It looks like you're using an Ad Blocker.

Please white-list or disable AboveTopSecret.com in your ad-blocking tool.

Thank you.

 

Some features of ATS will be disabled while you continue to use an ad-blocker.

 

The More Earth-Like Planets = The Lesser the Probability of Intelligent Alien Life???

page: 3
10
<< 1  2    4  5 >>

log in

join
share:

posted on Nov, 6 2013 @ 07:49 PM
link   

Ross 54
The scrambling of electromagnetic signals wouldn't even have be be on our account. As such signals become more efficient; more tightly beamed, and digitized, the more easily they can appear to the uninitiated as pure noise.
Communications theory finds that the most efficient signal is virtually indistinguishable from noise, without the proper decoding protocol.
These signal would also presumably be sent through bulk space, making a detour around normal space, achieving an effective speed well beyond that of light.
edit on 6-11-2013 by Ross 54 because: (no reason given)

edit on 6-11-2013 by Ross 54 because: (no reason given)


Agreed 100%.

The thing about our planet is that it has been getting quieter and quieter in the radio spectrum since about 1975. That is because we have more efficient ways of communicating involving spread spectrum, high bandwidth encoding, etc.

Even the carrier signals for such have been going down as we use fiber optics where once we used microwave towers for long distance telephone relays.

High power military radar is still in use but even that has gone down since the end of the cold war.

It could be that the more advanced a civilization gets, the more radio quiet they become.


However, one area where we have become louder and louder is the use of artificial light on larger and larger swaths of the earth. Also our use of energy produces waste heat,

Both of these things might be able to be detected.


I know you've seen this stuff Ross but some other people might want to have a look at this article:

"Detecting ET’s city lights" - www.astronomynow.com...

And these videos:



Google Hangout about it:


edit on 6-11-2013 by JadeStar because: (no reason given)

edit on 6-11-2013 by JadeStar because: (no reason given)




posted on Nov, 6 2013 @ 07:58 PM
link   

Ross 54
The scrambling of electromagnetic signals wouldn't even have be be on our account. As such signals become more efficient; more tightly beamed, and digitized, the more easily they can appear to the uninitiated as pure noise.


Actually the "tightly beamed" part; not so much, the efficient part, you betcha. Your wifi signal is either a 2.5Ghz or a 5Ghz carrier with up to a 100 MHz bandwidth for the data. If you could hear it; it would sound like nearly white noise.



Communications theory finds that the most efficient signal is virtually indistinguishable from noise, without the proper decoding protocol.
These signal would also presumably be sent through bulk space, making a detour around normal space, achieving an effective speed well beyond that of light.


I don't know about "bulk space", but, Maxwell (famous for electromagnetism, and some other stuff) had advanced equations that seemed to introduce the dimension of time to the propagation of EM fields. It seems that under the right conditions the "time vector" can be reversed; allowing for a signal being received before it is sent. The problem with these equations is that it is quite advanced vector and matrix math...not my strong suit.



posted on Nov, 6 2013 @ 08:10 PM
link   

JadeStar
The thing about our planet is that it has been getting quieter and quieter in the radio spectrum since about 1975. That is because we have more efficient ways of communicating involving spread spectrum, high bandwidth encoding, etc.

Even the carrier signals for such have been going down as we use fiber optics where once we used microwave towers for long distance telephone relays.

High power military radar is still in use but even that has gone down since the end of the cold war.

It could be that the more advanced a civilization gets, the more radio quiet they become.


Actually, not so much use of the fiber optics, except for "end users" from providers like Version.

The microwave towers have been replaced though, with satellite links, unless you are making a call across town, it probably goes through a satellite, and even then it would depend on traffic.

The thing is, it doesn't take as much RF power to reach space as it does to bounce a signal off the troposphere for long distance communication, thus the reduced RF signature.

And I would agree completely, advanced civilizations have a rather small RF signature; likely low power, very high frequency (microwave > 2.5 GHZ) with multiple high bandwidth channels. Kind of like Earth has now.



posted on Nov, 6 2013 @ 09:03 PM
link   
I was curious to see how many G-type stars there are within a relatively short distance from us. I found the information here. The number is about 512 within a hundred-light-year volume. Within fifty light-years of Sol, there are only about 64.

