Which factors in the Drake equation would have to be extremely small for us to be the only advance life?

Question

This is referring to our galaxy.

Answer 1

I am not that familiar with the Drake equation, but go to astronomycast.com and look under archive.

Answer 2

The Drake equation (see reference below) purports to calculate the number of intelligent civilizations other than the earth.  It uses various estimates of factors that are multiplied together to come up with an answer.

The problem is that to compute a probability one needs a probability distribution that is constructed from numerous observations.  So far, earth is the only planet with documented life, intelligent or otherwise.  There is only one data point.

One cannot construct a reasonable probability distribution from a single data point.  There is no way reasonable way to come up with a variance or standard deviation from a single instance.

Thus, the Drake equation may be interesting in a casual conversation at a bar, but it does not represent science at its best.

Answer 3

If any of the variables = 0 then there would not be any life in the galaxy.  So that is incorrect.

If fi = .001 and fc = .01, then we are likely the only life in the galaxy.  And this is what we actually know now.

The following is from (wiki)

    N = R*\times fp times ne times fe times fi times fc times L

where:

    N is the number of civilizations in our galaxy with which communication might be possible;

and

    R* is the average rate of star formation in our galaxy

    fp is the fraction of those stars that have planets

    ne is the average number of planets that can potentially support life per star that has planets

    fℓ is the fraction of the above that actually go on to develop life at some point

    fi is the fraction of the above that actually go on to develop intelligent life

    fc is the fraction of civilizations that develop a technology that releases detectable signs of their existence into space

    L is the length of time such civilizations release detectable signals into space

    R* = 10/year, fp = 0.5, ne = 2, fl = 1, fi = 0.001, fc = 0.01, and L = 500 years

    N = 10 × 0.5 × 2 × 1 × 0.001 × 0.01 × 500 = 0.05 (we are probably alone)

Answer 4

None of them or all of them. I never heard of Mr Drake, I have heard of Daffy Duck who is a very famous quack

Answer 5

fc = The number of planets that have the technology to communicate with us. These planets may no longer exist by now.

Answer 6

Here's a link to a video where Carl Sagan explains the Drake Equation:

http://www.youtube.com/watch?v=RB_v99FST...

Take your pick of the unknown variables.