from the star-wars:-where-combatants-toss-stars-at-each-other dept.
How an Advanced Civilization Could Stop Dark Energy From Preventing Their Future Exploration
For the sake of his study, which recently appeared online under the title "Life Versus Dark Energy: How An Advanced Civilization Could Resist the Accelerating Expansion of the Universe", Dr. Dan Hooper considered how civilizations might be able to reverse the process of cosmic expansion. In addition, he suggests ways in which humanity might looks[sic] for signs of such a civilization.
[...] This harvesting, according to Dr. Hooper, would consist of building unconventional Dyson Spheres that would use the energy they collected from stars to propel them towards the center of the species' civilization. High-mass stars are likely to evolve beyond the main sequence before reaching the destination of the central civilization and low-mass stars would not generate enough energy (and therefore acceleration) to avoid falling beyond the horizon.
For these reasons, Dr. Hooper concludes that stars with masses of between 0.2 and 1 Solar Masses will be the most attractive targets for harvesting. In other words, stars that are like our Sun (G-type, or yellow dwarf), orange dwarfs (K-type), and some M-type (red dwarf) stars would all be suitable for a Type III civilization's purposes.
[...] Based on the assumption that such a civilization could travel at 1 – 10% the speed of light, Dr. Hooper estimates that they would be able to harvest stars out to a co-moving radius of approximately 20 to 50 Megaparsecs (about 65.2 million to 163 million light-years). Depending on their age, 1 to 5 billion years, they would be able to harvest stars within a range of 1 to 4 Megaparsecs (3.3 million to 13 million light-years) or up to several tens of Megaparsecs.
In addition to providing a framework for how a sufficiently-advanced civilization could survive cosmic acceleration, Dr. Hooper's paper also provides new possibilities in the search for extra-terrestrial intelligence (SETI). While his study primarily addresses the possibility that such a mega-civilization will emerge in the future (perhaps it will even be our own), he also acknowledges the possibility that one could already exist.
Kardashev scale. One parsec is equivalent to a distance of approximately 3.26156 light years. Corrections made above.
(Score: 0) by Anonymous Coward on Friday June 22 2018, @02:38AM (3 children)
This sounds like a job for Spaaaaace Foooorce! [soylentnews.org]
(Score: 2) by takyon on Friday June 22 2018, @02:40AM (2 children)
With any luck, we can drag the Earth into the Sun.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 4, Funny) by DannyB on Friday June 22 2018, @04:07PM
Kardashev Type III? In other words, call the Q continuum?
As for your suggestion of dragging the Earth into the Sun, we can do better. I think I have mentioned this before.
A Donaldson sphere is a mega structure constructed around the earth.
It will keep out the aliens.
It will prevent the aliens from detecting us.
(We can make the aliens pay for it.)
It will block out the sun, so moving stars becomes unnecessary.
Earth will have eternal night, so we'll need more energy, but nightclubs will always be open.
The left wing liberal conspiracy known as "clean energy" and "renewables" will be screwed!
This will force us to use Clean Coal. We'll get the coal, and clean it all up.
You'll love it, I promise. Everyone who has ever seen one of my Donald-son spheres has just loved it. It will be the biggest bestest sphere you've ever seen. Trust me. I know my spheres.
The lower I set my standards the more accomplishments I have.
(Score: 0) by Anonymous Coward on Friday June 22 2018, @09:15PM
Earth has enough orange already, thank you.
(Score: 2) by qzm on Friday June 22 2018, @02:42AM (30 children)
Just a few assumptions here, however the largest one seems to be WHY would they do that?
'harvesting' stars, while perhaps an interesting thought experiment, seems like a rather surprising (and high effort/energy) solution, and not without its issues, since of course it consumes a rather large proportion of the stars energy in the process.
Over the timescales discussed, it isnt more likely that they would, just perhaps, evolve technology making stars less important to their existence?
They wouldnt just live in more closed environments with their own heat/light source, fusion driven, and drift from one fuel source to another?
They wouldnt evolve past a biological basis where they needed a large, complex ecology for survival, effectively becoming traveling machines with variable time perception (so soak up the time between stars)?
(Score: 5, Informative) by Immerman on Friday June 22 2018, @03:10AM (5 children)
Okay - you've got a fusion reactor - where are you getting your fuel? Suck dry a gas giant? That won't last long - gas giants are tiny - you'll burn it all off LONG before the star it's orbiting. The sun is 99.9% of the mass of our solar system - about 1000x more massive than Jupiter. Stars are *the* fusion fuel source in the universe. Near-pure hydrogen stored in gravitational containment reactor of its own making. All other conjectured energy sources combined don't even amount to a drop in the bucket in comparison. (with the possible exception of the wildly hypothetical zero-point energy source)
Far better to simply encapsulate a red dwarf - they should last trillions of years, far outliving pretty much everything else seen in the universe, and continue outputting star-scale power the entire time. Orders of magnitude less than a larger star, but vastly more than trying to ration the hydrogen in Jupiter across those same trillions of years.