We're hearing now that one in fifty of these has a planet in the Goldilocks Zone. So: about ten such planets within a hundred light-years of us, and only one (that would be Earth) within fifty.

Even if every such planet sprouted intelligent life, you can forget about any aliens finding us in a hurry. Or us finding them. The volume of space involved is so huge it couldn't happen except by a giant fluke.

And, of course, it would be silly to believe that every Goldilocks Zone planet evolved life, far less intelligent life.

My own view is that life is ubiquitous in the Galaxy and intelligence very rare, almost nonexistent. However, none of us — not even the best-informed exobiologist — has anything better to offer on this than a guess.

UFO enthusiasts and people looking for green-skinned messiahs to save us from ourselves will be disappointed by the odds, but anyone who has looked at this First Encounter business in pragmatic terms will be profoundly relieved. The probability of discovering intelligent alien life — or it discovering us — is almost zero. Long may it remain thus.


edit on 6/11/13 by Astyanax because: of longer odds.



posted on Nov, 6 2013 @ 09:28 PM
link   

Astyanax
I was curious to see how many G-type stars there are within a relatively short distance from us. I found the information here. The number is about 512 within a hundred-light-year volume. Within fifty light-years of Sol, there are only about 64.


You forgot K stars.

The study covers G and K stars.

The majority of stars in our Galaxy are K (8%) and M (80%) (88%). Both K and M stars last a lot longer than G-starss.



So yeah, throw in those K-stars.



Even if every such planet sprouted intelligent life, you can forget about any aliens finding us in a hurry. Or us finding them. The volume of space involved is so huge it couldn't happen except by a giant fluke.


Careful here. I'd caution against that line of thinking for a good reason: We know how to find them if they exist.

Assuming the 1% of habitable terrestrial planets (or moons) produces a technological civilization then that would equal about 6 of those per 100 light year radius.

We could easily find a good amount of aliens to the point where we could resolve their houses if we simply placed a hubble sized telescope at our Sun's gravitational lens focus (about 550 AU or 550 times as far from the Sun as the Earth is from the Sun).

All that mission costs is money.

I would think that an alien economy might be a little better than ours.

And like I said, it looks like it may be possible to detect alien city lights at interstellar distances with the right sized telescope and spectrograph.

And there are other ideas/projects (Colossus) which could detect waste heat.

Add on to all of this, our Earth has been sending a very loud signal that life exists here for about 3 billion years as there are gasses in our atmosphere in certain ratios that are like a 'cosmic fingerprint' that life exists here.

So alien astronomers could very well have known a billion, 2 billion or even 3 billion years ago that our planet had life. What they would not have known is that it now has intelligent life -UNLESS- they were within 115 light years (the first artificial city lights started back in the late 1800s).

And our radio signature only goes out to about 60-65 light years.

So imagine 3 shells around the Earth out to the following distances

The smallest is our radio signature = 60-65 light years

The middle one is our artificial light signature = 115 light years

The largest is our life signature which could be anywhere from 2-3 billion light years (

That's almost the distance to the next galaxy, Andromeda.

So, contrary to popular belief, any aliens who had enough ambition to systematically look for life in our Galaxy quite likely know the Earth has life and if they are within the 115 light year radius that our artificial light radius encompasses then they'd know intelligent, technological life was/is here.


edit on 6-11-2013 by JadeStar because: (no reason given)



posted on Nov, 6 2013 @ 10:41 PM
link   
reply to post by JadeStar
 


Gosh, this really means a lot to you, doesn't it?


You forgot K stars.

Roughly a thousand within 100lY, 155 within 50LY. Source

Now you've got thirty Goldilocks Zone planets within 100LY, and four within 50LY. Doesn't improve the odds very much.


We know how to find them if they exist.

