Zeraph

My question is about the first variable in the seven variable equation (N = R x fp x ne x fl x fi x fc x L). Some list it as R or the rate of star formation in our galaxy, and some list it as the amount of appropriate stars in our galaxy. Can it be either?

If R is the rate, then would that make the final result, N, the amount of civilizations we can talk to that are born each year? Or the total amount available in our galaxy?

Thanks.

Dilbert1234567

http://en.wikipedia.org/wiki/Drake_Equation
maybe this will help

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Zeraph

Heh, no not at all.

Dilbert1234567

sorry dude.

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Zeraph

Heh, no need to apologize. I think I figured it out anyway. N doesn't end up as a rate because your multiplying their life time in as well.

Willravel

I thought it was:

N = N* fp ne fl fi fc fL

N* = the number of stars in my (our) galaxy.

The Drake equation is, of course, massively flawed. Without knowing anything about life on other planets, all guesses are wastes. All we know about is some information from 1 planet out of billions. We could very easily be a fluke, and the Drake equation doesn't seem to take that into account. Imagine that we wanted to make a guess at how many cereals were in the world, but we've only ever had or known about one box of Cherios. Without any information about production necessary to any other cereal, or even knowing if it is possible for cereal to exist outside your house, how could you take guesses about Special K or Lucky Charms?

Zeraph

No offense, but no duh. Is there anyone who thinks the drake equation actually gives a real answer?

And it cant be the number of stars in our galaxy because at least half would be totally unsuitable for life because binary + systems. And a good part of the other half are too new of stars to have the correct compositions or burn too hot or too cold (and throught that a star's lifetime comes into account).

It ends up only being about 5% of our stars, or about 2 to 5 new stars a year for the appropriate G type star.

OzOz

Actually a binary would not necessarily be unsuitable for life. If the stars are far enough apart, gravitational perturbations on the orbits of planets around one of the stars due to the other star's gravity would be small, so the orbits would be stable. Also in that case, planets close to one star would not be significantly heated by the other star. It should be possible for planets in such a system to be habitable long-term.

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Willravel

You think agreeing with me is going to offend me? What offends me is when people state the Drake Equation is proof there is extra terrestrial life. Those people are idiots (I'm talking to you, my sophmore professor who tried to give me a C).
Frighteningly enough, there are many.
That's what the rest of the equation is about: N* = all stars, but the rest of the equation outlines that the answer must be N* minus the stars without planets, minus the stars that are incapable of sustaining life, minus star incapable of sustaining intellegent life, etc. etc.

Of course, the equation is an exercise in futility, as we don't know anything about the variables. Drake should be considered theocracy or fiction because of it's uselessness. It's like in the movie Time Cop: "the same matter cannot occupy the same space at the same time". It's unscientific dribble, meant to sound smart but completly hollow in meaning.

Zeraph

Not sure why I said that, thanks for pointing it out.

You're right, what the heck is the rate talking about then? Most of the newer sources that talk about it use rate instead of total stars.

Willravel

Maybe some guy named Drake wrote the equation as a joke, and then on a dare an astrophysicist tried to make it work.

Not sure. I've found like a dozen versions acorss the internet, plus two from back in school. Some say R* = the rate of star formation, which is what I suspect you're getting at. I guess you can look at it just as simply thinning the options from the top down. Even though there is no proof that stars are required for life, the basis of the equasion is that life requires stars to form, so we have to take into account that how amny and how often stars are created will be the first necessity for life. Let's say that, hypothetically, life only could exist in the very specific parameters here on Earth (or maybe Mars). In order to determine if there could be life elsewhere, you have to narrow down the instance to non instance ratio. The first step, beyond the big bang, would be to say that stars act as incubators for life and they are the first necessity for the development of intelligent life. That's the R*: the rate of star formation in or galaxy. This is also one of the fundamental flaws in the equation because:
1) There is no way to be certian that stars act as incubators to all life. There could be life forms in quasers or on cold rocks floating in the empty sea between stars for all we know.
2) This doesn't take into account the vast variables from different types of stars, anything from type to size to radiation levels and types to movement.
3) I'll think of another later.

balderdash111

Hi Will

We've done this particular dance before, but I'll put this out there for those who didn't see it last time.

I don't think any credible astrobiologist or other scientist believes the Drake equation is actually a mathematical model for the frequency of intelligent life. Rather, it is intended to illustrate a point - that given the very large numbers involved (of stars, of planets, etc), even if the conditions for life are very very improbable (thank you Douglas Adams), you still wind up with a good number of planets with intelligent life.

You can quibble with the details and the variables, but that's not really the point unless you think there are additional variables that make life less likely.

Enjoy.

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Willravel

Sorry, I missed this response. For several years.

The issue is that we don't have enough information to reasonably guess. We don't know all of the theoretical conditions of life. We don't know if the conditions that created us could create intelligent life anywhere else, or if there exist other, completely unknown conditions that can result in intelligent life. We are just scratching the surface of abiogenesis and evolution on Earth, and we really have nothing—abiogenesis or evolution—of an extraterrestrial nature to start to compare to.

Add to that the Fermi paradox and we find ourselves really grasping at straws in the dark. There's literally no direct evidence whatsoever of extraterrestrial life. Not a shred. Even the microfossil on the Martian meteor (ALH84001) which gained such notoriety back in 1996 isn't direct evidence.

Imagine that you have lived in a room your whole life, alone. Food and drink are supplied, you can exercise and read about scientific facts, listen to music, etc. You start to wonder if there are any other individuals such as yourself, so you look carefully out your window and see other forms. Some of those forms could be houses and in those houses there could be people. Do you know if there are people? No, not at all. You don't have nearly enough information to make a reasonable guess.

"The universe is really big, therefore there's probably life" is dishonest.

The_Jazz

Heh. Sometimes necroed threads are good. Nice rediscovery, Will.

I agree with several of your points, Will. We don't know all the theoretical conditions of life, we just know that we aren't receiving decipherable radio signals from elsewhere. That could mean any number of things: that we just haven't figured out the really obvious way to send FTL signals that all the cool aliens are using, that radio broadcasts attract the attention of the really bad guys in the universe or that intelligent life is so distant that radio signals from them get garbled so much or get "talked over" by stars and background noise that we can't hear them.

The numbers, though, are too big for us to be alone in the universe. And by "us" I mean all life on Earth, not just humans. It's possible that there's life within the solar system but that we're just not equiped to observe it at this point and that it's not intelligently sending signals out of its gravity well.

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mcgeedo

One of the fascinating terms in the Drake equation is L, the length of time that a civilization might radiate detectable signals. I guess I might add another term, the length of time that the one known civilization (us) might be able to detect such signals. Prior to about 1900, we might assume that we were looking for signal fires or some such optical medium. Since that time, we might be listening on radio frequencies. Only since about 1951 have we made the assumption that the best frequency for such intergalactic communication might be the hydrogen window. Only since around 1960 have we been listening at all, with any effort.

Note that both the L term and my new term don't change the number of possible civilaztions, just the likelihood of detecting them.