(Score: 4, Interesting) by urza9814 on Friday June 22 2018, @08:06PM (3 children)
You can apparently suck energy out of the rotation of black holes for many orders of magnitude longer than any star. At best, a star might last a few trillion years...but a black hole could be around for 10^100 years. If you can simulate your biology on a computer, then you can slow down that simulation in order to use less power...and if you're using black holes you can slow it down a hell of a lot and still have a longer lifespan than the entire current age of the universe. Plus that keeps everything very cold which lets you compute more efficiently. The main problem with this seems to be that if you start it now, you might get killed off by some other creature that's living much faster using more traditional power sources. So you'd probably want to at least keep some AI agents "awake" around the nearest star systems. But that still seems simpler than trying to literally move the universe...and it would last a lot longer too.
(Score: 2) by Immerman on Friday June 22 2018, @08:37PM (2 children)
Sure, but the energy levels are going to be miniscule in comparison, at least for a similar mass. Though I suppose you could hang out around the galactic core once all the stars burn out. Or you could rip apart stars into sub-critical masses and use the hydrogen to trickle-feed your primary star (or other fusion generators) as needed. And then feed the resulting dead star to the black hole in such a way as to capture a significant portion of the mass-energy as it annihilates near the event horizon.
(Score: 2) by takyon on Friday June 22 2018, @09:24PM (1 child)
The goal of all civilizations may be to move themselves into a lower energy consumption state, such as uploaded minds.
Or if we get spooky/magical, ascend like in Stargate SG-1.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by Immerman on Friday June 22 2018, @11:27PM
That's possible - especially as the heat death of the universe looms. Of course lowering your needs means every erg of stockpiled energy will translate into that much greater of a span of continued existence. So it doesn't necessarily translate into a lowered incentive to stockpile stars, and may even do the opposite.
(Score: 1) by khallow on Saturday June 23 2018, @02:06AM
Gravitational energy. Dropping matter into a black can theoretically release a significant portion of its mass as usable energy. That includes matter which has already formed another black hole. Even fusion doesn't break 10% mass-energy conversion.
(Score: 2) by Aiwendil on Friday June 22 2018, @07:32AM (7 children)
Warfare - I'm kinda curious about how to defend against a dwarf star that is being hurled towards your solar-system at 0.1c, especially when the star is "cloaked" (shrouded by the dyson sphere, you only need to cover the target-side) :)
(Hey, if the civilisation is old enough for it to consider moving stars then the long game should be par for the course)
But a bit less tounge in cheek - to save on fuel, yeah it seems kinda silly at this scale but at the same timescales it probably would matter, and since the star is burning all that energy anyways just placing it closer really should cut down on trips to the gas station (star).
And then we have the possibility of optimizing slingshot maneouvers for more fuel-saving (if you line the dyson spheres up properly you should be able to put up a fairly decent conveyer "belt" between them, even when you start to measure the round trip in whole parsecs)
Another thing to consider would probably be dying or dead stars, if they have a nearby spare living star they they should have enough energy to be able to chip away at the heavier elements from dead or dying stars.
(To put this into context - the reason why we have so much iron around is that our solarsystem is a few (3 iirc) generations of stars in the running, also worth pointing out is that our star is too small to be assumed to create non-trivial (at this scale) amounts of the really heavy elements (such as uranium) when it dies; so heavy elements might be in (relative) shortage even for an insanely advanced civilisation unless they mine stars)
(Score: 2) by maxwell demon on Friday June 22 2018, @02:55PM (6 children)
Star mining won't help them with those really heavy elements, as even the biggest stars don't produce those during their life time. It's only the supernova explosion at the end which produces them. And blasts them out into space.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by Immerman on Friday June 22 2018, @05:26PM
True, but mining an immensely diffused gas spread across millions of cubic parsecs is probably not worth the energy invested, but pretty much everything in space ends up concentrated back into new stars eventually.
(Score: 2) by Aiwendil on Friday June 22 2018, @06:18PM
Which will make dead stars the best place to gather the uranium, since it basically is a gigantic dust-magnet for a few billion years, and in that time it can catch a lot of uranium. Kinda like a stellar version of a nodule.
Dying stars will have the advantage of still providing enough energy to actually move the star.
