Posted on 12/18/2003 8:37:33 AM PST by KevinDavis
Speaking from a purely humanocentric point of view -- yes. Why start the project when you won't be the one seeing it completed? Even the pyramids were built in the lifetime of the pharaohs who commissioned them. Even the Great Wall of China was simply the linking of smaller defensive works, each completed in less than a generation.
Human beings are notoriously prone to boredom. Even if you signed onto a multi-generational trip to the nearest star, what happens when a few years out you decide you'd rather retire to Florida and soak up some sun on the beach? Sure, it sounds like great fun and adventure at first, but when reality kicks in it's going to suck. Who wants to be stuck in some technological tin can billions of kilometers from home and loved ones with no hope of ever seeing either one again?
You might get people to spend a couple of years on a round-trip to Mars or the Moons of Jupiter, but you're never going to get people to sign their lives away for a payoff they'll never see.
It's either going to be FTL or we're going to have to develop some sort of suspended animation to get people to explore the stars.
Not if subsequent missions can get there before Mission 1 (perhaps significantly before).
Example: Mission 1 takes 100 years to get there. Mission 2, launched 50 years after Mission 1 launched, has such advanced technology that it arrives in just 10 years - 40 years before Mission 1 arrives. By the time Mission 1 arrives, Mission 2 has already raising the 3rd generation of immigrants at the destination.
Sh*t, I'll do it, and I'm not the only one. Time to retire anyway and tackle that pile of philosophy literature.
It may have been created just to amuse us. Or so we might amuse the Creator as we try to figure out the puzzle.
-- God's last message to His creation.
I would volunteer to set up the base on Deimos, though, although that mission lacks interstellar glory.
Yes. Some don't like to think that depressing thought.
[3] intelligent life has no further interest in just another stupid lifeform?
We don't study every ant hill we come across - most are ignored.
[4] intelligent life prefers secrecy and stealth?
(c) Some of them will be as curious--or more curious--than we.
(d) Some of them will hit upon the idea of launching a modest number (~100) of "Von Neumann robots".
There is an underlying premise here that such advanced civilizations are also intent upon disclosing their presence, abilities, and location.
Why would they risk it? Why would they not observe passively, remotely?
What is gained by 'inserting themselves' (or otherwise allowing their presence and/or home location to become known) into environs selected not for low risk, but at random and ultimately encompassing the entire galaxy (if not universe)?
Why would they not endeavor to keep their observation undetected - if indeed observers are sent at all?
Wouldn't they risk potential extermination, either by conflict or by contamination?
(g) Occasionally, a probe wanders home by random walk.
This seems a rather haphazard way to collect information, but without reducing the risks noted. I.e, the risk/reward ratio is worse than if the observers were designed to 'phone home'.
Fermi seems to presume no competitve dangers to exploration. Which could be true, but if true, either implies no competitors or a gamble that any competitor encountered will be a lesser threat. But why take that gamble?
Doc
Fine. You still have not told me how they will do it. I asked if you were assuming generation ships, or shipment of sperm and ova for in vitro fertilization and birth...or what? Shipping humans is going to be difficult--given our short lifetimes. So I am asking what mechanism you foresee our descendants using to "conquer the galaxy in 1 million years".
--Boris
If they are as far advanced above us as we are to ants, you are correct. The folks we are interested in talking to are those who are still not quite that advanced. Again, if intelligent technological species are common, there should be some fraction that is interested in us as we are in them.
"[4] intelligent life prefers secrecy and stealth?"
Why? If they are advanced enough to explore the stars, sending robot probes at 0.05c, we offer little danger to them. Certainly we cannot harm them if all they send are probes. If they come "in person" again we cannot harm them. And again, assuming they are common, some fraction of them will NOT prefer secrecy and stealth.
"There is an underlying premise here that such advanced civilizations are also intent upon disclosing their presence, abilities, and location."
Sending a probe does not do any of that. It's a probe. We sent Voyager out with (among other things) a MAP of where we are!
"Why would they risk it? Why would they not observe passively, remotely?"
