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Not long ago, the center of the Milky Way exploded

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Re: Not long ago, the center of the Milky Way exploded

#111

Post by sliken »

rjf72 wrote: post #90
AnIdiotOnTheNet wrote: post #49

Earlier quoted context omitted.

Indeed. If we were serious about colonizing mars we should first colonize portions of the earth that are currently uninhabitable (self-sufficiently). They all are much easier to get to and have significantly more favorable conditions than Mars, but for some reason no one tries to make the Arctic self-sustaining or wants to build a deep ocean colony.

There are specific reasons for the things you're talking about. For Antarctica (which is not the Arctic, but I assume what you meant - Scandinavia is quite self sustaining!) you have the Antarctic Treaty System. [1] The TL/DR there is that pretty much every form of development in Antarctica is illegal, and you're not allowed to leave any waste whatsoever. When an antarctic researcher is on a mission, they're required…

The other things that was fakes was the ability to live in tents on the surface and travel on the surface for long periods of time. The radiation would kill you pretty quickly.

Re: Not long ago, the center of the Milky Way exploded

#112

Post by lifeisstillgood »

glandium wrote: post #108
lifeisstillgood wrote: post #18

Earlier quoted context omitted.

so ... wild guess 37 years * 365 days = 13,500 days universe has existed for 13.5 billion years So each day in a middle aged life is 1 million of the universe's years. I like it ! :-) * This flare: Last Friday * Dinosaur extinction: 3rd of August * Pangea breaks apart: about Valentines day * Earth formed: June 2007 * Universe Born: 1982 Of course this means the Universe would have listened to Flock Of Seagulls as a k…

* The Great Pyramids: 6 minutes and 37 seconds ago. * 1982: 3.2 seconds ago.

That surprisingly shows just how old the pyramids are - very cool. This idea from from @hanoz really has legs :-)

Re: Not long ago, the center of the Milky Way exploded

#113

Post by FrameworkFred »

mirimir wrote: post #101
FrameworkFred wrote: post #35

Given that we're able to aim telescopes at things that are billions of light years away, I wonder how close we are to being able to see the reflection of such a thing when it actually happens on some celestial body 3.5 million light years away.

We already have: Clavel et al. (2013) Echoes of multiple outbursts of Sagittarius A[star] revealed by Chandra.[0] Here's the abstract: > The relatively rapid spatial and temporal variability of the X-ray radiation from some molecular clouds near the Galactic center shows that this emission component is due to the reflection of X-rays generated by a source that was luminous in the past, most likely the central superma…

WOWWW...that's super cool. If you could find multiple reflections of the same source [edit: after a second look, that's actually what they did which is even more amazing], you could start piecing together a sequence.

But, darn it, now we're going to have to map the cosmic background light pollution. :)

Re: Not long ago, the center of the Milky Way exploded

#114

Post by mirimir »

FrameworkFred wrote: post #113
mirimir wrote: post #101

Earlier quoted context omitted.

We already have: Clavel et al. (2013) Echoes of multiple outbursts of Sagittarius A[star] revealed by Chandra.[0] Here's the abstract: > The relatively rapid spatial and temporal variability of the X-ray radiation from some molecular clouds near the Galactic center shows that this emission component is due to the reflection of X-rays generated by a source that was luminous in the past, most likely the central superma…

WOWWW...that's super cool. If you could find multiple reflections of the same source [edit: after a second look, that's actually what they did which is even more amazing], you could start piecing together a sequence. But, darn it, now we're going to have to map the cosmic background light pollution. :)

They have some sort of sequence worked out. There was a paper cited in previous discussion here of this flareup. Maybe a month or so ago. I've gotta deal with stuff now, or I'd find it.

Re: Not long ago, the center of the Milky Way exploded

#115

Post by jp555 »

snowwrestler wrote: post #44
jp555 wrote: post #38

Earlier quoted context omitted.

Don't you think two self-sufficient instances of a civilization separated by a ~dozen light-minutes decreases the risk of species extinction events?

I find it very hard to imagine a human civilization on Mars being self-sufficient. Getting there is not the hard part. The ecology of self-sufficiency is not something we understand currently, even on Earth.

Absolutely agree. The idea that we are anywhere close to being able to recreate a perfectly self-sustaining closed-loop ecosystem - do better than billions of years of evolution - is a little far fetched.

I think of Biosphere 2, where trees fell down because we didn't know that we didn't know that wind is required to make trees strong enough to support their own weight. I'm sure there's a lot more we dont know that we dont know.

But I mean more of a self-propagating civilization, a group of people learning to draw on the resources throughout the solar system to stay alive and raise the next generation. More about building a dynamic growing system than a perfectly balanced one. To raise a solar-system sized super-organism of humans. The space termite mound.

Re: Not long ago, the center of the Milky Way exploded

#116

Post by DataGata »

klank wrote: post #98
jerf wrote: post #87

Earlier quoted context omitted.

You need natural mirrors, because as others have pointed out, they have to already be there, you can't get ahead of the light to put them there. It has been suggested that black holes could provide this mirror, but it requires resolving not just something the size of Earth, but something much smaller , at a distance of 30 million light years +. Unfortunately you actually start hitting up against the limits of spaceti…

What are these "limits of spacetime's resolution" you speak of? Beyond speculation, I'm not aware of anything showing spacetime to be discrete.

Eventually you will get so far away from something that you cannot resolve it even at the plank distance.

Re: Not long ago, the center of the Milky Way exploded

#118

Post by dredmorbius »

rbanffy wrote: post #100
dredmorbius wrote: post #73

Earlier quoted context omitted.

The Krell, on the other hand, were near the peak of their development.

Their Great Machine is a metaphor for social networking. I'm quite sure it'll kill us all.

I say we take off and nuke the entire site from orbit. It's the only way to be sure.

Re: Not long ago, the center of the Milky Way exploded

#119

Post by klank »

DataGata wrote: post #116
klank wrote: post #98

Earlier quoted context omitted.

What are these "limits of spacetime's resolution" you speak of? Beyond speculation, I'm not aware of anything showing spacetime to be discrete.

Eventually you will get so far away from something that you cannot resolve it even at the plank distance.

How does that necessitate a discrete spacetime?

Re: Not long ago, the center of the Milky Way exploded

#120

Post by klank »

jerf wrote: post #109
fmihaila wrote: post #104

Earlier quoted context omitted.

> What are these "limits of spacetime's resolution" you speak of? > Beyond speculation, I'm not aware of anything showing spacetime to be discrete. It is a prediction of loop quantum gravity [1]: In 1988, Carlo Rovelli, Lee Smolin, and Abhay Ashtekar introduced a theory of quantum gravity called loop quantum gravity. In 1995, Rovelli and Smolin obtained a basis of states of quantum gravity, labelled by Penrose's spin…

It's a prediction of other things, too. Even just sheer every-day quantum mechanics sets a limit, too; eventually you're asking to nail down a photon's origin with so much precision that you lose the frequency or something, things you don't normally think about even in the most extreme astronomy today, but become relevant when discussing bouncing photons around a black hole 30 million light years away.

Modern QM formalization doesn't predict a discrete spacetime. Or, if it does, nobody has been able to demonstrate this, to my knowledge.
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