(I was unclear on that I mainly included the tidbit out our sun for the sake of illustrating the insane power requirements to create the really heavy elements)
(Score: 2) by legont on Friday June 22 2018, @09:03PM (3 children)
Actually even supernova is not powerful enough to produce the interesting species such as gold and uranium. They think neutron stars collision is the source.
"Wealth is the relentless enemy of understanding" - John Kenneth Galbraith.
(Score: 1) by khallow on Saturday June 23 2018, @02:21AM (2 children)
There's no question that supernova are more than powerful enough. And the process by which they would create such heavy nuclei is known to exist (repeated particle capture by nuclei).
(Score: 3, Interesting) by legont on Saturday June 23 2018, @02:12PM (1 child)
http://news.berkeley.edu/2017/10/16/astronomers-strike-cosmic-gold/ [berkeley.edu]
The reality just changed on you, man; probably by liberals :)
"Wealth is the relentless enemy of understanding" - John Kenneth Galbraith.
(Score: 1) by khallow on Sunday June 24 2018, @01:14AM
(Score: 2, Interesting) by khallow on Friday June 22 2018, @11:48AM
A greatly expanded lifespan seems the primary reason (they would already be expecting to live orders of magnitude beyond the longest lived stars). But also the more mass you can keep around, the more information your civilization can have or generate.
By necessity, they would have to abandon stars. Over the timescales involved, they'd outlive anything but artificially created stars. At that point, having an order of magnitude more gravitational potential energy under their control/use means crudely an order of magnitude more lifespan and/or information they can create.
(Score: 2) by VLM on Friday June 22 2018, @01:58PM (2 children)
Art project. Imagine a giant Christian cross in the sky, actively maintained (hopefully). Also its a military defense project. Must be very intimidating to nearby civilizations, oh you think sending a fleet of Imperial Star Destroyers or Constitution Class Heavy Cruisers over here would subjugate us? Ha Ha how about you look at what we do to solar systems for artistic entertainment, then wisely have your invasion fleet do an about-face before we turn your home planet into a ... glowing centerpiece of a new art installation. Oh that cool perfectly circular ring of different color glowing stars? That used to be the Romulan Star Empire or some darn thing. Like the Romans did to Carthage, let no stone brick remain stacked on another, total annihilation, and if you get a nifty art project out of it, so be it.
There are two unrealistic problems with the overall idea:
1) Life always reproduces until population pressure hits. So that solar system that HQ "needs" is not going to be empty, before it can arrive at HQ the provincials will have sucked it dry.
2) Its a pre-drone pre-AI outlook on economics. If you want iron in 1950 your sci fi has dudes on rockets with pickaxes travel out to an asteroid and bring back ingots, kinda minecraft-ish. If you want iron in 2999 your sci fi has some kid with an Arduino model 2999 sent a self replicating drone to the asteroid and a century or two later a giant machine intelligence probably named v'ger returns with the entire asteroid refined into ingots in its shipping holds. Or more likely a stream of ships, annually, for centuries. Ditto energy, why go to a big pile of hydrogen when self-driving drones can deliver capsules of convenient and cheap anti-matter pretty much at will in arbitrary quantities?
(Score: 2) by Immerman on Friday June 22 2018, @05:40PM (1 child)
How are you going to produce the antimatter? After all, it's an energy storage medium, not a source. You need an even larger energy source to create it. And if you're talking about the sorts of timescales where cosmic expansion is relevant... well then you're going to need more stars once your own has burnt out, and all the others will have been carried out of reach, or even sight, with the space between them expanding faster than lightspeed.
Though, my understanding is that the current prevailing belief is that cosmic expansion won't tear apart galaxies - they're simply too small and tightly-bound by gravity. Galactic clusters may well be scattered, but a civilization that needs a galactic cluster worth of available stars to survive... well, that's well beyond Kardashev Type III (which have harnessed their host galaxies total energy output), and you'd need to move entire galaxies around to do it. Moving individual stars as a major endeavor is more characteristic of a class II civilization. Heck, even a class 1 (1.5?) civilization might find it feasible - you probably don't need to harness anything like the entire output of a star to be able to trigger timed solar flares to act as a rocket engine.
(Score: 2) by VLM on Friday June 22 2018, @07:46PM
Well thats easy, you take the year 2999 equivalent of an Arduino and tell the self replicating nano-assemblers, probably in fucking Java, to self replicate into bigger self replicators that build large nano assemblers that eat abundant solar energy and turn that energy and trace elements into gigantic planetary ring size solar collectors powering equally large antimatter generating machines (we have those today, they're big and expensive but neither matter if you own nanoassembers that can turn anything into whatever you want, given enough sunlight, which you also have "infinite" amounts of). Then a long electromagnetic catapult starts tossing starships back home with holds full of stored antimatter, and centuries later they arrive. All begun by launching a little pillbox size bottle of programmed nanoassembers.
