just wondering: suppose an advanced civilization wanted to remain undetectable....should that be figured into the drake equation perhaps?

---

Excellent question. Considering all of the variables already in the Drake Equation I would love to see someone with a good grasp of mathematics take that one on.

After reading your post, my first response was to go and look up the Drake Equation. I was familiar with it but it has been a while since I really looked at it. For those others of you who, like myself, require a little refresher you will find below what I copied from a SETI site:


The Drake Equation was developed by Frank Drake in 1961 as a way to focus on the factors which determine how many intelligent, communicating civilizations there are in our galaxy. The Drake Equation is:

N = N* fp ne fl fi fc fL
The equation can really be looked at as a number of questions:

N* represents the number of stars in the Milky Way Galaxy
Question: How many stars are in the Milky Way Galaxy?
Answer: Current estimates are 100 billion.
fp is the fraction of stars that have planets around them
Question: What percentage of stars have planetary systems?
Answer: Current estimates range from 20% to 50%.
ne is the number of planets per star that are capable of sustaining life
Question: For each star that does have a planetary system, how many planets are capable of sustaining life?
Answer: Current estimates range from 1 to 5.
fl is the fraction of planets in ne where life evolves
Question: On what percentage of the planets that are capable of sustaining life does life actually evolve?
Answer: Current estimates range from 100% (where life can evolve it will) down to close to 0%.
fi is the fraction of fl where intelligent life evolves
Question: On the planets where life does evolve, what percentage evolves intelligent life?
Answer: Estimates range from 100% (intelligence is such a survival advantage that it will certainly evolve) down to near 0%.
fc is the fraction of fi that communicate
Question: What percentage of intelligent races have the means and the desire to communicate?
Answer: 10% to 20%
fL is fraction of the planet's life during which the communicating civilizations live
Question: For each civilization that does communicate, for what fraction of the planet's life does the civilization survive?
Answer: This is the toughest of the questions. If we take Earth as an example, the expected lifetime of our Sun and the Earth is roughly 10 billion years. So far we've been communicating with radio waves for less than 100 years. How long will our civilization survive? Will we destroy ourselves in a few years like some predict or will we overcome our problems and survive for millennia? If we were destroyed tomorrow the answer to this question would be 1/100,000,000th. If we survive for 10,000 years the answer will be 1/1,000,000th.
When all of these variables are multiplied together when come up with:
N, the number of communicating civilizations in the galaxy.


The real value of the Drake Equation is not in the answer itself, but the questions that are prompted when attempting to come up with an answer. Obviously there is a tremendous amount of guess work involved when filling in the variables.

---

To the victor goes not only the spoils of war but, more importantly, the bias of history.

just wondering: suppose an advanced civilization wanted to remain undetectable....should that be figured into the drake equation perhaps?

Nobody on this planet can even start to estimate this number.
In theory 100% want to remain undetectable or 0% or any number in between.

We lack information..

---

Would an alien race which WAS in the current stage of technological development we are right now have the foresight to ban radio and electromagnetic communication in order to remain silent to the galaxy?

Perhaps. We cannot hope to understand alien psychology.

But i think not.

If a race started transmitting 10,000 years ago. Transmitted for a few hundred years then stopped because they wanted to remain hidden to the galaxies other civilizations, that would STILL mean there is an expanding bubble of radio emissions from the time they did transmit. If we are SUPREMELY lucky, we may pick up that sweet spot in their history when they did transmit.

The other possibility is that they have access to vast and god like technologies which can filter out synthetic radio emissions and stop them reaching earth. I find that scenario both unlikely and scary. A good plot for a sci-fi maybe.

Who says there's only one group that wants to remain hidden?
Who says they use radio?
Why says they are intelligent?
Who says they even exist at all?

We just don't know. But science is the search for truth, and that's what we are all here for.

In my view there are alien civilizations out there, and whatever level of technological development they are at, I'm sure we'll pick up radio signals from some period in their history.

