Yeah people really will believe anything...More so now than ever...
The Flat Earth society
- Thread starter parsifal
- Start date
Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
mikewint
Captain
Being as the Universe is finite and boundless you are correct as is everyone else
There is no life in the universe as proven by Douglas Adams. There is a finite amount of inhabited planets, while there is an infinite amount of total planets. So finite divided by infinite means 0 part of the universe is inhabited.
mikewint
Captain
First proposed by radio astronomer Frank Drake in 1961, the equation calculates the number of communicating civilizations by multiplying several variables. It's usually written, according to the Search for Extraterrestrial Intelligence (SETI), as:
N = R* • fp • ne • fl • fi • fc • L
N = The number of civilizations in the Milky Way galaxy whose electromagnetic emissions are detectable.
R* =The rate of formation of stars suitable for the development of intelligent life.
fp = The fraction of those stars with planetary systems.
ne = The number of planets, per solar system, with an environment suitable for life.
fl = The fraction of suitable planets on which life actually appears.
fi = The fraction of life bearing planets on which intelligent life emerges.
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.
N = R* • fp • ne • fl • fi • fc • L
N = The number of civilizations in the Milky Way galaxy whose electromagnetic emissions are detectable.
R* =The rate of formation of stars suitable for the development of intelligent life.
fp = The fraction of those stars with planetary systems.
ne = The number of planets, per solar system, with an environment suitable for life.
fl = The fraction of suitable planets on which life actually appears.
fi = The fraction of life bearing planets on which intelligent life emerges.
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.
Robert Porter
Senior Master Sergeant
42
mikewint
Captain
mikewint
Captain
Yup, The Drake equation is definitely SWAG. Another factor seldom addressed is the distances involved.
Some of the quantities -- R*, fp, and ne -- are observable with our current technology. By observing many stellar systems, astronomers can come up with reasonable numbers. For example, let's say that astronomers look at 100,000 stars and find that 40,000 have planets. If the rest of the galaxy behaves like these 100,000 stars (and, chances are, it does), fp is 0.4, or 40%. But how would we know if a star has planets?
By watching and waiting for a planet to go in front of its star, astronomers can detect a small change in the star's brightness caused by this transit. They can also look for gravitational evidence of planets, such as changes in the star's orbit. Although such measurements were not possible in Drake's day, 506 exoplanets have been discovered since 1992. Based on the number of stars checked for planets versus the number of stars with planets, astronomers have determined that fp is about 0.4. Drake, without the help of the sensitive telescopes available today, estimated fp to be 0.5 -- pretty close!
R* (star formation rate), however, appears to be much lower than Drake suspected. While data in 1960 suggested that 10 new stars were born every year, the current number is more like 1 star per year. Since the first SETI meeting, we have been able to make many more observations of "star nurseries" -- nebulae, where stars are born -- and to gather statistics on the general population, to find stars' ages and deduce how many were forming at any given time.
Drake estimated ne, the number of habitable planets in each system, to be 2. This estimation was based on our solar system, where one planet is definitely habitable! Mars and moons like Europa and Titan could also still harbor life, or evidence of former life. To be considered habitable, planets need orbits that don't take them too close or too far from their star; they need an atmosphere; and they need access to life-sustaining chemistry, like organic molecules and water. Currently, we are much better at detecting large, hot planets (ones that are like Jupiter) than planets like Earth, so no consensus on this number has been reached. It is estimated to be between 0.5 and 2. As NASA's sensitive Kepler telescope, whose mission is to find exoplanets, provides more data, we will be able to pin ne down.
The last four terms are where the math starts to get dicier. fl, the fraction of planets where life develops, is not something we can currently discover, since we cannot travel to the exoplanets. By looking at their chemistry, we can say whether life is possible -- but not whether life actually is.
Astrobiologists are trying to determine whether, given the conditions for life (conditions like those early in Earth's history), life will arise. Is life inevitable, or is it an anomaly? Drake believed that it was inevitable and set fl to 1. Modern scientists tend to be more conservative with that estimate, so conservative that they don't like to speculate.
After we have life, how much of that life will become intelligent (fi)? Drake said 0.01, but that was even more of a guess than fl. Today, we can do no better. Some say that fi is tiny: of the billions of species on Earth, we are the only one that became intelligent. Others say that all those species were leading inevitably to us, and that given the chance to develop, life will always become intelligent -- meaning that fi would be 1. Who knows?