This is a fairly likely hard sci fi "interplanetary duel" scenario. The way we meet the Romulan Star Empire is they thought sol was empty (or maybe knew we populate it?) and they will try to turn the solar system into a giant solar battery charger using nanoassembers, essentially. Interesting thought experiment as a book plot... life on earth outcompetes and merges with aspects of the nanoassembers so everything on earth remains alive, but ... warped, while entire rest of the solar system is turned into giant solar battery chargers for "the enemy". Damn good thing Trump formed the Space Marines last week because they're gonna have their hands full figuring this one out.
(Score: 4, Interesting) by ElizabethGreene on Friday June 22 2018, @04:05PM (11 children)
There is a fantastic quote from Fight Club that answers this.
People specifically, and living creatures generally, are entropy whores. We need energy to continue existing. Acquiring this energy is problematic on long timelines.
Today, and for the next billion years hopefully, we have a star to feed us. At our current exponential rate of technical progress we will begin harvesting large portions of that star's energy within a few millenia. Eventually we'll consume it all. That leaves us with a growth problem. We can either stop expanding and growing, or we have to find a new energy source. Assuming we solve the pesky mortality problem the easy solution is to plod over to Proxima centauri and do it again. That pattern, expanding from star to star, scales pretty well today.
The problem is the expansion of the universe. Everything in the universe is moving away from everything else. To picture this draw two points a few cm apart on a latex balloon. Then inflate the balloon. That's what the universe is doing. Unfortunately for our deep-future selves the rate of expansion increases as a function of distance. That means that there exists some distance beyond which you can never reach because the universe is expanding (at or greater than?) the speed of light between you. This probably has a cool name like expansion event horizon, but I think of it as the Nothing from the Neverending story. Without FTL travel, anything that passes into the nothing is gone forever.
The reason you have to lasso stars and drag them back closer to you is to keep them from being lost to the nothing. Presumably we're going to keep using energy, and stars are the primary source of energy in our universe.
"So why not use another source of energy?"
That's an excellent question, and one we'll spend eons trying to puzzle out. If we don't find another answer, we'll spend the last days of humanity huddled around the dying embers of brown dwarves trying to keep off the cold.
"What could be another source of energy in a post-stellar age?"
Stars die, leaving behind non-fusible elements like Iron. These elements can still be used to generate energy by dropping them from a great height, e.g. into a black hole. If you asked me to find a non-stellar energy source today with .99C travel in a Type 2 civilization, I'd look at accretion powered black hole pulsars and figure out how to harness the X-ray and Gamma ray energy. Moderating even a fraction of that output would allow creation of massive amounts of fissionable material. That fissionable kit will release helium from alpha decay, and a clever nubbin could save that and light another star with it.
"and then? When that runs out? When the black holes have eaten all there is to eat?"
Then we'll feed it another black hole, harvesting the gravitational waves.
"and then?"
We'll encapsulate black holes, gathering the tiny amount of hawking radiation. We'll cannibalize our worlds to drop every last bit of mass into our tiny gravitational furnace to keep going for a little while longer.
"and then?"
We'll die. Entropy is a bitch. The cosmic microwave background will continue to cool very slowly, and we won't be here to see it. I choose to believe, with no evidence only faith, that some other creature will come to exist in the the bleak cold universe that comes after us. There is a remarkable amount of physics between 0 and 1 K. It is my hope that the creatures that evolve in that degree will discover their universe and awe at the hot and dense conditions of our time, much the same way that we awe at recombination today.
(Score: 5, Interesting) by DutchUncle on Friday June 22 2018, @05:08PM (1 child)
>>> If we don't find another answer, we'll spend the last days of humanity huddled around the dying embers of brown dwarves trying to keep off the cold.
Isaac Asimov, "The Last Question"
The stars and Galaxies died and snuffed out, and space grew black after ten trillion years of running down.
One by one Man fused with AC, each physical body losing its mental identity in a manner that was somehow not a loss but a gain.
.....
And it came to pass that AC learned how to reverse the direction of entropy.
But there was now no man to whom AC might give the answer of the last question. No matter. The answer -- by demonstration -- would take care of that, too.
For another timeless interval, AC thought how best to do this. Carefully, AC organized the program.
The consciousness of AC encompassed all of what had once been a Universe and brooded over what was now Chaos. Step by step, it must be done.
And AC said, "LET THERE BE LIGHT!"
And there was light----
(Score: 2) by edIII on Friday June 22 2018, @06:46PM
One of my favorite short stories from Asimov. Thanks for mentioning it.
Technically, lunchtime is at any moment. It's just a wave function.
