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Seti And Particularly Seti@home, The only SETI thread
ljk4-1
post Apr 19 2006, 02:05 PM
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QUOTE (Bill Thompson @ Apr 18 2006, 06:02 PM) *
Getting a signal from an intelligence society would be the most exciting thing I can imagine for humankind.

But I wonder this. As we continue to look and as we keep finding ourselves putting more energies into new ways to look, at what point do we decide to direct more energies in other things like, for instance, super telescopes and the launching of intergalatic AI probes?

Another thing to consider is this. At what point to we decide to dedicate our time and efforts inward towards things like finding a cure for cancer rather than looking for a signal from space?


Billions are spent annually on finding cures for diseases, while only a few million
are spent on SETI each year. And none of it is from your tax dollars, as ignorant
senators once liked to proclaim. All SETI programs are now private ventures ever
since NASA essentially bagged out of it in 1992.

Three billion dollars per year are spent on chewing gum in the United States.
How about everyone stop chewing gum and spending that money elsewhere?
Chewing gum certainly isn't vital for the survival of our species.

SETI is not taking away from "saving" the human race. People really need to
see the wider picture here. I am VERY tired of the same old song about taking
money from the space program and sciences and spending it on Earth. What
do you think most research and exploration endeavors are all about any way?

You say that getting a signal from an ETI would be the most exciting thing ever.
How do expect that to happen if we don't have a SETI program? And as much as
I would like to see a real interstellar probe, that is a project that will cost a lot
of money and not happen any time soon, unlike SETI. Plus checking out a few
star systems over centuries isn't going to help us find ETI any faster than a
group of dedicated SETI telescopes on Earth or in near space.

My theory is that folks like me who grew up during the heyday of the Space Age
(1950s and 1960s), when everything was new and exciting and we seemed on
the verge of colonizing the Sol system and making contact with intelligent beings
in the galaxy, were imbued with a real sense of optimism about our place in the
future.

But then the 1970s and 1980s came along and we had leaders on both sides of
the Atlantic who didn't care about space and SETI and we watched as our lunar
and planetary efforts stopped and collected the wrong kind of dust. Only in the
last few years have we seen a revival of our space dreams, but we have several
generations who are now adults who still carry that basic pessimism about exploring
and science.

Hopefully as our probes now return amazing images of alien worlds and SETI
technology has advanced enough to be free of dependence on government whims,
we can get the next generations feeling optimistic and excited about our future in
the Universe again.


--------------------
"After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance.
I see that such intercourse long continued would make one thoroughly prosaic, hard,
and coarse. But the longest intercourse with Nature, though in her rudest moods, does
not thus harden and make coarse. A hard, sensible man whom we liken to a rock is
indeed much harder than a rock. From hard, coarse, insensible men with whom I have
no sympathy, I go to commune with the rocks, whose hearts are comparatively soft."

- Henry David Thoreau, November 15, 1853

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Guest_Richard Trigaux_*
post Apr 21 2006, 07:21 AM
Post #182





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QUOTE (ljk4-1 @ Apr 19 2006, 02:05 PM) *
Billions are spent annually on finding cures for diseases, while only a few million
are spent on SETI each year. And none of it is from your tax dollars, as ignorant
senators once liked to proclaim. All SETI programs are now private ventures ever
since NASA essentially bagged out of it in 1992...
(snip)

...Hopefully as our probes now return amazing images of alien worlds and SETI
technology has advanced enough to be free of dependence on government whims,
we can get the next generations feeling optimistic and excited about our future in
the Universe again.


Perhaps the future of space is private. After all, we are seeing this in the world of software (free softs taking over commercial ones, and some even getting better, more standard compliant, etc.). Some small missions could even be envisionned, like a test for an inflatable radio antenna (radioastronomy, SETI, DSN... ) free of earth interferences and frequency limitations, or an Enceladus stardust mission (scooping Enceladus dust plume with a stardust-like aerogel, and return back on Earth) the whole thing launched by a Falcon. Such missions are not very far out of reach of amateur budgets, the worse problem being the capacity of amateurs to build the necessary organization. But SETI and mannaed amateur rocket to space demonstrated that this is possible, provided that a correct organization is put on place from the beginning.

In many sci-fi worlds too, large space undertakings are private.
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dvandorn
post Apr 21 2006, 09:47 AM
Post #183


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Richard, nothing -- and I mean, absolutely nothing -- in the private sector world *ever* gets done without *any* positive cash flow. No one is ever going to put up a few hundred million dollars for a planetary probe just because they want to see what's out there. Not without some way of generating some income out of it.

