The images we get with hubble from billions of lightyears away are of spectacularly, unfathomably large things. Planets are just too small relative to the distance.
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Star exhibits strange light patterns which could be a sign of alien activity
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The images we get with hubble from billions of lightyears away are of spectacularly, unfathomably large things. Planets are just too small relative to the distance.
AstroNut325
Member
Go outside with some binoculars. Look for ants that are 1+ miles away.
I don't really know what you mean. That is exactly what Hubble does.
Planets don't emit light. I'm fairly sure we don't observe then directly. They're found by seeing periodic dimming in a star or by seeing a slight wobble in the way a star moves.
Royal_Flush
Member
Because Exoplanets are way too small. I don't know the exact details but I think even the stars themselves are smaller than one pixel and the only reason we see them at all is because they emit light. The way you're detecting Exoplanets is by monitoring the brightness of a star over an extended period and if a planet passes by you'd see a tiny dip in brightness.
Exo planets don't shine and are masked by their stars presence . We detect them indirectly (eg by dimming of starlight I think not sure) etc etc
Clockwork5
Member
Because a galaxy at that distance is still much easier to see than a planet would be in the system next door.
Think of this, those images may be billions of light years away, but the pictures are millions of light years across.
Even Pluto, which Hubble cannot provide detailed images of, is several billion Km away and only a few thousand Km across. As such the ratio is much smaller and it is much more difficult to see.
The ratio of distance from the telescope to the area of the image is the limitation here.
This article explains it more clearly.
http://www.planetary.org/blogs/emily-lakdawalla/2013/02141014-hubble-galaxy-pluto.html
It's a good question and it comes up a lot.
Light scatters. So you need very large telescopes or arrays to see very faint objects.
Then the fact that stars tend to be millions of times brighter than their planets. It's like someone shining a flashlight in your eyes at night, you see the light fine, but can't see them behind the light. Let alone the piece of lint on their shirt.
Using science, astronomers have a plan to get around it. Just need the funding.
Royal_Flush
Member
Like actually seeing what a planet looks like? In the forseeable future not without a radical new "telescope" technology (and that means no telescope like we know it at all).
You can approximate the minimal angle between two objects (like the left and the right side of a planet) they need to have seen from your standpoint via sin(angle) = wavelength / diameter_of_lens. For earth-sizes objects in other star systems that would mean lenses of several kilometer in diameter. If you want to see the left and right edge of, let's say a tree on that planet we're probably talking diamenters of several thousend kilometers. (I just sloppily slapped the numbers into my calculator please correct me if I missed a few orders of magnitude somewhere)
Insane Metal
Member
HellBlazer
Member
Very interesting. I wonder what we could possibly see even with the starlight blocked out though. Even a relatively close (dwarf) planet like Pluto is a small blurry mess through Hubble, I can't imagine we would be able to see more than a couple pixels of a planet in another solar system. I suppose even that would offer scientific knowledge though; maybe spectroscopy would be possible.
What they need to do is combine the starshade with a giant telescope on the Moon.
Forgive me if it's already been asked, but have they determined that it is not massive sun spots? Pretty sure those darken certain regions of stars, and if they were numerous and large enough it could be confused for an object eclipsing it. Or is there scattering from beyond the corona that would indicate there are actual objects orbiting and reflecting light from the sides?
Very interesting. I wonder what we could possibly see even with the starlight blocked out though. Even a relatively close (dwarf) planet like Pluto is a small blurry mess through Hubble, I can't imagine we would be able to see more than a couple pixels of a planet in another solar system. I suppose even that would offer scientific knowledge though; maybe spectroscopy would be possible.
What they need to do is combine the starshade with a giant telescope on the Moon.
I've always thought Pluto is a focal length problem. Isnt it designed to focus at infinity, so looking at relatively close objects isn't possible because it didn't have the ability to change it's focal length resolve them.
Sort of like focusing on something in the distance and putting you finger in front of your eye. Finger is blurry.
In camera terms it would need a super macro lens option to see the fly on its nose.
Edit, I'm wrong. Emily to the rescue
No, a star turns into a red giant first when it is in its death throes. A star dies when it runs out of fuel. Once a star runs out of hydrogen, it starts to burn off less efficient elements. That causes the star to expand in size and turn red in color. I haven't heard that this star is in such a state.
When scientists say that they are stumped and can't figure out a reason, I am inclined to believe that they have considered such theories. I am not sure that sun spots could explain the overall constant darkening of the star over a period of several years, either.
CharminUltra
Member
"Welp, looks like earthlings are still stuck at the "ok story, boring gameplay" phase. It'll be at least another 1000 years before we let them 'discover' interstellar travel."
Yes, who could possibly think it's a good idea to build a Dyson Sphere to defend against a galactic alpha-predator?
Wait this actually happened? I played Halo 4 and never once heard about this. Thats cool af if so.
The Elite
BOSS
He was sealed away on the planet encased in a sphere.