. . . THAT "sweet spot" i believe, was once a Candidate during Classic SETI Days - was re-observed and then during the switCh-over to BOINC @ some tiME,

THAT same area was re-scanned & re-observed again [1999 - 2009] with the SETI@home Project's [Arecibo] Telescope . . .

> that Candidate: SAHGn18+13ce Remains INVISIBLE Today . . .



wonderin' IF 'thEy' know . . .

---

BOINC Wiki . . .

Science Status Page . . .

. . . wonderin' Out-Loud, if THIS Image could [mean] anything: in terms of a 'Message'




from a data cube: MF2mid - the heart-shaped filaments - on an opposite side of our local Spiral arm

- from the Canadian Galactic Plane Survey [& from the same 'cube' meaning that they are all the same piece of sky,

just emission at different 'channels' of the HI spectrometer] . . .


Thanks to KDPhD

Note: doesn't 'seem' THAT Invisible to me @ least . . . ;)

---

BOINC Wiki . . .

Science Status Page . . .

. . . wonderin' Out-Loud, if THIS Image could [mean] anything: in terms of a 'Message'




from a data cube: MF2mid - the heart-shaped filaments - on an opposite side of our local Spiral arm

- from the Canadian Galactic Plane Survey [& from the same 'cube' meaning that they are all the same piece of sky,

just emission at different 'channels' of the HI spectrometer] . . .


Thanks to KDPhD

Note: doesn't 'seem' THAT Invisible to me @ least . . . ;)

Regardless of intended or unintended message or just beautiful to behold, a great image. Thank you.

---

To the victor goes not only the spoils of war but, more importantly, the bias of history.

. . . THAT "sweet spot" i believe, was once a Candidate during Classic SETI Days - was re-observed and then during the switCh-over to BOINC @ some tiME,

THAT same area was re-scanned & re-observed again [1999 - 2009] with the SETI@home Project's [Arecibo] Telescope . . .

> that Candidate: SAHGn18+13ce Remains INVISIBLE Today . . .



wonderin' IF 'thEy' know . . .

Forbidden
You don't have permission to access /Candidates/reobs/SAHGn18+13ce/ on this server.

OOps my bad

---

Old enough to know better(but)still young enough not to care

. . . THAT "sweet spot" i believe, was once a Candidate during Classic SETI Days - was re-observed and then during the switCh-over to BOINC @ some tiME,

THAT same area was re-scanned & re-observed again [1999 - 2009] with the SETI@home Project's [Arecibo] Telescope . . .

> that Candidate: SAHGn18+13ce Remains INVISIBLE Today . . .



wonderin' IF 'thEy' know . . .

Forbidden
You don't have permission to access /Candidates/reobs/SAHGn18+13ce/ on this server.

OOps my bad

. . . still remains to be seen: i 'personally' would really like to see that again - where do 'Candidates' go anyway ? ;))

[i believe it doesn't 'exist' any longer on the Server @ Berkeley]

---

BOINC Wiki . . .

Science Status Page . . .

. . . THAT "sweet spot" i believe, was once a Candidate during Classic SETI Days - was re-observed and then during the switCh-over to BOINC @ some tiME,

THAT same area was re-scanned & re-observed again [1999 - 2009] with the SETI@home Project's [Arecibo] Telescope . . .

> that Candidate: SAHGn18+13ce Remains INVISIBLE Today . . .



wonderin' IF 'thEy' know . . .

Forbidden
You don't have permission to access /Candidates/reobs/SAHGn18+13ce/ on this server.

OOps my bad

. . . still remains to be seen: i 'personally' would really like to see that again - where do 'Candidates' go anyway ? ;))

[i believe it doesn't 'exist' any longer on the Server @ Berkeley]

If it does still exist on the server perhaps a prime candidate for the NitPicker.

---

Old enough to know better(but)still young enough not to care

. . . THAT "sweet spot" i believe, was once a Candidate during Classic SETI Days - was re-observed and then during the switCh-over to BOINC @ some tiME,

THAT same area was re-scanned & re-observed again [1999 - 2009] with the SETI@home Project's [Arecibo] Telescope . . .