How do we threaten them? Remember, THEY are the puissant ones; we are the inferior ones. How do I know? Because WE cannot go to them, and will not be able to do so for quite some time.
What is gained by 'inserting themselves' (or otherwise allowing their presence and/or home location to become known) into environs selected not for low risk, but at random and ultimately encompassing the entire galaxy (if not universe)?"
Suppose God suddenly granted humanity the means to travel at infinite speed to any location in the universe. Do you suppose nobody would go? Do you suppose a superior civilization would simply be content to meekly hide on a single planet forever? That no such intelligences would have the curiosity and exploratory itch that we have? That colonization would not interest them?...
"Why would they not endeavor to keep their observation undetected - if indeed observers are sent at all?"
Why are all your aliens so shy?
"Wouldn't they risk potential extermination, either by conflict or by contamination?"
From US?!!?
If you're worried about the "War of the Worlds" solution (earthly microbes kill the martians), I suppose both sides should be somewhat concerned. There are ways available to completely sterilize robot probes. This would prevent "forward contamination". Were they to show up in person I suppose protocols could be developed to test if either race harbors microbes inimical to the others. Remember, they're ahead of us by ~10,000 years in technology...
"(g) Occasionally, a probe wanders home by random walk. This seems a rather haphazard way to collect information, but without reducing the risks noted. I.e, the risk/reward ratio is worse than if the observers were designed to 'phone home'."
Bandwith and power--and the inverse-square law--are the enemies of this approach. Think about it this way. If one really can create a geometrical explosion of robot probes filling the Galaxy, even at 0.05 c, the probability of a probe wandering home eventually becomes very high. They keep multiplying! The rate of return of data is probably (in effect) faster than light signals--eventually. I still don't see the risk. A probe comes into the home system, says "here I am" and spills its guts. It does not have to land on your actual planet to do this...
Fermi seems to presume no competitve dangers to exploration. Which could be true, but if true, either implies no competitors or a gamble that any competitor encountered will be a lesser threat. But why take that gamble?"
The risk is to us. When a superior civilization encounters an inferior one, the inferior one always folds. I'm talking about examples from Earth history, like Amerinds vs. Europeans.
Sending probes is probably not dangerous to either side. Arriving in person a la "Independence Day" makes the risk only to us. And alien ships don't use Windows XP, can't be connected to a Mac...
--Boris
A big problem, the nearer to "c" you get. Interstellar particles--ions and random atoms--come at you like high-energy particles in accelerators. Preventing yourself from being cooked is a formidable problem.
Robert Bussard, when he invented his ramjet (Acta Astronatutica, 1969 I believe) understood this problem. Shielding of some sort for the particles is vital. Magnetic fields might deflect the charged ones. Good old lead might be needed in copious quantities to protect from the neutrals. What to do about dust grains?...Perhaps aerogels or their successors. Perhaps you fly a shield a few hundred kilometers in front of you to grab the particles. The problem with all these approaches are (a) mass and (b) drag. Anything that stops the interstellar medium relative to your ship exerts considerable drag due to momentum transfer...
--Boris
So how does it replicate? Unobtanium?
You never answered my previous question; does a Von Neumann robot have to recreate an entire industrial base to self replicate and then escape the gravity well of both the planet and star? And if not, how does it create the infrastructure to multiply and relaunch itself? Remember, the interstellar medium (ISM) certainly does not have the material or the required elements to accomplish this.
See my response at #83, which says:
"Quite the opposite. The universe is ~15 billion years old... As I mentioned, life began relatively quickly on Earth (~3.8 billion years ago) but modern life--including us--is the result of only the last 600 million years given Snowball Earth. Sagan's point--which remains valid despite all objections posted here--is that we are a newly-hatched technological civilization, only a century or two old. So we are the latest, arriving in the blink of an eye. Amazing hubris to believe we are the "first" or most advanced. Second-generation stars were probably quite capable of accumulating enough heavy elements, and many 3rd-generation stars are older than our Sun. The entire human race--all the way back to Homo Habilis--is only a few hundred thousand years old; another eye blink."
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