The chance of finding one with intelligent life on it is still effectively zero. What are you going to do, send unmanned probes to 1,500 stars and wait for them to come back from round-trips lasting hundreds or thousands of years? All that guff about waste heat and the rest is just hopeful speculation. We don't know enough to define the parameters of such experiments, even if we had the economic and technological capability to achieve them. A Hubble-type telescope 550AU from Earth? Why not just build a starship?

You are blithely assuming that
  1. Technological civilisations never collapse.

  2. Intelligent species never go extinct.

Both assumptions are wrong. Terrestrial civilisations, technological or not, have lifespans of a few hundred years at most. Intelligent species do go extinct; at least two already have on our planet alone.


Assuming the 1% of habitable terrestrial planets (or moons) produces a technological civilization...

Another piece of hopeful guesswork, far divorced from the reality of what we know.


edit on 6/11/13 by Astyanax because: of guessful hopework.



posted on Nov, 7 2013 @ 12:28 AM
link   

Astyanax
reply to post by JadeStar
 


Gosh, this really means a lot to you, doesn't it?


Well it's my field of study so I tend to be pretty deep into it and in the spirit of "Deny Ignorance" I'm correcting some incorrect information.

I spend a lot of time keeping up on the subject, doing coursework, attending lectures, doing data reduction, looking at models of various things, even a little observation as part of both my education and pleasure. Much of which requires advanced math... (not that I love -that- part of things but its very necessary).

This is probably a good thing as I'll likely be writing some papers beyond my undergrad status soon




Roughly a thousand within 100lY, 155 within 50LY. Source


Before I caution you about using Solstation as your only source of this information I will say that you have to be very careful with your math.

As for Solstation it's a nice site but it is not updated enough nor is it by any means, complete. If you talk to the guy who runs it he'll tell you as much.

It's a better idea to use the SIMBAD database which has everything from the Hipparcos catalog and beyond. SIMBAD is commonly used by most people in this field.

So there is a pretty large discrepancy between your numbers and the actual true numbers of stars of G and K spectral classes within 100 light years.

A simple query of G stars within 31 parsecs (101 light years) turns up 2427 G stars. Source.

A simple query of K stars within 31 parsecs (101 light years) turns up 2677 K stars. Source.

Total of G and K stars within 100 light years = 5,104

So you're off by a factor of 5. And that does change things considerably.

By the way if you counted all stars within 100 light years you're going to get a number around 14,600. Source.
Using the 0.120 stars/cubic parsec number, and using a volume for a distance 100 light-years = 100/3.26 = 30.7 parsecs

Number = density * volume
= 0.120 stars/cubic parsec * 4/3 pi (30.7 parsecs)^3
= 14,600 stars




Now you've got thirty Goldilocks Zone planets within 100LY, and four within 50LY. Doesn't improve the odds very much.


We call them 'habitable zones' (they are only called goldilocks zones by the media and general public because its an easy way to remember what they are, i.e.: just right, not too hot, not too cold). And your numbers are wrong because you started with a wrong assumption.


The chance of finding one with intelligent life on it is still effectively zero.


Really? Show your work. How did you determine this? Because if you did, you just might win a Nobel Prize.



What are you going to do, send unmanned probes to 1,500 stars and wait for them to come back from round-trips lasting hundreds or thousands of years?


No.

Luckily there are things which an intelligent species (even if you include ourselves) do that are detectable from interstellar distances. Among them... lighting up cities with artificial light, using energy at our level or above, and of course emissions due to communication or power transmission (microwaves/radio, etc).

There are probably things detectable by us such as Dyson Spheres or Dyson Shells (again look it up if you don't know what those are) which are beyond our current construction ability but not beyond our current engineering ability.

And that doesn't even get onto the subject of exotic physics like warp drives, wormholes, etc which may be detectable through microlensing surveys (again if you don't know what microlensing is, there is a whole page on Wiki to bring you up to speed) or via gravity wave interferometers in space (i referenced one such cancelled space interferometer to look for gravity waves called LISA, go back in the thread and read the link.)

NONE of this requires sending a probe to another star. All it requires is building instruments to collect the signatures of technology which are or may be detectable over interstellar distances.

