Extraterrestrial life Origin Of Life The Universe

At Universe Today: Maybe We Don’t See Aliens Because Nobody Wants to Come Here

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The Fermi Paradox won’t go away. It’s one of our most compelling thought experiments, and generations of scientists keep wrestling with it. The paradox pits high estimates for the number of civilizations in the galaxy against the fact that we don’t see any of those civs. It says that if rapidly expanding civilizations exist in the Milky Way, one should have arrived here in our Solar System. The fact that none have implies that none exist.

Artist impression of an alien civilization. Image credit: CfA

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.

To understand the Fermi Paradox, you need to understand the Drake Equation. The Drake Equation is a probabilistic estimate of the number of civilizations in the Milky Way. It doesn’t tell us how many civs there are; it summarizes the concepts we have to wrestle with if we want to think about how many civilizations there could be.

A critical component of the Drake Equation concerns stars. The Equation considers the rate of star formation in the galaxy, how many of those stars host planets, and how many of those planets could host life. The Equation gets more detailed by asking how many of those planets develop life, how much of that life becomes technological civilizations, and how many of those civilizations reveal their presence by releasing signals into space. Finally, it estimates the life spans of those civilizations.

The Drake Equation: Number of Communicative Civilizations (N) = R* (star formation rate) x fp (fraction of stars with planets) x Ne(number of habitable planets per system) x fl (fraction of habitable planets that develop life) x  fi (fraction of those that develop intelligent life) x fc (fraction of those that develop communicative technology) x L (average communicative lifetime for those civilizations.)
The Drake Equation: Number of Communicative Civilizations (N) = R* (star formation rate) x fp (fraction of stars with planets) x Ne(number of habitable planets per system) x fl (fraction of habitable planets that develop life) x fi (fraction of those that develop intelligent life) x fc (fraction of those that develop communicative technology) x L (average communicative lifetime for those civilizations.)

By using different variables to answer each of those questions, we get different estimates of how many technological civilizations there might be. It’s a thought experiment, but one informed by evidence, though the evidence is rudimentary.

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 paper begins with a summary of the Fermi Paradox: “An expanding civilization could rapidly spread through the galaxy, so the absence of extraterrestrial settlement in the solar system implies that such expansionist civilizations do not exist,” the authors plainly state.

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. In his paper, Hart showed how a civilization could expand through the galaxy in a period of time shorter than the galaxy’s age. Hart explained what would happen if a civilization sent out colony ships to the nearest 100 stars. They could colonize those star systems, then each of those colonies could do the same, and the process could keep repeating.

“If there were no pause between trips, the frontier of space exploration would then lie roughly on the surface of a sphere whose radius was increasing at a speed of 0.10c,” Hart wrote. “At that rate, most of our Galaxy would be traversed within 650,000 years.” Hart pointed out that a technological civilization would’ve had ample time to reach us unless they had started less than two 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.

See the rest of the article at Universe Today.

18 Replies to “At Universe Today: Maybe We Don’t See Aliens Because Nobody Wants to Come Here

  1. 1
    jerry says:

    Silly Asses

    In case anyone doesn’t understand the comment above. It is the name of a short story by Issac Asimov, titled “Silly Asses.”

    https://www.youtube.com/watch?v=m7DcTQzHgJo

  2. 2
    relatd says:

    Another stupid article. There is no reason to colonize the solar system. And, until a faster than light drive is developed, no way to colonize planets beyond our solar system.

  3. 3
    Seversky says:

    Well, would you want to come here if you had the choice? And, given our track record interacting with other cultures, I doubt they’d be too happy with our going there, assuming it’s ever going to be practicable to go there – wherever there is.

  4. 4
    relatd says:

    Seversky at 3,

    Put the science-fiction down and realize that there is zero evidence for aliens or life of any kind anywhere else. I do believe a faster than light drive will be built but there will be practical problems. Number one is colliding with anything the size of a grain of sand or larger when going from Point A to Point B. A force field would need to surround the craft. Slowing down before reaching the destination is another problem. In my view, an FTL Drive would operate in the 4 to 8 light year per day range. Your ship would need to decelerate about halfway through the trip, which requires the speed range I’ve indicated.

  5. 5
    AaronS1978 says:

    @sev
    keep in mind that any alien species that we are speaking of might not exactly be hospitable to us either.