Even if Falcon worked (which it has not, as of yet) and even if the Falcon developmental costs (suffering from little, seemingly unimportant expenses, like needing to launch six or seven of them before they get the bugs out, or building an oxygen liquifaction plant so they can actually launch the things without having to wrap them in blankets that flap back onto the thrust chambers and damage them) don't push the eventual costs of a Falcon launcher up into the same range as the currently available launchers, there are still a lot of significant costs you're overlooking. For example, the DSN isn't cheap. How are you going to command your private Enceladus probe, or get data back from it, unless you pay the $10,000 or more an hour that using the DSN costs? Gonna build a new DSN? If so, how are you going to make it cheaper than the current DSN (seeing as how, AIUI, the current DSN is already a private enterprise)?

There are *maybe* three people in the world who have enough money to do something like this, and even they can only do this once or twice, at most, without bankrupting themselves. Corporations simply will not undertake such missions, since there is no chance of ever generating any income from them to match the outflow, or even to pay for a tenth of the costs. Corporations simply do not spend out millions of dollars for no return.

It's a nice dream, Richard. But that's all it is -- a dream.

-the other Doug


--------------------
“The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Guest_Richard Trigaux_*
post Apr 21 2006, 09:53 AM
Post #184





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QUOTE (dvandorn @ Apr 21 2006, 09:47 AM) *
Richard, nothing -- and I mean, absolutely nothing -- in the private sector world *ever* gets done without *any* positive cash flow. ...

-the other Doug



I replied to this in the thread of the Enceladus stardust mission which seems more appropriate.
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Bob Shaw
post Apr 21 2006, 07:39 PM
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otherDoug:

Dozens of OSCARs and CubeSats and Cosmos-1 demonstrate that there are other ways of working in space which don't require megabucks; as for the DSN, if an amateur can detect the carrier from Voyager-1, then perhaps something could be organised just for the fun of it.

Bob Shaw


--------------------
Remember: Time Flies like the wind - but Fruit Flies like bananas!
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Guest_Richard Trigaux_*
post Apr 22 2006, 07:35 AM
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[quote name= again, avoid quoting when replying to it
[/quote]


Not accounting with the fact that a carrier with a modulation is not the most energy wise way to send information by radio. Radio amateurs, who have to work with severe legal power restrictions, use for long ago more econompic modes, such as the old morse (the most efficient mean of all to send speech) or unique sideband transmition (called BLU in frnch, I don't know the acronym in english, something like SSM perhaps). In this mode the carrier (which... carries no information) is simply suppressed by a sharp filter, together with one of the sidebands, so that all the power is into useful non-redundant info.

Such smart ideas will not make a Cassini mission out of cardboard boxes and wooden planks, but if technical-wise amateurs and some sponsors unite to do something, they could prick some interesting bits. For instance the DSN relies on a small number of large dishes (only one being operating at a time on a given target) but many small amateurs antennas spread in the world could obtain some results too. Afterall, radio amateurs is a useless activity, just for fun. But a real purpose would add some more fun.
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Bill Thompson
post May 1 2006, 11:45 PM
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I do not think that life on Earth is (for lack of a better term) a “natural” thing (there really is no such thing as “unnatural” and so I am limited by the English language to find a good adjective to use here). I think we are the result of extremely good luck. Now, before you dismiss this idea completely, I hope you will hear me out.

What I mean is this. For the first few hundred million years of life on Earth after microbes colonized into animal life, plants had not yet evolved. The life that existed on Earth was in a state of continuously consuming the oxygen supply. At this time life had not evolved on land either and if we were to go back in time and walk on the earth it would be difficult for us to breathe due to the high concentration of Carbon Dioxide in the atmosphere.

Fortunately, plants evolved and the Carbon Dioxide started to be converted into Oxygen.

Of all the fortunate events to have happened, this was the most fortunate. If this had not happened, life on Earth would have exhausted itself out of existence. I think normally in the universe life is like this. It is like a flame that flares into existence and then exhausts the resource it feeds on. Without any way to renew or replace the resource, it typically dies away.

In my mind, this is a pretty good explanation as to why we seem to be alone.

I think we are the result of the odds working out in our favor just the right way several times in a row like rolling the dice and the numbers coming up just right several times in the right order.
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dvandorn
post May 2 2006, 05:16 AM
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QUOTE (Bill Thompson @ May 1 2006, 06:45 PM) *
...I think we are the result of the odds working out in our favor just the right way several times in a row like rolling the dice and the numbers coming up just right several times in the right order.

