Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The Best Way to Find Aliens: Look for Their Solar Power Plants

theatlantic.com

Post reply on HN
Print view View original

21–30 of 61 posts

Re: The Best Way to Find Aliens: Look for Their Solar Power Plants

#21

Post by molmalo »

tzs wrote: post #13

Build your Dyson sphere with large gaps in the galactic plane. Then observers at most other stars in your galaxy will see your star, and then you don't have to either build a giant sphere or come up with exotic heat management systems to avoid detection.

The main problem is that the galactic plane is not really a plane :)

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. :)

Re: The Best Way to Find Aliens: Look for Their Solar Power Plants

#22

Post by lurker14 »

hollerith wrote: post #8

>the sun beams a total of 120,000 terrawatts per day onto our planet. That's 10,000 times the amount that flows through our industrial civilization. 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.)

"terawatts", not "terawatts".

Re: The Best Way to Find Aliens: Look for Their Solar Power Plants

#23

Post by lutusp »

jakeonthemove wrote: post #10
lutusp wrote: post #2

Let's be realistic. A civilization so advanced as to be able to capture the entire energy of a star, probably also has energy alternatives, and probably wouldn't want to attract the attention of lesser beings (like us) by trapping a star's output in a detectable way.

Sure, they could have their own nuclear fusion reactors or even something more sophisticated, but why let a perfectly good source of energy just go to waste? I don't think they'd care that anyone could detect them if they're that advanced...

> Sure, they could have their own nuclear fusion reactors or even something more sophisticated, but why let a perfectly good source of energy just go to waste?

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.

Re: The Best Way to Find Aliens: Look for Their Solar Power Plants

#24

Post by strait »

aplusbi wrote: post #12
lutusp wrote: post #2

Let's be realistic. A civilization so advanced as to be able to capture the entire energy of a star, probably also has energy alternatives, and probably wouldn't want to attract the attention of lesser beings (like us) by trapping a star's output in a detectable way.

Why wouldn't they want to attract the attention of lesser beings?

I'm guessing that it's not unlike why we don't leave food out when camping in bear country. If the bear realized what we were doing (hiding food from it), then it would surely come to the bear conclusion that our behavior was unreasonable, but we know better.

Re: The Best Way to Find Aliens: Look for Their Solar Power Plants

#25

Post by gibybo »

apedley wrote: post #15
lutusp wrote: post #2

Let's be realistic. A civilization so advanced as to be able to capture the entire energy of a star, probably also has energy alternatives, and probably wouldn't want to attract the attention of lesser beings (like us) by trapping a star's output in a detectable way.

I agree. From my limited knowledge of power sources, I understand that fusion and zero point energy would provide more easily accessible and vaster amounts of energy than one could build with a huge solar collector. Solar can only go to the maximum that the sun outputs in that direction. I would speculate that alien civilizations have found far more efficient means of power than a solar array.

It wouldn't just be one direction, it would be a sphere around the whole star. Stars are essentially just large fusion reactors, so it would take one the size of the star to compete with it (within an order of magnitude or so).

Re: The Best Way to Find Aliens: Look for Their Solar Power Plants

#26

Post by lutusp »

enraged_camel wrote: post #3
lutusp wrote: post #2

Let's be realistic. A civilization so advanced as to be able to capture the entire energy of a star, probably also has energy alternatives, and probably wouldn't want to attract the attention of lesser beings (like us) by trapping a star's output in a detectable way.

I've never understood such assumptions of intelligence. "If a civilization could do X, they could also do Y and Z." Says who? It's not like we're experts in alien intelligence. How can we be, when we have never encountered one?

All true, but applying common sense still has a point. For example, do we want to broadcast the fact of our own existence across interstellar distances? This is actually an active debate topic among those who think about stuff like this.

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.

Re: The Best Way to Find Aliens: Look for Their Solar Power Plants

#27

Post by lutusp »

aplusbi wrote: post #12
lutusp wrote: post #2

Let's be realistic. A civilization so advanced as to be able to capture the entire energy of a star, probably also has energy alternatives, and probably wouldn't want to attract the attention of lesser beings (like us) by trapping a star's output in a detectable way.

Why wouldn't they want to attract the attention of lesser beings?

> Why wouldn't they want to attract the attention of lesser beings?

Because they might attract the attention of greater beings.

Re: The Best Way to Find Aliens: Look for Their Solar Power Plants

#28

Post by lutusp »

grecy wrote: post #7
lutusp wrote: post #2

Let's be realistic. A civilization so advanced as to be able to capture the entire energy of a star, probably also has energy alternatives, and probably wouldn't want to attract the attention of lesser beings (like us) by trapping a star's output in a detectable way.

> also has energy alternatives What's an "energy alternative" ?

Fusion is an energy alternative to coal. Wind is an energy alternative to solar, and vice versa. Things like that.

Re: The Best Way to Find Aliens: Look for Their Solar Power Plants

#29

Post by mcantor »

lurker14 wrote: post #22
hollerith wrote: post #8

>the sun beams a total of 120,000 terrawatts per day onto our planet. That's 10,000 times the amount that flows through our industrial civilization. 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.)

"terawatts", not "terawatts".

'"terawatts", not "terrawatts"', not '"terawatts", not "terawatts"'.

Re: The Best Way to Find Aliens: Look for Their Solar Power Plants

#30

Post by sbierwagen »

mediocregopher wrote: post #19
sbierwagen wrote: post #18

Larry Niven, "Bigger Than Worlds" (1974) ...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 r…

Speaking of Larry Niven, my impression after reading Ringworld (in addition to "holy shit that was good") was that Dyson Spheres were kind of a non-workable, and that a species who'd advanced far enough to actually make one could probably just colonize another system anyway.

A swarm-Dyson sphere, which is the only kind that can be realistically built, is incremental. You just keep building habitats in orbit around the sun, until eventually you capture all the sunlight.
Post reply on HN