WeAreStarStuff
Member
Not really. Assuming the star is large enough to nova, once a star starts producing iron it collapses at a significant fraction of the speed of light.
There's a lot of ways to detect exoplanets:
- actually view them, after occulting the star (coronography), but it's basically only doable for giants, and far from the star, that's inefficient
- observe a dimming of the light coming from a star when the planet travel in front of the star, but you need big planets and be just in the planetary plane of the star, which require a lot of luck
- observe a dimming when the planet travel *behind* the star, because we don't receive light of the star reflected by the planet, with the previous limitations, and also the need of a high albedo for the planet
- seeing the star going back and forth, attracted by the planet like the planet is attracted by the star, either by direct mesurement of the position in the sky over time, or by measuring red shift over time ; you still need quite an heavy planet, and not be on the pole of the orbital plane (and a bright star) if you want to use redshift instead of direct movement observation
- observing specific deviation of the light of a star (gravitational lensing), when a closer star with a planet is travelling exactly between the first star and Earth, a method that require a perfect alignment, but also the only method that can detect earth-like planets, as far as I know
...
But, if I'm not wrong, observing a planet like Earth (1e7 m) at 50 lightyears (5e17 m) is like observing a fine grain of sand (1e-4m) on Los Angeles beach from New York (5e6 m) (or an ant on the Moon). It's tricky...
WeAreStarStuff
Member
OléGunner;213951606 said:
Yes...though future planned telescopes would provide even more clarity.
They've considered it. It could potentially explain some of what we're seeing, but not all of it.
Badlucktroll
Member
This star is fucked up somehow i bet. Fucked up in a way that we've never seen before, so its ultra rare but a natural phenom.
It might not even be that rare, just something we've never seen before in our immediate neighborhood. As far away as Tabby's Star is, it's practically right next door when you consider the rest of the galaxy. Hell, we can't even see most of the stars in our own galaxy, much less if they're doing anything like this one is.
Our knowledge of physics might need enhancing, however.
oreomunsta
Banned
Physics will always need enhancing. We only have theories, at the end of the day.
We still can't even explain dark matter, and that's majority of the universe :<
Caayn
Member
A Youtube channel called Space Time just put out a nice video where they talk about Dyson Spheres, and possible alternatives: https://www.youtube.com/watch?v=jW55cViXu6s
Wolfe
Member
I agree, hence why I said what I did.
PantherLotus
Professional Schmuck
That video was absolutely amazing, thanks for that. Dude perfectly explain things really well and knows how to sustain attention.
pbs space time has a ton of great videos.
diab0lus.ex.machina
Neo Member
Alright, I'll say it...
Dyson Spheres (or Dyson Anythings for that matter) don't make any sense (except vacuums). If you're advanced enough to even be able to make one, then chances are you're advanced enough to not need to in the first place.
I mean, even we are on the verge of finally getting fusion worked out, and once we do (and especially once we improve on it) we won't need to build a Dyson Sphere to harness the energy of a star when we can create artificial stars (that we can scale up or down as needed) whenever and wherever we want.
Side-note: Fusion is pretty much by default more or less the same thing as creating an artificial star--since lots of people here seem to be having their minds utterly blown at the idea of creating one as if it's this huge technological feat. Not to say it isn't since we're still having a hard time getting it worked out entirely, but it's definitely within our reach. And it's certainly a lot easier than trying to encapsulate an entire actual star inside a shell that you'd likely need several solar system's worth of material to even come close to building...
Dyson Spheres (or Dyson Anythings for that matter) don't make any sense (except vacuums). If you're advanced enough to even be able to make one, then chances are you're advanced enough to not need to in the first place.
I mean, even we are on the verge of finally getting fusion worked out, and once we do (and especially once we improve on it) we won't need to build a Dyson Sphere to harness the energy of a star when we can create artificial stars (that we can scale up or down as needed) whenever and wherever we want.
Side-note: Fusion is pretty much by default more or less the same thing as creating an artificial star--since lots of people here seem to be having their minds utterly blown at the idea of creating one as if it's this huge technological feat. Not to say it isn't since we're still having a hard time getting it worked out entirely, but it's definitely within our reach. And it's certainly a lot easier than trying to encapsulate an entire actual star inside a shell that you'd likely need several solar system's worth of material to even come close to building...
You need a lot of fusion power plants to get anywhere near a star's energy output. Also, you need a lot of fuel for that. And some method of getting rid of the heat... which is problematic on a planet and not great for the environment. And getting that energy where you need it... More efficient to move stuff from orbit to orbit than it is from surface to orbit. (To paraphrase Heinlein, "you're halfway there when you get to orbit".)
A solid shell around a star is nonsense due to practical issues. A swarm of orbiting solar collectors makes much more sense. This power can be either beamed somewhere (either as microwaves or lasers for solar sails) or used to manufacture anti-matter (which is a rather efficient fuel storage method). Or it can be used for something more exotic.