You know, kind of like how we are finding all of these planets.... Big telescopes on Earth... Modest sized ones in orbit around Earth or the Sun.

You just need to build big freaking telescopes or send one the size of Hubble out to our Suns gravitational lens (if you don't know what a gravitational lens is then let Wiki be your friend as I have already explained what it is capable of).



All that guff about waste heat and the rest is just hopeful speculation.


Actually it isn't. But I assume you haven't read the papers nor done the math. If you want I can refer you to them.


We don't know enough to define the parameters of such experiments.


We do. We just haven't built them yet. BTW: Colossus likely will be built as it is planned to be entirely privately funded, like the ATA and most large optical telescopes.


"Even if we had the economic and technological capability to achieve them. A Hubble-type telescope 550AU from Earth? Why not just build a starship?"


If you don't know the answer to that well there is no hope of talking with you further about this. But for the benefit of anyone else reading this.....

Getting to the Suns gravitational lens is a mission that could be done within our lifetime with present day technology which has existed since the 1960s ie: Nuclear fission propulsion or Electric Ion propulsion.

Getting to the next star, Proxima Centauri even with the most ambitious proposal (Project Longshot) would take 100 years IF it worked at all.

And it would take some PRETTY DUMB aliens to build a starship and send it aimlessly around the Galaxy rather than use it to travel to places they already know a) have life or b) have technological life, which they could find out without interstellar travel simply through good astronomy and big freakin telescopes.

And that only assumes aliens with our present or near term level of observing technology.

When talking aliens you should realize that due to the age of the Galaxy statistically most will be older than us, some of them substantially. We're not talking just by 100 years or even 1000 years but a million or even several billion year.

To say "Blah blah blah this is hard for us, we don't have the money or interest so neither do they." is the height of hubris and blind assumption given what we know and more importantly what we DON'T know about what's out there.


You are blithely assuming that
  1. Technological civilisations never collapse.


Not at all. But its a numbers game. Given the large numbers we are talking about someone will always be alive and kicking every 100-1000 light years (close enough to sniff our atmosphere remotely).

As to why I put so much into this post,it's what the site's all about. Denying ignorance. (bad math/bad assumptions) So consider yourself denied.
edit on 7-11-2013 by JadeStar because: (no reason given)



posted on Nov, 7 2013 @ 01:25 AM
link   

JadeStar

So there is a pretty large discrepancy between your numbers and the actual true numbers of stars of G and K spectral classes within 100 light years.

A simple query of G stars within 31 parsecs (101 light years) turns up 2427 G stars. Source.

A simple query of K stars within 31 parsecs (101 light years) turns up 2677 K stars. Source.

Total of G and K stars within 100 light years = 5,104


Well, I'm gonna ask that you verify your source. Like is there any chance to actually "see" the actual query?

I have a database, not a seriously complete one, but it does seem to have Y2K data in it, so it can't be too old. I'm only finding about 300 G class within 101 light years (distance < 101ly).

And, I'm sorry, but, most sciences are terrible with databases. For instance when I started looking at astronomical databases, it took me several days to figure out "what the hell" I had found. Basically, database schema is not normalized, nor is it really very logical. But, once one gets past the design issues, typically they're not too bad. Another issue with astronomy is there are too many, and the data content is inconsistent.

And, if you know of a good database, downloadable in excel (CSV) format, I'd really appreciate it.



posted on Nov, 7 2013 @ 01:34 AM
link   

tanka418

JadeStar

So there is a pretty large discrepancy between your numbers and the actual true numbers of stars of G and K spectral classes within 100 light years.

A simple query of G stars within 31 parsecs (101 light years) turns up 2427 G stars. Source.

A simple query of K stars within 31 parsecs (101 light years) turns up 2677 K stars. Source.

Total of G and K stars within 100 light years = 5,104


Well, I'm gonna ask that you verify your source. Like is there any chance to actually "see" the actual query?

I have a database, not a seriously complete one, but it does seem to have Y2K data in it, so it can't be too old. I'm only finding about 300 G class within 101 light years (distance < 101ly).


The source is the SIMBAD database. Think of it like a Google for almost all astronomical objects.

