Talk:Drake equation

This article in the press

This article is linked to in this press article: Man Uses Math to Explain Girlfriend Woes Samboy (talk) 05:22, 14 January 2010 (UTC)

So this is just a guess? —Preceding unsigned comment added by AdbMonkey (talk • contribs) 13:22, 26 October 2010 (UTC)

Wrong equation for R*

The equation

$N^{\ast }=\int _{0}^{T_{g}}R^{\ast }(t)dt,\,\!$

ignores the fact that all stars have a finite lifespan, as they will either undergo a supernova or become a white dwarf. In fact, our Galaxy is known to have multiple generations of stars, and not a single "first-generation" star (i.e. population III) has yet been discovered. Furthermore, assigning an age to a galaxy is rather ambiguous, since it is now known that galaxies (especially large ones) have undergone many mergers with other galaxies. Thus it can said that the age of all galaxies is (nearly) the age of the Universe.

Wrong statement for L

RM below about L to talk. If L is the length of time such civilizations release detectable signals into space then Grote Reber and radio astronomy have nothing to do with this value, his antenna was a receiver, not a transmitter. Maybe the example should date back to the Invention of radio. Fountains of Bryn Mawr (talk) 00:23, 4 March 2010 (UTC)

The value of L can be estimated from the lifetime of our current civilization from the advent of radio astronomy in 1938 (dated from Grote Reber's parabolic dish radio telescope) to the current date. In 2009, this gives an L of 71 years. However such an assumption would be erroneous. 71 for the value of L would be an artificial minimum based on Earth's broadcasting history to date and would make unlikely the possibility of other civilizations existing. 10,000 for L is still the most popular estimate.

Current estimate of f_l

In the "Current estimates of the parameters" section, it says that Drake estimated f_l to be 1, whereas a couple other guys more recently estimated it to be 0.13. However, in the two sections that calculate N based on the current estimates (both at the bottom of the "Historical estimates" section and the bottom of the "Current estimates" section), a value of 0.33 is used for f_l. Where did 0.33 come from? Should an explanation should be added regarding how 0.33 was derived, or should we be using 0.13 in our current estimate calculation of N? SnottyWong talk 21:29, 19 April 2010 (UTC)

Mayr vs Sagan out? Michael Crichton in?

Hello

The late Ernst Mayr was the most famous biologist at our times, especially in the theory of evolution which is most relevant here, and he criticised the SETI project in various occasions. I find the discussion he had with Carl Sagan, one of the fathers of SETI especially enlightening and that is why I added it. Now the current section about critics of the SETI project contains a cite of Michael Crichton, a science fiction writer and removed the Mayr link. With all due respect to Mr. Crichton but I think the critics of Ernst Mayr is far more relevant. One of his arguments, which he clearly emphasised as being speculative is based on the fact that of the many species on earth, which might be in the billions, only one developed intelligence. Now the wording of the paragraph I added can be changed of course and rephrased, but leaving Crichton in and Mayr out, seems to me sort of ridiculous. Oub (talk) 12:52, 28 April 2010 (UTC):

Mayr's argument is actually fallacious. The reason only one species on Earth developed a technological intelligence is that there is only one niche per planet for such a species. Reflect on the fate of the Neanderthals. WolfmanSF (talk) 22:57, 2 October 2010 (UTC)

factor missing in the equation?

In the equation appear the factors

:fc = the fraction of civilizations that develop a technology that releases detectable signs 
of their existence  into space
:L = the length of time such civilizations release detectable signals into space.

It might be, that such civilization existed for 1 million years, that would produce a good result of calculation for N.

But if that happened 100 million years ago, and 99 million years ago that civilization disappeared, we cannot communicate. Should a "factor of same time" be added to the equation? Is there anything in the literature? --Hans W (talk) 15:14, 14 August 2010 (UTC)

ε_Earth is not obtainable from Drake equation parameters

It is not true that ε_Earth = f_p x n_e (where ε_Earth is the the fraction of stars with Earth-like planets). Consider an extreme but illustrative example. If f_p = 0.01 (only 1% of stars have planets) and n_e = 100 (each of those stars has 100 Earthlike planets), then ε_Earth = 0.01, but f_p x n_e = 1.0. You need to know the statistical distribution of n_e to calculate ε_Earth. WolfmanSF (talk) 23:13, 2 October 2010 (UTC)

R* is the number of stars in the galaxy?

I'm not sure why this article emphasizes the number of stars formed per year, without multiplying that number by the number of years the galaxy has been forming stars! This matter is explained somewhat in the subsection "Alternative expression" but later ignored in the "Current estimates of the parameters" section. The result is that the first three terms of the right hand side give the number of earth-like planets formed per year. The end result, 2.31 civilizations, is an absurdly low estimate. The original Drake equation was: $N=N_{g}\times f_{p}\times n_{e}\times f_{\ell }\times f_{i}\times f_{c}\times L\!$ where the first term on the right-hand side is the number of stars in the galaxy. $N_{g}$ is on the order of 200 to 400 billion, not 7. I have edited the "Current estimates" section with the estimates made by James Kasting in his book "How To Find A Habitable Planet". 70.112.186.143 (talk) 03:23, 10 October 2010 (UTC) Eric

offensive anthropocentrism

I'm taking issue with the text

• fi = the fraction of the above that actually go on to develop intelligent life. Estimated by Drake as 0.01 based on little or no evidence. This value remains particularly controversial. Pessimists such as Ernst Mayr point out that of the billions of species that have existed on Earth, only one has become intelligent[18] and infer a tiny value for fi.

the view that Earth has only one intelligent species is ridiculous and offensive. in fact it harbours several very intelligent species. this aspect of the controversy has not been exposed in the article. some versions of the drake equation, however, do make the distinction between intelligence and technological advancement as different factors. -- 99.233.186.4 (talk) 01:43, 13 November 2010 (UTC)

Hm, please name another intelligence species on this planet! In order to prevent a fight over the word intelligence, the basic motivation of the Drake equations is to communicate. So instead of looking for an intelligent species one could say a species which posses a language with a full developed grammar, so I am curious which species do you have in mind? Oub (talk) 17:45, 16 November 2010 (UTC):