/sci/ - Science & Math

no

>>4471382
>assuming its containing all the light from the star
if it contains all the light from the star how would we be able to see it? the only way i think we could notice it if we observe it pass in font of another star

We'd only be able to detect that thing through gravitational lensing, OP

Not bloody likely.

>mfw there could be a matrioshka brain heading towards Earth right now to add us to the hive brain

>>4471424
I'm okay with this

>radius of 1AU

272 quadrillion km2 of potentially habitable land. Who fucking needs galaxies.

>>4471382
too close to see something like that.

>I want to play Halo Wars now.

What do you think all those "black holes" are? You don't really think such an absurd thing actually exists do you?

>>4471382
>defiantly

MY EYES, THEY HURT

Unlikely because (1) the universe is young, (2) the universe is finite, and (3) the existence life is a rarity. We most likely the only sentient beings in the whole universe.

>>4471507
>We most likely the only sentient beings in the whole universe.

And I'm sure you've done a lot of research to come up with this conclusion.

>>4471507
>Unlikely because (1) the universe is young, (2) the universe is finite, and (3) the existence life is a rarity. We most likely the only sentient beings in the whole universe.

Holy shit, learn to biology, geology, astronomy, chemistry, physics. That's quite possibly the dumbest thing I've ever heard on /sci/...ever.

>>4471507

>(3) the existence life is a rarity

So far we have sampled two planets in the habitable zone, one definitely has life on it and the other might. I don't see how you get your conclusion.

>>4471508
There is no rule requiring a plausible theory to be substantiated with evidence instead of logical deduction.

>>4471517
Out of how many planets painstakingly surveyed by telescopes?

Can the radio emissions of said star penetrate the sphere? Or are they sequestered too?

>>4471520

Out of habitable zone planets surveyed in enough detail to be able to detect signs of life?

One definite, one possible.

>>4471517
>2012
>Still believing there's a chance of Martian life
Seriously, it's bordering on fairy-tale level shit now. There's no life there. Accept it and move on.

>>4471529

There is some evidence for methane production, which is generally due to a geological or a biological source.

>LOL IT'S OBVIOUSLY GEOLOGICAL

As far as we are aware Mars is geologically dead. Evidence for geological life would be just as surprising as evidence for biological life.

Are dyson spheres even an effective use of resources for electricity? Surely if you could make one you'd probably already have achieved fusion as a means of generation. And if not the distance from sphere to planet is impractical for transmission.

What if dark matter is actually hidden stars concealed by alien dyson spheres?

>>4471540

If you can build something that fuckhuge why the fuck would you live on the planet?

Dyson spheres are magic. They don't exist. Physics says they don't exist.

>>4471543

I thought the gravitational effects of dark matter were known to be shaped like a giant universal spiderweb rather than balls?

>it's actually the structure for a universe dyson sphere

>>4471540
If you can build a dyson sphere, you have no use for planets.

Also, 100% output of a star > any fusion ever done on a planet

>>4471543
Fuck.

>>4471553

If you have sufficiently many balls distributed evenly throughout the halo, you get the same effects as a spider mesh.

When the Aliens (computers, biological or something different) come to kill us, what do we do?

>>4471565

If we aren't the ones coming to their home and doing the killing, we have failed as a species.

There is to be no sympathy for failures.

>>4471536
>Geologically dead
What the fuck does that even mean?

>>4471576
No geological activity.

Protip: Read very slowly and think three times about it before you post.

>>4471576
>>4471581

and before he asks geological activity means tectonics. plates. underground. up and down up and down over and under.

>>4471584
>>4471584

>plates. underground

nope. they ARE the ground.

>>4471382
Ah, but by thermodynamics a dyson sphere must radiate heat, so yes we could see it.

Dyson sphere are just big complicated heat engines, they must reject the heat somewhere, and we can detect said heat.

>>4471588
>>4471588

but what if that heat loss energy was being 100% harnessed?

>>4471424
By thermodynamics, matrioshka brains must also radiate heat, and a lot of it. Plus, if the brain was performing deceleration operations, it'd be lit up like a christmas tree.

>>4471520
Eights, and four of those are gas giants, a further one is practically in the sun. By your logic there is a 25% chance that ANY planet has light on it and a 50% chance that any non-gas giant has life.

>>4471589
If it doesn't radiate anything off, we can't see it.

As we can't see a fleet of 20 mile alien space stations hiding in the asteroid belt of our solar system, because we observe less than 1% of the sky at best.

>>4471589
Not necessarily 100% (since that'd be impossible), but perhaps near that star's Carnot limit (93% for the Sun's, for instance), which would be plenty to make it very difficult to detect.

>>4471589
The heat must still be radiated in order for the heat energy to be harnessed at all, otherwise you're breaking the second law of thermodynamics.

