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Re: I didn't mean to imply that were not talking to us because they looked down on us Isaac Send a noteboard - 01/10/2011 02:50:42 AM
And to be honest as I said in my first post the reason I don't think we are hearing anything is most likely because there is little to nothing out there to hear. Mostly I am just playing devil's advocate and killing time while some automated test run and I try to ignore the ass whipping the Rays are giving the Rangers.


Oh, doubtless, I'm just kinda replying to all the various theories en masse before they get repeated for the n-teenth time in the thread, force of habit, this whole subject matter is as you might guess, kinda dead horse and heavy interest simultaneously to me.

What I was thinking of is there may be something better than RF for communications and we just don't have the science for it yet. No I have no idea what that might be but I think it is possible that if this fantasy tech exist and most advanced species would find with a couple of thousand years of using radio. If it really is better they might abandon radio transmission for this more affective method. if you stretch disbelieve even further and make the system FTL then it doesn't really even make sense to monitor for new species because unless they are very close (and you would assume you have sent out enough probes to close stars to have an idea about the close ones) then by the time the signal reaches you they would have already contacted you with the FTL system. Like I said mostly just mental masturbation to try and come with a scenario where there could be a relatively large number of advanced civilizations out there and us not be able to hear them.


Well, an option like that is a sound explanation, on the surface, until one considers that it would be pretty common sense with such a FTL comm system to leave satellite monitors around pretty much every star just on general principal, and that they'd have some common sense antennae and sensors on them, and that presumably they'd have FTL comm ability too, and someone would think to include a little program with the parameter 'relay any non-natural emissions to high command'. I mean even assuming they utterly indifferent to new emerging life, which would seem improbable, they'd probably want to have early warning systems about sudden star fluctuations, supernova, or say ships that had problems and needed help and might need to signal for it in some natural fashion, like strobing their engine in galactic morse code so the local sensor buoy could say 'oh, someone needs help'. It would just make too much sense, especially with FTL comms, to have such a net, and if they had FTL comms but no FTL travel then they'd definitely want it whereas if the had both then it's so easy to deploy and maintain that they'd just tend to do it anyway I'd think.

One thing I was wondering about though. We keep hearing talk about how many stars there are out there but the way I understand it a large percentage of those stars are close to the core, much closer together than we are out here on the fringe. Since exploding stars are one of the things we do know will kill a planet if it is anywhere nearby and the one model we have shows 4 billions years as the time frame to develop intelligent life do you know if anyone has looked into the likelihood that a planet orbiting a star closer in would be removed from the running simply because of the increased likelihood that some hard radiation would rip its ozone off and fry everyone?


Well, we're not really 'on the fringe' that's kind of out of date, we're also kind of a mish-mash of at least seven other galaxies we've eaten plus a lot of the older stars are pretty far out from the core. Also, I think you need to be pretty much in the same system as a supernova to get a full blown planet kill, the release on a supernova is generally around 10^44 Joules, parallel to the energy our sun releases over its entire lifetime, however that is spreading of an obscenely large area to get anywhere, with a light year being about 10^16 meters, 1 Ly away you're surface is some 4πx10^32 m² and that means a given square meter is absorbing, at 1 Light year, around 10^11 Joules in a fairly short interval of time... a sunny day on earth you get about 1000 W/m² so 10^8 seconds worth of that, a few years worth of light, definitely crispy critter range though you might have surviving life on the other side of the planet especially in the sea... and stars do pack that tight in a lot places, but 10 Ly out that's down to 10^6 seconds worth of juice, a couple weeks worth, and I'd want to run the numbers to see how much actual immediate temperature rise that would cause, on Earth that would mean we'd absorb roughly 2.5x10^21 Joules of energy all at once, I'm sure it would blind anyone who saw it but a 1 megaton nuke packs 4x10^15 Joules of energy so this would parallel around a million nuclear warheads going off. Sounds utterly obliterating but I'd actually bet people in bunkers or even basement might live, and in terms of heat absorbtion, but it would be enough to heat up 10^18 liters of water by a degree fahreheit, for instance, which my on the fly math says would be enough to heat up the first ten feet of the oceans by a degree, it might be hugely cataclysmic but I can't see it wiping out all life on the planet and its entirely possible someone sleeping in an igloo might emerge an hour later unscathed. So they're definitely not going to leave a place unscathed, I wouldn't want to be within 100 Light years of one, but they don't blow up planets not already around them and probably don't sterilize anything but very near neighbors if that. Usually one talks about the effect absorbing that much gamma would have on a planets ozone layer more than anything else but the models I can think of usually say we would survive if 30+Ly away. You mentioned this but I always like to cold run the numbers to make it more solid. Another thing to remember is that early life, while it might develop near the core as that's where supernova would be most frequent and thus compile the heavy material for planets soonest, would probably tend to get zapped by Supernovae more... however supernova aren't really all that common, around one a century for the whole galaxy in any sort of recent time frame (since Earth formed). Now, I remember hearing a theory that life on Earht and elsewhere may all have been limited to stupid-simple for a long time as supernova were more prevalent and would come by and obliterate anything complex every few thousand-hundreds of thousands years while simple microbes would just respawn back to normal levels in a few years but I don't recall any data indicating supernova were ever that prevalent in terms of density and I can't remember who came up with it, so I don't take that one too seriously. The density thing does matter though, if supernova are occurring every century or so, and exterminating all life in a 100 Ly bubble around them (which as indicated is being generous about it's destructive potential) then in a billion year period one can expect around 10 million such events, charring up around a million cubic light years each, or about 10^13 cu. ly get roasted, pretty huge but the main stellar disc's volume itself is around 100,000 Ly across by 1000 ly thick, on an order of 10^13 cu Ly itself.

