Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

There Have Probably Been Aliens

nytimes.com

Post reply on HN
Print view View original

21–30 of 163 posts

Re: There Have Probably Been Aliens

#21

Post by venomsnake »

theaeolist wrote: post #18

I enjoy these quasi statistical arguments. Can anyone remind me what is the probability that God exists, or that we live in a computer simulation?

God in the religious sense probably does not exist. On the other hand the existance of type II creatures (that can manage and direct the energy of whole galactic clusters) would not surprise me the least. Their interference with human evolution and deeds would not be shocking too.

The quantum machanics behave disturbingly close to lazy evaluation - so this would not be surprising too.

Everyone of us is a god to a colony of ants.

Re: There Have Probably Been Aliens

#22

Post by reso »

apsec112 wrote: post #9

"In other words, given what we now know about the number and orbital positions of the galaxy’s planets, the degree of pessimism required to doubt the existence, at some point in time, of an advanced extraterrestrial civilization borders on the irrational." This is terribly silly. It reminds me of the Onion talks: "Step 1: Devise an idea to create a car that runs on compost. Step 2: Create the car. We’ve already compl…

I had a similar intuition reading the article. I don't think we understand much at all about the probabilities of life forming even under the ideal circumstances. The events that took place on earth could still be one in a billion, or they could be one in an incomprehensibly high number.

Nevertheless the progress on the other factors in the Drake equation is very interesting and impressive.

Re: There Have Probably Been Aliens

#23

Post by perlgeek »

jkeler wrote: post #10

> a probability for civilizations to form of one in 10 billion per planet was considered highly pessimistic I think people underestimate how low probabilities can really be. According to wiki the shortest self-replicating RNA is 165-bases long. Even if you convert all observable universe in RNA this is still not enough for this RNA to form by chance (4^165 is much larger than number of atoms in observable universe).

> Even if you convert all observable universe in RNA this is still not enough for this RNA to form by chance (4^165 is much larger than number of atoms in observable universe).

Which kinda suggests there is either a mechanism that promotes that, or there are other, easier paths to get self replication. Otherwise we mostly likely wouldn't be here.

Re: There Have Probably Been Aliens

#24

Post by [deleted] »

andrewstuart2 wrote: post #14
nielsbjerg wrote: post #11

Earlier quoted context omitted.

You got the units of the borehole wrong, it's in meters not kilometers.

Well, we've certainly drilled more than 12 meters. :-P (Note the decimal point: 12.262km; I just converted to km to keep it consistent with the other measurements I cited) Could be confusing if you're used to the inverse comma/period from what we use in the US (comma=thousands, period=decimal).

[deleted]

Re: There Have Probably Been Aliens

#25

Post by ekianjo »

throwaway_yy2Di wrote: post #17

If you parse the article carefully, the entire argument is summarized as "There are more than 10^22 planets, therefore ETI probably exists[ed] if P(intelligent life|planet) > 10^-22". Specifically, unless the probability for evolving a civilization on a habitable-zone planet is less than one in 10 billion trillion, then we are not the first. [...] In other words, given what we now know about the number and orbital po…

That was extremely shallow from the nytimes.

Re: There Have Probably Been Aliens

#26

Post by tluyben2 »

andrewstuart2 wrote: post #14
nielsbjerg wrote: post #11

Earlier quoted context omitted.

You got the units of the borehole wrong, it's in meters not kilometers.

Well, we've certainly drilled more than 12 meters. :-P (Note the decimal point: 12.262km; I just converted to km to keep it consistent with the other measurements I cited) Could be confusing if you're used to the inverse comma/period from what we use in the US (comma=thousands, period=decimal).

It is very confusing even though I know this to be the case. It is much harder to parse when the numbers are similar. I do not care which one, just wish everyone would use the same notation. In this case for me it would have been clearer if it said 12262km vs 12262m which is what I would have written. But he :) Interesting comment anyway.

Re: There Have Probably Been Aliens

#27

Post by qaq »

jkeler wrote: post #10

> a probability for civilizations to form of one in 10 billion per planet was considered highly pessimistic I think people underestimate how low probabilities can really be. According to wiki the shortest self-replicating RNA is 165-bases long. Even if you convert all observable universe in RNA this is still not enough for this RNA to form by chance (4^165 is much larger than number of atoms in observable universe).

Given enough time anything can form out of random fluctuations if it has >0 probability no matter how small.

Re: There Have Probably Been Aliens

#29

Post by sktrdie »

By pure probability, if we're the first intelligent species here on earth (that is able to build radio communicators) out of what, ~4 billion species that ever existed, what are the odds of us being the first in the entire universe?

My logic is that intelligence (as defined above) is clearly rare here on earth where life is prolific, hence by no means a certain development of evolution. I wouldn't be surprised if we're the first in the universe where the conditions are certainly less hospitable for life.

This game of probability doesn't only depend on the sample size, but also on what you're looking for. For instance, you can say that if you find a purple grain of sand, and you know there are trillions of other grains, then you'll be sure to find other purple grains. But what if the purple grain has written on it "hello how are you" by sheer chance. You'd probably never find another grain of sand with that same writing.

And then you can say, "us being the first is egocentric". Well, but we're the first (on earth) when it comes to building radio stations, so we clearly won that lottery big time. Is it such a stretch to say we won the lottery in the universe as well?

Re: There Have Probably Been Aliens

#30

Post by ThePhysicist »

apsec112 wrote: post #9

"In other words, given what we now know about the number and orbital positions of the galaxy’s planets, the degree of pessimism required to doubt the existence, at some point in time, of an advanced extraterrestrial civilization borders on the irrational." This is terribly silly. It reminds me of the Onion talks: "Step 1: Devise an idea to create a car that runs on compost. Step 2: Create the car. We’ve already compl…

I think what will really help us to get at a better estimate is to answer the question whether there exists life in our solar system that evolved independently of that on Earth. If we should find traces of bacteria on Mars or another planet, that would immediately take the corresponding probability factor in the Drake equation to a number close to 1 (i.e. most solar systems with planets in the habitable zone produce simple organic life), which would then leave us only with the question of how likely it is that such bacterial life evolves into something more complex. That's an incredibly hard question to answer as well of course, but it's also something that we might be able to tackle within the next 50 years given a deeper understanding of how living cells work and how they came to be (and it seems we're making good progress there). So personally I'm quite confident that we will be able to get to a much better estimate of Drake's equation in the next 50 years.
Post reply on HN