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Calculating the number of alien space artifacts in our solar system

Link here. The author attempts to make a back of the envelope calculation of the number of abandoned alien interstellar spacecraft in the Milky Way (like our Voyager and Pioneer spacecraft), and from this calculate the number that might actually be drifting through the solar system. His conclusions?

Wondering if there’s any alien goodies in our solar system?

Well, the distance inner edge of the Oort cloud is estimated to be 4,000 A.U. This would make the volume of the solar system = 201 million cubic A.U.s, and the chance of an alien artifact adrift in our solar system (other than our own) is less than 1 in a 1,000,000. Using the outer edge distance for the Oort cloud at 50,000 AU = gives the volume of the solar system at 31.4 billion, with a slightly better than 1-in-45 chance.

But the nearest star system, Alpha Centauri is 4.4 light years distant, which equals a sphere 243 cubic light years in volume, with lots of elbow room for alien space junk!

The author also admits that these calculations depend on many assumptions, and should not be taken very seriously. Nonetheless, they are intriguing, and fun to consider.


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From the press release: In this ground-breaking new history of early America, historian Robert Zimmerman not only exposes the lie behind The New York Times 1619 Project that falsely claims slavery is central to the history of the United States, he also provides profound lessons about the nature of human societies, lessons important for Americans today as well as for all future settlers on Mars and elsewhere in space.

Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space, is a riveting page-turning story that documents how slavery slowly became pervasive in the southern British colonies of North America, colonies founded by a people and culture that not only did not allow slavery but in every way were hostile to the practice.  
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  • Calvin G Dodge

    Having read Michael Crichton’s “Aliens Cause Global Warming”, I think Dickinson’s calculations are pretty much worthless.

  • LocalFluff

    Making up a probability figure to match sine if the the largest numbers in physics doesn’t impress me. But even Phobos is an alien spacecraft, according to Carl Sagan’s friend, so who knows? Is there a man in the hollow moon?'s_%22Hollow_Phobos%22_hypothesis

  • wodun

    Of course, we can think of several objections to this rough estimation: this assumes that civilizations rise and fall at a uniform rate, and they continue to launch objects out of their respective solar systems at once per decade. And it also assumes said spacecraft and civilizations are distributed evenly, when it may well be case that a galactic “habitable zone” exists.

    One object once per decade? Must not be very advanced.

  • wodun

    @ Calvin G Dodge

    I had never read that. It was enlightening. I have never read any of his books or essays, only the occasional quote, or even listened to him speak, so watched some youtube interviews. It is astonishing how well he characterizes the current state of science and the fallacies applied to global warming alarmists. I independently came to similar conclusions following a similar route, starting with anthropology.

    Much of science isn’t really about science and never has been. It is about people. The checks and balances built into the scientific method are not just about the actual science taking place but about mitigating the human factors.

    Most of the scientific speculation about the future isn’t based in science but rather the human evolutionary fear of an uncertain future. Some of it is kind of playful, like the London Bridge is falling down song, as the link above is but some of it is a nefarious way to manipulate and control people.

    That so many of the smartest humans fall for this or intentionally engage in it, doesn’t speak well to their actual intelligence or ethics and just goes to show that humans are just as primitive as they ever were.

  • Chris

    @ Calvin G Dodge: Thank you for the link to the Critchton lecture!
    Critchton has always been my favorite author. He was always the best at taking the state-of-the-art a few steps further into very interesting scenarios where his character development really shined. Critchton then also showed, as he does in this lecture, what science is and is not – especially in State of Fear.
    I really miss his novels.
    On the state of our “use” and “misuse” of science, I think the misuse that we see in much of science and that Critchton notes in his lecture is not from lack of knowledge but from lack of virtue and morals. Seek the truth or nothing at all.

  • Chris: To quote Thomas Jefferson, paraphrasing Montesquieu, “When virtue is banished, ambition invades the minds of those who are disposed to receive it, and avarice possesses the whole community.”

  • Chris

    Thanks Bob

  • Steve Earle

    wodun said:
    “…One object once per decade? Must not be very advanced….”

    If you think about it, we have the same cadence.

    We have launched 5 objects that have or will exit the Solar System. 4 of those, Pioneer 10 and 11, and Voyagers 1 and 2, were launched in the 70s. The 5th, New Horizons, was launched in the 2000’s.

    If you divide that by how long we have been capable of launching rockets that escape our planet you get about 1 per decade.

    However, if we fail to launch another spacecraft capable of leaving the Sol System before this decade has ended, we will actually fall below 1 per decade…… So how advanced are we?

  • Cotour

    I am wondering what high IQ science nerds think about this interview and credibility?

    Highly credible observation and technical recording and documentation far outside of known performance parameters but still no reasonable concrete answers. How can something be nothing?

    Just ignore it because it does not fit in a comfortable BTB “science” box?

  • wayne

    U2 Chase into Russia — “Dark Skies”

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