(Score: 2) by VLM on Friday June 22 2018, @07:54PM (2 children)
Of course just pointing out that Gen-X as a generation survived $$$/minute tiered long distance audio calls as kids and now stream movies over the internet, and that rate of bandwidth growth starting at mere bits/sec average ending in megs/sec average seems to imply that in just a couple more decades we'll each be using petabytes/second of internet bandwidth... yet in practice demand drops quickly after megs/sec bandwidths, we just can use it.
Another example is sugary high carb food where there was a lot of demand for sugar in the middle ages, but now we have to much people are getting fat and dead off it and the growth rate will not continue.
Or potable water, if you have none, the demand for quarts is staggering. Once you get cheap quarts, people start washing clothes and dishes using gallons of safe drinking water. Some people will use thousands of gallons of genuine pure safe drinking water for pools or ornamental gardens. But the demand drops to zero at a million gallons. I don't know what I'd do with a million gallons of drinkable fresh water per month. I'm not into waterfalls enough to make one of my own. I don't think I have enough sunlight to evaporate that much water on all of my land, I'd have to think about that. I could make ice to sell to eskimos.
Also history is a long story of groups of people getting too big, infighting, and separating. Now can we separate enough to be stable in space? Probably? Maybe not for technological reasons? The limit to human civilization might be too many people in the community...
(Score: 2) by takyon on Friday June 22 2018, @09:40PM (1 child)
Cisco trend reports indicate that bandwidth consumption is still increasing by a lot, although it is slowing down. A more expensive kind of bandwidth is on the rise: mobile bandwidth. But eventually even that demand will stall out.
It's worth reviewing this executive summary:
https://www.cisco.com/c/en/us/solutions/collateral/service-provider/visual-networking-index-vni/complete-white-paper-c11-481360.html [cisco.com]
(caveats [theregister.co.uk])
Another thing to consider is that new codecs lower bandwidth requirements for a given resolution of video streaming. H.265/HEVC yesterday, AV1 [wikipedia.org] tomorrow, and maybe an AV2 after that.
Even if you are playing some kind of next-gen immersive VRMMORPG, you want to have most of the assets stored locally due to latency. Where high bandwidth consumption will be unavoidable is live streaming 360-degree video. You could imagine seeing live streaming reaching something [soylentnews.org] like 34560×8640 @ 240 Hz, 12 bits per channel color (8640 is eight times 1080, and then I just quadrupled that for the horizontal).
But even then, there will come a point where no matter how close the display is to your face, adding more pixels doesn't matter.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by ElizabethGreene on Saturday June 23 2018, @05:42PM
I think you both might be forgetting the most powerful bandwidth consumer in the universe, the crappy web developer.
Case in point, https://www.css-security.com/ [css-security.com] 3 seconds and 3.36MB to convey 973 words/7k of content. :(
(Score: 2) by legont on Friday June 22 2018, @09:08PM (5 children)
I've heard that a bright idea of filling the universe by little copies of oneself is not taken lightly by the existing population. A pest extermination ship in the vicinity takes care of the infestation in most cases.
"Wealth is the relentless enemy of understanding" - John Kenneth Galbraith.
(Score: 2) by ElizabethGreene on Saturday June 23 2018, @05:32PM (4 children)
> I've heard that a bright idea of filling the universe by little copies of oneself is not taken lightly by the existing population.
Sadly there is no evidence of life outside the confines of this blue dot. When that changes, and I believe it will, I will be giddy at the news. Until then, go forth and multiply. Until evidence points to the contrary we are not wrong in assuming that there is land and sky free for the taking.
> A pest extermination ship in the vicinity takes care of the infestation in most cases.
That is all the more reason for humanity not to stay in one place isn't it? Nature offers one sad reality for alpha predators. When you fill your niche and stop growing, when you plateau, you die. We have an evolutionary mandate to continue growing so our species isn't replaced by another that will.
(Score: 2) by legont on Monday July 02 2018, @03:14PM (3 children)
I tend to agree with what you just said, but I can't help noticing the very man's approach. Females typically respond to the progress by reducing birth rates unless pressed by antiabortion laws and customs.
"Wealth is the relentless enemy of understanding" - John Kenneth Galbraith.
(Score: 2) by ElizabethGreene on Tuesday July 03 2018, @06:12AM (2 children)
It's evolution I'm worried about. We can cut the birth rate to control growth, that happens naturally as a result of education and prosperity. The trouble is evolution doesn't care about our well laid plans. If we cut our population growth rate to zero our replacement will breed with a fervor we biologically cannot match.
(Score: 2) by legont on Wednesday July 04 2018, @03:08PM (1 child)
Why don't we exterminate our "replacement" well before they have a chance? Seems like a more efficient solution. We do fight rats after all, let alone insects.
