[18holesin]

It lets you change the variables and see quite quickly the estimated number of intelligent civilisations out there might be. Small changes in the variables lead to large changes at the end, quite interesting.

http://www.bbc.com/future/story/2012...n-worlds-exist

[JosephEL]

It's a great graphic, but the big problem here is that there is no objective way to estimate any of the parameters in the second (Life) or third (Civilization) tiles.

[Zesavenue]

It lets you change the variables and see quite quickly the estimated number of intelligent civilisations out there might be. Small changes in the variables lead to large changes at the end, quite interesting.

http://www.bbc.com/future/story/2012...n-worlds-exist

I took a couple of minutes to enter the equation in a spreadsheet. Not nearly as flashy, but easier to see what's going on.

With my first run through of probable best guesses I got 0.75 civilisations per observable universe.

Spooky.


But seriously - I still have reservations about this Drake Equation thing. It seems to me that it's usually used to suggest that the Universe must be teeming with technological civilisations, whereas what it really shows is that we have NFI.

[janeseymore09092]

I took a couple of minutes to enter the equation in a spreadsheet. Not nearly as flashy, but easier to see what's going on.

With my first run through of probable best guesses I got 0.75 civilisations per observable universe.

Indeed - I often feel the urge to pop outside just confirm it's all still there.

But seriously - I still have reservations about this Drake Equation thing. It seems to me that it's usually used to suggest that the Universe must be teeming with technological civilisations, whereas what it really shows is that we have NFI.

True there's some important variables we don't really know much about. But it costs nothing to play with the equation and as time goes by we will hopefully get a more accurate idea as to more realistic values for some of the variables.
But until (if?) we bump into the Greys, it's just academic hand waving.

[swwatch]

But seriously - I still have reservations about this Drake Equation thing. It seems to me that it's usually used to suggest that the Universe must be teeming with technological civilisations, whereas what it really shows is that we have NFI. it is used to show we have nfi and as the guide to show us what we do need to find out. no one uses it to predict the number of civilisations and it wasn't really designed in the first place to actually do that. it is just the non-science types who like to trot it out as a predictive tool.

[XzBZB2UV]

it is used to show we have nfi and as the guide to show us what we do need to find out. no one uses it to predict the number of civilisations and it wasn't really designed in the first place to actually do that. it is just the non-science types who like to trot it out as a predictive tool.

Hmm, I don't know that that's true. I think many people (including scientists who should know better) have used it to suggest that there must be lots of intelligent life forms in the Universe, even with the lowest reasonable estimate on each figure.

The BBC site comes up with 79 Billion civilisations per universe as the number with "today's skeptical estimate" and about 11 million billion with an "optimistic" estimate.

[pongeystrhjst]

Purely on numbers involved, numbers of stars, numbers of planets, numbers of galaxies, the ingrediants of life being everywhere we look etc etc etc....The likelyhood of no other communicable life anywhere else is so low as to not be considered real according to most astro physicist and scientists in the business.

[ChexEcodece]

Hmm, I don't know that that's true. I think many people (including scientists who should know better) i include the latter in the non-science types, for that moment in time.

;-)

[klubneras]

Purely on numbers involved, numbers of stars, numbers of planets, numbers of galaxies, the ingrediants of life being everywhere we look etc etc etc....The likelyhood of no other communicable life anywhere else is so low as to not be considered real according to most astro physicist and scientists in the business.

Have you asked them all?

What evidence do you have for this suggestion?

Even the outrageously "optimistic" numbers on the BBC site only comes up with less than 1 Tech Civilization per galaxy with their "skeptical" numbers.

[FilmCriticAwezume]

I still have reservations about this Drake Equation thing. It seems to me that it's usually used to suggest That's because you still have the (engineer's) mindset that an equation must be there to get an answer.

For me - and for a lot of other people - the point of the equation is to focus the questions ie to indicate what are the variables that might be more significant than others, and where can uncertainty be reduced most effectively. That is really a different approach to the DE.

[Ferkilort]

i think we can forget about communicating with, or even "discovering", anybody not in this galaxy for a very very long time. .

[Keendwainge]

That's because you still have the (engineer's) mindset that an equation must be there to get an answer.

For me - and for a lot of other people - the point of the equation is to focus the questions ie to indicate what are the variables that might be more significant than others, and where can uncertainty be reduced most effectively. That is really a different approach to the DE.

Having "a lot" of people who use the Equation sensibly is entirely consistent with most people using it non-sensibly.

I cite the BBC site as evidence.

[Lhiistyssdds]

Well, if your "reservation" is that you think a lot of people misuse it, then I'll have to look elsewhere for an argument.

[herawaq]

Well, if your "reservation" is that you think a lot of people misuse it, then I'll have to look elsewhere for an argument.

Perhaps we could insert centrifugal force in there somewhere?

[Kamepherype]

If I were rewriting the DE I would break up Fi x Fc differently.

I would have a (Fraction of planets with life that develop complex, multicellular animal life). It seems to me that this is an important, non-trivial step, and at least potentially could be treated in a semi-rigorous factor. It would describe factors like the length of time that a planets surface remains tectonically active (if you hold to the importance of that, as described by Ward & Brownlee).

I'd also be tempted to then just combine the remaining (Fraction of planets with complex, multicellular animal life that develop intelligent life) and Fc into a single number. It's always bothered me that "intelligent life" is a somewhat arbitrary cutoff for a species, and "radio telescopes" is a somewhat arbitrary cutoff for a culture, so I don't see why you need two arbitrary points just to mark some nature/culture divide. That's a rather secondary issue though.

[hotsaucemidl]

MB - I agree with the first point, although I'm not sure how realistic it would be to come up with an estimate for the number (other than greater than 0 and less than 1).

Not sure about the second one. It seems to me that development of life forms that are capable of having and communicating complex abstract thoughts, and development of technological knowledge are two separate stages that should be recognised.

[mirvokrug]

That's because you still have the (engineer's) mindset that an equation must be there to get an answer.

For me - and for a lot of other people - the point of the equation is to focus the questions ie to indicate what are the variables that might be more significant than others, and where can uncertainty be reduced most effectively. That is really a different approach to the DE.

The significance of the factors relies heavily on the formulation of the equation. What if the relationships between the parameters is different to how they are modeled by the DE?

[Stengapsept]

Again, we certainly aren't going to get definitive answers. But it seems to me that at this step we can still do some relatively rigorous modelling
eg if complex life needs liquid water and a surface tectonically active for >2By then F should be something like...
if complex life needs a large moon, liquid water and a surface tectonically active for >3By then F should be something like...

[lovespellszz]

The significance of the factors relies heavily on the formulation of the equation. What if the relationships between the parameters is different to how they are modeled by the DE?

Not sure what you are getting at there.

Can you give an example of how they might be?

Or are you meaning inserting extra steps, and combining others, as Martin suggested?

[movlabc]

Again, we certainly aren't going to get definitive answers. But it seems to me that at this step we can still do some relatively rigorous modelling
eg if complex life needs liquid water and a surface tectonically active for >2By then F should be something like...
if complex life needs a large moon, liquid water and a surface tectonically active for >3By then F should be something like...

I'd agree we could put some sensible limits on the upper range.

I'm not sure we can do much at the lower end, until we understand the evolutionary processes better.