    Something from another planet might not care about anything culturally that we do or say, and very likely could be extremely hostile to us just on the sheer fact that we could be a resource to it

    I’ve always thought it was kind of silly to think that all aliens would be the Star Trek style sophisticated evolved society type. In all reality the process of evolution doesn’t give a crap about that, whatever evolves, it evolves for a reason and if the reason it got to where it was at was because it was extremely hostile and was good at consuming other resources from other living creatures, then there’s zero reason it would ever evolve to care about customs or cultures of different species

    So I doubt it’s because of our interaction with our own cultures repulses the obviously liberal aliens. It’s probably one of three things, either they don’t exist, they don’t care, or we are really really lucky.

  6. 6
    chuckdarwin says:

    Seversky/3
    I wouldn’t write earth off completely. I think there are a few national parks that might appeal to ET’s. After all, they did visit Devil’s Tower years back. And I think they’d get a kick out of the Ark Museum in Kentucky……….

  7. 7
    AaronS1978 says:

    @6 what’s the diagnosis doc? Give it to me straight.
    https://tenor.com/bVDll.gif

  8. 8
    Seversky says:

    Chuckdarwin/6

    I wouldn’t write earth off completely. I think there are a few national parks that might appeal to ET’s. After all, they did visit Devil’s Tower years back. And I think they’d get a kick out of the Ark Museum in Kentucky……….I wouldn’t write earth off completely. I think there are a few national parks that might appeal to ET’s. After all, they did visit Devil’s Tower years back. And I think they’d get a kick out of the Ark Museum in Kentucky……….

    … still waiting to feel an irresistible urge to sculpt the Devil’s Tower out of mashed potato …

  9. 9
    Seversky says:

    Chuckdarwin/6

    And I think they’d get a kick out of the Ark Museum in Kentucky……….

    When I first glanced at that line I thought it read “And I think they’d kick the Ark Museum out of Kentucky…”

  10. 10
    Seversky says:

    Relatd/4

    Put the science-fiction down and realize that there is zero evidence for aliens or life of any kind anywhere else.

    We have no reason to deny the possibility of alien life out there either. That we’re here shows it’s physically possible and, if it’s happened once, it could happen again.

    I do believe a faster than light drive will be built but there will be practical problems.

    The only theoretically possible option for FTL travel is the Alcubierre warp drive but that would be prohibitively expensive in terms of energy. The only alternatives are domains like “hyper-space” or “sub-space” but, as I understand it, contemporary physics doesn’t even allow that they are possible.

    Number one is colliding with anything the size of a grain of sand or larger when going from Point A to Point B. A force field would need to surround the craft. Slowing down before reaching the destination is another problem.

    A cheaper option would be the one suggested by Arthur C Clarke in one of his SF novels where the interstellar spacecraft had a huge “plug” of ice running ahead of it to “bore” a safe passage through the interstellar medium.

    In my view, an FTL Drive would operate in the 4 to 8 light year per day range. Your ship would need to decelerate about halfway through the trip, which requires the speed range I’ve indicated.

    In Star Trek, the secondary drive on the Enterprise is provided by the “impulse engines” which supposed to be based on the principle of hydrogen fusion, which is the reaction in the Sun which produces all that solar energy. Even so, Lawrence Krauss calculated in his Physics of Star Trek, that the ship, using only the impulse engines, would have to burn 81 times its entire mass of hydrogen just to accelerate to half the speed of light. What most people don’t realize is how far we are from having anything like those energies available.

    As for generation ships, you are talking about building probably the most complex machines ever constructed by humans that will have to work reliably for centuries relying only on what they can carry with them for maintenance. How many machines that we build now get even close to that?

  11. 11
    William J Murray says:

    Yes, when you dismiss all the evidence, then “there is no evidence.” Also works with psi, the afterlife and election fraud.

  12. 12
    Seversky says:

    Someone reports a near-death experience in which they leave their physical body, go and meet God and then return. Is that evidence and, if so, of what?

    Someone reports being outside a vote-counting facility one evening during an election and seeing boxes being carried from a van into that facility. Is that evidence and, if so, of what?

  13. 13
    relatd says:

    Seversky at 10,

    You lack imagination.

    News from The Future:

    The Future (AP), Startling Announcement of Trip to Another Planet!

    The world was greeted today by news that an unmanned probe has just returned from a planet orbiting our nearest solar system. We now reproduce the complete statement from the U.S. Air Force.

