following represents a challenge in using antimatter as fuel for an interstellar spacecraft?

A) generating the enormous amount of energy needed to produce it
B) the problem of safely storing it
C) how to make sufficiently large quantities of it
D) all of the above represent significant challenges

Question 54

In Einstein's General Theory of Relativity, higher dimensions beyond the three that we can comprehend are called

A) hidden space
B) hyperspace
C) excited space
D) extra space

Question 55

When an electron collides with a positron producing a pair of high gamma rays, we call this process

A) pair production
B) matter obliteration
C) photodisintegration
D) annihilation

Question 56

In the "Coral Model" of galactic colonization, if we assume that colonizing ships can travel at a few percent of the speed of light, then we might expect all of the habitable planets in the galaxy to be colonized within a few

A) tens of billions of years
B) billion of years
C) hundred thousand years
D) tens of millions of years

Question 57

During the annihilation of matter and antimatter, what percentage of the mass of the colliding particles is converted into energy?

A) 0.7%
B) 0.07%
C) 70%
D) 100%

Question 58

If we imagine that 1 in 10 million stars would eventually give rise to a civilization on an orbiting planet and assuming that there are 100 billion stars in our Milky Way galaxy, how often should a civilization randomly appear over a 5 billion year period?

A) once every 50 million years
B) once every 50,000 years
C) once every 500,000 years
D) once every 5 million years

Question 59

What might we expect to be a possible motivation for human beings to eventually colonize other star systems?

A) the rapid rise of the human population
B) depletion of natural resources
C) natural curiosity
D) all of the above might be motivators

Question 60

Based on human history, the likelihood that we will eventually colonize other habitable planets in our galaxy is

A) impossible to predict
B) high
C) zero
D) low

Question 61

You are traveling in a space ship at half the speed of light (0.5c) directly toward an oncoming photon traveling at the speed of light (c). At what speed would you see the photon coming toward you?

A) c
B) 0.25c
C) 1.5c
D) 0.5c

Question 62

The theory of relativity predicts that everything in the universe

A) is relative except the laws of physics, which are absolutes
B) is relative except the speed of light, which is an absolute
C) is relative, there are no absolutes
D) is relative except the laws of physics and the speed of light, which are absolutes

Question 63

If we accelerate a radioactive isotope of an element in a particle accelerator to a speed close to that of light, what would its observed mass be compared to its mass at rest?

A) higher
B) infinite
C) zero
D) lower

Question 64

One piece of evidence that proves that the speed of light is indeed constant comes from the observation

A) that the light from the stars in a binary system is smeared out by their mutual motion
B) that the light from the stars in binary system is Doppler shifted by their mutual motion
C) of gravitational waves emitted from binary systems
D) that stars in a binary system appear as distinct points of light

Question 65

If we accelerate a radioactive isotope of an element in a particle accelerator to a speed close to that of light, what would its observed rate of decay be compared to its rate of decay at rest?

A) faster
B) slower
C) infinite
D) zero

Question 66

The idea that other civilizations are waiting for us to reach a certain technological level before revealing themselves to us is referred to as the

A) conspiracy hypothesis
B) UFO hypothesis
C) sentinel hypothesis
D) zoo hypothesis