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Re: starship-design: It's a bad, bad world out there
I had written a long rebuttal to L. Parker's discussion, but then
I found the paper he obviously cribbed off of (F.E. Freiheit's
"The Possibilities of FTL: Or Fermi's Paradox Reconsidered). This
paper already included rebuttals, albeit succinct ones.
Anyway, here's my original rebuttal...
L. Parker wrote:
>On Sunday, October 26, 1997 7:03 PM, Isaac Kuo [SMTP:firstname.lastname@example.org]
>> L. Parker wrote:
>> >On Saturday, October 25, 1997 9:38 PM, Isaac Kuo
>> Actually, the conclusion of the Fermi Paradox is that the universe
>> should, with almost certain probability, already be colonized by
>> one or more intelligent species.
>No, it doesn't PROVE any such thing.
I never said it did. It is simply a mind experiment using probabilities.
Obviously, if it PROVED something, then the conclusion must be true.
However, _no_ scientific theory ever proves _anything_. It's
practically by definition that a scientific theory must be
disprovable. A scientific theory makes falsifiable predictions--and
thus there is always the possibility of being disproved by a failed
>It starts from a set of assumptions,
>adds more assumptions to them, then multiplies by still more
>assumptions....IF you accept the factors that are given in the paradox then
>you can arrive at such a conclusion.
Look. If you think there's a flaw in the reasoning of the Fermi
Paradox, point one out. Use DejaNews to search for the gazillion
threads on Fermi's Paradox, and you'll see someone else has already
thought of that and it's been shot down.
Or search Yahoo for more concise FAQs on the topic. (Be forewarned
that there is a lot of bogus nonsense on the Web which doesn't
include any rebuttal, as in USENET.)
>However, observed reality does not
>match theory, so I would submit that the theory (Fermi's Paradox) is wrong.
But that _is_ Fermi's paradox. The conclusion does not match reality.
If it matched reality, then it would be "Fermi's theory".
>The most likely source of error is in the factors that are used to arrive
>at the conclusion, the logic is actually pretty good.
Been thought of.
The inherent problem is that any factor which would make technological
life so rare (regardless of the factors) should also apply to us. But
we evolved in such a young solar system, how could we be so lucky to
evolve so quickly?
>> First you roughly calculate how often an interstellar capable
>> technological civilization should evolve. Be very very conservative
>> in your estimates--assume an Earth-like planet is needed, for carbon
>> based life including a roughly human-like intelligent species. Then
>> you calculate how long it should take for such a civilization to
>> completely colonize the entire galaxy--be very conservative here,
>> assuming, for instance, a .1%c asymptotic rate of expansion. Then
>> you look at how old the Milky Way galaxy is.
>f(hab) - fraction of star's with habitable planets
>f(sun) - fraction of sun-like stars
>f(I) - fraction of Population I stars (i.e. have heavy elements)
>f(p) - fraction of Population I stars with planets
>f(ec) - fraction of planets that orbit within the 'ecological' zone
>f(ter) - fraction of f(ec) planets that are Earth like or terrestrial
>f(ax) - fraction of planets with viable axial tilt
>f(rot) - fraction of planets with viable rotation rates
>f(hab) = f(sun)f(I)f(p)f(ec)f(ter)f(ax)f(rot)
>which can also be extended by:
>f(life) - fraction of planets developing life
>f(int) - fraction of life developing intelligence
>f(tech) - fraction of intelligence developing tool use
>f(civ) - fraction of tool users to develop advanced civilizations
>f(civ) = f(hap)f(life)f(int)f(tech)
>which derives a value of 0.001 for f(civ). This equates to 200 million
>advanced civilizations in our galaxy, assuming they all reached this point
>at the same time.
>In other words we are the only intelligent life in the closest 1,000 star
Congrats on using the Drake equation, but you forgot to factor in
the average lifespan of an advanced civilization. And your conclusion
is only valid if interstellar colonization is _impossible_.
The Drake equation's weakest point, arguably, is the factor of
"average lifespan of an advanced civilization". It's pure
guesswork, and there's a real question of why such advanced
civilizations would inherently die off.
