I think Authors is way way optimistic with these numbers: "Let’s imagine that after billions of years in existence, 1% of Earth-like planets develop life" and " "And imagine that on 1% of those planets, the life advances to an intelligent level like it did here on Earth" Why 1% and not 10^-10%?
The Fermi Paradox
81–90 of 168 posts
Re: The Fermi Paradox
#82Another possibility... there are plenty of civilisations within broadcasting distance from us that are all listening but not broadcasting for fear of predatory civilisations.
that exact possibility was listed in the article.
Re: The Fermi Paradox
#83The "we are the first" argument seemed less convincing than it could have been. A better argument from that perspective is the observation that Type III civilizations expand at an alarming rate. Whatever the motivation for expansion[1], basic simulations and back of the envelope calculations show that even with technology we could imagine building in the not so distant future, humans could expand into the cosmos at >…
I had this idea recently myself and to the best of my knowledge you're the only other person who's mentioned it. The closest I've found is the "galactic preemption" hypothesis published in the 80's, but that's more an explanation for why only one civilization would exist in a single galaxy, rather than for why a newborn civilization such as our own would look at the sky and see no signs of civilization in the whole u…
Full disclosure, my brother is the author of the first book.
Re: The Fermi Paradox
#84Earlier quoted context omitted.
But the Milky Way is only 50,000 light years in radius (~ average distance between stars?). That's not much at all on a evolutionary scale. So your argument explains why we're not currently observing an alien civilization (i.e. they would expand so close to light speed we would likely either be conquered or observing nothing -- so observing nothing is a consistent scenario). But it does not explain why no Type III ci…
The OP's post rests on the Anthropic Principle. Essentially, we don't see evidence of a Type III civilization because anyone who dies is very quickly thereafter consumed by that civilization as it expands across the observable universe. It's a terrifying idea.
Re: The Fermi Paradox
#85This article does a good job of covering a lot of different ideas on this paradox. I have a problem with the idea of "big numbers" in it though, like where it implies 500 billion billion is nearly infinite, or that one-in-a-billion is a freak occurrence. There is a saying that if enough monkeys pound on a keyboard, one will type Hamlet. This would take a lot of monkeys. If we take the odds of hitting one character to…
This is essentially the problem that I have with the Drake equation. It encourages--whether that's the intent or not--taking a reasonably known and very, very large number (number of stars) and multiplying it by probabilities/percentages, some of which (we think) we know with at least order of magnitude accuracy. But others we have absolutely no idea. And saying some of those events (such as the evolution of intellig…
Re: The Fermi Paradox
#86Earlier quoted context omitted.
I think it's a good assumption. If there are systems out there marginally different from our own, and the cost to send a "new civilization builder" doesn't completely exhaust Earth, how can it not be profitable?
Time delay. You're long dead before any profits return. How much current consumption are you willing to give for speculative distant future profit for others?
If you only live 100 years and your society will be unrecognizable after 500 years, it's obviously foolish to embark on a project that will turn a profit 1000 years later.
If you can live 1M years and your civilization has been more or less stable for 10M years, you can probably afford to wait 10K years for a shipment of unobtanium. It would be just like a 17th century European merchant who sends a ship to India and waits several months for it to return.
Even if the average lifespan is short, some industries can be profitable across generations. Lumber is often harvested 30-50 years after planting, and I've heard of people investing in coastal redwood that would take 100+ years before they can be cut down.
Re: The Fermi Paradox
#87> Let’s imagine that after billions of years in existence, 1% of Earth-like planets develop life... And imagine that on 1% of those planets, the life advances to an intelligent level like it did here on Earth. "
1% sounds like a small number, but it's a bit ridiculous to just throw it out there and assume it's reasonable. It's a little bit like when a startup does a top-down estimate of revenue - "If we only capture 1% of the e-commerce market, we'll be worth billions!"
I think if you do a "bottom-up" style analysis of the likelihood of atoms forming a replicating growing organism, or that organism evolving to think intelligently, you would get a far smaller number, say in the range of 0.00001% to 10^-20 for each one.
Re: The Fermi Paradox
#88Re: The Fermi Paradox
#89Earlier quoted context omitted.
I had this idea recently myself and to the best of my knowledge you're the only other person who's mentioned it. The closest I've found is the "galactic preemption" hypothesis published in the 80's, but that's more an explanation for why only one civilization would exist in a single galaxy, rather than for why a newborn civilization such as our own would look at the sky and see no signs of civilization in the whole u…
Two Scifi examples that come to mind are a book, GreenFlies ( http://www.amazon.com/Greenflies-Andrew-Darling-ebook/dp/B00... ) that has a fun example of a super-predator type-3-ish civilization, and the motivations that would create the galaxy we see today. David Brin also has a great book, Existence ( http://www.amazon.com/Existence-David-Brin-ebook/dp/B0079XPM... ), that is an example of a super-predator meme that…
The probability that a new civilization is born after the light from the expanding one has arrived, but before their colony ships have, is very small, so therefore we should expect that whenever our civilization was born and whatever the benevolence of the aliens, when we look into the sky we should see no sign of them.
Re: The Fermi Paradox
#90The "we are the first" argument seemed less convincing than it could have been. A better argument from that perspective is the observation that Type III civilizations expand at an alarming rate. Whatever the motivation for expansion[1], basic simulations and back of the envelope calculations show that even with technology we could imagine building in the not so distant future, humans could expand into the cosmos at >…
This model assumes that interstellar travel is profitable. There is no evidence that this is the case, even if we had Star Trek technology. If it isn't profitable, then it turns into a drain on the home planet. That isn't sustainable.