Aliens on 1k nearby stars could see us, new study suggests • Hacker News Board

Re: Aliens on 1k nearby stars could see us, new study suggests

#111

Post by e12e » Fri, Oct 23, 2020, 9:09 PM UTC

mistersquid wrote: post #107

e12e wrote: post #99

Earlier quoted context omitted.

You have to make an assumption about speed - it certainly won't be more than a tiny fraction light speed. Eg voyager appear to travel now at less than 0.00006 c (16 km/s). Than turns 100k light years into ballpark 150 M year journey (no it doesn't its 1.8 bn years as mentioned in reply) . Still possible to cross 10.000 times - but that would be a straight line. I suspect the distances will grow somewhat fractally if…

> Than turns 100k light years into ballpark 150 year journey. Forgive my confusion. If 100K light years is 100K years at c , how can > 0.00006 c yield 0.00150K (150) years?

It can't (unless you mistype into your plain android calculator app). Ed: Fwiw there was a typo there, too - it was supposed to say 150 million - but it's more like 1.5 billion.

Re: Aliens on 1k nearby stars could see us, new study suggests

#112

Post by vl » Fri, Oct 23, 2020, 9:14 PM UTC

vmception wrote: post #23

buran77 wrote: post #20

Earlier quoted context omitted.

It may be even worse, that different continent is on a different planet. Space(time) is absolutely, mind-boggling massive. Everyone knows it's big but it hard to comprehend how big and why there could be many alien civilizations out there capable of broadcasting or detecting but never intersect in any way because the detection windows of any 2 civilizations don't line up. The Milky Way alone is ~150000-200000 light y…

The fermi paradox does convey this.

Basically there is not need and motivation for humans to colonize anything outside the Earth. It's just too far, too expensive and too uncomfortable.

Humans evolved specifically to live on Earth, to live somewhere else, they need to be severely altered. Now you just seeded civilization of another species, that might turn out to be confrontational or outright hostile. Why would you do that?

Too see how well this works out on the local scale see colonization of Americas.

Re: Aliens on 1k nearby stars could see us, new study suggests

#113

Post by purplecats » Fri, Oct 23, 2020, 9:21 PM UTC

godelski wrote: post #104

koheripbal wrote: post #49

Earlier quoted context omitted.

Sure, but if you were a billion years old and had seen ants before, it's unlikely that you'd take interest in any specific ant hill you walk by.

Idk, there are still people that study ants. Both professionally and as a hobby. Just because you don't care doesn't mean someone doesn't. I don't know why the same wouldn't be true for aliens. Unless those aliens are ant like (hive mind...ish)

and those ants don't know they are being studied/farmed

Re: Aliens on 1k nearby stars could see us, new study suggests

#114

Post by jcims » Fri, Oct 23, 2020, 9:24 PM UTC

deeeeplearning wrote: post #71

bena wrote: post #48

Earlier quoted context omitted.

Not well. It makes the assumptions that all of the problems with space travel are logistically possible.

Given the age of the Milky Way, a civilization using even slow sub light travel with generation ships or autonomous probes could have colonized the entire galaxy many times over. Why has no one done that? Hence the paradox.

I'm fairly confident we'll eventually find that our form of life is the result of intentional or unintentional colonization of Earth.

If you look at how quickly life began after the oceans settled out, then look at precisely how complex even the most primitive forms of life are (in terms of likelihood of stochastic construction to the point of sophistication to support evolutionary mechanisms) it seems incredibly unlikely that we originated here.

Re: Aliens on 1k nearby stars could see us, new study suggests

#115

Post by ben_w » Fri, Oct 23, 2020, 9:26 PM UTC

bena wrote: post #83

deeeeplearning wrote: post #71

Earlier quoted context omitted.

Given the age of the Milky Way, a civilization using even slow sub light travel with generation ships or autonomous probes could have colonized the entire galaxy many times over. Why has no one done that? Hence the paradox.

Yes, I know the paradox. It's simple. It's too simple. It has huge assumptions. Namely the assumption that the current problems to colonization can be solved in a cost-effective manner. The longest continuous length of time spent in what limited space flight we have is just under 440 days. Not to mention, all of it was spent in low Earth orbit. Once we go beyond that, we lose all protection from the Earth's magnetosp…

> We can't fake gravity.

Yes we can, it’s a standard part of fairground rides.

(I’ll agree that the unknowns of space colonisation, and of the automation we’d need to be able to afford the infrastructure to even launch a serious effort, may prevent such colony efforts from happening)

Re: Aliens on 1k nearby stars could see us, new study suggests

#116

Post by tsimionescu » Fri, Oct 23, 2020, 9:31 PM UTC

baja_blast wrote: post #110

tsimionescu wrote: post #92

Given that life only appeared once on earth in 3.5 billion years on Earth, the Milky Way is around 14 billion years old, we don't really have a good reason to believe there were more than a handful of abiogenesis events in the history of the galaxy. Of course, its possible this is completely wrong, perhaps the Earth was completely unlucky, or perhaps there have been many abiogenesis events and they have just failed f…

Why would there be multiple abiogenesis events? It seems once life evolves it can survive a lot and has all extinction events. The fact life occurred almost immediately after it formed suggests abiogenesis is common and more the rule as opposed to the exception. Multicellular life on the other hand could be much rarer since it took billions of years to happen.