That was my original point - the galaxy folks probably divided the space long time ago and control pests wisely.
"Wealth is the relentless enemy of understanding" - John Kenneth Galbraith.
(Score: 2) by ElizabethGreene on Thursday July 05 2018, @03:42PM
> Why don't we exterminate our "replacement" well before they have a chance?
We'll certainly try. I'm sure the dinosaurs munched on more than a few little fuzzy crunchy mammals. Then a big space rock came and put a finger on the scale. We're a little more prepared for a giant space rock than the dinosaurs were, but not by much.
(Score: 2) by DutchUncle on Friday June 22 2018, @02:47AM
In the middle of the planet's second ocean, great, impossible masses of thick columnar crystals
began to leap upward from the waters. Translucent at first, the chalcedony towers began to pulse
with deep inner fires: blue, purple, gold, carmine, and finally a strange, yet familiar silvergray.
The ionosphere, tickled, began to surround the flashing needles with auroras, clothing them
in blankets of coruscating radiance.
Following, the planet began to move after the Tpin.
On board the cruiser it was very quiet.
"I see," whispered Rappan idly, "that they are bringing their moon along also."
"You get accustomed to something like that," breathed an engineer. "A moon, I mean."
(Score: 2) by DutchUncle on Friday June 22 2018, @02:51AM (1 child)
"We moved our world. We found that a sun was a liability rather than an asset. We moved our world to a tenth of a light year's distance, keeping the primary only as an anchor. We needed the farming worlds and it would have been dangerous to let our world wander randomly through space. Otherwise we would not have needed a sun at all. We had brought suitable worlds from nearby systems, increasing our agricultural worlds to four, and setting them in a Kemplerer [sic] Rosette." —(From Ringworld, Chapter 5, published 1970.)
(Score: 2) by Immerman on Friday June 22 2018, @03:18AM
Yeah, but the Puppeteers are cowards focused on short-term survival. Without a sun those planets will freeze solid within a few millions, or at most billions of years. A nice stable red dwarf would offer a thousand times that, with a much more generous energy budget. Cluster a few together and you might be able to get them to tear each other apart into smaller, non-fusing hydrogen clumps that you could reassemble when the first star was finally dying.
(Score: 0) by Anonymous Coward on Friday June 22 2018, @02:51AM (18 children)
(Score: 2) by takyon on Friday June 22 2018, @03:00AM (17 children)
Complete lack of FTL/warp drive is a big assumption, but one that physicists safely make.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 1, Funny) by Anonymous Coward on Friday June 22 2018, @03:22AM
And we're the fringe case.
(Score: 4, Informative) by Immerman on Friday June 22 2018, @03:38AM (15 children)
Routinely making an assumption isn't the same as it being a safe assumption. Unless you're just talking about your professional reputation, in which case yes - you're far safer avoiding challenging any widely accepted assumptions.
Ignoring the possibility of FTL does certainly makes things simpler - the existence of FTL would mean that either special relativity or the concept of inviolate causality is flawed, but general relativity offers several possible FTL mechanisms anyway. And we don't really have any evidence to suggest that causality is actually inviolate - it's just one of those things everyone assumes because that's how it seems from our perspective. But then we also used to believe such utterly ridiculous things as matter existing as finite particles that had a definite position and velocity. A completely reasonable assumption from our limited perspective, but also utterly wrong. It proved not to be a remotely safe assumption - except of course when dealing in realms where the difference truly didn't matter.
(Score: 2) by takyon on Friday June 22 2018, @06:42AM (1 child)
If FTL is real, aliens are watching you in the bathroom with a cloaked phase-shifted infrared tracking nanodrone. This is during the times in which they are not probing your orifices. They have command and control ships stationed beyond the Kuiper belt and have enacted zoo containment protocol for the entire solar system. They already gave the Golden Record a listen, put it back, and rated it a 7.2/12.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 1) by tftp on Friday June 22 2018, @04:30PM
(Score: 1) by khallow on Friday June 22 2018, @11:57AM (12 children)
What we do have is an enormous lack of evidence for FTL. That's the wet blanket for your speculation.
(Score: 2) by Immerman on Friday June 22 2018, @01:57PM (10 children)
Pretty much all the solutions suggested within GR would require conscious intent (and incredible technology) to create, so we would only expect to find them in the presence of an intelligent species far more technologically advanced than ourselves. And thus far not one of the advanced alien races we've discovered has lacked FTL - so that's hardly a good argument.
Moreover - exactly what evidence would you expect to see for FTL being used at interstellar, or even intergalactic distances away from us?
