There seem to be no great obstacles to intelligent life devouring the galaxy. So why are we here.
If life on earth arose on earth , and produced humans in a few billion years, why not on some other planet ten billion years ago?
Simplest and most likely explanation is that life is unlikely – requiring a stupendously improbable assemblage of molecules to form.
No one has constructed a plausible high probability origin of life.
Indeed, it looks to me that water based life just cannot form spontaneously. The minimum complexity of life in water is just far too high. RNA based life just does not work without DNA and cell membranes, and you don’t get RNA and DNA spontaneously forming in water.
Here is what I think happened:
There is some environment, perhaps a mixture of liquid cyanide, liquid formamide, and polyphosphoric acid with star tar dissolved in it, in which life can form spontaneously.
Cold temperature origins seem most likely, since cold temperature life can easily spread from planet to planet, because cold temperature planets with liquids are smaller and lower gravity than warm planets with liquids. Volcanic eruptions etc can easily spit rocks into space.
This low temperature, non water based, life evolved, over ten billion years or so, to adapt to environments increasingly alien to its origins, eventually becoming water based life living in hot deep rocks on asteroids.
From which it infected earth. To produce complex life, you need an oxygen environment so that cells will gang together for defense and attack. For an oxygen environment, you need a water environment. We are the first, because it just took that long. And, in due course we, or some other earth species if we fail, will devour the galaxy.
Loop de loop de loo. Hard to believe this is what you plausibly believe created life. I think you need to re-examine your premises.
Needs more trigger warnings, aye.
You just know we’re going to get him. Maybe at deathbed, but I hope not.
Another possibility as to why the universe isn’t inundated with life: Our Moon. Our moon stabilizes the weather on this planet, making it possible for larger forms of sentient life to develop. (The moon’s tidal action might have also led to the formation of bacteria in pools.) It’s rare for a planet to have a big geo-synchronous moon like ours. Maybe it’s the one factor that is absolutely essential for the formation of higher forms of life.
Correction that doesn’t necessarily negate your point: The moon is tidally locked, not geosynchronous. That is, one side of it always faces Earth, but it’s period of revolution about the Earth is about 27 times longer than the 1 day period required for a geosynchronous orbit. Hence, the month.
Why is the moon important to life, other than tides. If just the tides, how does that work?
Stabilizing the Earth’s rotation. Intercepting asteroids.
Absent a large moon, axis is apt to wander. Also, a large distant moon with a tidal force very similar to that of the sun creates a tidal zone that facilitates evolution from sea to land. At one end you have rocks that are exposed to air once a month, at the other end, exposed to sea once a month. So there are many small intermediate baby steps to becoming a land animal.
Compared to this narrative, the Creator God sounds positively reasonable.
I used to believe in evolution, but the low probabilities of life arising from non-life were too hard to swallow. So, when I became a Christian, it was so much easier to believe in a non-physical, transcendant, intelligent designer than to hold to old beliefs.
Your stalwart dedication to presenting all the existing well thought-out arguments and experiments regarding the possible origins of life and various panspermia-type hypotheses really engenders a lot of confidence in me that you’re approaching other arenas of discourse with a similar level of rigor.
http://en.wikipedia.org/wiki/Rare_Earth_hypothesis lists many preconditions for intelligent life, such as a large moon, plate tectonics, the right amounts of carbon and water, etc.
One topic I haven’t seen mentioned is that interstellar transport is really, really hard. A one-kilogram projectile traveling 1/100 the speed of light has a kinetic energy of nine terajoules = 2500 megawatt hours = 2150 tons of TNT. That’s what you’d need to launch it from an asteroid-mounted magnetic gun. Rockets require vastly more energy per kg payload because they haul so much propellant.
This tiny payload must hold petabytes of data plus a self-assembly mechanism, like a mustard seed. It must gather organic matter and turn it into humans and other Earthly organisms. And it must be rugged enough to survive a gun launch, a crash landing, and millenia of highly-penetrating, atom-scrambling cosmic radiation.
Fission powered ion drive or plasma drive, fusion powered plasma drive. The exhaust velocity of a fission powered plasma drive expelling the waste products of fission would be about 10000 kilometers per second, three percent of the speed of light. So nuclear powered starships should be able to reach a few percent of the speed of light, getting to nearby stars in a few thousand years or so, crossing the galaxy in ten million years or so.
0.03c = 80 terajoules per kilogram, which is the energy density of uranium and thorium. According to Tsiolkovsky’s equation, each kilogram of payload needs 4.67 kg of fuel to accelerate to exhaust speed and 1.72 kg to stop. I suppose the stopping fuel would be stored in a shell around the payload to shield it from cosmic rays.