If abiogenesis is common, we should expect it to keep happening everywhere around us. We should have noticed at least a few instances by now, given that we have been trying explicitly to produce it.

So at the very least, we can say that the conditions for the apparition of life and the conditions for the proliferation of life seem to be quite different.

Also, given the amount of isolated biomes on earth, if abiogenesis had ever been a common occurrence, i think we should expect for there to still exist some survivors of those other events.

Re: Aliens on 1k nearby stars could see us, new study suggests

#117

Post by dyingkneepad » Fri, Oct 23, 2020, 9:31 PM UTC

vl wrote: post #112

vmception wrote: post #23

Earlier quoted context omitted.

The fermi paradox does convey this.

Basically there is not need and motivation for humans to colonize anything outside the Earth. It's just too far, too expensive and too uncomfortable. Humans evolved specifically to live on Earth, to live somewhere else, they need to be severely altered. Now you just seeded civilization of another species, that might turn out to be confrontational or outright hostile. Why would you do that? Too see how well this works…

> Basically there is not need and motivation for humans to colonize anything outside the Earth.

Our current gas emissions would disagree.

Also, asteroids, gamma ray bursts, curiosity, sheer ambition, etc, etc.

The thing is: we don't need to convince all of mankind to colonize another planet. All it takes is a few people. Crazy rich Mr. Musk is one example. He may not be able to achieve it, but maybe all we need is a few other Musks in the next generations and suddenly we'll be in other planets.

The Fermi Paradox discussion is fascinating.

Re: Aliens on 1k nearby stars could see us, new study suggests

#118

Post by skissane » Fri, Oct 23, 2020, 9:33 PM UTC

ben_w wrote: post #79

anonAndOn wrote: post #56

Earlier quoted context omitted.

While interstellar travel would be impossible using conventional thrust in a straight line, could you overcome the distance by bending space time?[0] [0] https://www.nasa.gov/centers/glenn/technology/warp/gravstat....

Going fast in a straight line with conventional rockets is achievable, just not very timely. Bending spacetime enough to make a difference — even just to the time taken between here and Alpha Centauri — is beyond any known mechanism humans could build, even in principle, using the total resources of our entire solar system. (Using unknown mechanisms: perhaps, but they’re unknown)

> Going fast in a straight line with conventional rockets is achievable, just not very timely.

A constant-acceleration spacecraft could reach the opposite side of the galaxy in 24 years ship time. (That'd be over 100,000 years of Earth time, however.)

Conventional chemical propulsion don't have high enough impulse to do that. Possibly some kind of nuclear or matter-antimatter propulsion could?

Re: Aliens on 1k nearby stars could see us, new study suggests

#119

Post by tsimionescu » Fri, Oct 23, 2020, 9:35 PM UTC

rosywoozlechan wrote: post #100

tsimionescu wrote: post #92

Given that life only appeared once on earth in 3.5 billion years on Earth, the Milky Way is around 14 billion years old, we don't really have a good reason to believe there were more than a handful of abiogenesis events in the history of the galaxy. Of course, its possible this is completely wrong, perhaps the Earth was completely unlucky, or perhaps there have been many abiogenesis events and they have just failed f…

I imagine it's much harder for life to develop a second time once there's already life present. So I'm not sure how that affects your 3.5 billion time window. Prior to life appearing on Earth, the planet's conditions may not have been suitable. It may be that life appeared as soon as possible once the conditions allowed for it and that life developed to become so good at taking up available resources needed for life…

That only makes sense if we imagine life appearing in a primordial pool. But if abiogenesis were a common event on Earth, life should have formed all around, at distances far too large to immediately consume other proto-life forms. I also find it hard to imagine that, had this been a common event, a single strain of life should have resisted all the way to today.

Of course, until we manage to reproduce abiogenesis or find other examples of life, we won't know for sure. But I would say the theory with the least amount of assumptions right now is that life only appeared once in Earth's history or at least in one single relatively small place.

Re: Aliens on 1k nearby stars could see us, new study suggests

#120

Post by sosborn » Fri, Oct 23, 2020, 9:35 PM UTC

jessaustin wrote: post #78

jcelerier wrote: post #75

Earlier quoted context omitted.

the only thing that matters is for it to look like the consciousness has been attached.

I've never forgotten the scene in the OSC short story "Fat Farm", in which the protagonist's mind has been copied to his clone, which clone has left the facility to "continue" to enjoy his fine life, and the protagonist realizes he hasn't thought about what comes next. The answer is grim. A consciousness might awake in the machine, but it won't be my consciousness.

But for the consciousness in the machine, does that distinction matter at all?