The Best Way to Find Aliens: Look for Their Solar Power Plants
theatlantic.com
theatlantic.com
So if a civilization were to completely mask itself in the EM spectrum, the only way to detect them would be to look for gravitational distortions assuming those can't be masked. A civilization might do this either to hide from others or because the maximum efficiency of their energy extraction system would occur when their waste heat matched the background ration. So a really advanced (and paranoid or efficient) civilization would be indistinguishable from dark matter.
This brings up another interesting hypothesis: dark matter is actually the computronium of all of the alien civilizations in the universe that have achieved a technological singularity. Unfortunately, this hypothesis can't be tested until humanity gets to the same level.
This seems to be an unsupported assumption.
Technological singularity describes the aftermath as an entity achieves an intelligence significantly superior to that of the average unaided human mind. The term gets thrown at a lot of things that don't seem to have anything to do with it. In this case I don't see why humans level intelligence is not enough to build a Dyson Sphere.
Why would they try to hide this from others? Are we trying to hide our satellites, or our probes that we are sending out?
Assuming hiding is technologically feasible, why take the risk?
But looking at how fellow humans behave with each other. I would say that is definitely a possibility.
...assuming that the galaxy's most advanced civilizations are protoplasmic. But
beings whose chemistry is based on molten copper, say, would want a hotter
environment. They might have evolved faster, in temperatures where chemistry and
biochemistry would move far faster. There might be a lot more of them than of
us. And their red-hot Dyson spheres would look deceptively like red giant or
supergiant stars. One wonders.The need for energy is definite, but the amount and character of such need is debatable. Maybe civilizations shrink and don't use so much energy? Maybe they mine million of stars at once? Maybe they get their energy out of thin vacuum?
Suppose your star is located exactly in the plane, and its axis is orthogonal to the galactic plane. Then, defining "up" and "down" as the opposing directions in that star's axis, you would still have a lot of stars "up" and "down" the plane.
So, even if you only have only one disk orbiting the star, with a high enough orbital inclination, that's still visible from a lot of stars.
And of course, there would still exist a plane containing the disk's orbit, from where the disk eclipses the star.
Even more, the disk itself would still be detectable from other planes, because it's hotter than the background.
Then, if your civilization wants to keep hidden its existance, you still need to develop some kind of stealth tech for the sphere. :)
Should be "terrawatts", not "terrawatts per day". (I stopped reading there. There 100s of 1000s of people who know enough physics never to make such a mistake. I'll read one of them instead.)
Isn't it too pretentious to think that, not only other similar civilizations do exist (which is a stretch already), but also predict their infra-structure necessities and what kind of solution they are going to come up with?
I known I'm nobody and Mr. Dyson is a Nobel-prize grade genius, but come on... this is (much) more fiction than science.
PS: Let the downvotes commence.
Whither comes the energy for a million year civilization? Should they ignore their star? Just let all that power go streaming by?
(Dyson won theHeineman Prize, Harvey Prize, Wolf Prize, Templeton Prize, Pomeranchuk Prize, Fermi Award, and the Poincare Prize; but did not win a Nobel.)
1. That a civilization similar to ours exists 2. That such civilization exists in the same time frame as us 3. That such civilization's demands on energy are similar to ours 4. That such civilization expands enough to face energy shortcomings 5. That the best source of energy such civilization finds is a nearby star 6. That they arrive to the same conclusion as Mr. Dyson about the best way to harness the power from this star (the biggest pretension by far in my opinion) 7. That they manage to build it
A very interesting chain of propositions, but really? I find amusing that are people willing to take this more seriously than a simple imagination/future prediction exercise.
We can't even reliably predict how our own civilization will look like in a matter of decades. Now imagine how naive is to think we can predict which problems hypothetical begins similar to us are going to face, let alone predict a particular the solution they are going to come up with.
All life uses energy. All civilizations will always use energy, because they are made of life forms. (biological or silicon-- who cares)
If civilizations grow steadily, then their need for energy will grow steadily. If they don't flame out, then they'll need to expand beyond their host planet, and intercept more solar energy, until eventually all sunlight is captured, and you've got a Dyson sphere.