This is a good of a theory as any I’ve yet heard. Thanks, “Jim”.
I like this explanation much better than all the other higher forms of complex life arose and destroyed themselves. Of course our knowledge is so limited that it’s very hard to make any type guess with any certainty.
[…] Source: Jim […]
Maybe the initial premise is wrong- there seem to be a great many obstacles to intelligent life devouring the galaxy, primarily due to the sheer amount of empty stuff in between everything interesting.
Immortality could solve that problem. Or we could create humans that, like tardigrades, can survive freeze drying. Or uploads.
>>There seem to be no great obstacles to intelligent life devouring the galaxy. So why are we here.
Like Will, I can think of more than a few obstacles involved in interstellar travel. The biggest, though, is simple motivation. Natural selection helps generate species that are optimized to proliferate in their home environments, but it doesn’t help much in instilling instincts to leave the planet, since such behavior won’t help an Earthly species proliferate on Earth. An interstellar project is high cost with high risk and little to no material benefit to those who stay behind. Motivating any species to undertake such a project would be difficult since the drive to proliferate generated by natural selection tends to work through instinctual behaviors rather than a conscious strategy.
I am pretty sure that humans are to some considerable extent motivated by conscious strategy.
Leaving the initial life starting conditions aside, this view is the only coherent one I know. Life is extremely rare, it’s still early in the history. But the first flower in the spring, can be the last one, too.
[…] sees this implying that many civilizations are exterminated  Shortly thereafter, Jim posted a response that the Great Filter lies not before us, but behind […]
“Star tar” isn’t a technical term, can you be more specific?
The organic soluble fraction of carbonaceous chondrites.
“Star tar”
In this world gone mad, we won’t spank the monkey, the monkey will spank us.
erik pitoniak
The great silence « Jim?s Blog
Jim,
Your hypothesis holds only if the Big Bang is wrong as the time since the Big Bang, circa 14 Billion years, is insufficient. Whereas if the Steady State Universe is correct, time is not a constraint to panspermia populating the galaxies with life.
Dan Kurt
Steady state makes the Great filter *much* scarier, and is basically falsified anyways.
Why is 14 billion years insufficient? It’s plausible that it happened in 4.5 billion.
erik pitoniak
The great silence « Jim?s Blog
Erik Pitoniak
The great silence « Jim?s Blog
We have this idea that once a world has life (or maybe multicellular life) then intelligence and toolmaking are inevitable.
There is no evidence to support this. Earth has had complex land-dwelling life for 400 million years (about 10 percent of the planet’s lifetime). It has only had intelligent tool-users for 1 million years (and that’s being generous).
Moreover, intelligent tool-users are a single lineage, the hominids. There is no sign of parallel evolution among different organisms. Apparently, the animal kingdom can get along just fine without intelligence.
This suggests that the “Great Filter” is behind us. If we venture out into the universe we may find hundreds of worlds full of exotic creatures, but none capable of building a radio telescope or a starship. For better or worse, we are the Elder Space Gods.
The encephalization ratio has been rising steadily for the past four hundred million years. Chimps, parrots, dolphins and octopi are of roughly equal intelligence. So the intelligence of the smartest creatures in each group has been rising at almost exactly the same speed. Some parrots are tool users. If we humans screw it up, parrots will be the next sentients, after them octopi.
But parrots have serious physical obstacles to tool use, and cephalopods are unlikely to master fire, being aquatic and all.
Also: does encephalization necessarily map to intelligence? I ask because cephalopods, for instance, need a lot of brainpower just to manage their bodies; and dolphins have big brains for sonar imaging. I’m not sure those large “dedicated processors” can be repurposed for general intelligence.
There is a bunch of you tube videos of octopi solving puzzles. They are at least as smart as chimps. The smartest parrots can not merely mimic human speech, but speak considerably better than chimps using sign language.
Brain mass is vulnerable and uses allot of calories so if its not useful for intelligence you have to come up with alternate reason for why it would be so strongly selected for.
[…] his post, “The great silenceâ€, Jim hypothesizes the improbability, if not impossibility of the first proto-life forming on the […]
All the smart races are hiding from the “Crushers”. As soon as the Crushers find out we exist they will crush us. We’ve got less than 100,000 years before they come. 100,000 light years being the approximate width of the Milky Way Galaxy.
“If life on earth arose on earth , and produced humans in a few billion years, why not on some other planet ten billion years ago?”
Life needs some rather heavy elements (Fe, P, S etc.). These were not available until the first generation of stars had died, and still pretty rare in the second generation of stars. Ten billion years ago, the ingredients for live simply were not yet created.