Should The Galaxy Have Been Colonized By Now?

[SpaceTiger]

Then would you say the "great silence" proves that no one has colonized the galaxy yet, therefore there isn't any really advanced alien civilizations in the MW?

No, the Fermi paradox isn't proof of anything. It's just idle speculation. These things can be fun to think about, but you shouldn't waste your time trying to "prove" anything about extraterrestrial intelligence. That is the way of the crank, my son.

 

[marcus]

Then would you say the "great silence" proves that no one has colonized the galaxy yet, therefore there isn't any really advanced alien civilizations in the MW?

No, the Fermi paradox isn't proof of anything. It's just idle speculation. These things can be fun to think about, but you shouldn't waste your time trying to "prove" anything about extraterrestrial intelligence. That is the way of the crank, my son.

Hello G.B. what SpaceTiger says sounds like good advice. You could be needing to spend more time learning college physics and basic astronomy and less on speculation. He cautions against "wasting your time" on overly speculative thinking. Probably right.

However I am not quite so averse to speculation and I am willing to consider arguments that (while not RIGOROUS) involve judgements of probability and reasonableness.

So I would say that "the great silence" IS INFORMATION and does suggest drawing some conclusions about the liklihood that intelligent lifeforms have already colonized substantial parts of the galaxy. Without claiming that anything has been rigorously proven, or that the terms have even been carefully defined, I nevertheless surmise that the great silence makes it LESS LIKELY that some such thing has already happened.

Have to go. back after supper.

 

[Gold Barz]

But we pretty much are still in the dark though, right? plus we don't even know if radio is a good marker...so the great silence may not be permanent.

 

[WarrenPlatts]

Entropy wrote:

"who's to say aliens have a sense of adventure, or feelings at all? Won't aliens be different not only physically but mentally as well? Scientists relate extraterrestials to much to themselves, but with a different physical shape. They assume aliens are explorers/scientists like they are, heck most people on Earth don't have scientific minds."

The thing is that any intelligence will have to evolve from the jungle--just like we did. Probably, they will have evolved from predators--just like we did (chimpanzees are the most sophisticated predators apart from humans). Most likely they will be land animals; as I've argued before, intelligence and culture might evolve in the ocean, but it would be difficult to get a technological civilization off the "ground" in such an environment.

Emotional feelings seem to be a primitive trait found in all advanced forms of the various animal phyla (mollusks, arthropods, vertebrates). And since insects are the most diverse fauna on the planet, and since they have six legs, then most animals on this planet actually have six legs. Granted, culture and human-level intelligence might evolve within a snake-like species; but they would have a difficult time getting technology started. Thus, according to the law of convergence in evolution, we should expect that extra-terrestrial civilizations will share our spirit of adventure that we retained from the jungle, and that they will be land animals with good hand/claw/tentacle-eye coordination.

I also grant that most humans don't have a scientific mind-set. And arguably, western-style science is an historical fluke that depended on a lot of coincidences (e.g., the confluence of Christianity and Greek philosophy). So, maybe we need to add a new factor to the Drake equation that would estimate the probability that a technological civilization would hit upon the western-style scientific method that seems to be necessary to become spacefaring. However, once a society figures out spacefaring technology, we should expect them to use it. Even the most primitive human societies historically expanded their range to just about every habitable area they could find.

Thus, once an extra-terrestrial civilization colonized several star systems, it would be difficult to blow themselves up--even if they wanted to. That is, the Drake equation factor that measures the longevity of civilizations would be large.

So, there are 2 basic explanations for the great silence: (1) we are the first; (2) they are already here, and we just don't know about it because their technology is beyond our ken and their ethics are advanced enough so that they don't overtly meddle in our society.

 

[robousy]

Galactic Extinction

I have a gut feeling that we aren't the only intelligent lifeforms in the galaxy and I also doubt that we are the first spacefaring.

This begs the question (as has already been pointed out) WHY is the galaxy not already colonized - certainly the timescales from the 'birth' of a spacefaring civ. to the eventual colonization is 'small' in with respect to geological timescales. (millions of years).

As an attempt to at saying something that has not already been said I will propose the following alternative scenario: The concept of a 'galactic' mass extinction (GME) - which is some hypothetical event which periodically destroys a large % of life in a galaxy. Possible GME mechanisms may include hypernovas (google this - its a newish idea).

I am not really promoting this idea - merely throwing it out there as a possible reason why the galaxy is not already colonized.

Any comments?

Also, can anyone else thing of what might cause a GME other than a hypernova. Let's see where this goes...

 

[marcus]

...
As an attempt to at saying something that has not already been said I will propose the following alternative scenario: The concept of a 'galactic' mass extinction (GME) - which is some hypothetical event which periodically destroys a large % of life in a galaxy. Possible GME mechanisms may include hypernovas (google this - its a newish idea).
I am not really promoting this idea - merely throwing it out there as a possible reason why the galaxy is not already colonized.
Any comments?
...

my hat is off to you
in my experience original ideas are rare and this is one
for me, this is a new possible explanation for the apparent silence

(and the short time that colonization should take, compared with the age of the galaxy)

I realize you are just throwing it out, not promoting, but since it seems to work and is new (to me) I see it as a handsome contribution.

