"sonic boom"?

<<Are there any objects observed that produce about the same amount of energy as the Sun, but radiates it at a lower temperature from a larger surface?>>

The MACHO project detected a population of stellar mass objects that were too cool for their size, towards the galactic bulge if I remember correctly. I think these are supposed to be related to white dwarfs but perhaps we can speculate....

I don't see why a super civilisation should build a Dyson sphere.
Because super civilized mean super big ? This has no sense.
And what is the purpose of a Dyson sphere if it is possible to build one ? What aim do you seek when planning for one ?

Multiplying like rabbits until it is full and you have to do it again ? What an expense of cleverness and ressources for such a stupid reason !

I think a supercivilization must be able to control its own population , after all , we are already doing it on earth in every industrialized country and even in some part of the third world.

And also like Larry Niven show in the Ringwold novels, these structure are so vast , so bigger than the people living in it will be trapped.
They are dead end and just an example of our own megalomania. IMO I don't know what a super civilization will do but sure they will not build Dyson sphere.

You seem to be assuming the shell version of a Dyson Sphere, a single unified structure; which would require such a massive planned effort. But the assumption in the OP seems to lean more towards Dyson's original Swarm concept, which could develop gradually over the lifespan of a spacefaring civilization.

3 main problems with that assumption. 1., we haven't been "controlling" our population growth, just reducing the average in a few, closely related cultures for a couple of generations. Neither long enough nor widespread enough to see if it'll last. 2., over the time frame needed to build up a spherical swarm of habitats so thick it blocks sunlight, a mere .01 percent population growth or less will build up over time into a horde. 3., we can't make assumptions about an alien's biology or culture to know what their reproductive rate, or intentions, are.

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"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
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"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

But, one way or another, population will be limited, barring infinite resources. If a civilization gets to the Dyson swarm stage without population control, it won't last for long.

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The Leif Ericson Cruiser

Not necessarily. "Population control" is not a clearly defined term; nor is it absolute. As long as there are resources available, a population can continue to expend to fill any available niche. So in this case, the number of habitats built can continue to increase as long as materials are available; and in an entire planetary system, that's a lot of matter. Not to mention interstellar materials such as Oort cloud comets. So the "sphere" may actually be a cloud spreading through all the nearby star systems. A very advanced civilization can technically even siphon matter from their star magnetically, which not only gives them additional fuel and building materials but also lengthens the active span of the star.

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"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

Nevertheless, populations can't expand geometrically under any circumstances. Even if we converted the entire solar system into habitats those habitats would one day be half full, then shortly afterwards they would be completely full; the very next day population growth would be forced to stop.

And the possibility of life extension makes population growth a lot worse. Once the death rate goes down, the birth rate will have to follow eventually- and with geometric growth, that is sooner than one might think.

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Geometric growth and zero growth are not the only two options. There's plenty of room for controlled expansion, over the lifetime of a star system.

__________________
"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

No matter how you slice it, exponential population growth cannot last very long with finite resources. Therefore, population growth would be limited, one way or another. Even with very optimistic assumptions, exponential growth in something like the solar system could last a few centuries - hardly any time at all on geological time scales.

And then it must stop. Sure, there could be a trickle of additional growth, but it wouldn't be exponential.

Any finite limit stops exponential growth - that includes the speed of light.

Unless the star is used up. To be sure, a star represents a huge amount of mass, but it is just as finite as anything else. A civilization that resorts to star lifting must still limit itself. At the extreme, we might imagine a civilization that takes a star apart and fuses it all up to iron to support continued expansion, but at that point, it would collapse. In practice, even an advanced civilization would probably hit limits long before it reached that point.

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The Leif Ericson Cruiser

(Emphasis added) That's what I would call "population control."

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The Leif Ericson Cruiser

See what I mean about it being poorly defined?

__________________
"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

No, it seems to be a pretty clear cut issue.

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The Leif Ericson Cruiser

Apparently not, or there'd be no confusion over the term. A population can be "controlled" and still grow rapidly, "controlled" and growing slowly, "controlled" and zero, "controlled" and reduced, all depending on circumtances and how control is defined; is it by traditions, cultural values, legal sanctions, medical means, limited survival rates, limited infant mortality, selctive euthanasia, etc.

__________________
"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

I don't see the confusion. You took issue with my statement here:

I didn't say anything about the method of control, just that there would be a need for it, as you seem say as well.

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I say there is an invisible elf in my backyard. How do you prove that I am wrong?

Disclaimer: Avatar is not an official NASA image and does not imply any specific interplanetary or interstellar capability.

The Leif Ericson Cruiser

Your assumption of exponential population growth is what I took issue with*, really. It's an unlikely scenario for humans and an unknown-possibility scenario for an alien species of unknown reproductive methods. But if we are using the broadest possible definition of "controlled", as you seem to be, then by that standard there is no such thing as uncontrolled population growth, since it will always be limited-- and therefore controlled --by the species' limits of growth.

*EDIT: Let me correct that, I was taking issue with galacsi's assumptions, not yours.

__________________
"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

Noclevername pick your battles trust me every battle isn't worth it.

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perfect is an opinion word-3dknight

it doesn't matter if I get 3 hours of sleep or 6, I still wake up just as tired!-Neverfly

These are the questions that boggle my mind-3dknight

If somepeople say supercivilzations are beyond imagination it really means beyond human comprehension. So we may be looking at a supercivilzation right now but if your mind can't comprehend it it's not there.

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perfect is an opinion word-3dknight

it doesn't matter if I get 3 hours of sleep or 6, I still wake up just as tired!-Neverfly

These are the questions that boggle my mind-3dknight

galsci , who's that guy ?
By controlled , i mean planed and in case of humans meaning voluntary planed.Family planning is not something new depending only on technology. Many cultures did it in the past.