No dyson spheres in local galaxies

[PB666]

http://www.iflscience.com/space/search-advanced-alien-civilizations-our-local-universe-finds-nothing

[Tex_NL]

Click bait!

How long have they been searching? It's like scooping a bucket of water from the ocean, not seeing any fish and concluding it's devoid of life.

SETI has been searching and listening for decades and still found nothing. Absence of proof is not proof of absence.

Edited September 20, 2015 by Tex_NL

[Bill Phil]

"Absence of evidence, is not evidence of absence."

Basically what Tex_NL said.

[PB666]

Whoa there, not my data. But you know, im going to agree with them, they should be able to detect them in the ir if thay exist. I think that such high level civilizations don't exist, and dysan sphere is hard stuff.

[More Boosters]

Wouldn't a dyson sphere absorb most of the energy and thus make a star even harder to see?

[RainDreamer]

Dyson spheres are still a concept a human thought up based on human technologies. Perhaps an advanced alien civilization will have a different idea to harness the power of their local star.

Though, how do you detect something like a dyson sphere amongst all the stars in a galaxy? And in 100000 galaxies?

Wouldn't a dyson sphere absorb most of the energy and thus make a star even harder to see?

A civilization using that much energy would still light themselves up pretty well - all that energy has to go somewhere in some form (wasted heat, light, radiowaves, etc). But of course, this is based on the assumption that they have similar technology to us. They could be converting that energy to something else that we can't detect, or their tech is so good they use all the energy of the star somehow with 100% efficiency, and so on.

Edited September 20, 2015 by RainDreamer

[rtxoff]

All the dark matter is Dyson spheres, all problems solved.

No seriously, i have no doubt that something like a Dyson sphere is practically impossible and does not exist. Nowhere in the known universe.

[More Boosters]

All the dark matter is Dyson spheres, all problems solved.

No seriously, i have no doubt that something like a Dyson sphere is practically impossible and does not exist. Nowhere in the known universe.

That's a bit harsh. How can you be so sure? Whether it's worth speculating about is another matter though, I mean it would be a happy coincidence if we somehow came across one but that's it. Not worth talking about until then.

[Tex_NL]

That's a bit harsh. How can you be so sure? Whether it's worth speculating about is another matter though, I mean it would be a happy coincidence if we somehow came across one but that's it. Not worth talking about until then.

The logistics required to build one make them all but impossible. Any civilization that can spare the resources can easily colonize other star systems.

[cantab]

The Kardashev Scale has its limitations anyway. Energy use is only one aspect of a civilization, and one relating more to scale than technological advancement. With it Kardashev didn't seem to anticipate the rapid progress of miniaturisation - semiconductor devices with features 50-100 atoms across are now commonly owned.

[Bill Phil]

The logistics required to build one make them all but impossible. Any civilization that can spare the resources can easily colonize other star systems.

In most possible cases, they already have.

[Superfluous J]

It's like scooping a bucket of water from the ocean, not seeing any fish and concluding it's devoid of life.

No it's more like taking hundreds of buckets of water all over the world from different depths, including as many as possible where we've figured life was most likely, and not finding any life.

Still not sure but far more than "Welp, may as well throw in the towel now" after a quick glance.

[baggers]

No it's more like taking hundreds of buckets of water all over the world from different depths, including as many as possible where we've figured life was most likely, and not finding any life.

Still not sure but far more than "Welp, may as well throw in the towel now" after a quick glance.

You have no idea of how vast the "local universe" was, and how small and pierced our bucket is ^^

[PB666]

You have no idea of how vast the "local universe" was, and how small and pierced our bucket is ^^

The problem with this is if you look at portion of galaxy for specific frequencies. A star will emit at hv, mostly in the 400nm range at the surface, the light will be absorbed on the inside of the sphere. The sphere being 10,000,000,000 of meters in radius the hv the radiation would emmit in the mid IR range. intensity at the new lower wavelength would increas by a magnitude and would be increadibly evident in the absence of the nascent starlight.

[Endersmens]

I see a title "No Dyson Spheres Found in Local..." And I thought it was gonna say "stores" after it.

I was confused on why a thread about vacuums was in the science labs.

[baggers]

Maybe building a full Dyson Sphere is not a viable way to trade work for energy?

Who need that much energy, after all? If it's only for one or 2 local planet consumption?

Even if you need room and energy, a very partial Dyson sphere, like a relatively small "ring" over the planet it give it's energy will largely have a dozen of hundert time the surface of the planet and be absolutely not noticeable for any of our telescopes.

- - - Updated - - -

Look: If the ring of Saturn were an artificial surface like an embryonal Dyson sphere:

The dense main rings extend from 7,000 km to 80,000 km above Saturn's equator (see Major subdivisions of the rings; Saturn's equatorial radius is 60,300 km)

So, it a surface of Pi*2*140.000² - Pi*2*67.000² = 109 billions square kilometers

Earth full surface is about 0.5 billions square kilometers

So, Saturns main ring "surface" is more than 200 times the earth surface, including oceans, blabla.