After smart life exists, what chance does it have of using electromagnetic waves to communicate? Drake said 0.01, or 1%. There is evidence for pretty much any number on the 1-100% spectrum. Until we detect a civilization -- or, really, unless we detect hundreds of civilizations -- we can't know too much about this number. At that point, we won't care very much about the Drake Equation!
The same is true of L, the length of time that a typical civilization communicates: The only example we can have, until we find ETI, is ourselves, and we don't know when our communication will end. A world war could easily end us. So could a supernova. Or runaway greenhouse effect. Or an asteroid. Or, alternatively, civilization could progress for millions of years. The problem is, we'll never know until we get there. Drake said L was 10,000 years, but, again, that was just guessing, and hope.
L is the term that has the most potential to change the equation's outcome. While most parameters must be between 0 and 1, and can only make N smaller, L can be anything. The lifetime of civilizations is the most important factor determining our chances of finding ETI.
Taking the current numbers (or the average of the estimates) and multiplying them, we get N=(1)(0.4)(1)(0.5)(0.5)(0.5)(10,000) -- Drake's L thrown in for good measure -- or
N=500 communicating civilizations in the galaxy.
Our galaxy is pretty big. It's a flat disk about 100,000 light years across and a thousand light years thick. The volume of a disk is its area (pi x radius^2) times its thickness. So:
Volume = pi x (50,000)^2 x 1000 = 8 trillion cubic light years
If evenly spaced throughout the entire galaxy:
8 trillion cu ly / 500 = 1.6 X 10^10 cu Ly per civilization or about 8,000,000,000 Light Years apart!!
But that's a lot of "fringe territory" so lets assume that these civilizations are distributed along the galactic equator, say a slice 10 light years thick, then:
Volume = 3.141 X 50,000^2 X 10 = 7.85 X 10^10 cu ly / 500 = 1.57 X 10^8 cu ly per civilization or roughly 7.85 X 10^7 light years apart
So with distances like these to deal with changing the number of civilizations by 10, 100, or even a 1000 still puts each civilization thousands of light years apart.
The Drake Equation must be one of the SWAGiest equations ever created because of the uncertainty associated with its parameters. The Drake Equation does do a great job of identifying and categorizing the relevant parameters. It also accomplishes the task of providing structure to the ongoing debate about the search for extraterrestrial intelligence and the likelihood of its existence. The large degree of uncertainty associated with so many of its parameters does tell us one important thing: that we have a lot more to learn.
Some of the quantities -- R*, fp, and ne -- are observable with our current technology. By observing many stellar systems, astronomers can come up with reasonable numbers. For example, let's say that astronomers look at 100,000 stars and find that 40,000 have planets. If the rest of the galaxy behaves like these 100,000 stars (and, chances are, it does), fp is 0.4, or 40%. But how would we know if a star has planets?
By watching and waiting for a planet to go in front of its star, astronomers can detect a small change in the star's brightness caused by this transit. They can also look for gravitational evidence of planets, such as changes in the star's orbit. Although such measurements were not possible in Drake's day, 506 exoplanets have been discovered since 1992. Based on the number of stars checked for planets versus the number of stars with planets, astronomers have determined that fp is about 0.4. Drake, without the help of the sensitive telescopes available today, estimated fp to be 0.5 -- pretty close!
R* (star formation rate), however, appears to be much lower than Drake suspected. While data in 1960 suggested that 10 new stars were born every year, the current number is more like 1 star per year. Since the first SETI meeting, we have been able to make many more observations of "star nurseries" -- nebulae, where stars are born -- and to gather statistics on the general population, to find stars' ages and deduce how many were forming at any given time.
Drake estimated ne, the number of habitable planets in each system, to be 2. This estimation was based on our solar system, where one planet is definitely habitable! Mars and moons like Europa and Titan could also still harbor life, or evidence of former life. To be considered habitable, planets need orbits that don't take them too close or too far from their star; they need an atmosphere; and they need access to life-sustaining chemistry, like organic molecules and water. Currently, we are much better at detecting large, hot planets (ones that are like Jupiter) than planets like Earth, so no consensus on this number has been reached. It is estimated to be between 0.5 and 2. As NASA's sensitive Kepler telescope, whose mission is to find exoplanets, provides more data, we will be able to pin ne down.
The last four terms are where the math starts to get dicier. fl, the fraction of planets where life develops, is not something we can currently discover, since we cannot travel to the exoplanets. By looking at their chemistry, we can say whether life is possible -- but not whether life actually is.
