Ch 12

The rare-Earth hypothesis would predict that the factor f life, in the Drake equation should be close to

0

Given that life on Earth appears to have arisen quite easily and rapidly suggests that the factor f life, in the Drake equation could be close to

1

Suppose there are a million habitable planets in our galaxy, that one in ten are habitable, that one in a hundred civilizations that has ever existed is in existence now. Given this, how many civilizations are in existence now?

1

a SETI search using the 300-meter diameter Arecibo radio telescope can pick up a 10 million Watt at a distance of 1,000 ly. If we were ti detect a similar signal coming from 10,000 ly away, how powerful would the alien antenna have to be?

1 billion Watts

If the communication lifetime of civilizations in our galaxy is 10,000 years and our galaxy is 13 billion years old, what is the chance of us detecting another intelligent civilization now

1 in 1,300,000

If the communication lifetime of civilizations in our galaxy is 100 million years and our galaxy is 13 billion years old, what is the chance of us detecting another intelligent civilization now?

1 in 1300

Approximately how soon might we expect an immediate response from a civilization that received the signal we sent to the globur cluster M13 (21,000 ly away. in 1974?

42,000 years

Given that there are several hundred billion stars in the Milky Way Galaxy and preliminary data from exoplanet studies suggest that as many as one in five star systems may have one or more habitable planets, then a reasonable estimate for the number of habitable planets could be about

100 billion or more

Which of the following is a prime number

13

Suppose that there are 10 billion (10,000,000,000,000. habitable planets in our galaxy, that 1 in 5 habitable planets have life, that 1 in 100 civilizations that have ever existed is in existence now. How many civilizations would exist at present?

2,000,000

Given that our galaxy has a volume of approximately 8 10^12 ly^3, what is the average distance between civilizations if there are currently 1 million intelligent civilizations in our galaxy?

200ly

If you arrange the following 15 bits (111001111100111. into 5 rows of 3 bits starting with the first bit, what number does it spell out?

3

Given that our galaxy has a volume of approximately 8 10^12 ly^3, what would be the average minimum amount of time to exchange messages between civilizations if there are currently 125,000 intelligent civilization in our galaxy?

800 years

Which Lagrange points in the Earth -- Moon system are stable?

L4 and L5

the most likely method of interstellar communication is similar to which type of communication on Earth?

Morse code

In the simplified Drake equation, the total number of life-bearing planets in our galaxy is given by

NHP x flife

Which of the following factors in the simplified Drake equation is best known?

Nhp, the number of habitable planets in our galaxy

Which scientist built a radio transmitting tower at the turn of the 20th century and claimed that he was receiving interplanetary communications with it?

Nikola Tesla

What type of civilization can life on Earth currently be classified as?

Type I

What type of civilization would be able to construct a "Dyson Sphere" around its parent star to capture its radiation?

Type II

In the novel Contact by Carl Sagan, an extremely advanced civilization has constructed a labyrinth of wormholes throughout the galaxy. A civilization capable of such a feat would most likely be classifies as what kind of civilization?

Type III

How is intelligence defined in the Drake Equation?

a civilization willing and able to communicate over interstellar distances

If we were to intercept a signal from civilization that was sent to another of its colonies on the other side of the galaxy, this would be an example of

a signal used communication between a civilization's home world and another star system

If we were to detect radio and TV signals that had leaked out into space from another civilization, this would be an example of

a signal used for local communication in the world where the intelligent beings exist

An organism with and Encephalization Quotient (EQ of 4 is expected to be of

above-average intelligence

In the simplified Drake equation, a value of f life = 1 would imply that

all habitable planets in the galaxy have life

The 1420 MHz (21 cm radio line generated by neutral hydrogen a toms is a good choice for interstellar communications because

all intelligent civilizations should be aware of its universal significance and would probably also think of sending and receiving signals at this frequency

Which type of electromagnetic radiation is able to carry the most information?

all types have equal ability

If we were to intercept a strong radio signal at 1420 MHz in binary format from another civilization, this would be an example of

an intentional signal beacon

Which of the following kinds of signal so we currently have the best chance of detecting with currently technology?

an intentional signal beacon

a UFO is

an unidentified object seen in the sky

Which of the following cases in the Drake equation would be the minimum necessary condition fro us to be the only intelligent civilization currently in our galaxy?

any one of the factors to be zero

Approximately what proportion of people in the United States believe we have been visited by extraterrestrials?

