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Why Haven't Aliens Contacted Us Yet? (Fermi Paradox)

SciFi books and movies talk about silicon based life.

Silicon oxides to a solid, so silicon can not replace carbon.

Assuming the elements are the same everywhere in the universe, you have to have carbon to live, thus any humanoid would be carbon based just like us.

All elements came from the same “ Big Bang “.

There is no element beside carbon that can support life.
 
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It is possible that by its very expansion, it establishes a presence where no material presence has previously existed.
Only a spiritual one.
It's a problem of language, the word "spiritual" have medieval teological connections, but is completely feasible to build a concept that is at the same time scientific and that involves that kind of meanings. As you said the tridimensional space-time bubble expands, but ....expands into what? Maybe the most simple answer would be the mathematical one, the 3 dimension universe expands on the 2 dimensions universe. And that 3 and 2 universes are in reality the same. But in one there is space and time and in the other not. That is at the same time coherent with all the spiritual traditions that humankind have known through ages. The most known being the emerald table " As above so below..." But whit one correction nowadays, in reality we live in the above universe, and what we can grasp by many means is the below universe, the 2D version of the universe.
 
SciFi books and movies talk about silicon based life.
Silicon oxides to a solid, so silicon can not replace carbon.
Assuming the elements are the same everywhere in the universe, you have to have carbon to live, thus any humanoid would be carbon based just like us.
All elements came from the same “ Big Bang “.
There is no element beside carbon that can support life.
This may be true, since naturally-occuring life probably emerges from abiogenesis on a range of planets in the universe, and the most likely form of naturally-occurring life is probably carbon-based, because of the factors you mention.

However this does not rule out the possibility of artificial life supported within a processing substrate such as a computer. AI-based, artificial silicon life may not only be possible but might be manufactured by advanced alien civilisations as a method of exploring, and exploiting, the universe. Self-replicating, silicon-based robots may indeed turn out to be the most common form of 'life' in the universe.
 
It is possible that by its very expansion, it establishes a presence where no material presence has previously existed.
That is probably the best way to visualise it. The new spatial volume of an expanding universe doesn't exist until the metric expands to create it.

One hypothesis about the Big Bang is that it occurred in an empty, ancient, dead universe, long after the stars and atoms of the previous incarnation have evaporated and decayed into infinitely-redshifted energy. After untold gazillions of years, a new expansion might emerge because of random quantum fluctuations. This expansion would occur within the existing space-time metric of the old, dead universe, and so would (in one sense) be 'expanding into' that older three-dimensional matrix; but in another (very real) sense, it would be expanding into itself - that is to say, the new space created inside the expanding sphere is being created ex nihilo and is entirely new.

It might even be possible to stand outside the new region of expanding space and not even be able to see it, since it would only expand within the sphere of expansion and not outside that region. A new Big Bang volume could be entirely self-contained and invisible from without, even if it grew to millions of billions of light-years in radius.

Note that this visualisation of the expansion of the universe also works if there was no original, old universe to expand into. Because the metric of the expanding-universe is entirely self-contained, you don't need any space for it to expand into - it creates new space by itself, simply in the act of expansion.
 
But to build some thing tridimensional you need first something bidimensional, its a logical need.
 
Four dimensions seem to be the absolute minimum requirement, assuming you want time to pass within your cosmos.

Current string theory posits eleven, but I wouldn't be surprised to find out that that turns out to be bullshit.
 
Everything is relative.

An ant on the ground might think, if it could think, that it’s surroundings are infinite.

I think one day the universe will hit a boundary and collapse on itself, and possibly start all over again.

I actually believe the universe is a living entity.

We live inside an entity.
 
Nobody has mentioned the creepiest - and, I suspect, the most likely - reason that we haven't heard from the aliens yet.

It's called the 'Dark Forest Hypothesis'. In a nutshell, there's an older species that has learned that you can't trust these emerging civilizations. You never know, they might turn nasty, they might become a threat, so the safest course is to keep watch on emerging species and simply eliminate them as soon as they look like developing technology.

There's a reasonable discussion of the hypothesis at:

https://bigthink.com/surprising-sci...ation-of-why-we-havent-heard-from-aliens-yet/

So we haven't heard from aliens because there aren't any, not any longer, apart from the one Big Bad that you don't want to hear about!
 
Nobody has mentioned the creepiest - and, I suspect, the most likely - reason that we haven't heard from the aliens yet.
It's called the 'Dark Forest Hypothesis'.
This idea has been mentioned in the thread earlier; see, for instance, post #51, where I called it the 'Big Bad Wolf Hypothesis.'
https://forums.forteana.org/index.p...us-yet-fermi-paradox.28807/page-2#post-688259

It is an old idea that has been around in SF for a very long time. More likely is a 'Balance of Terror' scenario, where several widely separated expansive civilisations maintain large exclusion zones around their spheres of influence.

