Other Worlds: Thoughts to Encourage the Interested
Created | Updated Jul 12, 2006
Note: This does not pretend to be a technical treatise on extrasolar planets but is intended to generate thought about, and encourage research into what lies out in horribly deep space.
Of the estimated 300 billion stars in the Milky Way Galaxy alone it is already known there are an infinite number of planets in orbit around lots of them. Infinite as in ‘great, very many’. Just how that infinite number of planets is made finite is the tricky bit, although a few (over 154 in the last 10 years or so*1) have already been detected. What is even trickier is finding the number of planets where life in one form or another exists. The even trickier part of the trickier bit is finding the number of planets where intelligent life exists or could exist. To take it one stage further, finding the number of planets where technically advanced intelligent life exists is at present beyond the descriptive tricky, but more power to the elbows of those trying.
Whilst all forms of life in the galaxy and by default the rest of the universe are of great scientific interest, it is the technically advanced variety capable of communicating which really gets the attention of a lot of logical, open minded, forward thinking people. Included here are all those astrobiologists et al to whom the detection of other non-communicating life-forms are their important (and rightly so too), thing.
Given the mind boggling size of our galaxy, life which is technically capable of communication in one form or another must by probability alone when taken in conjunction with the vast numbers of stars and planets involved, exist in more places than just the one (i.e. us). This singular assumption can and should be accepted with more confidence than it is in some quarters. Bold statement of fact without proof? Yes. Proof is of course required in all science but such a positive statement should, given what is already known and can be extrapolated from that knowledge, be up there at the forefront of progressive scientific thinking along with all the hard facts. Science should at our stage of development be looking not just at facts but also ‘outside the box’.
Whether any such technically advanced life out there would want to communicate with other life is another matter. Indeed, whether from the point of view of this planet particularly in its present cultural state it is desirable to have such a link or even [public] knowledge of other non- terrestrial life is a question on the huge side of massive. And, given the staggering problems, diversity of opinion and lets face it panic it would throw up, maybe not for discussion in this entry. However, it is bordering on arrogance for anyone to seriously think that Earth is home to the only sentient beings in the entire universe.
It is well known that serious scientific research into and for extra terrestrial intelligence has been well under way for many years and technology has advanced to the point where individual planets can and are being detected. Given the leap forward in our technical expertise it seems clear that this branch of the search should be pushed to the forefront and steps have already been taken by a number of scientists to do just that. This enlightened research should be vigorously
encouraged and not just at the professional level; amateur astronomers and planet seekers can and should be involved. Even just finding new planets whether life bearing or not is progress in itself and another big step forward in our knowledge of the universe and what makes it tick.
If anyone wants to play around with figures, the Drake equation is set out below. This puts into some sort of perspective the number of likely candidate planets in the Milky Way galaxy alone, never mind The Local Group, The Local Supercluster or anywhere else that could be technically capable of sporting communicative life.
Communicating with other intelligent life is one thing but actually travelling to distant reaches of the galaxy or indeed meeting up with fellow inhabitants is entirely another matter. If we really want to do the travelling as many do then an entirely new can of technical worms is opened up. To this end the reader may wish to explore the fascinating ideas put forward in the entry ‘The Valkyrie Project – The next Giant Leap?’ by Cardi-Bling.
Some Technical Stuff.
The Drake Equation (Frank Drake 1961): N* fp ne fI fi fc fL
Where:
N* = the number of stars in the Milky Way galaxy (current est. 300 billion)
fp = fraction of stars with planets around them.
ne = number of planets per star ecologically able to sustain life
fI = fraction of those planets where life actually evolves
fi = the fraction of fl that evolves intelligent life
fc = the fraction of fi that communicates
fL = the fraction of the planet's life during which the communicating civilizations survives
The following example puts some flesh on the bones:
N* = 300 billion
fp = 50%
ne = 1
fl = 50%
fi = 20%
fc = 20%
fL = 10,000
On these figures the result is 3,000. Playing around with the figures does of course produce differant answers at the whim of the reader and the latest information to hand, but even with modest figures the case for there being multiple communicating civilisatons is still at worst, good. And that is just for this galaxy.
Planetary discoveries outside the solar system: currently [February 2006] in excess of 154, many of them gas giants. For the purposes of extraterrestrial life capable of communication, a planet can be defined as any solid body above asteroid size capable of retaining an atmosphere.
Extrasolar planetary detection: the majority discovered by the spectroscopic Doppler method.
The Kepler mission: due to launch in 2008 will look for the dimming of stars caused by planets that produce mini-eclipses when, in the course of their orbit they transit the star’s disk.*2
Although the planned NASA Terrestrial Planet Finder (TPF) has recently been shelved, the ESA Darwin mission is being designed to directly detect and characterise terrestrial extrasolar planets. The mission is due to launch within the next 10 to 15 years [2006+]. The Darwin instruments will search for terrestrial planets around a core sample of at least 35 nearby stars, with a goal to observe as many as 250.*3
Speed of Light: in excess of 186,000 miles per second or around 7,000,000 mph (ish)
Time for light to cross the Milky Way galaxy: 100,000 years
Number of stars in the Milky Way galaxy: Estimated to be 300 billion
Number of stars in the nearest galaxy to us: Estimated to be 600 billion
Number of galaxies in the universe: Unknown. Estimated to be 100 - 300 billion
1 Billion: English = 1 million million. American = 1,000 million. Touch of a difference there.
Sources:
*1 Giovana Tinetti, SETI
*2 Seth Shostak, SETI
*3 Giovana Tinetti, SETI & info from The Planetary Society.
