Occam's Razor
Occam's Razor would have saved them $107k!
Dyson spheres just suck!
Sorry to burst your bubble, folks, but the mysteriously dimming Tabby's Star isn't due to an "alien megastructure" after all – it's just obscured by dust, according to a paper published today. KIC 8462852 (but Tabby's Star is catchier) was first spotted by NASA's Kepler telescope. It quickly became an object of fascination for …
Occam's Razor would have saved them $107k!
There are dumb ways to spend large amounts of crowdfunding, like a $55,000 bowl of potato salad, an $8,000 Lionel Richie head, or a $107 million presidential inauguration. $107,000 on an astronomical research project, even if it has a predictable answer, seems comparatively sensible.
Yeah...that's what they want you to believe...right up to the moment when the invasion fleet full of little green men appears
Or:
[Several thousand years ago... give or take a couple]
Yzrak, the leader of the Ngda, flashed his chromatophores at the assembled beings in the Hall of Science, "There must be intelligent life elsewhere out there. How can we communicate with it?"
Myriad beings flash a confused babble of lights as they mutter among themselves, until a strobe of consensus flashes through the hall.
Gathered scientists in unison, "Great Yzrak, if we sent a fleet of small probes into the great dust cloud that encircles our sun, within a few rotations they could manipulate the cloud to modulate our sun's rays into a beacon that would proclaim, "We are here, Welcome." to all stars for thousands of lightyears around.
Any species capable of intelligent flashing will be able to see it and know we are here and sapient."
Pylok the otherthinker flashed in disagreement, "But what if other intelligent life out there don't communicate by light?"
Yzrak flashed mockingly, "And how else would an intelligent species communicate? Farts and belches?"
The laughter of the assembled was visible for yergs around.
Sigh, you mean half way through their flight when they turn the ships round and burn to decelerate? Then we will see them coming. Interstellar invasion 101, that which accelerates must decelerate to arrive. See Oumumua on what happens when you don't decelerate, except be quick as it is disappearing fast.
Has anyone on our planet ever considered building a large device that would sit in between our sun and a chosen star, and would blink the light on and off in order to send messages? Like a huge Venetian blind.
Given the size of the moon needed at Earth to eclipse the sun, it might be practical to build such a thing if it were 80AU out, only needing to be 80x smaller than the moon. Is that right? Or it wouldn't have to be that big, only big enough to noticeably vary the light output, which would be how big?
A light signal would be noticeable by any old astronomer looking at the star who would notice the unusual activity.
True, but that presupposes that the alien species in question has evolved some form of optical sense, in a similar way to how we Earthlings developed eyes.
Considering the countless ways in which things could evolve, I don't think *any* form of communication could be taken as a given.
Visible light signals would require an alien species that had eyes that use the same wavelengths as us, which might be the case if we're looking at a similar planet and sun to our own, but it's an unknown.
Perhaps a better idea would be to transmit in one of the absorption lines, where it should look out of place to an alien radio astronomer, and hence pique their interest.
Moon works to eclipse, as seen from Earth, because it is much closer to Earth than it is to the Sun.
You have got your thinking the wrong way round geometrically.
One could either:
A) Make the eclipsing object small, but close to the aliens. Then why signal at all, just reach out and touch, in terms of astronomical distance. Something asteroid sized is easily big enough, if located in their home system. If you want something 1/80th of the size of the sun, you have to be 79/80 of the way there......
B) Make the eclipsing object of order sun-sized, but located in *our* system. Parallel light rays etc, means this is a good eclipsing body. This is hard, but actually *not quite* as nuts as it sounds. Nearly, but not quite.
Compare the energy cost of signalling -*the total output of our sun* with manufacturing a couple of mm thick, electrically controllable glass (which does exist) and a million kilometres in diameter. Spin forward technology to make it electrically controllable Mylar, and modulating the suns output to 1% depth => 100000 kilometres. This would be an engineering feat for the 22nd century, but *not completely impossible*
The problems are more - where do you put it?
1) The eclipse is aimed at a particular star. You have to already know where they are, and that they might be looking.
2) What happens to the reflected energy?......
Given our current tech can only find earth size exoplanets that kinda puts a *big* lower bound on the size of your blind assuming early 21C Earth tech.
And 80 AU is approx double the average orbital radius of Pluto and only 5 man made objects have passed Pluto (2 Voyagers and Pioneers + New Horizons)
"Is that right?"
No, not really. The moon eclipse the sun because it is about 400 times closer and the sun is 400 times bigger. Given that the closest star is over 270 000 AU away then 80 won't do much difference, some, but not much. So we have to look at dimming, and assuming at least our capabilities at the receiving end it would have to the size of a planet. Our planet is something we would have trouble spotting, depending on the size of the star it orbits. So even with greatly superior techniques we are talking a rather large device. After all at these distances there is only that many photons left.
If you build further out the orbital speed would be lower and thus you should be able to keep it longer between the target star and our sun, but the further out the more narrow the shadow also becomes. Also at 80 AU the speed is still 3.35 km/s so keeping it still will not be an option.
Then there is the time aspect. We are talking many years for light to reach the systems in the neighbourhood and we don't even know if there are anybody around the see it.
I do like the idea though. Made me think.
This post has been deleted by its author
This post has been deleted by its author