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Biggest void in space is 1B light years across (2007)

newscientist.com

31–40 of 79 posts

Re: Biggest void in space is 1B light years across (2007)

#31

Earlier quoted context omitted.

Imagine being a civilization alone in the void, and not even a generation ship could make contact with anyone else, even if they knew which direction to send it.

Sounds like you have a sci-fi novel to write!

https://en.wikipedia.org/wiki/Against_a_Dark_Background

Paints a bleak picture of a civilization in this situation. Great book though.

Re: Biggest void in space is 1B light years across (2007)

#32
post #14
post #11

Earlier quoted context omitted.

I've heard this idea in the context of Dyson spheres/swarms. The issue is that, while they'd be invisible or dim to the eye, the areas would be very bright in infrared.

Depends on how large the swarm is. Using our sun as the example a 1AU swarm would be very warm, but at 100 AU it would be extremely cold and much harder to detect. Really though, a Dyson’s swarm isn’t that efficient long term. It’s likely better to dismantle large stars and use fusion reactors with heat sinks at close to 2.73 Kelvin as possible.

> Really though, a Dyson’s swarm isn’t that efficient long term. It’s likely better to dismantle large stars and use fusion reactors with heat sinks at close to 2.73 Kelvin as possible.

Would like a referral to science fiction that talks about this.

Re: Biggest void in space is 1B light years across (2007)

#33
post #14

Earlier quoted context omitted.

Depends on how large the swarm is. Using our sun as the example a 1AU swarm would be very warm, but at 100 AU it would be extremely cold and much harder to detect. Really though, a Dyson’s swarm isn’t that efficient long term. It’s likely better to dismantle large stars and use fusion reactors with heat sinks at close to 2.73 Kelvin as possible.

Fossil fuels vs solar, it’s a sustainability question. Plus, dismantling a sun isn’t much help to the planets orbiting it, and then you need to find a way to efficiently get that energy to another system to be used.

Planets ? Who cares about planets when building a Dyson swarm - other the possibly as a bootstrap cache of materials to get thing going.

Yeah, you might occasionally leave one in place for historical reasons, but otherwise they are just too useless not to make use of their mass for something better. Not to mention traffic management headaches given that normal planets usually stubbornly refuse to do any orbit corrections when needed.

Re: Biggest void in space is 1B light years across (2007)

#34
post #14

Earlier quoted context omitted.

Depends on how large the swarm is. Using our sun as the example a 1AU swarm would be very warm, but at 100 AU it would be extremely cold and much harder to detect. Really though, a Dyson’s swarm isn’t that efficient long term. It’s likely better to dismantle large stars and use fusion reactors with heat sinks at close to 2.73 Kelvin as possible.

> Really though, a Dyson’s swarm isn’t that efficient long term. It’s likely better to dismantle large stars and use fusion reactors with heat sinks at close to 2.73 Kelvin as possible. Would like a referral to science fiction that talks about this.

Here you go: https://en.m.wikipedia.org/wiki/Stellar_engineering

Also used in many places in Orions Arm: https://www.orionsarm.com/eg-article/47897e8b1947c

Whole star system optimized into a giant computing cluster with projected sun energy output for computing available for next 14 trillion years: https://orionsarm.com/eg-article/49125f5d1c049 (Or 100000 sun output for 140 milion years.)

Himmelsschmiede - a full star system converted to useful heavy elements using a deep well industrial zone (basically an artificial black hole accreation disk): https://www.orionsarm.com/eg-article/46709da5de6be

Re: Biggest void in space is 1B light years across (2007)

#35
post #27
post #11

Earlier quoted context omitted.

I've heard this idea in the context of Dyson spheres/swarms. The issue is that, while they'd be invisible or dim to the eye, the areas would be very bright in infrared.

The whole concept of Dyson Spheres, or anything even vaguely like that, is totally absurd. (Even Dyson said so.) Any space-faring culture will have mastered controlled fusion long ago, and have entirely left behind any material dependence on stars. The best places to live, then, are out in the Kuiper belts and beyond, where unlimited room and cold are available for free, and valuable gases are lying about, frozen. In…

Unless you can harvest interstellar medium at scale stars are where most mass is locked up, conveniently in a single place even. Outer belt objects are quite small in volume in comparison and inconveniently far from each other.

Re: Biggest void in space is 1B light years across (2007)

#36

Voids aren’t empty they just have less stuff in them. There’s galaxies and things in there.

Sometimes I wonder about the percentage of HN commenters who actually read the article. Literally a few paragraphs in: “The lack of radio sources means that there are no galaxies or clusters in that volume.”

Please don't comment on whether someone read an article. "Did you even read the article? It mentions that" can be shortened to "The article mentions that."

https://news.ycombinator.com/newsguidelines.html

Re: Biggest void in space is 1B light years across (2007)

#37

Earlier quoted context omitted.

Sometimes I wonder about the percentage of HN commenters who actually read the article. Literally a few paragraphs in: “The lack of radio sources means that there are no galaxies or clusters in that volume.”

The parent commenter is correct, and you (despite your username) and the article are not. If you read the paper it notes a dip in radio sources, not a complete absence of them. An entirely empty void a billion light years across is essentially too improbable to exist. “Voids” are just areas with fewer galaxies, relatively, not places with a none of them. In fact, the Milky Way (and the entire Local Supercluster) itse…

https://en.wikipedia.org/wiki/KBC_Void

"an immense, comparatively empty region of space...proposed to be roughly spherical, approximately 2 billion light-years in diameter. As other voids, it is not completely empty but contains the Milky Way, the Local Group, and a larger part of the Laniakea Supercluster. The Milky Way is within a few hundred million light-years of the void's center."

A void has by "working definition" "less than one tenth of the average density of matter abundance that is considered typical for the observable universe."

https://en.wikipedia.org/wiki/Void_(astronomy)

Re: Biggest void in space is 1B light years across (2007)

#38

Earlier quoted context omitted.

Sounds like you have a sci-fi novel to write!

https://en.wikipedia.org/wiki/Against_a_Dark_Background Paints a bleak picture of a civilization in this situation. Great book though.

This is why I Love and lurk around in HN.

Thanks !

Re: Biggest void in space is 1B light years across (2007)

#39
post #19
post #4

Earlier quoted context omitted.

You mean like in Vernor Vinge's 1992 A Fire Upon the Deep ?

Sort of. In Vinge's world, the slow zone is just a natural phenomenon, not something artificially created. And in the slow zone you're basically limited to nearly-speed-of-light travel consistent with our contemporary understanding of relativistic physics (which is unbearably slow to anyone who can travel much faster than that outside the slow zone). Whereas in Liu Cixin's books, if I remember correctly, they actuall…

If I remember correctly, there's some ambiguity whether the slow zone was created by some power or naturally occurring (or a bit of both) although a bit of both is perhaps the natural answer.

Re: Biggest void in space is 1B light years across (2007)

#40
post #13

Imagine being a civilization on the edge of a galaxy on the edge of the void. One direction, nothing whatsoever. The other direction, billions upon billions of galaxies. Would be neat!

Imagine being a civilization alone in the void, and not even a generation ship could make contact with anyone else, even if they knew which direction to send it.

Star Trek Voyager had an episode where the crew got lost in a void 2,500 light years across . . . pretty interesting.

https://memory-alpha.fandom.com/wiki/The_Void_(region)

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