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

Have we already been visited by aliens?

newyorker.com

Post reply on HN
Print view View original

321–330 of 366 posts

Re: Have we already been visited by aliens?

#321

Post by GoblinSlayer »

naikrovek wrote: post #301
matteocantiello wrote: post #276

Earlier quoted context omitted.

Why would the pollution vastly outlive the polluters? It's not obvious to me. Mixing and recycling timescale of an atmosphere seem very short compared to other relevant timescales of the problem. Impactors, volcanic eruptions... the memory of the atmospheric impact of those events is in the sediments, not the air we breathe (e.g. KT boundary). Finally, civilizations that do not destroy themselves in the short-lived p…

If the pollution is severe enough to KILL the species creating it, it is already being produced far faster than nature can absorb it or counteract it. It also seems feasible that other species are killed as well; species which may have helped clean the pollution from the planet, which would slow the cleaning process or, if enough species die off, stopping the cleansing process almost entirely. Pollution doesn't vanis…

So far volcanic eruptions were the most dangerous for life.

Re: Have we already been visited by aliens?

#322

Post by astrange »

asdff wrote: post #200
jwally wrote: post #178

Earlier quoted context omitted.

Are there any guides / heuristics on how a layperson can evaluate technical literature? For example my mother-in-law is starting to micro-dose lithium and cited this article as evidence: https://www.lifeextension.com/magazine/2020/12/lithium-and-a... Which cites 19 medical journals. The website itself reeks of bullshit, but how can I tell if the journals it cites are valid or just woo?

A good measure is to see if there is consensus in the literature. Do other papers report something similar? Is this paper widely cited and/or results accepted in more recent papers? But to begin with, the article you cite is not a proper peer reviewed article. It's merely a webpage on a private website. It's not indexed on pubmed. No one has cited it, nor will they.

Except for his mother-in-law.

Re: Have we already been visited by aliens?

#323

Post by King-Aaron »

trestenhortz wrote: post #315
King-Aaron wrote: post #310

Earlier quoted context omitted.

So this wouldn't be an issue if you solved the ageing problem - a problem which we are presently working on solving ourselves. I don't see why it's out of the question that a civilization that's hypothetically a hundred thousand years ahead of us wouldn't have worked out how to suspend themselves, preserve themselves or negate their ageing. Or for that matter, work out how to sidestep the distance argument though som…

To put it in perspective, if the furthest distance man has travelled from the earth is the moon, and we represent that as 1 inch, then the closest star is about 200km / 125 miles away. In such a scale, Voyager has travelled 80 feet.

The distances aren't lost on me by any stretch - However I don't feel that the argument about distance would be as relevant to a hypothetical "class 3" civilisation.

Re: Have we already been visited by aliens?

#324

Post by imtringued »

sli wrote: post #192
anamexis wrote: post #182

Earlier quoted context omitted.

I think antivax claims have been given equal credence, they've just been found false.

A better example is that equal time is frequently given to both sides of the climate change debate despite the actually numbers showing that calling it a "debate" is journalistic laziness. Equal credence would mean the deniers only get about 3% of the allotted time to make their crackpot case, because that's the closest they come to being a "side" in this non-debate against the other 93% that also have 100% of the da…

It's like spam in a decentralized system. Attackers can't change consensus within the system but they can slow it down to a crawl. Proof of work in Bitcoin is just an anti spam mechanism.

Re: Have we already been visited by aliens?

#325

Post by [deleted] »

jwally wrote: post #196
johnisgood wrote: post #193

Earlier quoted context omitted.

I am currently working on redesigning the entire academic publishing system which is not an easy task and since because I am alone, it may take an entire lifetime of mine, and it is on hold sadly. I wish someone could take it up with me. I was "squatting" on a domain which is about to expire because I cannot even pay for it. :/ I have no time to work on the design itself, let alone the implementation, because I have…

This is great info. Thanks for this. With sites like this, it feels like the citations are a form of DDOS or EULA boilerplating where they could demand naming rights to your first born because they know you won't read it.

[deleted]

Re: Have we already been visited by aliens?