Astrobiologists are trying to determine whether, given the conditions for life (conditions like those early in Earth's history), life will arise. Is life inevitable, or is it an anomaly? Drake believed that it was inevitable and set fl to 1. Modern scientists tend to be more conservative with that estimate, so conservative that they don't like to speculate.
After we have life, how much of that life will become intelligent (fi)? Drake said 0.01, but that was even more of a guess than fl. Today, we can do no better. Some say that fi is tiny: of the billions of species on Earth, we are the only one that became intelligent. Others say that all those species were leading inevitably to us, and that given the chance to develop, life will always become intelligent -- meaning that fi would be 1. Who knows?
After smart life exists, what chance does it have of using electromagnetic waves to communicate? Drake said 0.01, or 1%. There is evidence for pretty much any number on the 1-100% spectrum. Until we detect a civilization -- or, really, unless we detect hundreds of civilizations -- we can't know too much about this number. At that point, we won't care very much about the Drake Equation!
The same is true of L, the length of time that a typical civilization communicates: The only example we can have, until we find ETI, is ourselves, and we don't know when our communication will end. A world war could easily end us. So could a supernova. Or runaway greenhouse effect. Or an asteroid. Or, alternatively, civilization could progress for millions of years. The problem is, we'll never know until we get there. Drake said L was 10,000 years, but, again, that was just guessing, and hope.
L is the term that has the most potential to change the equation's outcome. While most parameters must be between 0 and 1, and can only make N smaller, L can be anything. The lifetime of civilizations is the most important factor determining our chances of finding ETI.
Taking the current numbers (or the average of the estimates) and multiplying them, we get N=(1)(0.4)(1)(0.5)(0.5)(0.5)(10,000) -- Drake's L thrown in for good measure -- or
N=500 communicating civilizations in the galaxy.
Our galaxy is pretty big. It's a flat disk about 100,000 light years across and a thousand light years thick. The volume of a disk is its area (pi x radius^2) times its thickness. So:
Volume = pi x (50,000)^2 x 1000 = 8 trillion cubic light years
If evenly spaced throughout the entire galaxy:
8 trillion cu ly / 500 = 1.6 X 10^10 cu Ly per civilization or about 8,000,000,000 Light Years apart!!
But that's a lot of "fringe territory" so lets assume that these civilizations are distributed along the galactic equator, say a slice 10 light years thick, then:
Volume = 3.141 X 50,000^2 X 10 = 7.85 X 10^10 cu ly / 500 = 1.57 X 10^8 cu ly per civilization or roughly 7.85 X 10^7 light years apart
So with distances like these to deal with changing the number of civilizations by 10, 100, or even a 1000 still puts each civilization thousands of light years apart.
The Drake Equation must be one of the SWAGiest equations ever created because of the uncertainty associated with its parameters. The Drake Equation does do a great job of identifying and categorizing the relevant parameters. It also accomplishes the task of providing structure to the ongoing debate about the search for extraterrestrial intelligence and the likelihood of its existence. The large degree of uncertainty associated with so many of its parameters does tell us one important thing: that we have a lot more to learn.
Robert Porter
Senior Master Sergeant
You mean like Scientology? LOL!!!
You are all wrong
It was the Magratheans who constructed the planet-sized computer named Earth (for a race of hyperintelligent pandimensional beings, the mice) to determine the ultimate question of Life, the Universe, and Everything, which is required to understand the Answer to Life, the Universe, and Everything.
It was the Magratheans who constructed the planet-sized computer named Earth (for a race of hyperintelligent pandimensional beings, the mice) to determine the ultimate question of Life, the Universe, and Everything, which is required to understand the Answer to Life, the Universe, and Everything.
Old Wizard
2nd Lieutenant
The Basket
Senior Master Sergeant
- 3,712
- Jun 27, 2007
I wonder if the search for intelligent life on Earth has been successful yet.
Cruising the internet would suggest a big zero on that.
Cruising the internet would suggest a big zero on that.
mikewint
Captain
Last edited:
vikingBerserker
Lieutenant General
I miss the olden days when the stupid people got eaten by lions.
Now they just continue to breed.
Now they just continue to breed.
Old Wizard
2nd Lieutenant
Robert Porter
Senior Master Sergeant
Pretty sure they are a protected species now under EPA rules.
mikewint
Captain
Viking, I'll give you the fact that it's not as easy today as in a bygone age. The morons REALLY have to work at it nowadays and silly things like warning signs, fences, moats, and pay for admission gates are NOT going to stop them!
- Thread starter
- #60
parsifal
Colonel
Oh lord. Stupidity knows no limit for some. I hope those people were eaten to be frank.