Oh and if it didn't radiate any heat, it'd accumulate heat and turn into molten slag.

There is no stealth in space.

>>4471589
Thermodynamics. Energy isn't harnessed, it doesn't disappear like magic. It's transformed from different forms. Unless they were using it all to only produce forms of energy other than heat, like electricity, matter/antimatter and whatever else, there's still gonna be a hell of a lot of heat going out into the universe, and I'm pretty certain that scenario just proposed isn't even possible.

>>4471596
>>93% efficiency

Ah, but what are our alien friends doing with all this energy? Surely they are utilizing it? If they are utilizing it, they are converting it to heat.

After all, all the electricity that you use goes to heat. It all goes to heat, which must be radiated.

>>4471599
>There is no stealth in space.
Yes, there is.

>>4471605
Who the fuck knows. They could be storing it. They could be blasting it off in a narrow beam somewhere for some sort of intergalactic communication device.

We ARE talking about fucking DYSON SPHERES, here. We've already made a huge leap of faith, we can afford to make a few more.

>>4471595
>>As we can't see a fleet of 20 mile alien space stations hiding in the asteroid belt of our solar system, because we observe less than 1% of the sky at best.

Yeah, I doubt that, surely the transient flashes of light coming from their engines and ships would be more than enough to attract just about any astronomer's attention.

Not to mention, we can detect a spaceshuttle main engine firing from pluto.

>>4471610
>>we can make a huge leap of faith
However, we cannot ignore the laws of thermodynamics.

>>They could be blasting it off in a narrow beam somewhere for some sort of intergalactic communication device.
lasers aren't 100% efficient and computers must turn energy into heat. Heat must be generated and radiated, even with 94% carnot efficiency.

>>4471608
le sigh...
http://www.projectrho.com/rocket/spacewardetect.php#id--There_Ain't_No_Stealth_In_Space

>>4471403
Black body radiation; It's not possible to just absorb all of the energy and some would inevitably be radiated from the outside of the sphere.

>>4471608
Stealth in space is based on the idea that space is big and hopefully nobody's looking at you. But that's pretty true.

http://www.gwern.net/Colder%20Wars
Here's an interesting discussion on how war might work in space. My only counter to it would be that aiming would be difficult, and that smaller distributed colonies, or the colonization of multiple planets, could ensure that no entire solar system is ever wiped out, though it still seems that retaliation would be difficult.

>>4471621
I don't see why the accuracy problem would be a problem. Just fire a ship in the general direction of the target, then when it gets close enough, fire dead weight at it.

where the fuck, do they get all the matter to make a 1 A.U Dyson sphere?

>>4471611
>Not to mention, we can detect a spaceshuttle main engine firing from pluto.
Sure, if you happen to have a fucking massive space telescope at maximum magnification pointed perfectly in the right direction at just the right time...

>>4471621
>Stealth in space is based on the idea that space is big and hopefully nobody's looking at you. But that's pretty true.
That's how stealth works here on Earth, too. Nothing is PERFECTLY undetectable, but a stealthy vehicle will have extensive measures put into reducing the likelyhood that it will be detected by common sensors.

>>4471722
no

Stealth in Earth revolves around the idea of preventing the object from reflecting radio waves and minimizing infrared radiation

>>4471691

Zimbabwe dollars

>>4471611
>Yeah, I doubt that, surely the transient flashes of light coming from their engines and ships would be more than enough to attract just about any astronomer's attention.
>Not to mention, we can detect a spaceshuttle main engine firing from pluto.
wtf_am_I_reading.jpeg

>Not to mention, we can detect a spaceshuttle main engine firing from pluto.
That's like saying we can detect a phone's backlight from space.

>>4471529 Seriously, it's bordering on fairy-tale level shit now. There's no life there. Accept it and move on.


Because all of those material samples we've brought to Earth and analysed have been sooo conclusive.

>>4471382
>defiantly

Kill yourself.

>>4471843
>implying we wouldn't notice it and say something along the line of "look at those faggots building Dyson spheres because they are huge pansies"

>>4471714

"A full spherical sky search is 41,000 square degrees. A wide angle lens will cover about 100 square degrees (a typical SLR personal camera is about 1 square degree); you'll want overlap, so call it 480 exposures for a full sky search, with each exposure taking about 350 megapixels. Estimated exposure time is about 30 seconds per 100 square degrees of sky looking for a magnitude 12 object (which is roughly what the drive I spec'd out earlier would be). So, 480 / 2 is 240 minutes, or about 4 HOURS for a complete sky survey. This will require signal processing of about 150 gigapizels per two hours, and take a terabyte of storage per sweep.