#326

Post by newsbinator »

naikrovek wrote: post #307
stefanmichael wrote: post #274

Earlier quoted context omitted.

I thought this might be the case as well but at least for CFCs the lifespan without replenishment from human pollution is only about 140 years. so "a bit" for this particular circumstance is not very long at all in the eyes of the universe

CFCs are not the only pollutants. An alien society may produce pollutants which last a million years. Plastics can last millions of years. Sufficient pollution could cause climate change severe enough to keep all kinds of things airborne for who knows how long. We are constantly surprised by what we learn about other worlds. It is silly to me to presume that anything we know about Earth pollution will be a given on a…

I wish we could develop a technology to detect plastics across space.

Re: Have we already been visited by aliens?

#327

Post by [deleted] »

johnisgood wrote: post #193
jwally wrote: post #178

Earlier quoted context omitted.

Are there any guides / heuristics on how a layperson can evaluate technical literature? For example my mother-in-law is starting to micro-dose lithium and cited this article as evidence: https://www.lifeextension.com/magazine/2020/12/lithium-and-a... Which cites 19 medical journals. The website itself reeks of bullshit, but how can I tell if the journals it cites are valid or just woo?

I am currently working on redesigning the entire academic publishing system which is not an easy task and since because I am alone, it may take an entire lifetime of mine, and it is on hold sadly. I wish someone could take it up with me. I was "squatting" on a domain which is about to expire because I cannot even pay for it. :/ I have no time to work on the design itself, let alone the implementation, because I have…

[deleted]

Re: Have we already been visited by aliens?

#328

Post by nobody9999 »

LargoLasskhyfv wrote: post #284
yoz-y wrote: post #120

Earlier quoted context omitted.

The books and all are nice but the Dark Forest Theory doesn't hold agains much scrutiny. Among other reasons because if that were true we would be already dead. https://www.youtube.com/watch?v=zmCTmgavkrQ

Why is that? Let's say we've emitted since about 100 years. They are bound by lightspeed like we are. Our wavefront hasn't reached them so far, OR it has, and they are about 50 lightyears away, busy building a slow annihilation fleet, arriving here anytime about 100 years from now, depending on how high up to lightspeed they can go?

>and they are about 50 lightyears away, busy building a slow annihilation fleet, arriving here anytime about 100 years from now,

It's an interesting idea, but it raises the reasonable (IMHO) question, "Why would they bother?"

It seems like an awfully big investment of resources for actions which wouldn't be of real benefit to them.

Re: Have we already been visited by aliens?

#329

Post by GoblinSlayer »

svachalek wrote: post #287
confidantlake wrote: post #255

Earlier quoted context omitted.

I haven't read the third book so maybe they expanded on it, but from the first 2 books the theory seemed different. It is far too dangerous to let a non advanced civilization live because they can quickly develop to an advanced civilization.

That's how I understand it: light speed is so slow and technological progress is so fast that any intelligent species could develop the ability to wipe you out faster than you could realize the threat is coming. Ergo, the only possible way to be safe is to destroy other civilizations as soon as they pop up their heads. I feel like a lot of so-called solutions to the Fermi paradox fail when they speculate on what "ali…

The very idea "wage wars to be safe" is a bit puzzling, honestly, even animals know better.

Re: Have we already been visited by aliens?

#330

Post by yoz-y »

LargoLasskhyfv wrote: post #284
yoz-y wrote: post #120

Earlier quoted context omitted.

The books and all are nice but the Dark Forest Theory doesn't hold agains much scrutiny. Among other reasons because if that were true we would be already dead. https://www.youtube.com/watch?v=zmCTmgavkrQ

Why is that? Let's say we've emitted since about 100 years. They are bound by lightspeed like we are. Our wavefront hasn't reached them so far, OR it has, and they are about 50 lightyears away, busy building a slow annihilation fleet, arriving here anytime about 100 years from now, depending on how high up to lightspeed they can go?

If your goal is annihilation you don't bother with a fleet, you hurl a relativistic kill vehicle (aka, a hunk of rock or metal) at them.
Post reply on HN