Strictly speaking making such a Dyson swarm isn't even terribly difficult, though obviously efficiency of such thing depends heavily on one's technological capability. Like, if we were to send solar collectors around the sun... well, would be kinda silly but not impossible.
At a solar system scale, using the local star as a power source makes a lot of sense, especially if one has ambitions to get outside the system, solar sails and anti-matter rockets are among more practical ideas for interstellar travel. And stars provide a lot of cheap energy.
A solid shell around a star is nonsense due to practical issues. A swarm of orbiting solar collectors makes much more sense. This power can be either beamed somewhere (either as microwaves or lasers for solar sails) or used to manufacture anti-matter (which is a rather efficient fuel storage method). Or it can be used for something more exotic.
Strictly speaking making such a Dyson swarm isn't even terribly difficult, though obviously efficiency of such thing depends heavily on one's technological capability. Like, if we were to send solar collectors around the sun... well, would be kinda silly but not impossible.
At a solar system scale, using the local star as a power source makes a lot of sense, especially if one has ambitions to get outside the system, solar sails and anti-matter rockets are among more practical ideas for interstellar travel. And stars provide a lot of cheap energy.
Man that really killed the idea of a Dyson Whatevers.
The Sun outputs 3.8x10^26 Joules of energy each second. That is a completely mind-blowing amount of energy that is being constantly released. That one second of energy produced by the Sun is a million times greater than the human populations entire annual energy usage. An hour's worth of the energy produced by the sun, if converted into mechanical energy, would be enough to stop the rotation of the Earth or de-orbit the Moon. It is enough energy to use laser propulsion to launch spaceships out of the solar system at near-light speeds around the clock. The amount of energy that could be captured by a Dyson sphere would utterly transform what human beings are capable of.
A lot is an understatement.
what if dyson spheres are used to power swarms of replicating robots to either mine or terraforming planets?
Yeah, well, you need so many fusion plants there's not much point in trying to give a number for that. It is high enough a number it is impractical. So, i cannot think of any other way to say that than "a lot".
diab0lus.ex.machina
Neo Member
My point is that if you've mastered fusion you can scale it all over the place as needed. You wouldn't really need the energy of an entire star if you could just use localized fusion scaled to whatever energy requirements you might have. You could have a miniature fusion reactor that could power each individual ship, for example.
Building a Dyson Sphere is impractical and a huge waste of resources. If you have the ability to make one, you've probably come across other ways of creating energy that make a lot more sense and are far easier to accomplish.
Granted, speculating about what some super advanced civilization (with likely an entirely alien evolutionary, technological, and cultural history) is probably pretty impossible, but it just doesn't make sense to me. Again, you'd have to assemble quite a lot of material to make one. All the material in the solar system smooshed together would only maybe block MAYBE like 3% of the sun's light (let alone ~22%), and the sun is a lot smaller than this star is.
Don't get me wrong, on some level I hope it's some kind of sign of other life out there, but even if it is I don't think it'd be a Dyson Sphere...
Building a Dyson Sphere is impractical and a huge waste of resources. If you have the ability to make one, you've probably come across other ways of creating energy that make a lot more sense and are far easier to accomplish.
Granted, speculating about what some super advanced civilization (with likely an entirely alien evolutionary, technological, and cultural history) is probably pretty impossible, but it just doesn't make sense to me. Again, you'd have to assemble quite a lot of material to make one. All the material in the solar system smooshed together would only maybe block MAYBE like 3% of the sun's light (let alone ~22%), and the sun is a lot smaller than this star is.
Don't get me wrong, on some level I hope it's some kind of sign of other life out there, but even if it is I don't think it'd be a Dyson Sphere...
That's why you don't build an actual shell, you build a Dyson swarm that might not absorb every bit of energy from the sun but will certainly provide more than humanity will most likely ever need in their home system once completed.
Seems to me like it could be an advanced civilisations way of letting not so advanced species know of its existence since you would logically conclude said not so advanced species would develop super powerful telescopes.
You can't send radio transmissions because how would you know they could understand it. But if a group of beings are smart enough they would easily be able to tell that a star was acting unnaturally and investigate.
First contact and we don't even realize it.
You can't send radio transmissions because how would you know they could understand it. But if a group of beings are smart enough they would easily be able to tell that a star was acting unnaturally and investigate.
First contact and we don't even realize it.
Well, you don't have to assume that radio transmissions are understood. Just having unnatural radio emissions are just as efficient if you can produce them. Modulated light or modulated radio waves is the same, it's not as if one part of the EM spectrum was more a "logical choice" than another.
SETI detects something strange - http://arstechnica.com/science/2016...gnal-that-may-originate-from-a-sun-like-star/
The Elite
BOSS
OH FFS. Stop getting my hopes up.
Edit: This isn't the same star. Guess it should get its own thread.
Why in the hell did you post that in this topic?
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