 

[Gold Barz]

Is there no one else but me that thinks the idea of colonizing the galaxy might actually be harder than we think, alot more harder and longer...maybe billions of years?

 

[russ_watters]

Who is this "we" you're talking about? No one thinks it will be easy.

 

[Gold Barz]

I never said anything about it being easy, I just noticed that a lot of people seemed to think that if these hypothetical E.T.'s did exist that the Milky Way should have been packed and colonized by now, I just asked if anyone else felt differently.

 

[Chronos]

Colonizing the galaxy just might be as difficult as we think it is. It's an expensive trip and folks back home might object so long as they are still running around barefoot and hungry.

 

[turbo]

I never said anything about it being easy, I just noticed that a lot of people seemed to think that if these hypothetical E.T.'s did exist that the Milky Way should have been packed and colonized by now, I just asked if anyone else felt differently.

Set aside "easy" for the time being and let's address "possible"... Right now, despite George W. Bush's clueless pronouncement (doesn't anybody with an education vet his speeches?) we are incapable of sending humans to Mars, to say nothing of colonizing that planet. We cannot adequate shield them from Solar "tantrums" once they are beyond the Earth's magnetic field, and we simply cannot loft enough food, water, supplies, equipment, fuels, etc to get a crew to Mars and back with today's technology.

For fun, you might want to calculate the ratio of the Earth/Mars distance to the Earth/Proxima Centauri distance and estimate the travel time (assuming that we can develop a propulsion technology that doesn't require us to gather all the reaction mass we need at the beginning of the journey!). Then figure your optimum crew size and start estimating supply needs, etc. Don't forget that humans have finite life spans...

 

[Chronos]

Agreed. According to science as we know it, ET simply can't afford to colonize the galaxy. It's a logistics nightmare. Time is not the issue. If our science is even modestly close to correct, interstellar travel is impractical - save, perhaps, as an act of desperation.

 

[Garth]

Agreed. According to science as we know it, ET simply can't afford to colonize the galaxy. It's a logistics nightmare. Time is not the issue. If our science is even modestly close to correct, interstellar travel is impractical - save, perhaps, as an act of desperation.

"We've had massive budget cuts..."

Or, perhaps, all inter-stellar space-faring civilizations self destruct.

In other words survivablity and inter-stellar space-faring are mutually incompatible attributes of any ET civilization. i.e. Only those that do not take the technological-space-faring route are able to survive the technology crisis.

On the other hand we might be alone...
(but what a waste of space!)

 

[Entropy]

If in fact, it is truly impossible to travel faster than light, then the galaxy will probably never be colonized. If we ever find that it is possible that faster than light travel is possible, then we can assume that we are the first wave or life is rare in the galaxy.

 

[CarlB]

My vote is that we're the first intelligent life to mature in the galaxy and that we will likely be able to colonize the rest of it before anything else shows up.

Carl

 

[Garth]

My vote is that we're the first intelligent life to mature in the galaxy and that we will likely be able to colonize the rest of it before anything else shows up.
Carl

So long as we don't destroy ourselves first!

Garth

 

[Efimka]

Compare to earth, which is colonized by different types of creatures, of whom we count ourselves as the dominant race. Ants, or flies had also colonized the Earth way earlier than men, but are they dominating anyone?
My point is that even if the galaxy is colonized by some ceratures resembling to humans (including the green men) it doesn't necessarily mean that we are dominant in Milky Way.

 

[Daminc]

So, there are 2 basic explanations for the great silence: (1) we are the first; (2) they are already here, and we just don't know about it because their technology is beyond our ken and their ethics are advanced enough so that they don't overtly meddle in our society.

There is another possibility for a great silence and that is the 'Alien lifeforms' may communicate via lightwaves or scent like some of the lifeforms on Earth do.

 

[marcus]

My vote is that we're the first intelligent life to mature in the galaxy and that we will likely be able to colonize the rest of it before anything else shows up.
Carl

sounds like a plan

let's go for it

 

[vincentm]

My vote is that we're the first intelligent life to mature in the galaxy and that we will likely be able to colonize the rest of it before anything else shows up.
Carl

You could be right, but who knows? The sheer amount of stars is overwhelming and to cancel out the idea that there isn't any other life in our galaxy alone is just proposterous.

 

[marcus]

I made a poll for reactions to CarlB's idea

https://www.physicsforums.com/showthread.php?t=97989

It seemed like something to get some focus on.

You are invited to register your take on it so we can see how opinions sort out or if there is any PF consensus on it.

 

[robousy]

my hat is off to you
in my experience original ideas are rare and this is one
for me, this is a new possible explanation for the apparent silence
(and the short time that colonization should take, compared with the age of the galaxy)
I realize you are just throwing it out, not promoting, but since it seems to work and is new (to me) I see it as a handsome contribution.