around 33% or a third

an organism with an Encephalization Quotient (EQ. of 1 is expected to be of

average intelligence

the range of frequencies that a radio telescope is sensitive to is referred to as its

band

The range of frequencies that are contained in a particular radio signal is referred to as its

bandwidth

an organism with an Encephalization Quotient (EQ of 0.1 is expected to be of

below-average intelligence

The Declaration of Principles Concerning Activities Following the Detection of Extraterrestrial Intelligence states that the first thing to do after the detection of a possible signal is to

confirm that it is genuine

About 90% of UFO sightings

can be explained by natural phenomena

The adoption of very similar streamlined body shapes by both sharks and dolphins provides evidence for

convergent evolution

The fact that many different organisms on Earth have developed eyesight provides evidence for

convergent evolution

The fact that Encephalization Quotients (EQ of organisms have generally increased with time provides evidence for

convergent evolution toward intelligence

If there around 10,000 transmitting civilizations in the Milky Way, then theoretically the Allen Telescope Array, when it is complete, might be capable of detecting a signal within a few

decades

The organisms with the next highest Encephalization Quotient (EQ ratios after humans are

dolphins

Which term in the simplified Drake equations depends on sociological factors?

f now

Which of the following factors in the simplified Drake equation is least well known?

fnow, fraction of civilization-bearing planets that have intelligent civilizations on them now

Optical SETI is useful for

focused communication over short distances and in particular directions

Why was the global cluster M13 selected as the target fro the 1974 Arecibo message?

globular clusters are densely packed with stars, hence maximizing the probability of interception by an advanced civilization

in 1974 we transmitted a message toward the globur cluster M13 which is 21,000 ly away. What is one reason that we will probably have stopped communicating before we receive and return signal

globur clusters contain, old, low mass stars fewer heavy elements and hence are not ideal places for life

Intelligence may be subject to convergent evolution because it

has survival value

Which of the following signals from an advanced civilization would be easiest to detect?

high intensity, narrow bandwidth

The factor f now, in the Drake equation depends on

how long civilizations survive once they have arisen

The organisms with the highest Encephalization Quotient (EQ ratios are

humans

A Lagrange point in the Earth -- Moon system is a position

in space where the effects of the Earth's and Moon's gravity cancel each other out

the ratio of an animal's brain weight to body weight is though to be roughly proportional to its

intelligence

The Drake equation allows us to estimate the number of

intelligent civilizations capable of communicating in our galaxy now

Which type of signal could carry the largest amount of information?

large bandwidth

A dinosaur like a Brontosaurus with a small head and a large body would be expected to have an Encephalization Quotient (EQ of

less than 1 but greater than zero

On the basis of the scientific method, which of the following would be considered conclusive evidence that we are being visited aliens?

none of these would be conclusive

Due to increasing amounts of terrestrial radio noise, in the future SETI telescopes may be placed

on the far side of the Moon

Sending signals at optical wavelengths might be a viable alternative to radio wavelengths

over relatively short distances where absorption by interstellar matter would not be a problem

Currently in the USA, SETI programs are mostly funded

privately

Why are radio waves probably the most efficient way to communicate between civilizations?

radio waves are easy to produce and are not affected much by interstellar matter in the galaxy

An optical SETI signal would most likely consist of

rapid, short bursts of intense laser light

any reply to a detected SETI signal should

represent a consensus of the Earth's population

It is unlikely that we will be able to detect the signals from civilizations in other galaxies because

signals from other galaxies will be severely weakened by distance, making them far harder fro us to detect

The sweep technique used in SETI programs is also known as a

sky survey

The Inner Galactic Plane Survey conducted with the Allen Telescope Array in northern California is an example of a

targeted search

The search for radio signals from intelligent civilizations on planets around nearby solar-type stars is an example of a

targeted search

The main problem with early attempts to listen for radio signals from space was

that they were conducted at relatively low frequencies which have problems penetrating the Earth's upper atmosphere

One of the most likely places an advanced civilization might leave an artifact for us to find would be

the L4 and L5 points in the Earth -- Moon system

Which of the following physical parameters is NOT under the control of a radio telescope?

the bandwidth

After World War II, the US Government spent two decades investigating UFOs because they

thought that they might be new types of aircraft being developed by the Soviet Union

Encephalization Quotient (EQ values can be estimated for extinct species because

we can estimate their body masses from their fossilized remains and their brain masses from the sizes of their fossilized cranial cavities

In principle, the Drake equation should enable us to calculate the exact number of intelligent civilizations capable of interstellar communication in our galaxy right now. However, currently this is not feasible because

we do not have exact numbers fro any of the factors in the equation