I wouldn't call that even odds since I've been rounding an awful lot, bad thing when squaring and cubing values, and because stars to tend to huddle up... they also tend to huddle by type. Also, if you drop that boom radius to 35-30 ly your char volume drops to around 10^11, or less than 1% over a billion years. An astrophysicists could give you better values but I don't think anyone has tried for a comprehensive model. Dreaded Anomaly might know for that matter, he seems more up to date and interested in such things, I'm kind of yanking this out of semi-thin-air. I pick a billion year because that's longer than life's really been on the surface, I don't think the super-simple deep oceans soup stuff from a billion years ago would be seriously impacted by anything but a very close nova, I gather multi-celullar life didn't even pick start till about 600 My ago, and the rate at which unicellular life multiplies I think you'd need to damn near kill it all to keep it from being fully recovered in a couple years. But it is what brought that theory to mind, that life may simply not have been able to get complex anywhere until about the time we did because the only places with enough heavy material to form planets were all getting zapped by supernova sufficiently frequently to prevent complex life emerging... again I can't even remember who's theory that is though and I have no idea if it included modern data or is even scientific and not just a crackpot concept that I heard at some point and got stuck in the back of my head. My SWAG is that for billions of years now planets have been able to exist with relatively low odds individually of being hit by cataclysmic supernova and thus wouldn't be a reasonable Fermi Paradox solution.
The intuitive mind is a sacred gift and the rational mind is a faithful servant. We have created a society that honors the servant and has forgotten the gift.
- Albert Einstein

King of Cairhien 20-7-2
Chancellor of the Landsraad, Archduke of Is'Mod
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An interesting thought I had that may be worth discussion. - 29/09/2011 07:22:01 PM 741 Views
Well, Fermi Paradox discussions usually end with ???? - 29/09/2011 07:51:59 PM 418 Views
you do have to hope there's intelligent life somewhere out there - 29/09/2011 07:56:48 PM 475 Views
I definitely agree with the first part. - 29/09/2011 08:32:33 PM 569 Views
why do you think only those options would be available? - 29/09/2011 08:35:53 PM 422 Views
Could be cultural domination. - 29/09/2011 09:32:18 PM 439 Views
*shrug* Humans aren't that bad - 29/09/2011 09:51:32 PM 407 Views
Oh yes we are. - 29/09/2011 10:27:52 PM 431 Views
Unless their advancement is so great they are VERY ethically enlightened, her fears seem valid. - 30/09/2011 03:04:40 AM 486 Views
hmmm - 30/09/2011 02:34:47 PM 416 Views
"And hey. I'll eat most anything once." - 30/09/2011 07:22:01 PM 396 Views
I think I've met a few aliens... - 30/09/2011 01:31:55 AM 428 Views
Why do fossil fuels have to be involved? - 29/09/2011 08:33:26 PM 401 Views
Going into the fossil fuel vs wood thing - 29/09/2011 08:51:07 PM 497 Views
The big issue is energy density, IMHO. - 30/09/2011 02:53:39 AM 508 Views
That's so perfect. - 30/09/2011 06:43:31 AM 447 Views
We really have no idea how rare advance technologies societies are - 30/09/2011 02:00:56 PM 546 Views
That's a really good point. - 30/09/2011 04:34:28 PM 459 Views
The doomsdays options don't really hold up well though - 30/09/2011 05:22:57 PM 476 Views
I think we have different interpretations of "silence" - 30/09/2011 07:47:32 PM 577 Views
It kind of comes down to whether FTL is possible - 30/09/2011 09:12:32 PM 540 Views
hmmm - 30/09/2011 07:51:42 PM 332 Views
Yeah but that's just a variant of "Highly advanced aliens who for some reason are totally stupid" - 30/09/2011 10:21:34 PM 553 Views
I didn't mean to imply that were not talking to us because they looked down on us - 01/10/2011 01:07:02 AM 499 Views
Re: I didn't mean to imply that were not talking to us because they looked down on us - 01/10/2011 02:50:42 AM 496 Views
thanks for the detailed answer - 01/10/2011 03:08:48 PM 485 Views
No prob, hopefully it's not all inaccurate nonsense - 01/10/2011 03:18:05 PM 522 Views
not to mention that the universe is HUGE - 30/09/2011 07:53:33 PM 411 Views
True - 30/09/2011 10:37:58 PM 374 Views
of course I can't say, that was my point - 30/09/2011 07:42:55 PM 424 Views
I was totally agreeing with you until I wasn't. - 30/09/2011 08:09:08 PM 558 Views
That's pessimistic, though. The "blaze of glory" is ongoing. - 01/10/2011 04:25:28 AM 402 Views
another thing for consideration - 01/10/2011 11:55:12 AM 409 Views

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