If civilizations grow until they hit a threshold, then stay steady-state for the rest of the universe's lifespan, then we'll only be able to detect them if the threshold is pretty big-- if they just stay on their planet, then they'll be hard to spot, without really big space telescopes.
Intelligence and wisdom are different qualities.
Ironically, after a brief spell of broadcasting our existence with powerful radio and radar waves, we're gradually shutting down the big transmitters for reasons of economy and efficiency. Satellites allow us to accomplish the same end with much less power than the old high-powered transmitters, and GPS-guided aircraft makes more sense that long-range radars for all but military purposes.
There are those who argue that we should transmit the basic facts of our existence with high-powered radio transmitters and lasers, and await a reply. Others argue that we shouldn't. Both arguments have merit.
We are already doing it(http://en.wikipedia.org/wiki/Arecibo_message). We are also sent a probe with heck lot of details on it(http://en.wikipedia.org/wiki/Voyager_Golden_Record).
>>This is actually an active debate topic among those who think about stuff like this.
True, but we have always been sending radio signals in space and probably will continue to.
Yes, absolutely. It is said that, because of radar, we're the brightest object within several light-years in those wavelengths. Add to that the periodic nature of radar, and we're signaling with an obviously unnatural beacon for anyone willing to listen.
I'm just saying the debate goes on, even though we're providing quite a beacon for anyone interested in detecting signs of semi-intelligent life. :)
> True, but we have always been sending radio signals in space and probably will continue to.
I wouldn't say "always". The first reasonably strong, narrow-band radio signals commenced in the 1920s. Not even 100 years. And we're quickly reducing our EM radiation footprint for economic reasons unrelated to anything resembling policy.
I see the point of both arguments -- that we should, and shouldn't, broadcast our existence. I actually prefer the "should" argument overall, considering the difficulty that an alien species would have getting here. We might learn something remarkable from a safe remove.
I don't think they'd care that anyone could detect them if they're that advanced...
TO avoid detection by some other warlike species?
Regardless of the alienness of a life form, there are certain principles one can rely on, under average circumstances:
* Resource aren't infinite anywhere, and an intelligent species won't deliberately waste resources.
* No civilization is invulnerable.
* The duration of existence of any lifeform is finite.
There will always be outliers, but if we're after a set of reliable assumptions, these are on the list.
> I don't think they'd care that anyone could detect them if they're that advanced...
If you wrap a star in collection surfaces, thermodynamics dictates that the result will be a much larger surface at a lower temperature. If that isn't true, then the point of the exercise (energy collection) won't pan out.
Obviously this is rank speculation, but knowing what we do about living species, some speculations are more likely than others.
The next most likely is probably relativistic projectiles, which are dangerous in proportion to the energy required to send them (i.e., they aren't that likely a threat).
Direct invasions of civilizations that can shape the matter of an entire solar system seem pretty much destined to failure (I guess you could come in on a ship built from an entire solar system, but I wonder if you are war mongering at that point).
Because they might attract the attention of greater beings.
As a life form we don't seem to be taking any precautions to 'hide' from others.
Why are assuming others would like to 'hide'?
What's an "energy alternative" ?
Your parent comment implies they would have an "energy alternative" to... energy.
When you say "A civilization so advanced as to be able to capture the entire energy of a star, probably also has energy alternatives".
What "energy alternatives" are you talking about?
No, not at all. A walking alternative is bicycling, not being a double amputee. A coffee alternative is tea, not dehydration.
"Energy Alternatives":
http://www.energyalternative.com/home.html
Wikipedia: Alternative Energy:
http://en.wikipedia.org/wiki/Alternative_energy
A quote: "Alternative energy is an umbrella term that refers to any source of usable energy intended to replace fuel sources without the undesired consequences of the replaced fuels."
"The energy alternative":
http://www.theenergyalternative.com/
"Alternative Energy News":
http://www.alternative-energy-news.info/
> What "energy alternatives" are you talking about?
Want more links?
(My understanding is that solar is the alternative to things like coal)
On the other hand, if you put your solar collector well inside Mercury's orbit, where the solar flux is dramatically higher, then you get plenty of power, without having to maintain and fuel a reactor.