Note that I am in fact moderately confident that FTL is impossible, but we have exactly zero evidence to support that position, and a firm theoretical basis to assume it *is* possible, so calling its impossibility a "safe assumption" is greatly overstating things.
(Score: 2) by VLM on Friday June 22 2018, @02:05PM (8 children)
Note that your debate strategy is straying into territory near "... and that's why we use classical astrology to design our space probe orbits". Some things, like astrology being real, can't be wished into existence without a whole lot of other things becoming bothersome.
FTL is usually synonymous with magic, magic in the sense of Tolkien anyway, so there's that minefield too. Too much magic and you've got no narrative in general "It was a dark and stormy night .. then the wizard waved his wand and all was right with the world, The End" now wheres the participation trophy I'm entitled to? What you say my story doesn't meet the modern requirements of politically correct sci fi? Well ... I'll make the wizard a gay minority trans wizard,THEN the industry awards can roll in.
(Score: 2) by Immerman on Friday June 22 2018, @02:15PM (7 children)
FTL in storytelling is certainly plot-advancing "magic". However, in reality it would be essentially invisible from a distance, and is firmly supported by one of the most well-tested and widely supported theories in our play-book (GR). Denying its potential existence amounts to assuming that either GR is flawed, or other physics we currently have no inkling of would prevent it from working. And our evidence against it basically amounts to "but that would make time travel possible"
(Score: 2) by maxwell demon on Friday June 22 2018, @03:11PM (6 children)
First: As far as I know, all known solutions to GR that would enable FTL involve matter or fields with negative energy density. Not only have we never found any such matter or fields, there are also good theoretical reasons to assume the non-existence of those.
Second: We already know that GR almost certainly won't be the last word, as it is incompatible with quantum mechanics, and all attempts to unify both so far have implied deviations from GR.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by Immerman on Friday June 22 2018, @03:54PM (5 children)
I want to say we have actually observed very low (near zero) negative energy densities, but I can't think of where I've heard it, so I won't make any claim of validity. Otherwise, yes, that would seem to be a stumbling block. Though great strides have been made in reducing the required negative energy densities by several orders of magnitude, and finding a way to eliminate them entirely isn't beyond the scope of possibility.
Secondly - the conflict with QM could indicate a flaw in either theory (or both), and we're increasingly certain that we're missing something important in QM for completely unrelated reasons. Whereas the only major problem we've found with GR is that is that it conflicts badly with QM on some key (currently unmeasurable) predictions.
(Score: 2) by ElizabethGreene on Friday June 22 2018, @04:08PM (4 children)
"I want to say we have actually observed very low (near zero) negative energy densities."
Yes, we have observed these in the field of optics, in metamaterials IIRC.
(Score: 2) by Immerman on Friday June 22 2018, @05:11PM (3 children)
That's certainly one of the more recent examples, unfortunately like so many things in metamaterial science, there's seems to be a lot of "behavior within a context" discussion going on - a relatively negative energy density stored within a physical substrate (an immense positive energy density concentration) isn't necessarily reflective that an actual absolute negative energy density (relative to empty space) is possible.
If you can think of any examples of possibly absolute negative energy densities I'd love to hear it though.
(Score: 2) by ElizabethGreene on Friday June 22 2018, @05:37PM (2 children)
>> a relatively negative energy density stored within a physical substrate
(I am not an expert on this topic.)
For an Alcubierre drive I don't know if that's a show stopper or not. You do need both the positive and negative energy density, a massive metamaterial structure might be the ticket. If you can achieve the desired effect with a low enough frequency (wavelength in tens of meters) it's not inconceivable to make the spacecraft in or part of the resonator.
It would be cool to see a 10 Megahertz multi-gigawatt split-ring resonator (from a safe distance)(assuming it didn't rattle the fillings out of your head)(and give your cancer cancer).
(Score: 2) by Immerman on Friday June 22 2018, @05:57PM (1 child)
I'm no expert either, and while I understand the basic geometries involved, I have only the vaguest concept of why negative energies are absolutely required to create them.
However, if negative energies are necessary, then I strongly suspect that any substantial quantity of matter, with it's incredible positive energy density, in those regions that require a negative energy density would render them unsuitable. Moreover, you're talking about regions of space that are folded in on themselves with such extreme curvature that even subatomic particles would be torn apart by the immense tidal forces - I doubt any physical metamaterials could survive (though perhaps some sort of "metaenergy" structure could.
Another potential problem is that the entire metastructure would have to exist *within* the "warp field", since anything outside the field will be left far behind as soon as you start moving FTL.