Actually, I think that, for the system to have survived so many global catastrophes which have erased as much as 90% (or more) of all species then extant, and to still be producing such a wild variety of lifeforms to occupy nearly every niche that exists -- that has to mean that the system has to be awfully forgiving of error.

At what point did the overall biosphere become so well-designed that it could survive global extinctions and re-radiate different forms back into every niche? I have to believe that it happened pretty early on.

Now, as for the evolution of intelligence -- that's another matter. But it just seems inevitable to me that any rich biosphere will eventually generate at least *one* intelligent species. (And don't forget, it's possible that some of the cetacean species are as sapient as we are... so our biosphere may have, indeed, generated multiple sapient lifeforms over the course of life on Earth.) I do admit to some amount of terracentrism in this sentiment, though...

Of course, with only one sample to work with, it's impossible to tell just how forgiving the system is when it comes to eventual evolution of sapience. I cannot imagine how we can ever get a handle on the actual likelihood of the process until and unless we have other examples to study.

-the other Doug


--------------------
“The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Guest_Richard Trigaux_*
post May 2 2006, 08:45 AM
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QUOTE (Bill Thompson @ May 1 2006, 11:45 PM) *
I think we are the result of the odds working out in our favor just the right way several times in a row like rolling the dice and the numbers coming up just right several times in the right order.


Not sure.

If we consider the appearance of life and intelligence as a long chain of events which are more or less probable, we can note than, on Earth, none of this events took more than one billion years to happen. (And this is still a pessimistic view, as major changes like the appearance of multicellular beings, took place progressively by little steps which are each much more probable, so the length between major steps is rather representative of the number of mini-steps). This indicates that, in a total duration of 4.5 billion years, such an event had a total probability of 95% to appear.

So, if conditions similar to Earth exist, and are sustained long enough, they should give the same results, in roughly the same time. The problem is that we don't really know the percentage of planets which have such conditions, and which sustained it long enough to give an Earth-like evolution. Perhaps such planets are very rare, but until now nothing authorises us to state that they MUST be rare. This is an astrophysics problem which is until today not resolved, and not likely to be resolved in the short run.

But anyway the total probability to have all the chain of events leading to intelligent life is not low, so us being the result of a very lucky drawing lot is very unlikely.

So the solution of the Fermi paradox is not here, it would be either:
-planets suitable for life would be very rare
-we would be very lucky to have life-allowing conditions for so long
-we would be very lucky if the total process would have be much shorter on earth, so we would be the firsts
-there are many civilizations, but they don't evolve in the sci-fi way we think.
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Toymaker
post May 4 2006, 02:21 AM
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QUOTE (Richard Trigaux @ May 2 2006, 08:45 AM) *
So the solution of the Fermi paradox is not here, it would be either:
-planets suitable for life would be very rare
-we would be very lucky to have life-allowing conditions for so long
-we would be very lucky if the total process would have be much shorter on earth, so we would be the firsts
-there are many civilizations, but they don't evolve in the sci-fi way we think.

Also:
-they don't send signals aimed at reaching other civilisations like expected(Humans did this only once)
-they use methods of communication that aren't received(for example tight beams etc)

I think that rare+different path of development then expected, +tight beam communication + no intent of sending signals to other civilisations would seem plausible.

Even now we see that megascale engineering, massive buildings etc aren't our path.
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Guest_PhilCo126_*
post May 6 2006, 08:29 PM
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Well, I guess most of the large Radio-dishes are quiet busy and getting time on them to conduct SETI would be difficult... Richard idea of going 'private' might work for a Radio-astronomy project.
On the other hand, it's great to know that the Deep Space Network antennes are being used, be it indirectly, by Spaceguard Survey, in order to give 3D images of NEar Earth Asteroids... wink.gif
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Bill Thompson
post May 12 2006, 07:34 AM
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QUOTE (Richard Trigaux @ May 2 2006, 08:45 AM) *
So the solution of the Fermi paradox is not here, it would be either:
-planets suitable for life would be very rare
-we would be very lucky to have life-allowing conditions for so long
-we would be very lucky if the total process would have be much shorter on earth, so we would be the firsts
-there are many civilizations, but they don't evolve in the sci-fi way we think.