See as well the Grabby Aliens scenario, recently developed by Robin Hanson.
 
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Four dimensions seem to be the absolute minimum requirement, assuming you want time to pass within your cosmos.

Yes.

Though I think string theory could well be onto something...the use of the other seven dimensions to bypass the rule so of the foundation four?

But I have no way of proving it.
 
This idea has been mentioned in the thread earlier; see, for instance, post #51, where I called it the 'Big Bad Wolf Hypothesis.'
https://forums.forteana.org/index.p...us-yet-fermi-paradox.28807/page-2#post-688259

It is an old idea that has been around in SF for a very long time. More likely is a 'Balance of Terror' scenario, where several widely separated expansive civilisations maintain large exclusion zones around their spheres of influence.

See as well the Grabby Aliens scenario, recently developed by Robin Hanson.
I must apologise, I hadn't noticed that. It's still the hypothesis that seems to make most sense to me, because it's based on the great biological imperative of survival.
 
Nobody has mentioned the creepiest - and, I suspect, the most likely - reason that we haven't heard from the aliens yet.

It's called the 'Dark Forest Hypothesis'. In a nutshell, there's an older species that has learned that you can't trust these emerging civilizations. You never know, they might turn nasty, they might become a threat, so the safest course is to keep watch on emerging species and simply eliminate them as soon as they look like developing technology.

There's a reasonable discussion of the hypothesis at:

https://bigthink.com/surprising-sci...ation-of-why-we-havent-heard-from-aliens-yet/

So we haven't heard from aliens because there aren't any, not any longer, apart from the one Big Bad that you don't want to hear about!

Which is the overarching plot behind the computer game Mass Effect Legendary, which I started playing a couple of weeks ago.
Every 50,000 years or so a race of immortal AI beings known as the Reapers eliminate any organic species that has become too advanced.
 
If I remember correctly, in the last series of 'Lexx' (TV Sci-fi ~2002) the intrepid crew finally landed on our planet. As Earth was in the centre of the Dark Universe, it was assumed to be a very dangerous place. It also didn't have a future, as the overwhelming majority of technology-based civilisations reach a point in evolution where some-one tries to measure the mass of the Higgs Boson (resulting in the planet shrinking to the size of a pea).
 
A new research report awaiting final publication argues that prior estimates for the time it would take a spacefaring species to colonize our galaxy are wrong because they don't consider how such expanding civilizations might select the stars whose planetary systems they would target.
New Study Suggests Aliens Don't Visit Us Because Our Sun Is Too Boring

Many thinkers and scientists have addressed the Fermi Paradox and tried to come up with a reason why we don't see any evidence of an expanding technological civilization.

Life may be extraordinarily rare, and the obstacles to interstellar travel may be too challenging. It could be that simple.

But a new paper has a new answer: Maybe our Solar System doesn't offer what long-lived, rapidly expanding civilizations desire – the correct type of star. ...

A new paper addresses the Fermi Paradox by focusing on star types. It says that not all types of stars are desirable to an expanding technological civilization. Low-mass stars, particularly K-dwarf stars, are the best migration targets for long-lived civilizations.

The paper is "Galactic settlement of low-mass stars as a resolution to the Fermi paradox," and the Astrophysical Journal has accepted it for publication. The authors are Jacob Haqq-Misra and Thomas J. Fauchez. Haqq-Misra is a Senior Research Investigator at the Blue Marble Space Institute of Science in Seattle, Washington. Fauchez is a Research Assistant Professor in Physics from the American University in Washington, DC. ...

The authors point to one of the most famous analyses of the Fermi Paradox. It came from American astrophysicist Michael Hart in 1975.

Hart's paper was "An Explanation for the Absence of Extraterrestrials on Earth," and it was published in the Quarterly Journal of the Royal Astronomical Society. It's considered to be the first rigorous analysis of the paradox. ...

Hart pointed out that a technological civilization would've had ample time to reach us unless they had started less than 2 million years ago. For Hart, the only explanation for the lack of evidence of alien civilizations is that there are none.

In his paper, Hart arrived at a couple of conclusions: SETI and similar efforts are a waste of time and money, and if anyone colonizes our Solar System, it'll probably be our descendants who do it.

The authors of this paper disagree. ...

An underlying assumption for many people who contemplate the Fermi Paradox is that stars are uniformly attractive to a spacefaring civilization, and the civilization would spread everywhere equally. But is that true?

The authors of this new paper don't think so. "We suggest, following the hypothesis of Hansen & Zuckerman (2021), that an expanding civilization will preferentially settle on low-mass K- or M-dwarf systems, avoiding higher-mass stars, in order to maximize their longevity in the galaxy," they write. ...

The authors of this new paper calculated a new estimate for the time a galactic civilization needs to colonize the galaxy if that civilization only targeted K dwarfs and M dwarfs. They say it would take two billion years for a galactic civ to reach all low-mass stars. ...