You can submit different queries for different things. It's pretty flexible. You can even specify output options. Check it out:

simbad.u-strasbg.fr...


And, I'm sorry, but, most sciences are terrible with databases. For instance when I started looking at astronomical databases, it took me several days to figure out "what the hell" I had found. Basically, database schema is not normalized, nor is it really very logical. But, once one gets past the design issues, typically they're not too bad. Another issue with astronomy is there are too many, and the data content is inconsistent.


Well that's due to so many different areas of astronomy requiring different bits of information while other areas of the field find the same bits irrelevant.




And, if you know of a good database, downloadable in excel (CSV) format, I'd really appreciate it.



NASA used to have one..... until the budget got cut.... lol

NStars - NASA Nearby Stars Database

There is an old archive.org capture of it here: web.archive.org...://www.chara.gsu.edu/RECONS/TOP100.posted.htm

You can also use a chrome extension to turn tables into google spreadsheets which of course you can export as .csv files.

I'll see what I can find tomorrow, I think someone took their database and unofficially keeps it updated but i believe it was in .csv format.

I'll send you a PM tomorrow, i promise.

BTW if anyone is interested about the methodology about how "they" (as in the alien "they") might find or view us (and how in the not too distant future we may find or view them), check out this paper by one of the leading, if not THE leading exoplanet researcher. It gets technical but if that doesn't scare you off:



"Alien Maps of an Ocean-Bearing World"
arxiv.org...


edit on 7-11-2013 by JadeStar because: (no reason given)

edit on 7-11-2013 by JadeStar because: (no reason given)

edit on 7-11-2013 by JadeStar because: (no reason given)

edit on 7-11-2013 by JadeStar because: (no reason given)



posted on Nov, 7 2013 @ 06:35 AM
link   
reply to post by Krazysh0t
 


Thanks for that information Krazysh0t.

They'd have to be listening very carefully to pick up broadcasts then.

That's assuming they even realize a species would use radio to communicate with in the first place...if they are far, far in advance of Earth technology, they may even deliberately discount ANY species that used such an archaic communications system, deeming them and therefore us, not advanced enough to be either a danger or valuable to them.

A bit like comparing modern laser communications against smoke signals...those using smoke signals to communicate would be thought pretty backwards and unsophisticated and probably not worth contacting..there wouldn't be much to gain IOW.

If we wanted to communicate effectively, we really ought to be developing technologies that differ markedly from natural sources found in the cosmos..radio is everywhere naturally, we need something that is going to show up as being obviously unnatural if we wanted to get anyone elses' attention (assuming we wanted to anyway).



posted on Nov, 7 2013 @ 07:51 AM
link   
reply to post by JadeStar
 




Well that's due to so many different areas of astronomy requiring different bits of information while other areas of the field find the same bits irrelevant.


Well, I could say; "If that's what ya believe." don't seem to friendly though.

The reality is that all those bits of data can live in the same database in harmony, and not interfere with their "siblings". It is a matter of design.




NASA used to have one..... until the budget got cut.... lol

NStars - NASA Nearby Stars Database

There is an old archive.org capture of it here: web.archive.org...://www.chara.gsu.edu/RECONS/TOP100.posted.htm

You can also use a chrome extension to turn tables into google spreadsheets which of course you can export as .csv files.

I'll see what I can find tomorrow, I think someone took their database and unofficially keeps it updated but i believe it was in .csv format.

I'll send you a PM tomorrow, i promise.


Did you know that it costs the Government almost nothing to keep that database available and online? Hell, IF they "zipped" it up and sent it to, I would have no problem hosting it (only need a small corner of my existing SQL server.

But that's the government for ya...

I've seen the SIMBAD database, useful as all hell, IF you are an astronomer, but, poorly designed, from a "data perspective".

I also do not like the seriously limited query abilities, but then I am used to the kind of "control" one gets from the "database engine" itself (the interface that is never available "online" due to security issues). Which is why I would like "y own" copy. And a CSV is nearly the "perfect" format as it allows me to import the data directly into "SQL Server".

