Do You BELIEVE there is life outside Earth?

[Just Jim]

41 minutes ago, GoSlash27 said:

Well... That's definitely one way to convince them that there's no intelligent life here, anyway...

-Slashy

I've thought about this before... and if it's true someone out there may someday pick up our broadcasts, and got them right from the beginning of our radio and television age... Can you imagine? The Three Stooges... Marx's brothers... Nosferatu.... H.G. Well's broadcast of War of the Worlds... hehe

Yeah, you're so right, they definitely going to write us off as non-intelligent... and more than a little mad... 

Edited December 13, 2017 by Just Jim

[magnemoe]

19 hours ago, Matuchkin said:

Yes. I am a firm believer that there is life outside earth. I believe that the probability of there being life outside Earth exceeds 99.99%. However, I have two answers to the Fermi paradox that I can dig the most:

1. Great Filter - something that prevents civilisations from evolving past a certain point.

There are multiple candidates in our world that I can perceive to be a great filter:

a) The Chicxulub asteroid impact. An instant event that wiped out most of the species on Earth. The reason why we are not royally screwed (or at least incapacitated) is that it happened at the wrong time.

b) The Bubonic Plague. I'd say this was a crazy near-miss. If the outbreak that wiped out half of Europe would have happened in, say, the 1800s or 1700s, it would have been spread across the globe and inflicted even more havoc. The only difference is that it happened right before that, just 400 or so years.

c) MOST PROBABLE FILTER: Nuclear weaponry. Logically, the nuclear weapon is the first step any civilisation can take to develop something with which it can commit suicide. For the latter half of the 20th century, our nuclear forces were fastened in place by crappy systems: old computers and unreliable satellites, as well as politicians who didn't manage to extrapolate by a few decades to determine the future capabilities of these weapons. Glitches actually happened, and there were tens of events that could have led to the whole Northern Hemisphere being ignited less than 24 hours later. Yet, there was always this one thing that happened, this one event of sheer luck: people who didn't push the button, voices over the radio that shouted to cancel the order mere split-seconds before the switch on a submarine was flicked, et al. We rolled sixes every time, and we're still not done with nukes. I believe that I may be witnessing a great filter event, or that we have just been incredibly lucky to pass one. The former is more likely.

2. Physical limitations - perhaps there are limits to how fast we can travel? Maybe, the space outside the Oort cloud is a hellscape of debris, space rocks, and radiation from Sagittarius A*?

Plenty of early filters, life itself might be one, advanced cells took 1.5 billion years on earth and is an very obvious one, intelligence is another. Civilization might be one too. 

b) However diseases rarely kill off successful species. Do we have any examples of animals getting extinct because of an pest? An healthy population an disease might wipe of an red listed animal species. 

a) It would need to be an even larger impact than the dinosaur killer, humanity would survive that, yes it would kill almost all humans. but the species would survive. 
We are also better at spotting asteroids and it don't look like its an immediate danger. 
c) is an weaker a) even during the cold war. 

You have various future dangers, AI is popular now, bio weapons is another. Note that for something to be an kill all human event it pretty much be an kill one on first try. If AI shows to be maniacs it would limt their use. and they would be used a lot of places over an long time before they got real power. 

2)  you have speed of light, you also have energy requirements who is very high. Now if we find faster than light or even an reactonless drive that would change, it would also imply its probably no advanced civilizations nearby. 

Note that aliens might have issues humans don't have, an large predator would be limited in numbers making progress slower, same if alien is intelligent but not as much as humans. 
They might now work well in large groups, just the smell of all the others make cities impossible. 
Unable or unwillingly to keep population growth down is another one. 

 

[Green Baron]

True, life in general and its whole evolution is in a constant filter (selection) situation on several scales, including cosmic scale and self inflicted/constructed things, like bacteria dying of their own excretions in a limited environment. That's how it works and i fear humans are nothing special here.

25 minutes ago, magnemoe said:

b) However diseases rarely kill off successful species. Do we have any examples of animals getting extinct because of an pest? An healthy population an disease might wipe of an red listed animal species. 

That's a good point imo, if they are in a bottle-neck situation anyway a disease might finish of the rest. A healthy population wiped out, idk, i'd consider is possible, maybe extremely aggressive bacteria that leave the affected no time, but improbable.

[YNM]

1 hour ago, magnemoe said:

However diseases rarely kill off successful species. Do we have any examples of animals getting extinct because of an pest? An healthy population an disease might wipe of an red listed animal species. 

By definition, that's "evolution" and "natural selection".

 

Things did went bananas when we interfere though.

Also, birds.

Edited December 14, 2017 by YNM

[KG3]

21 hours ago, Matuchkin said:

 

c) MOST PROBABLE FILTER: Nuclear weaponry. Logically, the nuclear weapon is the first step any civilisation can take to develop something with which it can commit suicide. For the latter half of the 20th century, our nuclear forces were fastened in place by crappy systems: old computers and unreliable satellites, as well as politicians who didn't manage to extrapolate by a few decades to determine the future capabilities of these weapons. Glitches actually happened, and there were tens of events that could have led to the whole Northern Hemisphere being ignited less than 24 hours later. Yet, there was always this one thing that happened, this one event of sheer luck: people who didn't push the button, voices over the radio that shouted to cancel the order mere split-seconds before the switch on a submarine was flicked, et al. We rolled sixes every time, and we're still not done with nukes. I believe that I may be witnessing a great filter event, or that we have just been incredibly lucky to pass one. The former is more likely.

 

2. Physical limitations - perhaps there are limits to how fast we can travel? Maybe, the space outside the Oort cloud is a hellscape of debris, space rocks, and radiation from Sagittarius A*?

  Nuclear weaponry might be a filter, however if civilization and to other solar systems we'd need a very good grasp of nuclear power and be able to deal with radiation too.

  Another possible filter is genetic engineering.  Could make for some awful weapons but maybe needed for living in space if you are going to be making food and oxygen and other stuff.  

  Migrations tend to follow resources.  If everything available in the Oort cloud gets used up civilization might just follow space crumbs to another solar system.  It might take tens of thousands of years or longer.