Name: 【TED-Ed】Calculating the odds of intelligent alien life - Jill Tarter
Uploaded: 2015-01-13T08:04:32.000Z
Duration: 7 min 28 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

The basic question is, does life exist beyond Earth?

Basic passive voice

Scientists who are called astrobiologists

Most astrobiologists are trying to figure out

or in the ocean under the frozen surface of Jupiter's moon Europa,

But one group of astrobiologists works on SETI.

SETI is the Search for Extraterrestrial Intelligence,

and SETI researchers are trying to detect some evidence

have used technology to build a transmitter of some sort.

There are certainly no guarantees when it comes to SETI,

that there will be a solution to the equation,

The Drake equation, however, is different,

and we can estimate an answer a bit better.

But there won't be a definite answer to the Drake equation

Earthlings are the only intelligent species in our portion of the cosmos.

it is really useful to consider the unknowns.

the number of technological civilizations

in the Milky Way Galaxy -- we call that N --

that we might be able to detect right now.

stars have been born in the Milky Way Galaxy

and early in its history stars formed at a different rate.

Each one must be less than or equal to one.

F-sub-p is the fraction of stars that have planets.

is the average number of habitable planets

is the fraction of planets on which life actually begins

and f-sub-i is the fraction of all those life forms

F-sub-c is the fraction of intelligent life

that decides to use some sort of transmitting technology.

do those transmitters continue to operate?

to tell us what the product of the first three terms is.

We're now finding exoplanets almost everywhere.

The fractions dealing with life and intelligence

we only know of one place in the universe

So the number two is a very important number here.