The authors say it's still worth looking for signs of another civilization expanding, if only to place more evidence-based constraints on our ponderings. And our target should be low-mass stars. ...
FULL STORY: https://www.sciencealert.com/new-study-suggests-aliens-dont-visit-us-because-our-sun-is-too-boring
DRAFT RESEARCH REPORT (Accepted for Publication): https://arxiv.org/pdf/2210.10656.pdf
 
A new research report awaiting final publication argues that prior estimates for the time it would take a spacefaring species to colonize our galaxy are wrong because they don't consider how such expanding civilizations might select the stars whose planetary systems they would target.

FULL STORY: https://www.sciencealert.com/new-study-suggests-aliens-dont-visit-us-because-our-sun-is-too-boring
DRAFT RESEARCH REPORT (Accepted for Publication): https://arxiv.org/pdf/2210.10656.pdf
I now think Aliens are boring as this long drawn out game of Hide and Seek is getting tiring.
 
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I now think Aliens are boring as this long drawn out game of Hide and Seek is get tiring.
Ha ha but we have only been seriously thinking about and trying to find alien life outside our solar system since our early space probes discounted alien life within our own star system. If you think that sounds somewhat preposterous from 2022 then have a look back at the 1950s science fiction magazines and comics that were full of Earth explorers meeting Venusians and Martians. We have been searching for a cosmic blink of an eye. We also have no idea if we were contacted when we were in the early stages of our evolution or when Britain was under Roman rule (to name but two examples). The probe will have had a look at us and filed a report that we were a typical exoplanet hosting humanoid life and moved on... It is only our human egos that makes us believe we are so special.
 
I wonder whether our planetary set up is unusual though. Effectively a double planet rather than dwarf planet or asteroid where doubles seem fairly common. Therefore planet sized and in the goldilocks zone may be quite rare. This has all sort of effects on tectonic plate movement, magnetic core, tides etc. which may have a role in the suitability for life as well as stellar life spans.

If most life in the universe is on moons of gas giants or planets of red dwarfs where maybe the sun’s tidal influence is greater because the planet is nearer its primary then maybe after a quick check of the Jovian moons and Titan they’ve decided nothing of interest here.

That plus the longer life of red dwarfs that the paper mentions may be why we’re low on the list – after all the Earth Moon setup won’t last that long…
 
Also to add that we are not a threat to an alien species until we master interstellar or inter-dimensional travel and that could be in a thousand years, five thousand years or never. A visiting probe from an advanced or AI civilisation may simply look to make that calculation and move on.
 
Also to add that we are not a threat to an alien species until we master interstellar or inter-dimensional travel and that could be in a thousand years, five thousand years or never. A visiting probe from an advanced or AI civilisation may simply look to make that calculation and move on.
Imagine being advanced civilisation by passing Earth and missing out some gems of Earths life like The Beatles, Oktoberest, Bruce Lee films and Muhammed Ali etc etc etc
 
Imagine being advanced civilisation by passing Earth and missing out some gems of Earths life like The Beatles, Oktoberest, Bruce Lee films and Muhammed Ali etc etc etc
Balanced against hostile nations facing each other with huge arsenals of nuclear warheads….
 
Of course if we are living in a computer simulation then anything beyond say, the Edgewoth Kuiper belt may just be that bit of the programme that's there to look pretty and which you can sometimes look at in more detail but never actually get to visit.
 
Of course if we are living in a computer simulation then anything beyond say, the Edgewoth Kuiper belt may just be that bit of the programme that's there to look pretty and which you can sometimes look at in more detail but never actually get to visit.
Well Voyager 1 is now sending back some weird messages:

https://www.inverse.com/science/voyager-1-computer-is-acting-wonky

I wonder what the number 377 might mean, the answer to life, the universe and everything...?
 
The unknown factor that avoids colonization of the universe by extraterrestrials has a name nowadays, great filter. Wikipedia can be consulted about it. [ https://en.wikipedia.org/wiki/Great_Filter ] ...

The Great Filter hypothesis is back in the news. A team including two researchers at NASA's JPL has posted an online essay (not yet peer-reviewed or formally published) updating and expanding upon the earlier writings about the Great Filter.

Their online essay can be accessed at: https://arxiv.org/ftp/arxiv/papers/2210/2210.10582.pdf

The Daily Beast notes the essay and provides more news about it and reactions to it at:

NASA Has a Theory for Why We Might Be Alone in the Universe
https://www.thedailybeast.com/nasa-...-life-in-the-universe?source=articles&via=rss

If you're interested in the history of this hypothesis, the revised 1998 edition of Robin Hanson's seminal 1996 paper can be accessed at:

https://web.archive.org/web/20100507074729/http://hanson.gmu.edu/greatfilter.html
 
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