And even if the _average_ lifespan of an advanced civilization
was rather low (e.g. because of global nuclear war), all it takes
is _one_ to be lucky enough to go interstellar, and it should only
take them another 100 million years to colonize the entire galaxy
(assuming they can only colonize outward at .1% c).
>> The three factors conspiring here are the sheer number of stars in
>> the Milky Way, the great age of the Milky Way, and the relatively
>> small size of the Milky Way compared to its age. The conclusion
>> is that the probability should be nearly 100% that an interstellar
>> capable technological civilazation should have already been colonized
>> the entire Milky Way (every star, every nebula, every planet, and
>> every moon--everything).
>Granted, even assuming the above numbers, which are based on Fermi's
>assumptions are correct, we should still have been colonized by now.
>> Name one reason why an interstellar capable intelligent civilization
>> which has colonized Earth, controlling and using its resources, would
>> never be visible to us (other than the fact that we probably shouldn't
>> have evolved in the first place).
>It would be foolish to assume that all civilizations survive their
>childhood and reach a stage where they are capable of colonizing the
>galaxy. In addition to childhood diseases there are threats to mature
>civilizations as well and those that can occur to any civilization, young
>or old. A partial litany of these threats are:
These two are valid problems, but ones which presumably a significant
fraction of civilizations survive indefinitely. We seem to be doing
pretty well on this front (after a shakey start)--although it's
possible for our foolishness to cause mass death and suffering, it's
unlikely that we will completely wipe ourselves out.
Neither of these are plausible ways to go extinct. They are self
correcting problems (even though the correction mechanism can be
While there is a certain window of risk when a civilization is
bound to a single planet, after interplanetary colonization
a civilization is probably safe from this. Given the relatively
short time it seems for technological creatures to develop
interplanetary colonization, this window of risk should only
eliminate a small fraction of candidate alien races.
A recent thread on rec.arts.sf.science addressed this possibility
in reference to "gamma ray bursters".
>Delicate Balance Disruption
Huh? Do you mean an environmental disaster? This one should only
eliminate a small faction of candidate alien races, too, since
it wouldn't eliminate interplanetary colonized races.
Dying of boredom? Well, anything is POSSIBLE...
Now here is a serious factor. One possible answer to Fermi's
paradox, which also supplies that last factor in the Drake
equation, is that there is some sort of really really really
lethal "bomb" capable of wiping out even an interstellar
colonized civilization (something a hell of a lot nastier
than a dinky little supernova).
The problem with this is that you'd expect something like that
to leave effects which would be trivially easy to detect by
modern astronomers. One thing Erik Max Francis noted on
rec.arts.sf.science is that we don't understand the nature of
"gamma ray bursters".
>>>What type of emissions would an ADVANCED civilization emit? How about
>>>neutrinos? Gravitons? Not only are these types of emissions almost a
>>>necessity for a spaceborne civilization, they are practically impossible
>>Neutrinos and gravitons? Why? We don't emit any. None of the
>>interstellar drives we've discussed on this list would emit any
>>(other than Alcubierre's, which requires more energy than exists
>>in the universe to run anyway).
>Not true, we do emit neutrinos, not in significant numbers yet, but it will
>>>>But you see, it doesn't make sense. Yes, the aliens have the ability
>>>>to wipe us out. However, we do _not_ have the ability to wipe out
>>>>the aliens. Therefore, they do not have to choose between them and
>>>That is what a pre-emptive strike is all about, wipe them out BEFORE
>>>they have the ability (much less the inclination) to wipe you out.
>> Actually, not necessarily--if you look at what "pre-emptive strike"
>> had always refered to during the height of the Cold War, both sides
>> already had the ability to wipe out the other side. A pre-emptive
>> strike was supposed to eliminate the other side's ability to do
>> so (by heavily attacking the other side's missile silos and airbases,
>> rather than civilian targets). Having eliminated the enemy's ability
>> to retaliate, the side which fired the pre-emptive strike could demand
>> unconditional surrender without slaughtering the other side's civilian
>> targets. This is what made the pre-emptive strike so scary--it looked
>> like an attractive option even if the leader doing it was not a
>> genocidally bloodthirsty maniac--and neither side could afford to let
>> the other do it first.