Of the estimated 300 billion stars in the Milky Way Galaxy alone it is already known there are an infinite number of planets in orbit around lots of them. Infinite as in ‘great, very many’. Just how that infinite number of planets is made finite is the tricky bit, although a few (over 154 in the last 10 years or so*1) have already been detected. What is even trickier is finding the number of planets where life in one form or another exists. The even trickier part of the trickier bit is finding the number of planets where intelligent life exists or could exist. To take it one stage further, finding the number of planets where technically advanced intelligent life exists is at present beyond the descriptive tricky, but more power to the elbows of those trying.
Whilst all forms of life in the galaxy and by default the rest of the universe are of great scientific interest, it is the technically advanced variety capable of communicating which really gets the attention of a lot of logical, open minded, forward thinking people. Included here are all those astrobiologists et al to whom the detection of other non-communicating life-forms are their important (and rightly so too), thing.
Given the mind boggling size of our galaxy, life which is technically capable of communication in one form or another must by probability alone when taken in conjunction with the vast numbers of stars and planets involved, exist in more places than just the one (i.e. us). This singular assumption can and should be accepted with more confidence than it is in some quarters. Bold statement of fact without proof? Yes. Proof is of course required in all science but such a positive statement should, given what is already known and can be extrapolated from that knowledge, be up there at the forefront of progressive scientific thinking along with all the hard facts. Science should at our stage of development be looking not just at facts but also ‘outside the box’.
Whether any such technically advanced life out there would want to communicate with other life is another matter. Indeed, whether from the point of view of this planet particularly in its present cultural state it is desirable to have such a link or even [public] knowledge of other non- terrestrial life is a question on the huge side of massive. And, given the staggering problems, diversity of opinion and lets face it panic it would throw up, maybe not for discussion in this entry. However, it is bordering on arrogance for anyone to seriously think that Earth is home to the only sentient beings in the entire universe.
It is well known that serious scientific research into and for extra terrestrial intelligence has been well under way for many years and technology has advanced to the point where individual planets can and are being detected. Given the leap forward in our technical expertise it seems clear that this branch of the search should be pushed to the forefront and steps have already been taken by a number of scientists to do just that. This enlightened research should be vigorously
encouraged and not just at the professional level; amateur astronomers and planet seekers can and should be involved. Even just finding new planets whether life bearing or not is progress in itself and another big step forward in our knowledge of the universe and what makes it tick.
If anyone wants to play around with figures, the Drake equation is set out below. This puts into some sort of perspective the number of likely candidate planets in the Milky Way galaxy alone, never mind The Local Group, The Local Supercluster or anywhere else that could be technically capable of sporting communicative life.
Communicating with other intelligent life is one thing but actually travelling to distant reaches of the galaxy or indeed meeting up with fellow inhabitants is entirely another matter. If we really want to do the travelling as many do then an entirely new can of technical worms is opened up. To this end the reader may wish to explore the fascinating ideas put forward in the entry ‘The Valkyrie Project – The next Giant Leap?’ by Cardi-Bling.
Some Technical Stuff.
The Drake Equation (Frank Drake 1961): N* fp ne fI fi fc fL
Where:
N* = the number of stars in the Milky Way galaxy (current est. 300 billion)
fp = fraction of stars with planets around them.
ne = number of planets per star ecologically able to sustain life
fI = fraction of those planets where life actually evolves
fi = the fraction of fl that evolves intelligent life
fc = the fraction of fi that communicates
fL = the fraction of the planet's life during which the communicating civilizations survives
The following example puts some flesh on the bones:
N* = 300 billion
fp = 50%
ne = 1
fl = 50%
fi = 20%
fc = 20%
fL = 10,000
On these figures the result is 3,000. Playing around with the figures does of course produce differant answers at the whim of the reader and the latest information to hand, but even with modest figures the case for there being multiple communicating civilisatons is still at worst, good. And that is just for this galaxy.
Planetary discoveries outside the solar system: currently [February 2006] in excess of 154, many of them gas giants. For the purposes of extraterrestrial life capable of communication, a planet can be defined as any solid body above asteroid size capable of retaining an atmosphere.
Extrasolar planetary detection: the majority discovered by the spectroscopic Doppler method.
The Kepler mission: due to launch in 2008 will look for the dimming of stars caused by planets that produce mini-eclipses when, in the course of their orbit they transit the star’s disk.*2
Although the planned NASA Terrestrial Planet Finder (TPF) has recently been shelved, the ESA Darwin mission is being designed to directly detect and characterise terrestrial extrasolar planets. The mission is due to launch within the next 10 to 15 years [2006+]. The Darwin instruments will search for terrestrial planets around a core sample of at least 35 nearby stars, with a goal to observe as many as 250.*3
Speed of Light: in excess of 186,000 miles per second or around 7,000,000 mph (ish)
Time for light to cross the Milky Way galaxy: 100,000 years
Number of stars in the Milky Way galaxy: Estimated to be 300 billion
Number of stars in the nearest galaxy to us: Estimated to be 600 billion
Number of galaxies in the universe: Unknown. Estimated to be 100 - 300 billion
1 Billion: English = 1 million million. American = 1,000 million. Touch of a difference there.
Sources:
*1 Giovana Tinetti, SETI
*2 Seth Shostak, SETI
*3 Giovana Tinetti, SETI & info from The Planetary Society.
