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What made Earth a giant snowball 700M years ago? Scientists have an answer

sydney.edu.au

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Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#181

Post by WarOnPrivacy »

ianburrell wrote: post #116
WarOnPrivacy wrote: post #14

Earlier quoted context omitted.

> Have you done the calculation how much material is required for such an endeavor? It's a tiny fraction of what's required for a proper Dyson sphere. And we know civilizations can afford those because we can no longer see their stars. For anyone who's hung up on saving nickle, we could do a low budget Worldring² or even thriftier Shadow Squares®. ²Nivenlarry ®Larry Niven

The flaw with your theory is Dyson Spheres don't hide the star. They convert visible light into infrared light. No energy conversion is perfect and always produces waste heat. Dyson Sphere basically looks like a really large star. The infrared star stands out because it is different than normal stars.

> The flaw with your theory is Dyson Spheres don't hide the star. [follows with sound reasons]

These are really good points. I figured the flaw in my theory is we haven't had precision observation long enough for DS to get constructed. Also that if we noticed the disappearance of a star, that we'd attribute it to a DS and not some natural occluding object.

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#182

Post by WarOnPrivacy »

SketchySeaBeast wrote: post #127
WarOnPrivacy wrote: post #125

Earlier quoted context omitted.

> But it doesn't make any sense, given we do not have good evidence of alien civilizations, not to mention Dyson spheres. Also correct. Even past that, we haven't been mass-cataloging stars long enough for a Dyson sphere to be constructed and remove a star from our view.

So why make the initial claim "And we know civilizations can afford those because we can no longer see their stars."? Is it humor or irony I'm missing?

The absurdity of it makes me happy.

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#184

Post by digging »

slashdev wrote: post #140
digging wrote: post #126

Earlier quoted context omitted.

> a really big rock ... nicely sterlizes the planet Have you seen Earth? We've been hit with a big rock, we've turned out atmosphere into poison, and had several other mass extinctions, none of which sterilized the Earth. Unless you mean a Theia-level rock to turn the entire surface into lava, but you risk changing the mass, composition, and satellite system of the planet. At that point it's a different planet entire…

It came pretty close, remember life slowly bounced back afterward. Something a little larger would almost do the trick. You just clean up what survives.

No I don't think it did. I'm not sure you're understanding the scale of things here. I don't believe it came close at all, if "close" means that a ground team could have sterilized the planet afterward. Even if 99% of life were destroyed, that doesn't mean there's one little tide pool with some barnacles surviving, that means there's extremely hardy single-celled organisms living in the deepest nooks and crannies all over the planet.

We can't even "just clean up what survives" in the cleanest rooms on Earth, using techniques specifically intended to do that. Life is incredibly tenacious, I really don't think you're going to wipe it off a planet's surface without destroying the surface (and atmosphere, probably) of the planet in the process. And if that's acceptable - again, why wouldn't you just pick a barren planet.

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#185

Post by lamontcg »

dr_dshiv wrote: post #183
lamontcg wrote: post #163

Earlier quoted context omitted.

wat

If we are very dull, then we might get switched off

you have no idea what the purpose of the simulation is.

turns out the purpose was for them to study how the borg collective spreads across galaxies, and when we wipe out the borg we've ruined their experiment and they just pull the plug, because none of it was about us. oops.

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#186

Post by simonh »

todd8 wrote: post #161
simonh wrote: post #114

Earlier quoted context omitted.

If you think about it, a computer's not going to be able to perfectly simulate it's own physical operation, so the limit of a system's ability to simulate things is it's own complexity.

This isn’t obvious to me. It doesn’t have to simulate itself in real time. It may not be able to simulate itself simulating itself. There may be proof of this using a diagonalization proof. Consider programs that are quines, programs are able to output the exact source code of the program. See [1]. And there are abstract computers that can produce any computable output. These are called Universal Turing Machines, see…

It needs to be able to store a complete representation of different versions of it's own state, in it's own state.

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#187

Post by dr_dshiv »

lamontcg wrote: post #185
dr_dshiv wrote: post #183

Earlier quoted context omitted.

If we are very dull, then we might get switched off

you have no idea what the purpose of the simulation is. turns out the purpose was for them to study how the borg collective spreads across galaxies, and when we wipe out the borg we've ruined their experiment and they just pull the plug, because none of it was about us. oops.

The purpose of the simulation is always to learn something new.

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#188

Post by dredmorbius »

js2 wrote: post #96
macintux wrote: post #87

Earlier quoted context omitted.

Rumsfeld’s unknown unknowns.

Rumsfeld is famous for the quip, but it's basically an expression of the first stage of the four stages of competence: 1. You don't know what you don't know. 2. You know what you don't know. 3. You know what you know. 4. You don't know what you know. https://en.wikipedia.org/wiki/Four_stages_of_competence

The Rumsfeld formulation itself dates to at least the 1950s and development of the Johari window (named for Joseph Luft and Harrington Ingham).

I'd first encountered it in print in a 1982 book, Forced Options, by Roger Lincoln Shinn, two decades before Rumsfeld's famous 2002 usage:

https://archive.org/details/forcedoptionssoc0000shin_c8x7/pa...>

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#189

Post by jaredhallen »

smdyc1 wrote: post #136
justinator wrote: post #113

Earlier quoted context omitted.

There's a chance - however small - that WE live in that simulation.

Then can I ask the owner of whatever device we're running on, to add one or two zeros to my bank balance?

Hopefully you're not overdrafted when they come through on that request.

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#190

Post by SketchySeaBeast »

WarOnPrivacy wrote: post #182
SketchySeaBeast wrote: post #127

Earlier quoted context omitted.

So why make the initial claim "And we know civilizations can afford those because we can no longer see their stars."? Is it humor or irony I'm missing?

The absurdity of it makes me happy.

Fair enough. Poisoning the well for giggles.
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