>Also not true. Isaac, you weren't even alive during the Cold War and
>obviously slept through history. Several of our Generals were pressing for
>exactly that at the end of World War II.
That was not at the height of the Cold War.
>> That's just an aside. I know the "pre-emptive strike" you refer to
>> is fundamentally different.
>> The kind of "pre-emptive strike" you refer to is really something
>> different. It makes the assumption that eliminating an interstellar
>> capable species with billions of years more advanced technology is
>> even plausible.
>Now you are confused, you got it backwards. It is the species which is MORE
>advanced which goes aropund eliminating the less advanced one, you said so
>yourself just a few paragraphs ago...
Let's call the more advanced species species A. Let's call the
less advanced species species B.
You are saying that species A wants to eliminate species B before
species B can develop the ability to eliminate species A.
This implicitely assumes that species B can eventually develop the
ability to eliminate species A, even though species A will always
have such a head start.
>> Umm, what do dolphins have to do with anything we're talking about?
Why? They are not technological creatures. They will probably
never be technological creatures, and probably will never even
evolve into technological creatures.
>> Besides, I doubt anyone who knew what he was talking about ever used
>> the term "pacifistic" to describe dolphins. They're carnivores which
>> hunt to live. They're quite openly aggressive.
>And at the top of the ladder in their environment...
In what sense? In that they don't have any natural predators? You
can say the same of most of the larger sharks. Oh wait. Occasionally
a large shark will kill a dolphin (or even a human) and eat (at least
some of) it. Not the other way around.
>> Back to the topic, what does "top dog" mean, anyway? Does it mean
>> the richest person in the world (which would mean Bill Gates, but
>> none of the rest of us)? Does it mean any species which has no
>> natural predators (which would include Panda Bears)?
>Umm, good example. Vegetarian, pacifistic, non-aggressive, nearly
That's my point. It's a silly definition of "top dog" that includes
Panda Bears. Obviously not what Pellegrino meant.
So what does he mean?
>> Competition for resources is a constant theme on Earth, but the end
>> result is many different things.
>> Interspecies interaction between predators and prey are often quite
>> complex--no predator can afford to completely eliminate their prey.
>Nor will it ignore competition from other predators.
Not necessarily. One of the most successful predators are driver ants.
For all practical purposes, they ingore the many birds which compete
for the same prey (and happilly snap up critters driven ahead of the
driver ant columns). There just isn't anything those driver ants can
do about it, even if they had the capability to recognize the raiders.
>> Within a species, direct competition is nearly inevitable--but there's
>> a wide range of possibilities, including simple competition by
>> outreproducing and stylized enforcement of territory borders.
>These are individual survival behavior patterns, not species. You misread
I'm talking about intra-species competition in this paragraph. That's
what "within a species" means. Therefore, I must discuss behavior
patterns of individuals or groups of individuals.
Just how do you discuss intra-species competition in terms of
species behavior patterns?
>> In the context of what in the world "top dog" means, both might be
>> relevant, depending upon what "top dog" means. Pelligrino implicitely
>> assumes that the "top dog" must be an entire species. Therefore,
>> interspecies interaction is what's relevant. He tacitly implies
>> that on Earth, homo sapiens is the "top dog". And yet we go out
>> of our way to avoid exterminating species like Spotted Owls, which
>> we are no more dependent upon than Dodo Birds or Passenger Pigeons.
>Which were the arguments the unfortunate captives tried to advance, that we
>weren't really like that, that Rules 2 and 3 didn't apply. Pellegrino's
>point was simply that the other species can't (and won't) take the chance.
Which gets back to the inadequacy of his first law. The
implicit implication that the alien species must choose between
their survival or ours. Which is nonsense.
>BTW, the working draft of the timeline is up, it is at:
_____ Isaac Kuo email@example.com http://www.csc.lsu.edu/~kuo
/___________\ "Mari-san... Yokatta...
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