Thanks Marcus!

 

[robousy]

According to Kaku, we are now in what he calls a Type 0 civilization. A type 1 civilization will be able to capture the free energy of an entire planet, and will have mastered the interplanetary environment. A type 2 civilization will be able to gather the free energy of entire solar systems, allowing the colonization of nearby star systems. And finally, a type 3 civilization will be capable of roaming entire galaxies. A type 1 civilization would be able to survive calamities natural or man-made limited to the Earth itself, but would still be vulnerable to nearby supernovae and gamma ray bursts, the impending collision with the Andromeda galaxy in 4 billion years, and the death of the Sun itself. Type 2 civilizations would have more survivability, and a type 3 civilization would be for practical purposes immortal—until, that is, the entire universe runs out of free energy.
Granted, we humans have our dark side, and we may cause our own extinction. On the bright side, it should be noted that human evolution seems to be accelerating. After 100,000 years of stone-age technology, it took only 10,000 years to reach the industrial revolution that began 200 years ago. Therefore, we can predict that humans will reach full type 1 status within the next 800 years or less. Indeed, considering that humans already co-opt 40% of Earth’s net primary productivity, that we have sent men to the Moon and probes to every planet except Pluto, and that we could—if we had the political will—manage the Earth’s atmosphere to maintain any desirable, global, average temperature, it would seem that we are already half-way to type 1 status. Michio Kaku himself has suggested that we will achieve type 1 status within a century—as long as we can stave off the terrorists who would have us return to a type -1 civilization.

Nice post.

Just wanted to add a little if you don't mind. The 'type' of a civilization you are referring to is based on the Kardashev Scale. Read here for a little more info:

http://en.wikipedia.org/wiki/Kardashev_scale

Also - we are currently estimated to be a type 0.7 on the scale - not 0.
This is based on an equation by Carl Sagan.

Lastly with reference to terrorists returning us to a type -1 civ. There is actually a negative Kardashev scale - I think proposed by Frank Tipler et al.
The -ve scale is 'good' though and is an indication of a civilizations ability to harness smaller and smaller scales - eg, nanotech - genetics, molecular biology etc.

Personally I think that the Kardashev scale, though brilliant when suggested, is a little outdated. A type 2 civ for example would have to construct a Dyson sphere to be considered type 2 - eg, utilize all the available energy in the solar system. It is my humble opinion that humanity will have mastery of newer forms of energy that will open up reservoirs of energy far vaster than the output of the sun - with far less effort than the construction of such a behemoth (Dyson Sphere).

At a crude and naive guess it may be in the form of vacuum energy, singularity energy or perhaps something to do with strings and extra dims.
Don't quote me on this :) But the Dyson sphere is very '20th century' thinking.
We are 21st century physicists now and have some extremely exciting physics developing.

 

[Chronos]

Pardon my pessimism, but I see no future in attempting to extract 'energy' from empty space. I must see the lower available energy state before considering that possibility.

 

[robousy]

Pardon my pessimism, but I see no future in attempting to extract 'energy' from empty space. I must see the lower available energy state before considering that possibility.

Maybe casimir plates?

Forward has shown how the Casimir force could in principle be used to extract energy from the quantum vacuum:

Phys. Rev. B, 30, 1700, 1984

Just a start...like noticing magnetism for the first time.

 

[robousy]

...although personally I have recently began thinking that old people should be put to work in huge factories and forced to pedal on cycle machines hooked up to a massive national grid network.

 

[marcus]

...although personally I have recently began thinking...

or pessimistic people generally, since it would confirm the correctness of their expectations and thereby provide an empowering experience for them.

 

[turbo]

...although personally I have recently began thinking that old people should be put to work in huge factories and forced to pedal on cycle machines hooked up to a massive national grid network.

Would you arrange to have the "old people" receive painful shocks if we fail to pedal fast enough, or would you prefer to whip us instead?

 

[robousy]

Would you arrange to have the "old people" receive painful shocks if we fail to pedal fast enough, or would you prefer to whip us instead?

lol.

I think electric shocks would be too extreme and whips certainly inhumane.

Perhaps a device that tickled you if you failed to produce over 70 rpm.

 

[Chronos]

It would seem more efficient to implant a pleasure center stimulator powered by a generator affixed to the peddling mechanism.

 

[scott1]

Colonzation of the galaxy whould require a lot of energy.A civilation to colonize the entire galaxy whould have to a type 3 civiltion.Our civiltion has existed for 12,000 years and were still a type 0 civiltion.It should take us about 1 millon years to become a type 3 cilivtion.I don't think if there is anyother intellgent life it probally whouldn't have enough time to evole to become a type 3 civiltion.There might an type 2 cilivtion and probally a type 1 cilivtion(if were not the frist farring civiltion)We might just be in a remote region where there's really no reason to colonize.If there are any earth-like planets they might not all have intellgent life on it Earth didn't have Intellgent life for billions of years