And of course, finally; I don't use Chrome...ever. it is, in my professional opinion, redundant, and unnecessary. IE and FireFox are all that I need.



posted on Nov, 7 2013 @ 07:58 AM
link   

Astyanax
The probability of discovering intelligent alien life — or it discovering us — is almost zero. Long may it remain thus.


edit on 6/11/13 by Astyanax because: of longer odds.


There are many sightings that have been reported with very credible and multiple witnesses, although its not really considered 100% proof, imo they have discovered us, we just don't know why they haven't tried to associate with us on a planetwide level.



posted on Nov, 7 2013 @ 10:30 AM
link   

Blue Shift

Blarneystoner
Lets say that the nearest star to Earth has intelligent life... Proxima Centauri is about 4.2 some odd light years from Earth. IF they were broadcasting standard radio waves we probably wouldn't be able to detect them due to signal degredation.

If there are millions or billions of intelligent civilizations out there at various stages of development, then the odds are that some of them are or have been using better equipment than us. A decent percentage is going to be thousands or millions of years ahead of us technologically. The universe should be awash with signals riding radio or light or whatever, that we should be able to see. But it's suspiciously quiet.

If there was another civilization orbiting around Proxima Centauri, it's extremely unlikely that their technology would be at the same level as ours. If they were just 1,000 years ahead of us, that would greatly increase our chances of hearing them. But we don't hear or see anything coming from Proxima Centauri. We don't see or hear anything from anybody.

The more we should hear from aliens, the more suspicious it becomes when we don't.


The universe IS awash with radio signals... common stars, neutron stars, our own galactic center, supernova, pulsars, etc... all emmit radio waves.

The radio wave spectrum ranges from 300 GHz to as low as 3KHz.

In order to discern a "signal" from an intelligent artificial source you would need to tune into a single frequency! But first you would have to isolate that radio signal from all the background "noise" from other, natural radio sources.

...and as I pointed out previously. The likelyhood of an intelligent signal reaching Earth without being completely degraded is almost none.

And addressing your comment about ETs using better equipment than us... well sure! Do we have the equipment to recieve, tune in and translate those signals? Probably not.

No... I still believe that the premise of this thread is invalid.
edit on 7-11-2013 by Blarneystoner because: (no reason given)



posted on Nov, 7 2013 @ 11:19 AM
link   
JadeStar; I noted your reference to placing an optical telescope at the Sun's focal point in order to observe details of civilizations on exoplanets. From what I read, the distance limit for our own radio wave signature, whether it be the 60- 65 light years you mentioned, or some other discouragingly small figure, might be greatly increased by a modest radio telescope at a similar point around another star with a civilization that wished to observe us.
As long ago, at least, as 1992, Frank Drake mentioned this idea in one of his popular book-- 'Is Anyone Out There'? 550 A.U. is reportedly the minimum distance for such an observatory in our own solar system, but interference from the solar atmosphere, and an infinity of focal points beyond that distance would make 1000 A.U. ideal, he thought.



posted on Nov, 7 2013 @ 11:47 AM
link   
Time is a factor. The amount of time in which we have been able to observe is minute compared to the time it takes even radio signals to cross the vastness of space. Time is as big a barrier as distance.



posted on Nov, 7 2013 @ 02:28 PM
link   
reply to post by carewemust
 
. Commune with, no war and no more thoughts of war. We will find them so fabulously nubile that we will consummate our meeting with sensual abandon to find our partners shape shift at will and at the crest of the orgasmic wave reveal themselves to be truly hideous beyond the darkest imaging.



edit on 7-11-2013 by HUMBLEONE because: (no reason given)



posted on Nov, 7 2013 @ 03:06 PM
link   

carewemust

Even if only 1 percent of those planets have life similar to Humans, that is equally or more advanced, we should be "seeing" radio emissions and/or have solid evidence of their existence...like a UFO hovering over downtown Chicago for a few minutes with thousands of smartphone videos recorded.



Someone might have mentioned it but in case they havent I will.

I saw something recently that made mention to the fact that the whole Contact idea revolving around things like 'The first broadcast aliens will see is Hitler at the Berlin games' is actually a bit of a myth, if not completely impossible.

