"Similar Event Within 100 Light Years of Earth Would Be Catastrophic" --Astronomers...

If one didn’t occur, then probability demands that there would be life everywhere. That’s the consequence of living in a universe as immense as ours. Even a very remote probability will happen countless times.

Therefore, unless you are arguing that such events occurred, your arguments are insufficient to explain away the paradox, so you’re wasting breath anyway.

If you elect Hillary it will be more destructive than a massive exploding ball of nuclear fire, so....I’d take my chances with the supernova.

“It’s worse than that. We haven’t even found another stellar system that resembles our own, which has effectively thrown their “nebular hypothesis” for planetary evolution into the trash bin.”

Actually, there are computer models which do show solar systems relatively like ours forming. The problem is that gas giants tend to shred such systems to bits. Something ... and this is more plausible than the use of vague language may suggest ... stopped Jupiter from descending into a very short orbit and pulled it back to a wider orbit. This knocks a few zeroes off any estimate acquired using Drake’s equation, but in no way disproves the nebular hypothesis.

>> Correct, although most scientists refuse to acknowledge this and cling to the “cosmological principle”, an assumption that contradicts the evidence. <<

Well, the Hercules-Corona Borealis Great Wall apparently contradicts the cosmological principle, but that’s actually irrelevant. It’s a quirk of relativity that no matter where you are, you are at the center of the universe. Not that you seem to be relatively in the middlish region of the universe, but the exact center to as precise a degree as can ever be measured. So it’s not coincidental that we’re at the oldest part of the universe, but it’s not meaningless, either. Further portions of the universe are shown to have galaxies composed mostly of star systems with very low levels of heavy elements, demonstrating that they are younger, and therefore lack the prerequisites of life.

>> The only thing I’m wondering is, does temporal distortion kick in if the motion is due to the expansion of space itself? <<

Wow... I have to retrace all my thinking on this. (Which is based purely on following the logic of the physics; I don’t have near the math skills to know any real, math-based physics.) The quick, sloppy answer, which I’m not sure is right, is that to catch up the matter, you’d have to go travel faster than light, which would mean you’d go backwards in time. If you simply always were at a distant part of the universe, you’d be going closer to the speed of light, relative to earth, and so you’d be age slower, and so again, the universe would be younger. But if you warped time-space, I guess you’d be on a time-space island of old universe surrounded by younger universe? But any light (or any form of entropy) reaching you would be the same light reaching the younger universe, so you’d still appear to be at the center of the universe, with nothing but your advanced age to suggest otherwise?

>> Seems like an optimistic estimate to me even so. If we didn’t know there was life on at least one planet, I would say the probability was effectively zero. Since there is life on at least one planet, then either it’s due to some extraordinary circumstance (like divine intervention), or we hit the biggest lottery drawing ever held. <<

Well, the anthropological principle would say that if there’s going to be life on any planet in the universe, and you’re life, you’re going to be on that planet. I think applying the anthropological principle to the multiverse is a copout, until the dimensions past four are somehow proven to be substantially thick... but it’s not like you’re going to pop into sentience on the wrong planet and then say, “Oh no! Wrong planet!” and die.

I was just thinking that.

Another factor not in the Drake equation:

You need tides for life. That means you need a massive moon, relative to the host planet. Earth, so far, has the only such massive moon. There are moons on Jupiter larger than ours, but Jupiter is so much massive, that they are puny relative to Jupiter, and as such were simple for Jupiter to catch. Earth catching the moon by gravity might be something like sinking a hole in one from 10,000 yards without hitting the grass. The present theory for the existence of such a massive moon around such a modestly-sized planet is that it’s the result of a direct (yet glancing) collision.

But a collision with what?

But Keith Richards would survive.

Well he is indestructible man. So he doesn't count.

“But a collision with what?”

Another restrictive condition... whatever hits the planet has to be big enough to knock off a significant chunk of mass but not large enough to obliterate the whole planet.

“Actually, there are computer models which do show solar systems relatively like ours forming.”

A computer model can be made to show you anything you want to see though. In the real world observations of systems with exoplanets, we haven’t found any resembling our configuration yet.

We’ll never be able to actually witness a system forming over a long enough timescale to confirm or deny the nebular hypothesis, so you cannot test the models that way. However, we have predictions from the models BEFORE exoplanets were observed, and that precludes scientists from having done any funny business to force their algorithms to fit observations when they produced those predictions. The predictions were a failure, and that should doom the hypothesis, as far as I’m concerned. I wouldn’t trust any new predictions to not simply be the result of tweaking the algorithm to produce the results they want.

“The quick, sloppy answer, which I’m not sure is right, is that to catch up the matter, you’d have to go travel faster than light, which would mean you’d go backwards in time.”

This can’t be right, because anything with mass can’t even reach the speed of light, much less go faster. I’m thinking that temporal distortion must happen regardless of whether you are moving or the space expanding is moving you though, because according to relavity, the cause of the motion wouldn’t matter, only the rate of motion from whichever frame of reference you pick.

“I think applying the anthropological principle to the multiverse is a copout, until the dimensions past four are somehow proven to be substantially thick... but it’s not like you’re going to pop into sentience on the wrong planet and then say, “Oh no! Wrong planet!” and die.”

I think the whole multiverse stuff is silly... it isn’t wholly illogical, but it’s also not really science, since the nature of the proposition makes it impossible we could ever prove or disprove it by scientific means. So it’s more philosophy dressed up like science than science.

>> A computer model can be made to show you anything you want to see though. <<

Weeeellll, yeah. You can model to the point of simply showing a computer portrayal of your assumptions, and this is basic critique of global-warming models. But I’m referring to computer-based simulations of the behavior of gasses and distinct particles with very little inputs besides mass and momentum.

>> This can’t be right, because anything with mass can’t even reach the speed of light, much less go faster. <<

Yes, you can regard it as a thought exercise.

And I agree vis-a-vis multiverses. An intellectual copout.

Note: this topic is from 07/28/2016. Thanks LibWhacker.

Most astronomers today believe that one of the plausible reasons we have yet to detect intelligent life in the universe is due to the deadly effects of local supernova explosions within 100 light years that wipe out all life in a given region of a galaxy. While there is, on average, only one supernova per galaxy per century, there is something on the order of 100 billion galaxies in the observable Universe. Taking 10 billion years for the age of the Universe (it's actually 13.7 billion, but stars didn't form for the first few hundred million), Dr. Richard Mushotzky of the NASA Goddard Space Flight Center, derived a figure of 1 billion supernovae per year, or 30 supernovae per second in the observable Universe!



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The Cycle of Cosmic Catastrophes:
Flood, Fire, and Famine
in the History of Civilization
by Richard Firestone,
Allen West, and
Simon Warwick-Smith

Note: this topic is from 07/28/2016. Thanks LibWhacker.

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