xD; Does anybody even know what this is..??

:'D If you wanna know, check the entry here on Wikipedia.


Specifically, the Drake equation is a means to achieving an estimate of the number of planets in the universe that have some form of intelligent, communicable lifeforms. The equation is as follows:

N = R* x fp x ne x fl x fi x fc x L

N is the number of civilizations which we may be able to come in contact with at some point.
R* Is the rate of star formation
fp is the number of stars that have planets
ne is the number of planets around said stars capable of supporting life
fl is the number of said planets on which life develops (of any complexity)
fi is the number of life which will become intelligent
fc is the number of intelligent lifeforms with which we can communicate
L is the span of a civilization (i.e. just because it exists it doesn't mean we'll exist concurrently.


:D So discuss:
Variables of the equation and the various factors you think should be taken into account when deciding on a number for each
How likely you think it is that we'll ever come into contact with any other extraterrestrial life form.



xD fyi I know of this equation because I am an astronomy minor, not because I believe in aliens~

That is the most confusing equation i have ever seen.

xD;; It's really not too confusing if you think about it some. :'D Like the concept is really easy to grasp. xD;;; Getting the numbers down and having a reason for why you chose those numbers is the hard part~


:'D But yeah I am an astronomy minor so I am currently taking a class called Search for Extraterrestrial Life. xD; This equation is basically the basis of the whole class!!

This is an interesting formula. But the problem is, you're really basing it on nothing, so it isn't too good.
Don't you also need to calculate the rate of planet formation?

An interesting formula, but really completely ludicrous. Trying to accurately predict the number of civilizations we will encounter is something beyond the human scope, I think. :/

My first question is, how do you fill in the variables lower down the list? We know, for instance, that certain other planets in other systems probably at least have the capability of supporting life. What I've never heard any definite evidence about is whether life ACTUALLY exists on them, let alone whether it's evolved beyond the microbial level, or whether said life has reached sentience and developed civilization.

Obviously the better our knowledge of these variables, the more accurate the prediction in regards to how many alien civilizations we might come into contact with. At this point all we know is that there are a number of planets that have the potential for life, and there are probably many more we haven't discovered yet. So at this point our prediction has to leave a lot to chance.

@LemonWarlord ~ xD; It's not based on nothing~ It's based on a large amount of other complex equations per variable~ :'D And scientific evidence, such as the fact that we exist. xD; So we know its worked at least once!

And at this point it would be impossible to calculate the rate of planet formation. :'D It's too hard to find planets orbiting other stars, and there are too many variables to which kind of stars might have planets. Just because our solar system has eight doesn't mean that's universally common. There are only two hundred planets known to us in our galaxy, and there are bound to be much more. Most of the planets we are able to find are large gaseous planets with close orbits to their star like Jupiter. xD; It's really hard if not impossible with todays technology to discover terrestrial planets that are more likely candidates for the formation of life.



Intoxicate ~ :'D It's not completely ludicrous, and nobody said that it would accurately predict anything. What it is is a formula to give us an estimate. There are no solid numbers for any of the variables. At the most, they will have a range, which gives us an estimate of how many other planets are likely to form intelligent, communicable life within some sort of range.


@Berginyon ~ :'D It does get more complicated as the variables go down, and you have to take iinto account the previous variables as well, but it's possible to make a good estimation. The last few are mostly a question of biology and probability. So if we know 100 planets are capable of supporting life, but that there is only a one in ten chance that any type of protolife would form, then that would mean around 10 planets. etc. etc.

It gets a little complicated and arbitrary because people aren't exactly sure what to define as 'life'. So it comes down as much to personal definitions as it does to probability and statistical analysis.


As for other planets having the capability, it's true that Mars, Venus, Jupiter, and at least two of its moons have the capability of supporting some kind of organic lifeform. However, it's not just a matter of if a planet was capable at some point, is capable now, or will be capable in the future. Life takes a long time to evolve, and there is the CHZ, or continuously Habitable Zone to take in to account. If a planet could not maintain a CHZ, then there wouldn't be enough time for life to develop on it anyway.

Mars, for example, while it may have had an aqueous solution capable of forming life at some point (whether it be liquid ammonia, liquid methane, or liquid water), has a very thin atmosphere. Unlike on Earth, Mars recycles it's carbon at a much slower rate, and because Hydrogen is such a light element, it can easily escape the atmosphere, meaning that there wasn't much of a time span for Mars to have developed life in. Because COOH and CH2 are essential in developing life, the more Hydrogen Mars loses the less and less likely it becomes that any kind of life form would arise.

But yeah, this equation isn't meant to tell people an exact number for every variable, and an exact number for every solution. Widely accepted numbers are changing constantly due to scientific breakthroughs, and it's very likely we'll never have an exact answer for any of the variables.


:'D Because honestly, even assuming there was at least one other planet with intelligent, communicable lifeforms, the universe is a big, big place, the odds of us meeting are still pretty close to zero.

Given the infinite possibilities of the universe and our scarce knowledge of life outside of Earth, I would say that it is impossible to quantify any probability of making contact.

In fact, we do not even know if we have already made contact. Many people speculate that life on Earth is already extraterrestrial in origin. And how can you judge what can be considered a "civilization"? An alien civilization may be unrecognizable as such to us. There could be sentient life forms that we cannot perceive or communicate with. What about organisms that are merely one celled or gaseous, or insect like? They could possibly have a civilized society and be intelligent, and we could never know about it, even if it exists.