The Physics of Extra-Terrestrial Civilizations

http://www.mkaku.org/ ^ | unk | Michio Kaku

[js1138]

Here is the rub. Do we want to waste our limited resources on sending one-way robots into space?

For the same reason we build monuments and time capsules. I think it will be a century or two before we have the technology to send self supporting, self replicating probes into interstellar space.

But my point is, given hundreds of millions of years, why hasn't someone else done this? Or have they?

[Robert A Cook PE]

At which point, when such single-celled life is discovered, we might destroy it (accidently or intentionally!) or it might destroy us (accidently or incidently by infection or replacement or injestion ...)

Are we REALLY, REALLY sure we (without defenses against their potential/probable weapons and intentions), REALLY, REALLY want to attract outside life here BEFORE we have some place to escape to?

People leave bees and wasps alone as long as the bees stay away from people ans children and pets and property.

Now, just being ignored is no sign we are NOT in danger of accidental annilation. For example, as soon as the house needs painting, the wasp nest gets fumigated and washed away without a care for the lives of those inside the nest!

[RadioAstronomer]

So you didn't find it this time? Well, our mission wasn't a failure we just weren't looking in the right place, let's search some more. And since everyone who is looking believes something is out there, how will this be a discovery? Time to kick Saganism to the curb.

Actually NASA can do both. Where do you see "Saganism" as the main goal of NASA? If I send out an interplanetary, why not add an experiment that looks for life? Actually life elsewhere would be one of the biggest discoveries since the advent of fire. Intelligent life even doubly so. Money pit? Explain. I sure don't see it unless you advocate the canceling of interplanetary spacecraft and space based telescopes. BTW, these are multiple use platforms. So, lets talk about SETI. Show me one NASA dollar spent specifically on SETI.

Searching for life is a money pit and intellectually dishonest.

Total codswallop!

[RadioAstronomer]

But my point is, given hundreds of millions of years, why hasn't someone else done this? Or have they?

Maybe they have. :-) However, this universe is BIG. :-) Here is another rub; you are a race that finally reaches this point in technological evolution. Do you advocate "polluting" or swarming a series of stars with self-replicating nano-probes?

[boris]

"I don't think I completely agree. Machines fail over time, and self-replicating ones would have replicating errors over time. Also, why would a race use the extremely valuable resources of their solar system to create one-way journeys that would give zero return for their effort?"

I don't think I understand. For a very small investment, a hypothetical civilization could launch, say, 100 Von Neumann robots (jumbo sized). Upon reaching their target star, the instructions are: gather all available data and then build a copy (scion) of yourself; dump your memory into it and then BOTH head at random to another pair of stars.

The payoff comes when one--inevitably--wanders home, bearing the complete data collected by all of its ancestors. Remember, we are positing very-long-life civilizations, with long-term views. This is a tautology; if it has taken you 100,000 years to reach the level of sophistication needed for this plan, you do not expect to wink out in 100 years and your civilization can afford to wait a few thousand years for a probe or two to come home.

In principle, only one probe might be needed--but occasionally probes will be destroyed, find no raw materials, etc. So you should start with several.

For an ultra-advanced civilization, this should be easy as 'pi'.

Even at 0.05"c", there has been ample time for every star in the galaxy to be visited. If there are multiple advanced civilizations, there should be a traffic jam. In particular, at Sol. And if they are using nano probes, it should be even more certain that aliens will land on the White House lawn. So where are they?

My answer: they are not anywhere. Else we would see them.

--Boris

[myheroesareDeadandRegistered]

I don't think "they" are waiting for us to attain some higher stage of galactic enlightenment............they're just waiting so see if we're going to put on some more weight. :)

[boris]

"Unless we are absolutely unique, odds are we have neighbors who are way ahead of us."

And if this is so, they should already be here. We fail to observe them. Hence the premise is flawed: there are no neighbors who are way ahead of us.

--Boris

[boris]

"Biological evolution has ocurred without the help of war for billions of years."

Biological evolution is war...among species, for survival. All we have done is accelerated the pace...for machines, not meat.

--Boris

[boris]

"Are we REALLY, REALLY sure we (without defenses against their potential/probable weapons and intentions), REALLY, REALLY want to attract outside life here BEFORE we have some place to escape to?"