I still think it is interesting to note that plant life was not around for a long time in our early existance and if we were not fortunate enough for them to come about, we would not be here. I think there is an overlooked key here in understanding why we might be a rare thing in the galaxy.
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Guest_Richard Trigaux_*
post May 12 2006, 09:05 AM
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Yes, plants are a difficult problem. Only an oxygen-rich environment can allow for muscles, neurones and generally large beings. An oxygen-poor world can only have some small worms and the like.

So on Earth the "precambrian explosion of life" 800-600 millions years ago was in fact the coincidence of two unrelated events:
-appearance of organized multicellular animals
-drastic increase in oxygen level, allowing for large animals, muscles, brain, etc.

In is all the more puzzling if we consider that photosynthesis existed since long before (at least two billion years-old stromatolithes) and was already providing oxygen. But the today oxygen level was achieved only recently (800-600 millions years ago). Why? Is it because early plants were not so effective? Or because the oxygen was absorbed by some sink, for instance large iron deposits? I don't know, and probably nobody knows.

Another curious coincidence is that plants and animals achieved multicellularity simultaneously. However the two lineages diverged billions years before. But is this sure? Are the stromatolites the ancestors of modern plants? Or did the bacteria, plants, mushrooms and animals diverged only a bit before the pre-cambrian life explosion? (In this case we must admit that photosynthesis appeared several times in different branches and at different ages).

So the simple vision of evolution of life as a linear series of steps gets a bit complicated, if several lineages are evolving simultaneously (plants and animals, both indispensible for intelligence) together with geochemical conditions (consuming oxygen sinks).

In a way, Bill, you are true that the need with such coincidence may make lose a factor ten, or more, in the Drake equation. Or, said in a more today way, the probability to find a civilization on a planet of a given age increases slowlier with this age, and is thus globally smaller.
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Thorsten
post May 12 2006, 08:56 PM
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QUOTE (Richard Trigaux @ May 12 2006, 11:05 AM) *
Yes, plants are a difficult problem. Only an oxygen-rich environment can allow for muscles, neurones and generally large beings. An oxygen-poor world can only have some small worms and the like.


One photosynthesis-related point that thing that might be interesting for SETI discussion:

Photosynthesis does not necessarily include the production of oxygen. In fact, a fully functional photosynthetic apparatus existed for a long time – and is now still present in green sulphur bacteria – which contains only one photosynthetic reaction centre and thus uses H2S (hydrogen sulphide) as electron donor that is oxidised to H2SO4 (sulphuric acid).
Only later – in cyanobacteria and plants – a highly efficient process of photosynthesis evolved by the combination of two reaction centres, arranged in tandem. This system allowed the use of the much more abundant molecule water as an electron donor, which is oxidised to molecular oxygen.

Interestingly, it has been pointed out by some biologists, that life could had very well stopped at the point of H2S photosynthesis. In that case green sulphur bacteria would be the very high point of biological evolution – no free oxygen, no plants, no animals, no intelligence.
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ljk4-1
post May 12 2006, 09:07 PM
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I know the first comment to what I am going to say is "We work with
what we know", but perhaps we should start toying more with other
ways life - as we don't usually think about it - could exist on other
worlds, especially those that don't seem like very nice places at first.

Hey, we used to think nothing lived at the bottom of the oceans or
under miles of rock or in hot, hot acidic geysers, right?

I know Part 2 - but how can intelligent life come from those tough
little bugs in such nasty environments?

I don't know, that's why we need to search and run computer simulations
and think outside the box.

And for those who say But how can we communicate or learn anything
from beings so truly different from us?

So we stop searching just because some aliens might actually be ALIEN
instead of near clones ala Star Trek? It's called making bold explorations
and discoveries in science. Plus how can we learn anything new if we
just keep searching for guys like us?

Judging from the comments here and some of the more recent books on
the subject, I would say we are going through another negative phase in
our thinking about ETI. It comes and goes depending on the political
and social climate of the time and the progress (or lack thereof) being
made in SETI and astrobiology.

My thought on the subject is there's this amazing, dynamic and lively
(in numerous senses of the word) galaxy out there, but the majority of
the talking monkeys on Sol 3 are too busy focusing on their little problems
and thinking they are the focal point of the Cosmos to get out there and
really search for others in the Universe.


--------------------
"After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance.
I see that such intercourse long continued would make one thoroughly prosaic, hard,
and coarse. But the longest intercourse with Nature, though in her rudest moods, does
not thus harden and make coarse. A hard, sensible man whom we liken to a rock is
indeed much harder than a rock. From hard, coarse, insensible men with whom I have
no sympathy, I go to commune with the rocks, whose hearts are comparatively soft."

- Henry David Thoreau, November 15, 1853

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