> that Candidate: SAHGn18+13ce Remains INVISIBLE Today . . .



wonderin' IF 'thEy' know . . .

Forbidden
You don't have permission to access /Candidates/reobs/SAHGn18+13ce/ on this server.

OOps my bad

. . . still remains to be seen: i 'personally' would really like to see that again - where do 'Candidates' go anyway ? ;))

[i believe it doesn't 'exist' any longer on the Server @ Berkeley]

If it does still exist on the server perhaps a prime candidate for the NitPicker.

< i believe that' NTPCkr . . . ;)

---

BOINC Wiki . . .

Science Status Page . . .

https://setisvn.ssl.berkeley.edu/trac/export/329/seti_boinc_html/sah_sci_newsletters/rescore/gn_rescored.html


Non-Barycentric Gaussians: Rescored Candidates

AH bon ?!?

---

SETI@Home Informational message -9 result_overflow
with a general handicap of 80% and it makes much d' efforts for the community and s' expimer, thank you d' to be understanding.

https://setisvn.ssl.berkeley.edu/trac/export/329/seti_boinc_html/sah_sci_newsletters/rescore/gn_rescored.html


Non-Barycentric Gaussians: Rescored Candidates

AH bon ?!?

Thanks [c'est bon!!!]

SAHGn18+13ce / -11.41146 / -30.70852 - better

Q. how would you locate the actual date / position of that 'portion of the scan / sky' . . . wonderin' IF it's from the Year 1999 ???

Q. Comment voulez-vous situer la date effective / position de ce «portion du scan / ciel» . . . Si' si c'est de l'année 1999 ???

---

BOINC Wiki . . .

Science Status Page . . .

Excellent question. Considering all of the variables already in the Drake Equation I would love to see someone with a good grasp of mathematics take that one on.

After reading your post, my first response was to go and look up the Drake Equation. I was familiar with it but it has been a while since I really looked at it. For those others of you who, like myself, require a little refresher you will find below what I copied from a SETI site:


The Drake Equation was developed by Frank Drake in 1961 as a way to focus on the factors which determine how many intelligent, communicating civilizations there are in our galaxy. The Drake Equation is:

N = N* fp ne fl fi fc fL
The equation can really be looked at as a number of questions:

N* represents the number of stars in the Milky Way Galaxy
Question: How many stars are in the Milky Way Galaxy?
Answer: Current estimates are 100 billion.
fp is the fraction of stars that have planets around them
Question: What percentage of stars have planetary systems?
Answer: Current estimates range from 20% to 50%.
ne is the number of planets per star that are capable of sustaining life
Question: For each star that does have a planetary system, how many planets are capable of sustaining life?
Answer: Current estimates range from 1 to 5.
fl is the fraction of planets in ne where life evolves
Question: On what percentage of the planets that are capable of sustaining life does life actually evolve?
Answer: Current estimates range from 100% (where life can evolve it will) down to close to 0%.
fi is the fraction of fl where intelligent life evolves
Question: On the planets where life does evolve, what percentage evolves intelligent life?
Answer: Estimates range from 100% (intelligence is such a survival advantage that it will certainly evolve) down to near 0%.
fc is the fraction of fi that communicate
Question: What percentage of intelligent races have the means and the desire to communicate?
Answer: 10% to 20%
fL is fraction of the planet's life during which the communicating civilizations live
Question: For each civilization that does communicate, for what fraction of the planet's life does the civilization survive?
Answer: This is the toughest of the questions. If we take Earth as an example, the expected lifetime of our Sun and the Earth is roughly 10 billion years. So far we've been communicating with radio waves for less than 100 years. How long will our civilization survive? Will we destroy ourselves in a few years like some predict or will we overcome our problems and survive for millennia? If we were destroyed tomorrow the answer to this question would be 1/100,000,000th. If we survive for 10,000 years the answer will be 1/1,000,000th.
When all of these variables are multiplied together when come up with:
N, the number of communicating civilizations in the galaxy.