Space is cluttered and full of noise, heck suns and other phenomena are pumping out all sorts of stuff, really our presence here in the universe is more or less masked completely by this background noise, heck I think the program I watched said that basically our transmission wouldnt even be able to make it outside the property so to speak. Its like a person standing out in the desert and expecting to be able to yell at a guy a mile away on a mountain and have them hear them, they'd be lucky someone even a few hundred meters away would hear them.

As such to expect to find those same transmission ourselves from others out there is just as likely to be impossible unless they direct the signal right at us or we pass through it and happen to be listening and the aliens are 'on the property ' ie really really close, so to speak... heck the signal if it could make it that far would be so worn down, so broken and warped by its travels through space I doubt we'd even recognize it as anything but static.

The fact we havent heard anything with all these billion of planets around doesnt mean they arent all teaming with human like life oozing tech... we just wouldnt be able to hear them at all anyway. Not with the system of communication we use now basically... One day we might make a communications breakthrough like subspace transmission like in Star Trek and suddenly find our airwaves flooded with outside signals from other worlds... heck maybe thats how first contact and disclosure will happen, not with advances in space craft technology or observation, but through a revolution in communications technology.

The same goes for us being found by them, its like some people using smoke signals and expecting someone using a cell phone passing by to notice and understand, all they see is some smoke... and probably dont even relate it to communication if that concept of transmission to them was so long ago its totally forgotten.

So i wouldnt loose hope, if anything it makes it stronger... I mean come on, 20+ years ago a lot of us still thought the idea of other planets outside of our solar system was impossible... looking back at it now, what where we thinking?!

Now we think there could be billions in the neighborhood, that makes me more than happy... all we gotta do is get out there and go forth and multiply, the first great and bountiful human galactic empire
Ill never see it, but I wish em luck.

Edit:- oops seems Blarneystoner mentioned it, further up this page. Damn it gotta read a thread more fully before posting, someone even used my smoke signal analogy


Edit2:- Jadestars link to that paper of viewing extrasolar planets while incomprehensible was interesting... heck even a alien world only 20+ years ahead of ours tech wise may have already spotted us and is already setting up sending us a signal. so who knows it could be soon we get a knock at the door (granted we already have others visiting here, but would be funny as all hell in getting first contact from someone else near our own level of advancement rather than someone much much higher up the tech tree of existence whos already zipping around our atmosphere in secret (or at least attempting to do so in secret)

edit on 7-11-2013 by BigfootNZ because: (no reason given)



posted on Nov, 7 2013 @ 05:07 PM
link   

Ross 54
JadeStar; I noted your reference to placing an optical telescope at the Sun's focal point in order to observe details of civilizations on exoplanets. From what I read, the distance limit for our own radio wave signature, whether it be the 60- 65 light years you mentioned, or some other discouragingly small figure, might be greatly increased by a modest radio telescope at a similar point around another star with a civilization that wished to observe us.
As long ago, at least, as 1992, Frank Drake mentioned this idea in one of his popular book-- 'Is Anyone Out There'? 550 A.U. is reportedly the minimum distance for such an observatory in our own solar system, but interference from the solar atmosphere, and an infinity of focal points beyond that distance would make 1000 A.U. ideal, he thought.


100% correct. Think of the Sun's gravitational lens focus less as a point (like in a traditional telescope) but more like a fuzzy line/ring where a spacecraft could be placed anywhere along it. And... ALL electromagnetic radiation (radio, light waves, etc) from the occulted object is boosted by a factor of roughly 10 to the 8th power!

You might be interested in Claudio Maccone's work as he's focused a lot on using the Sun's gravitational lens as a communications tool in which the transmitter would only need to be 40 watts(!) to effectively communicate with the nearest star. Or to turn it around another way, we could hear a 40 watt transmitter at interstellar distances with a receiver at the Sun's gravitational lens. BER = Bit Error Rate.



The Gravitational Lens and Communications: www.centauri-dreams.org...