Too late. If there are Independence Day bad guys, we've been announcing our presence to them for almost 100 years.

You want to maintain radio silence and hope they'll not notice us? I Love Lucy et al are our calling card. I suppose we could--in a fit of racial paranoia--stop using EM communication and go 100% fiber-optic...but the wavefront is advancing, at one light-year per year...

--Boris

[RadioAstronomer]

I still don't see it. Even at .05c (~9000 miles/second), it would take longer than a lifetime to just get to the nearest star, much less find the suitable resources to build more machines and return etc. Where does the delta-V come from? Remember you have to escape every stellar gravity well for each machine. The other rub, is with sufficiently advanced telescopes, do you need to send the probes just in case one wanders back someday thousands of years in the future?

[RadioAstronomer]

Indeed it is. However, with the advent of frequency hopping broadband and more efficient badndwidth use, we are getting harder to see every year.

[boris]

Yes, both the Ringworld and Dyson sphere have been shown to be unstable; ie., both require a negative-feedback active controller to keep the star centered. Eventually such devices will fail, which will rapidly reduce the property values on such artifacts.

--Boris

[Little Ray]

The Ringworld is unstable! The Ringworld is unstable! ^_^

[harbingr]

Click on my name and read about 'Fallen Angels', 'The Great Deception', and the 'Three Days of Darkness'...

[Junior]

At which point, when such single-celled life is discovered, we might destroy it (accidently or intentionally!) or it might destroy us (accidently or incidently by infection or replacement or injestion ...)

You're assuming compatible biologies. Alien microbes might not be able to infect Earthly life; conversely Earthly life might have absolutely no impact on extraterrestrial life.

[boris]

"I still don't see it. Even at .05c (~9000 miles/second), it would take longer than a lifetime to just get to the nearest star, much less find the suitable resources to build more machines and return etc. Where does the delta-V come from? Remember you have to escape every stellar gravity well for each machine. The other rub, is with sufficiently advanced telescopes, do you need to send the probes just in case one wanders back someday thousands of years in the future?"

Longer than a human lifetime. Who says intelligent ETs must live <100 years? Perhaps they've uploaded themselves into machines. It matters little: if intelligent civilizations are everywhere, some fraction will use this strategem; the payoff is too big to ignore.

If our civilization lasts 10,000 or 100,000 years, what velocity do you think our machines might be capable of? 0.05 c is pretty modest for a 100-kilo-year-old civilization. Bussard ramjets? Laser powered sails? Antimatter? Baloneyum nitrate? Remember that one gee is 1.032 light years/year/year.

Telescopes cannot begin to get all the data that is available 'up close'. All you get is images and spectra. On-site probes can take samples, do comprehensive analyses, find and analyze life forms (if any)...a million things that even super-Hubbles cannot do.

--Boris

[Congressman Billybob]

You are behind the curve in this discussion. What you just said, "we would have observed them," was raised by Enrico Fermi fifty years ago. His comment, "So why aren't they here?" was quoted by me, about fifty posts above this one.

That led to a discussion of the "non-interference" principle. They've seen us, find us hopelessly backward, and choose to leave us alone for a few millenia to see if we grow up and mature as a civilization.

No way to prove it either way, without venturing into the Von Daniken tin-foil theories, but there it is.

Congressman Billybob

Latest column, "Open Judicial Mouth, Insert Foot," discussion thread. IF YOU WANT A FREEPER IN CONGRESS, CLICK HERE.

[Little Ray]

Another theory: prodution is so automated and efficient, and entertainment is so incredibly advanced, that the entire population of advance civilizations are still at home wired into their "better than life" VR systems. Or even uploaded into the same. Apathy wins.

[RadioAstronomer]

Agree with most of your post. :-) (I like unobtainium or seldomseenium hehehe)

I still don't see colonizing an entire galaxy. That's a tall order even for an advanced race. All speculation anyway. (on both sides) :-)

What if only third generation stars produce life? Maybe there are thousands of races out there that are just beginning to invent the wheel and a few who destroyed themselves? I have no idea. In fact I don't "believe" in ET. I suspect there may be so I search. :-)

If we are alone this is profound, if we are not, this is also profound. SETI is a win win science. :-)

[jpl]

I just hope that when the day comes for us to ship off this rock, we take Douglas Adams' advice, and send all the lawyers off on a collision course into the sun.