Pull solar panel all over a "small" artificial ring over earth, and you solve all energy problems. And it's still a dust of a dust of a "real" dyson sphere, undetectable from the next solar system. And even detected, undiscernable from "natural" rings until very close.

And it will look pretty cool too:

http://www.planetary.org/blogs/jason-davis/20130626-earths-skies-saturns-rings.html

Edited September 21, 2015 by baggers

[PB666]

Barring warp drives you need the type of energy for interstellar travel.

1000000 kg * 10E16 = 10E24 joules

yearly world energy consumption = 10E21 joules, we'de need 1000 earths to launch a sigle ship close to the speed of light.

Before the ........ come running in no, there is no known way of storing or transmiiting this for flight.

[baggers]

I will look more for the energy given by the sun to the "Dyson ring", rather than the earth consumption:

I assume the ring move with earth, but rotate to present alway his "face" to the sun.

http://www.itacanet.org/the-sun-as-a-source-of-energy/part-2-solar-energy-reaching-the-earths-surface/

The sun give 1367W/m² So 1,367W * 10E9 /km²

In a year, for 1km²: 43,1 *10E15 J

For 109 billions km²: 4,687 * 10E30 J

How many launch do you want per day? ^^ Even at 1% energy convertion ratio for the Dyson ring solar panels, it's still a whole bunch of ligth-speed 1000 tons aircrafts every days! (easily tens per days) And you still can save 4/5 of the ring surface for others purposes.

A civilisation with such a small "Dyson ring" will certainly have already colonized all galaxy. No need for an overkill full Dyson Sphere.

Edited September 21, 2015 by baggers

[baggers]

Even more funny a Dyson Sphere made of fully transparent solar panels!!!

http://www.extremetech.com/extreme/188667-a-fully-transparent-solar-cell-that-could-make-every-window-and-screen-a-power-source

It's not really "transparent": it just absorb a specific non-visible wavelength of light.

If a civilization will make a "discrete" Dyson sphere, it could just absorb some wavelength of ligth so a regular Sun will for example look like a credible red dwarf from outside the Dyson Shere.

[YNM]

Dyson sphere: implausible, even on a super-advanced tech civilization. The sphere could warp a bit and one side be attracted to the star...

Dyson ring: depends on placement, not possible yet by earth-dwellers tech.

Transparent dyson ring / sphere: should be detectable by IR spectrograph already.

[baggers]

Dyson sphere: implausible, even on a super-advanced tech civilization. The sphere could warp a bit and one side be attracted to the star...

Sphere rotate, hop, problem solved.

Transparent dyson ring / sphere: should be detectable by IR spectrograph already.

A saturn-like ring: non-detectable actually. We need a whole bunch of order of magnitude from actual telescopes, and even with, making the difference from "regular" rings will be extremely difficult if not at closes ranges.

Transparent Dyson sphere: If you don't take all spectrum, but just sligty ajust them (like a filter of wavelengths: it's what these transparents solar panels do), It will be indecernable from a bit more aged star for example.

[Grumman]

If you have enough energy to build a Dyson sphere, you have enough energy that you don't need a Dyson sphere.

[Superfluous J]

You have no idea of how vast the "local universe" was, and how small and pierced our bucket is ^^

I have many ideas, actually. You have no idea how Statistics works.

[baggers]

I have many ideas, actually. You have no idea how Statistics works.

Sorry, I don't really intend to offense. I lack a bit of vocabulary and training in english ^^.

Looking further in the study from the OP, I actually find that they haven't researched a Dyson sphere. But a galaxy full of Dysons spheres. They have looked at the global galaxies spectrums.

So, for a 100 billions stars average galaxy, You would need a billions Dysons spheres for noticing a 1% change in the spectrum. And probably 10 billions Dysons spheres for an "evidence".

So, they have proved it certainly havent any galaxy full of dysons spheres. But it's not "no Dyson spheres in local galaxy"

It's a first step.

Edited September 21, 2015 by baggers

[More Boosters]

Look at all these members of a 10.000 year old civilization so sure that something not possible for them is not possible, sensible, or practical in way, shape, or form, under any possible circumstance in the mind bogglingly large universe.

Seriously. I'm not saying think about it and waste time looking for Dyson spheres, but why are you so sure that something in the realm of fiction here was not done elsewhere. That's dogmatic. Don't be like that, don't be that sure of anything.

And please, don't twist what I just said into something about religion. In fact let me do it before you do. You can't be sure about the existence of any number of deities, you can only reach your own conclusions looking at the available evidence. To me it doesn't seem like a deity, at least in the way mainstream religions describe, exists. On a similar note, don't be so sure that such structures don't exist just because the chances are infinitesimally small. You lose nothing by just stating that they probably don't exist. Otherwise you'll just feel silly if, at a ridiculously low chance, that we come across a power station around a star that was apparently worth building to hyper advanced aliens who don't have the same problems we do.