That sounds like a lot, but...Assuming 1280x1024 resolution, playing an MMO at 60 frames per second...78,643,200 = 78 megapixels per second. Multiply by 14400 seconds for 4 hours, and you're in the realm of 1 terapixel per sky sweep Now, digital image comparison is in some ways harder, some ways easier than a 3-D gaming environment. We'll say it's about 8x as difficult - that means playing World of Warcraft on a gaming system for four hours is about comparable to 75 gigapixels of full sky search. So not quite current hardware, but probably a computer generation (2 years) away. Making it radiation hardened to work in space, and built to government procurement specs, maybe 8-10 years away.

I can buy terabyte hard drive arrays now.

>>4472640
>cont


I can reduce scan time by adding more sensors, but my choke point becomes data processing. On the other hand, it's not unreasonable to assume that the data processing equipment will get significantly better at about the same rate that gaming PCs get significantly better.

Now, this system has limits - it'll have trouble picking up a target within about 2 degrees of the sun without an occlusion filter, and even with one, it'll take extra time for those exposures. It won't positively identify a target - it'll just give brightness and temperature and the fact that it's something radiating like a star that moves relative to the background. On the other hand, at the thrusts given above, it'll take somewhere around 2 days of thrust to generate the delta v to move from Earth to Mars, and the ship will be in transit for about 1-4 months depending on planetary positions."

Why does everyone always imagine Dyson spheres to be 1 AU from a star?

So much mass can be saved simply by decreasing the diameter of the shell.

>>4472641
>>4472640

Here's the full article, if you want to see all the reasons there ain't no stealth in space.

http://www.projectrho.com/rocket/spacewardetect.php

Long story short: anything running engines will stand out like a star against the background of space, a star that is moving relative to the backdrop and therefor a space vehicle of some kind. Even with engines off, in order to keep the crew from freezing to death, your ship makes a moving bright spot that can be spotted from an incredible distance away. Refridgeration won't work, because that requires power, and power plants are hot. Heat cannot be stored without melting the ship. Directional radiation won't work because the enemy will have many different detection platforms, looking at you from a myriad of directions, which of course may also be MOBILE, meaning you will have no idea where it's safe to radiate to, and the closer you get to them, the harder it will be to find a "safe" place to radiate to, even assuming you can somehow tell where that would be, given that their sensor platforms are moving around.

>>4471834
>That's like saying we can detect a phone's backlight from space.
not as hard as you would imagine.
>The Near Infrared Camera for the Keck I telescope is so sensitive it could detect the equivalent of a single candle flame on the Moon.
http://en.wikipedia.org/wiki/W._M._Keck_Observatory
quite a few telescopes are capable of this.

>>4472664
What engines?
Why are you supposing there are engines involved at all?

>>4471543
Oooooooh....

>pic related

>>4471570
>this

Only the strongest species will survive... until the universe is filled with the "best" life-form.
>... and then they'll create the Singularity.

Wasn't there some article about a dyson sphere being detected in space?

>>4473572
'the singularity' is a social metaphor, not an object, and certainly not a totem of religious fervor as you make it sound.
It might even be a very horrible event, destroying whatever is left of humanity to preserve the very worst of what people are.
Stop wallowing in the stupidity of that fantasy.

>>4473595
There was an attempt to look for such a thing; many people seem to think looking is the same thing as finding one.
The study found something like 14 potential sites in their first run, and the only one of those that was near their specs was discarded as not likely.

So, no, there was no Dyson sphere discovered -- and wouldn't you hope it would generate a lot more specific excitement in the news than your vague recollection?

>>4471845
Are you trying to get us all vaporized by a laser with a stellar power output?!

>>4471507
>Unlikely because (1) the universe is young, (2) the universe is finite, and (3) the existence life is a rarity. We most likely the only sentient beings in the whole universe.

Get out.

>>4473572
The galaxy is a big place. If the galaxy is ever colonized it will be colonized by many species, because even if only one species begins the colonization it will fracture into new different species long before it gets to the other side of the galaxy.

>>4474138
>it will fracture into new different species long before it gets to the other side of the galaxy.
I maintain the hope that there are methods around the extensive periods of relative time it would take to traverse the galaxy at relativistic speeds. For some strange reason I don't think 100,000 lightyears is very big at all (on the Universal scale)

>>4474149
>Relativistic travel.
Even if you could travel so fast that you could make it there in the passenger's equivalent of a year, it would take 100,000 years to get to the other side of the galaxy. Do you really think the entire galaxy will expend all if its power just swapping humans to keep your idea of humanity pure?

Face it. One species cannot occupy the entire galaxy at once. Embrace the diversity. Diversity ensures our survival.

They've already looked, faggots.

http://seti.berkeley.edu/IR_Excess_Search

>>4474274
>mfw 33 possible Dyson spheres
>I have no face because it's been blown away by awesome

How the fuck could someone who has looked at the stars believe we are the only sentient species in the universe. You can't say oh well they sould have contacted us by now. Really we have barely been in space. Aliens and shit could have passed through this solar system when dinosaurs were around. So unless they had FTL it would takes a long as time to get places and even thenn they probably settled planets close to them or just don't have an urge to explore or maybe they did explore and got fucked up by some other aliens.

