

Fermi Paradox – Possibilities on why humanity is alone - mw67


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sixQuarks
Here's a scary fact: Once humanity figures out how to reach and colonize our
nearest star system, assuming it takes us 1,000 years each time we colonize
the next closest star systems, it would only take 25 million years to colonize
the entire galaxy. 25 million years is nothing. So why isn't the entire galaxy
teeming with intelligent life? Our universe has been around for 13 billion
years - plenty of time for this to have taken place.

The most likely answer (and one we don't want to admit to ourselves) is that
intelligent species have a certain lifetime limit. Most species die off within
3 million years.

An alternative answer would be that advanced intelligence figures out a way to
delve into mind or other dimensions, rather than outwards into physical space.

~~~
yzzxy
Other prominent answers:

\- Intelligent species are extremely uncommon - life could be common, but
mostly bacteria / simple single-cell.

\- Intelligent species choose to hide themselves from us or others somehow -
I'm no cosmologist, but maybe some of the dark matter we've calculated be
accounted for by dyson spheres?

\- Intelligent design - not personally a proponent of this approach but any
form of intelligent design (fundamentalist/whole-earth creationist or adapted
to evolution) could explain the dark sky paradox

Required (fiction) reading on the implications of Fermi Paradox:

\- Mass Effect

\- Stephen Baxer - Manifold books, esp. Space and Time

\- Too much Asimov to list

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jones1618
Two possible explanations for lack of observable neighbors are: 1) Any
sufficiently advanced civilization will learn how to stimulate/entertain
itself to the point of not needing external stimuli such as exploration and
conquest. In other words, E.T. is too busy playing his holographic, neural-
tapped X-Box to communicate or look for us. (E.M. Forrester's prophetic story,
"The Machine Stops" foreshadowed this for mankind in 1909.) or possibility 2)
A.I. and/or sentient life evolves into a higher-level, transdimensional
abstraction beyond our perception and understanding (also known as the
Singularity).

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kobey
One interesting possibility that doesn't seem to get discussed much is
metallicity. Stars containing more heavy elements tend to be younger, while
older stars tend to have a lower metallicity.

Looking at our own biochemistry, you don't just need carbon, nitrogen, oxygen,
and hydrogen to make it work. Heavier elements from the fourth and fifth
periods of the periodic table are also required.

I wouldn't be surprised if life is rare but also becoming more common over the
last few billion years. Evolution also doesn't necessarily lead to intelligent
life capable of harnessing technology.

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pdx
Intelligence is not enough. You can be intelligent without being
technological.

The dolphin will never make a spacecraft, even if he is twice as smart as we
are. Lack of hands is a problem. Also, lack of ability to create fire is a
problem. Also, lack of ability to easily pour liquids from one isolated vessel
to another, without diluting them is a problem. Basically, no "water worlds"
will create a technological civilization, in my opinion.

There's also something cultural that may not happen for some reason. Look at
the Native Americans. They still didn't have the wheel or metal, four thousand
years after others had them. If there is nothing forcing you to develop tech,
you won't, even if you're technically smart enough and have the resources that
would allow it.

I can also imagine some sort of plateau being reached, after a particularly
nasty government takes over. What would happen here, if certain
countries/groups were suddenly in control of the entire world?

We may already be reaching a plateau ourselves. The desire is waning, I think.
It has certainly waned in my lifetime, both personally, and as a world, I
think. At some point, you become "practical", and decide to expend your time
and resources on things closer to home.

Add it all up, and it's at least a couple more multipliers for your fermi
equation.

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taprun
One more possibility - as human populations get wealthier and more educated,
their population growth rate decreases.

Maybe by the time lifeforms get the technology to travel to other stars, they
find that they don't need to expand.

There are many places (even within the USA) that we have the technology to
colonize, but not the desire.