It's more like 550 AU ~ 1000 AU because there are different points along it which are good for different types of observations depending on what wavelength you plan on observing at. ie: optical, near IR, far IR, sub-millimeter, microwave, radio, etc....

Thats the elegance of the idea. It's using something nature made (our Sun) as technology to do something we could not construct (a huge, gigantic aperture full spectrum telescope) to do anything from see extra solar planet continents, oceans, perhaps city lights to hearing a 1 megawatt transmitter a quarter of the way across the Galaxy.

But yeah, that kind of mission will be done at some point. It's hard and will cost a lot of money but so did the Apollo program. It's just too enticing a mission to not do. (Kinda like how Kepler was in the 1980s).

There have been a number of papers and design studies done for just such a mission. Most could be dusted off and upgraded based on where technology is today or at the point in the future where such a mission could take place..

One such proposal that's slowly moving forward is a mission called FOCAL:

FOCAL: Using the Gravitational Lens (2005): www.centauri-dreams.org...

The FOCAL Mission: To the Sun’s Gravity Lens (2006): www.centauri-dreams.org...

FOCAL: Renewed Call for Papers (2010): www.centauri-dreams.org...

A FOCAL Mission into the Oort Cloud (2010): www.centauri-dreams.org...

Catching up with FOCAL (2013): www.centauri-dreams.org...

Another such mission concept is the Innovative Interstellar Explorer: interstellarexplorer.jhuapl.edu...

A lot of papers refer to these mission concepts as an "Interstellar Precursor Mission". So its likely that many species, before they venture to another star go a and park some telescopes (optical, radio, etc) at their own star's gravitational lens.

The interesting thing is that for M-stars the gravitational lens is much closer (due to their low mass) and M-stars make up 80 percent of the Galaxy and have lifetimes close to the age of the universe.

If an intelligence developed around an low mass M-Star they'd have the advantage that their star's gravitational lens would only be around ~70-280 AU


Math....I used the common formula below to derive that....


Assuming a spherical-symmetric lens.


For comparison that's within the range our relatively slow moving Voyager probes are now!



CONCLUSION:

It may be much easier for technological civilization around an M or K class star to get to their stars gravitational lens with sensitive telescopes/receivers perhaps to observe us, than it is for us to get to ours to observe them.

edit on 7-11-2013 by JadeStar because: (no reason given)



posted on Nov, 7 2013 @ 05:24 PM
link   
reply to post by carewemust
 


the numbers for "earth-like" planets they're giving out are exaggerated.

i put it at around 235 million a big difference from 8 billion. Civs will be rare enough to be spread out by thousands of light years
edit on 7-11-2013 by yeti101 because: (no reason given)



posted on Nov, 7 2013 @ 05:45 PM
link   

yeti101
reply to post by carewemust
 


the numbers for "earth-like" planets they're giving out are exaggerated.

i put it at around 235 million a big difference from 8 billion. Civs will be rare enough to be spread out by thousands of light years
edit on 7-11-2013 by yeti101 because: (no reason given)


The context of the number has to be taken into consideration.

When they say 8 billion earthlike planets they are saying 8 billion rocky worlds in habitable zones which MAY be earthlike.

We still do not know enough about these planets in terms of habitability. A good amount may be like Venus due to various reasons. Habitable zones change slowly with time.

Others may be "Hoth"-like (star wars reference) worlds that are almost complete snowballs for other reasons.

Clouds, atmospheric density, even things like amounts of silicates vs carbon has a huge impact on whether a planet would be more like Venus, "Hoth" or the Earth.

The point is that until we know more about their atmospheres we won't be able to definitively say which category of planet many of them fall into.

There are reasons to be optimistic but they are based on "bleeding edge" analysis of data from Kepler and ground observations which will need to be proven out more thoroughly.

That said, 8 billion terrestrial planets in habitable zones is a huge number and it would take something equally huge (which you didn't specify) to pare that down to only 235 million like our home.

I'd love to know why you think the number would be reduced so severely?
edit on 7-11-2013 by JadeStar because: (no reason given)



new topics

top topics



 
10
<< 1  2    4  5 >>

log in

join