Deck 13: Interstellar Travel and the Fermi Paradox

Question 1

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

Answer 1

5.3

Question 2

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

Answer 2

minimum velocity required for an object to escape the Earth's gravity

Question 3

What was the main difference between the time capsules carried on the Pioneer probes and the time capsules carried on the Voyager probes?

A) no difference, the time capsules were identical
B) the time capsule on Voyager contained a record with video and audio messages
C) the time capsule on Pioneer contained a record with video and audio messages
D) the time capsule on Voyager contained video, but no audio

Answer 3

the time capsule on Voyager contained a record with video and audio messages

Question 4

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 5

The Voyager probes carry what kind of physical time capsule?

A) a small engraved plaque
B) a gold-plated record containing pictures, multilingual greetings and music
C) a DVD containing pictures
D) these probes do not carry a physical time capsule

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

Who started launching liquid-filled rockets in the United States in 1926?

A) Robert Goddard
B) Konstantin Tsiolkovsky
C) Hermann Oberth
D) Wernher von Braun

Question 8

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

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

Question 9

The New Horizons probe carries what kind of physical time capsule?

A) a small engraved plaque
B) a gold-plated record containing pictures, multilingual greetings and music
C) a DVD containing pictures
D) this probe does not carry a physical time capsule but a message will eventually be uploaded to its computers

Question 10

Which of the following is a difficulty associated with interstellar travel?

A) all three are difficulties
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) the huge distances between the stars

Question 11

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 12

The Pioneer probes carry what kind of physical time capsule?

A) a small engraved plaque
B) a gold-plated record containing pictures, multilingual greetings and music
C) a DVD containing pictures
D) these probes do not carry a physical time capsule

Question 13

The fastest 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) 100% of the speed of light

Question 14

The rocket equation describes how a vehicle's final speed depends on

A) its mass
B) the propellant's velocity
C) the type of the fuel used
D) its aerodynamic shape

Question 15

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

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

Question 16

The cosmic speed limit, the speed of light is established by

A) Newton's Laws of Motion
B) Einstein's General Theory of Relativity
C) Einstein's Special Theory of Relativity
D) Kepler's Laws of Planetary Motion

Question 17

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 18

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 19

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 20

Traveling at their current speeds, how long would it take the Pioneer and Voyager probes to travel the distance to 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 21

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 22

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 23

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 24

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

Question 25

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

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

Question 26

If we could observe a spacecraft actually traveling past us at the speed of light, we would measure its mass to be

A) zero
B) slightly greater
C) infinite
D) the same as at rest

Question 27

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) matterantimatter rocket
D) nuclear rocket

Question 28

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 29

In 1955, the US Government embarked on an experiment aimed at developing nuclear fission reactors that could be flown on a rocket. This was called Project

A) Rover
B) Orion
C) Daedalus
D) Bluebook

Question 30

The antimatter equivalent of an electron is called a

A) positron
B) antielectron
C) antipositron
D) poselectron

Question 31

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 32

The fastest we could accelerate a nuclear-powered 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 33

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 34

The fastest we could accelerate a vehicle powered with an ion engine to is approximately

A) 1% 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 35

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 36

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 37

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 38

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 39

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 40

The 100 Year Starship initiative aims to devise a plan for sending a crewed spacecraft to a nearby star

A) at a cost of less than a 100 billion US dollars
B) with a travel time of one century or less
C) within the next century
D) a hundred light years distant

Question 41

Which of the following is not a conventional spacecraft design?

A) a matter-antimatter rocket
B) a chemical rocket
C) a solar sail
D) a nuclear rocket

Question 42

In Einstein's General Theory of Relativity, spacetime is

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

Question 43

Which kind of interstellar spacecraft collects its fuel during its passage?

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

Question 44

Relativity predicts that everything in the universe is relative

A) except the laws of nature, which are absolutes
B) except the speed of light, which is an absolute
C) ast here are no absolutes
D) except the laws of nature and the speed of light, which are absolutes

Question 45

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 46

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 47

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 48

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 49

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 50

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 51

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 52

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 53

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 54

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 55

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

Question 56

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 57

If in the future significant amounts of antimatter could be made, it might be prevented from annihilating with ordinary matter by containing it in

A) a magnetic field
B) a gravitational filed
C) an electric field
D) a wormhole

Question 58

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 59

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 60

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 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

It is very likely that the general theory of relativity will need to be refined because it is currently incompatible with

A) electromagnetism
B) quantum mechanics
C) Newtonian gravity
D) all of these

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

If the speed of light were not absolute, the speed at which light from a star in a binary system came towards the Earth would depends on the star's

A) position and velocity
B) distance
C) masses
D) sizes

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