The real value of the Drake Equation is not in the answer itself, but the questions that are prompted when attempting to come up with an answer. Obviously there is a tremendous amount of guess work involved when filling in the variables.

http://www.pbs.org/lifebeyondearth/listening/drake.html

Calculator :)[/url]

---

SETI@Home Informational message -9 result_overflow
with a general handicap of 80% and it makes much d' efforts for the community and s' expimer, thank you d' to be understanding.

https://setisvn.ssl.berkeley.edu/trac/export/329/seti_boinc_html/sah_sci_newsletters/rescore/gn_rescored.html


Non-Barycentric Gaussians: Rescored Candidates

AH bon ?!?

Thanks [c'est bon!!!]

SAHGn18+13ce / -11.41146 / -30.70852 - better

Q. how would you locate the actual date / position of that 'portion of the scan / sky' . . . wonderin' IF it's from the Year 1999 ???

Q. Comment voulez-vous situer la date effective / position de ce «portion du scan / ciel» . . . Si' si c'est de l'année 1999 ???

https://setisvn.ssl.berkeley.edu/trac/export/329/seti_boinc_html/sah_sci_newsletters/rescore/index.html

---

SETI@Home Informational message -9 result_overflow
with a general handicap of 80% and it makes much d' efforts for the community and s' expimer, thank you d' to be understanding.

Excellent question. Considering all of the variables already in the Drake Equation I would love to see someone with a good grasp of mathematics take that one on.

After reading your post, my first response was to go and look up the Drake Equation. I was familiar with it but it has been a while since I really looked at it. For those others of you who, like myself, require a little refresher you will find below what I copied from a SETI site:


The Drake Equation was developed by Frank Drake in 1961 as a way to focus on the factors which determine how many intelligent, communicating civilizations there are in our galaxy. The Drake Equation is:

N = N* fp ne fl fi fc fL
The equation can really be looked at as a number of questions:

N* represents the number of stars in the Milky Way Galaxy
Question: How many stars are in the Milky Way Galaxy?
Answer: Current estimates are 100 billion.
fp is the fraction of stars that have planets around them
Question: What percentage of stars have planetary systems?
Answer: Current estimates range from 20% to 50%.
ne is the number of planets per star that are capable of sustaining life
Question: For each star that does have a planetary system, how many planets are capable of sustaining life?
Answer: Current estimates range from 1 to 5.
fl is the fraction of planets in ne where life evolves
Question: On what percentage of the planets that are capable of sustaining life does life actually evolve?
Answer: Current estimates range from 100% (where life can evolve it will) down to close to 0%.
fi is the fraction of fl where intelligent life evolves
Question: On the planets where life does evolve, what percentage evolves intelligent life?
Answer: Estimates range from 100% (intelligence is such a survival advantage that it will certainly evolve) down to near 0%.
fc is the fraction of fi that communicate
Question: What percentage of intelligent races have the means and the desire to communicate?
Answer: 10% to 20%
fL is fraction of the planet's life during which the communicating civilizations live
Question: For each civilization that does communicate, for what fraction of the planet's life does the civilization survive?
Answer: This is the toughest of the questions. If we take Earth as an example, the expected lifetime of our Sun and the Earth is roughly 10 billion years. So far we've been communicating with radio waves for less than 100 years. How long will our civilization survive? Will we destroy ourselves in a few years like some predict or will we overcome our problems and survive for millennia? If we were destroyed tomorrow the answer to this question would be 1/100,000,000th. If we survive for 10,000 years the answer will be 1/1,000,000th.
When all of these variables are multiplied together when come up with:
N, the number of communicating civilizations in the galaxy.


The real value of the Drake Equation is not in the answer itself, but the questions that are prompted when attempting to come up with an answer. Obviously there is a tremendous amount of guess work involved when filling in the variables.

http://www.pbs.org/lifebeyondearth/listening/drake.html

Calculator :)[/url]

Thank you for the web address. I did enjoy it. I must say that my estimate was lower than Drake's, but then again he knew more about it than I do.

---

To the victor goes not only the spoils of war but, more importantly, the bias of history.