>>4474297
>>mfw 33 possible Dyson spheres
>>I have no face because it's been blown away by awesome

God-DAMN you're an idiot.
The article specifically states NOTHING FOUND, and you come away with this insipid comment?

Read all of the TWO SENTENCES once again:
33 IR excess candidates were found and subsequently searched for anomalous radio emission nanosecond-scale optical pulses. No convincing signals were found.

>>4474303
same argument can be used for god

how do you know that Jesus wasn't an alien? and God was president of some planet somewhere and that the bible is how the plebs 2000 years ago interpreted his visit because they couldn't comprehend life outside of earth.

>>4475090
HOW DO YOU KNOW

>>4475071
Just because our primitive tech didn't find anything of "interest" doesn't mean that there's nothing there. We really can't make any assumptions about super-advanced civilizations, though you could be right.

You sound mad.

>>4475597
>Just because our primitive tech didn't find anything of "interest" doesn't mean that there's nothing there.
it's not about our tech, their tech, or absolutism: the study was about one thing we assume to be true of a Dyson sphere and it was not found.

>We really can't make any assumptions about super-advanced civilizations, though you could be right.
No, of course not; but that study was about a specific thing, and that thing was not found.
It is pointless to discard the study afterward just because we can imagine we aren't looking for the right thing.

There are only two logical approaches to this survey: ignore it completely because our search tech (or criterion) is flawed/incomplete,
or accept it as the best we know so far.
We can't use the results of the study to confirm Dyson spheres, or accept the study in concept but reject it for the results.

And you (>>4474297) definitely have to understand what the results tell you before you respond.

>>4474303
>How the fuck could someone who has looked at the stars believe we are the only sentient species in the universe.
No one was talking about the possibility of alien life somewhere.

>You can't say oh well they sould have contacted us by now.
…and no one did.

>Really we have barely been in space.
completely irrelevant; our activities have nothing to do with theirs, and again, neither of those are the topic.

>Aliens and shit could have passed through this solar system when dinosaurs were around.
That was a completely different thread: ancient aliens. This one is about Dyson spheres.

>So unless they had FTL it would takes a long as time to get places and even thenn they probably settled planets close to them or just don't have an urge to explore or maybe they did explore and got fucked up by some other aliens.
That's a third topic, the difficulty of actually meeting anyone else in space.

It's good you have a grasp of some of these topics, but I really don't know how you get them into, or out of, this discussion.
This one is: if there is a Dyson sphere near, would we have noticed by now?

>>4475597
We can assume the laws of thermodynamics hold. This assumption alone gives you most of the criteria required.

do you know how fucking awesome it would be to stand on the inner surface of one? The horizon would be stretching up for millions of km. You could stick some planets a couple million km above the surface so you re not just looking at the sun. But what would happen since its always day? Too much heat for earth life?

Why do Dyson sphere's have to be at 1 AU?

>>4476790
1au is earth distance from the sun. Better chance to make the inner surface habitable. They dont have to be but unless a species can make a smaller artificial star....

I think I've spotted angry simian guy, posting the image.

I don't really see how a Dyson sphere could sustain life on the inner surface. What about the radiation from the sun? Also, how would it keep stability?

I mean, with the Hairy ball theorem and all that jazz.

>visible girders in dyson sphere

It's kind of cute when an artist tries to depict something like this without really understanding the scales involved.

>and assuming its containing all the light from the star within it

The sphere itself would still radiate, and as difficult as it would be to locate without knowing where to look in that 50LY envelope, we likely would have found it by now.

>>4471507
2/10 because of the others responses.

>>4477817
>What about the radiation from the sun?

What about it? Are you worried that a distance of 1AU is too close to survive stellar radiation?

>how would it keep stability?

We have no idea. At the very least it would require materials far stronger than anything we have ever seen.

What if our solar system was inside a giant sphere and it was just displaying an image of a universe?

>>4471520
Even our own solar system might yet have forms of lower life on other planets, such as Mars.

http://news.bbc.co.uk/1/hi/sci/tech/7829315.stm

"Solid" Dyson spheres are not even physical possible anyway.

>>4478167
then the voyager spacecraft are about to crash into it!

>>4471587
He means the core

/sci/ should be well versed in explorers of space as well of earth. I recently read the diary of Richard Evelyn Byrd, I'm not quite sure what to make of it. What do you guys think of his little 'encounter' in Antartica?

>>4478184
also worth remembering that there would be no gravity from the sphere. You would have to rely on centripetal force which would make much of the sphere uninhabitable.

>>4477841

We just need to figure out how to make skrith.