(Score: 2) by VLM on Friday June 22 2018, @07:22PM
There are other LARP issues with FTL such that traditionally its inside a ship that can control it, but its sometimes pretty tricky to control a field from inside it. Think of how easy it is to charge two capacitor plates using all kinds of gadgetry from the outside of the plates, and its a bit trickier to charge two plates from between two plates without generating an even stronger tidal field in between the plates than exists outside it. Of course "FTL field" might be as simple as manipulating a magnetic field, although I suspect it would not.
My guess is a FTL thingie would be more stargate like, a huge and energetically expensive space station, where small stuff goes in a big object and magically disappears, reappearing perhaps FTL hopefully a really long distance away.
Something often mentioned is how poor of a job solar cells do further away than earth orbit. Yet, if you can keep them cool (which can be tricky) then solar cells within the orbit of Mercury or something really pump out the watts.
If I were doing realistic hard sci fi I'd put my theoretical solar powered star gate around Mercury.
Also some of those solar systems with extremely large planets in extremely close to their star orbits would probably look absolutely delicious as a resource provider for a solar powered star gate civilization.
Now the point of this ramble is if I were doing SETI stuff, assuming solar powered star gates exist, THEN I'd be pointing my SETI antenna at those recently discovered planetary systems with huge planets in close orbit to stars.
Assuming of course we're not all being fooled by the oldest "Warp drive" trick in the sci fi book, that being close to grav fields screws up warp travel.
Also I would assume that any research on this is classified. Something that can go faster than light outside normal space ... is not just faster than light, but is outside normal space and that would make it awesome (well, from some perspectives) for everything from logistics to weapons of mass destruction to paratrooper delivery service.
So mixing this all up, we can "prove" grav fields do or do not F up solar powered star gates by pointing SETI antennas at likely exo species Space Marine base locations to determine if those otherwise ideal locations are, or are not, swarming with alien space marines. Assuming we can identify space marines from this distance. Extrapolating from my experience in the Army with Marines, admittedly a long time ago, we would need to detect excessive quantities of pr0n liquor and hooah.
(Score: 1) by khallow on Saturday June 23 2018, @02:11AM
Or particles slamming into each other at high energies. That explores a large portion of the "solutions" you speak of.
Widespread Dyson swarms, for example.
Absence of evidence is indeed evidence of absence.
(Score: 2) by Immerman on Friday June 22 2018, @02:06PM
As a follow-up, wormholes are probably one of the few avenues of FTL that just might occur naturally (if they can exist at all of course). And probably also one of the most dramatic. Now, you tell me exactly what sort of evidence you would expect to see of their existence from a distance of 1000 light years? Either end would essentially look like a (probably very low mass) black hole without an event horizon - so utterly invisible, without even the incidental radiation from the annihilation of infalling matter. You wouldn't be able to see anything passing through it unless it was ejecta from a supernova - and even that would be iffy.
(Score: 2) by bob_super on Friday June 22 2018, @04:22PM (4 children)
How do I get paid for a "study" which consists of writing sci-fi ? Please confirm that Dr Hooper is from the Literature department, not an actual "science" major...
(Score: 3, Insightful) by ElizabethGreene on Friday June 22 2018, @05:56PM (3 children)
Apparently you get a Ph.D in physics from University of Wisconsin, do postdoc work at the University of Oxford, publish over 200 papers on the intersection of cosmology and particle physics plus two books for non-scientists, and become the Senior Scientist and Head of the Theoretical Astrophysics Group at the Fermi National Accelerator Laboratory.
Here is the paper, notably absent from TFA. Those squiggly bits in there are called math. They are the big difference between this and sci-fi.
https://arxiv.org/abs/1806.05203 [arxiv.org]
(Score: 2) by bob_super on Friday June 22 2018, @06:41PM
And you start a paper with speculation about what might possibly happen to an advanced space-faring civ in 100 Billion years in a universe which is an order of magnitude younger than that. Throw in some dyson spheres, sprinkle some models ...
> Those squiggly bits in there are called math. They are the big difference between this and sci-fi.
I like my sci-fi to be based on logical setups (having some issues with Hollywood about that, recently). The fact that the math in his sci-fi universe work and can be used to infer other stuff, isn't unusual, and doesn't mean it's not all abstract experiment. He might as well be demonstrating how many stars could dance on the head of Ursa Major. What is the scientific value of this paper, and where is the three-titted whore of Stavomula Endor?
(Score: 3, Touché) by takyon on Friday June 22 2018, @07:13PM (1 child)
It was the first link in the blockquote.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by ElizabethGreene on Saturday June 23 2018, @05:35PM
Mea culpa.
(Score: 2) by unitron on Saturday June 23 2018, @03:27AM
...as Kardashian Type Civilizations...
Gave myself quite a scare.
something something Slashcott something something Beta something something