    “I am announcing today that an unmanned probe has just returned from orbiting a planet at Alpha Centauri. Sophisticated sensors and imaging equipment have shown land masses and oceans, plus two small moons. The propulsion system is the result of several breakthroughs, none of which violate physical laws but which made construction of a faster than light engine possible. Its exact operational details must remain a closely guarded secret for now. With this successful mission, a manned mission will be launched within the next 30 days. Astronauts will land and return specimens. The complete trip will take only a matter of days. Just after their return, photos of the spacecraft will be provided to the media.

    Photos accompanying the article show the two moons above the unnamed planet, and another from low orbit shows land masses, oceans and clouds.

  14. 14
    chuckdarwin says:

    Seversky/9
    Either way, the ETs will likely make short work of Mr. Hamm’s monument to biblical absurdity.
    As far back as I can remember the notion of ETs wasn’t just a possibility, it was virtually certain. Then came Star Trek and it became almost a quasi-reality. Dumb looking uniforms, hokey sets, but story lines to amaze and great characters. And always ETs. Then Kubrik’s masterpiece, 2001: A Space Odyssey added intellectual heft pulling together everything from the origins of man to blackholes to AI to our place in the cosmos.
    Despite all the ID naysaying I am still convinced that there is other life out there….

  15. 15
    doubter says:

    Seversky@12

    Concerning NDEs. Your remark predictably closed-mindedly ignores a boatload of evidence that NDEs are real glimpses of an afterlife existence. Of course you won’t read it, but it would be instructive to peruse The Self Does Not Die by Rivas, Dirven and Smit, a book that documents over 100 reliable, often firsthand accounts of perceptions during NDEs that were later verified as accurate by independent investigators.

    The authors of this book divide their independently verified accounts into a number of different categories. For example, there are many experiences in which the NDEers found themselves out of the body and hovering near the ceiling of the emergency or operating room observing the doctors working on their body, where the NDEer accurately reported details of the resuscitation that they could not have been normally aware of, for several reasons but most importantly because their brains were dysfunctional due to cardiac arrest or other trauma.

    Another category is cases where the experiencer reports traveling to another place, where they encountered and communicated with the apparent spirit of a departed loved one, and it turns out that the NDEer did not know that he/she was dead.

    This volume is a compilation of the manifold veridical evidence for the reality of NDEs as something vastly more than hallucinations of dying brains.

  16. 16
    chuckdarwin says:

    NDE = Not Dead Experience
    It seems to me if these experiences were truly glimpses of the “afterlife,” they would all involve the exact same experience. The fact that these folks report idiosyncratic experiences suggests to me that these experiences are likely physiological artifacts of a dying brain along with highly suggestive post-experience interviews or simply made up. After all, anyone that watches cop shows or doctor shows has absorbed a fairly vivid image of what goes on at accident scenes and hospital ERs and ORs.

    Looking at the Rivas book blurb on Amazon, it appears to be anecdotal. According to CIA data, the crude average yearly US deaths, as of 2020 (pre-covid), was 8.3 per 1000 or roughly 2.3 million deaths per year give or take. Data for the entire world is approximately 7 deaths per 1000 people per year over 7.5 billion people. The 100+ “documented” NDE reports are not even a rounding error in comparison. Moreover, in reviewing the forward to the Rivas book on Amazon, these 100 cases occurred over multiple years going back at least to the 1980s, so the prevalence of these so-called near-death experiences is exceedingly small. Also, without actually reviewing the entire book, I’m guessing that many of the folks were not from the US because the authors of the book are Dutch, which reduces the significance of these 100 folks’ reports as a percentage of overall deaths even more when compared to world-wide death statistics.

    It causes one to speculate that if these experiences are so vivid and profound, you’d think that at least a few more people would be coming out of the woodwork to share their stories…..

  17. 17
    AaronS1978 says:

    https://uncommondescent.com/mind/do-all-people-have-same-near-death-experiences/

    This has been addressed before and often

    I’m also kinda surprised BA77 hasn’t posted on this yet because this is literally his thing

  18. 18
    relatd says:

    CD at 14,

    Kubrik’s masterpiece? It was more realistic but ended up with an ending no sane person could decipher. The original Star Trek was excellent for the most part. For the second time, a spaceship from Earth was not just a tube with a pointed end and flame coming out the other.

    That there may be life elsewhere is a possibility but those running space programs have yet to complete the work.

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