Assuming signals could be interpreted on the other side your looking at a 2.5 million year ping to send something to Andromeda.
- WhatAmLemmy@lemmy.worldEnglish2 days
“Oh you don’t like that latency? Is the speed of light too slow for you, motherfucker? You try building a universe without time!”
— God, probably
Yes. This has been theorized, but with the obvious limitation of building anything big enough to attenuate the sun’s output to a visible degree.
Right now we look for periodic dimming of distant stars, in order to ID exoplanets as they orbit and block light. We also look for any wobble from the gravitational pull of a large orbiting body, like Jupiter-sized things.
As for artificial dimming, that more or less falls under the concept of a “Dyson Swarm/Sphere”, and is something we’re keeping an eye out for too. Your signal concept would be carefully orchestrated windows in that swarm, as it orbits. But the energy and sheer mass requirements (measured in substantial fractions of whole planets) are at a level of civilization well beyond anything we can do at present. So there may be something out there, but we’re in no position to do the same.
- 2 days
Hypotheticly yes, but you would need something very big to block the light or reduce it. Planet sized for example, this is one way we detect planets around other stars, by measuring how much the light dims.
Another potential problem is that (at leas according to this wikipedia article https://en.wikipedia.org/wiki/List_of_nearest_galaxies) the closest galaxy is around 33000 light years away. So any signal we send will take 33000 years to get there and any potential return would take the same amount of time, so 66000 years in total. That is far longer than any human civilization exists
- 2 days
Ah sorry, I probably wasn’t clear enough what I meant (and am not super knowledgable here and probably have a western bias). What I meant was civilization defined like this https://en.wikipedia.org/wiki/Cradle_of_civilization not that there weren’t any cultures earlier. I basically just wanted to say that 66000 years is a very long time in human time scales
2 daysFirst part, wouldnt that only depend on the amount of light that you need to block for them to detect and couldn’t you place the shutter further away to reduce its size?
Also, name a faster way to transmit data intergalaxtically
Edit: also, since we are already transmitting light couldn’t we just send images. If life such as us is who we want to reach wouldnt it only make sense to design for our own light receptors?
I am willing enter the dumbass territory here, but - raido waves, being electromagnetic, and light travel at the same speed. Even if there is technically a difference, it is probably insignifact for the amount of distance each would have to cover before it can effectively transmit anything.
The convenience of a radio signal is that the transmitter is much easier to point in different directions, primarily because it’s a lot smaller than a star, but also because it can (at least in theory) be pointed in directions normally blocked by other celestial bodies. Given the position and orbital physics of a solar system, it would insanely difficult to position something directly “above” or “below” the Sun, let alone something as big and technologically advanced to block enough light, at an adequate frequency, to transmit any data. While a radio transmitter can be launched into space and positioned sufficiently far from other objects in the solar system to send data into various points of space. There can even be multiple such satellites, for all sorts of directions, coupled with repeaters and everything, while we only have one star in the system.
Of course, radio also depends on the receivers, even regardless of the data transmitted, but I believe in aliens, they’ll figure something out.
- 2 days
Nothing would beat light as far as transmission goes. Also, the further the shutter the further that doesn’t matter. As the galaxy expands you might block light for something that’ll have moved away and miss the signal, so it’s a pretty big risk to try and position this shutter strategically enough to make that work.
However, a fun thing to think about is, after you make your signal thing to broadcast, by the time that message reaches other galaxies, 33k years is long enough that other life might very well have come into existence and evolved.
Even crazier to think someone out there may have already broadcast their own message and we don’t have the means or technology to receive it or notice because they are so many others out there, OR it just hasn’t reached us yet. Maybe in another could thousand years.
- 2 days
Sure you can put it farther away, but the sun is massive, it would still need to be pretty big I would guess, but I’m not an astronomer so I don’t know the numbers.
As far as I know we don’t know of any faster way to send signals. That doesn’t make sending the signals impossible, just very impractical.
How about this, we point it at blackholes hoping they act as a worm hole and then are transmitted to people a million years in the past and we instruct them to write the data down on stone tablets so when they advance due to also giving them advance technology they remember to send a note back.
- 2 days
Sure we can do that, but then we can also just think hard about it and hope anyone hears it, not much of a difference
Thats all just math’s. We could create a theoretical model and send enough data where we maximize the probability. All be, the probability would still be starkly low but still an interesting thought experiment.
- slazer2au@lemmy.worldEnglish2 days
While radio telescopes are arguably slower then the speed of light, being able to encode and compress data into a radiowave is a faster way to communicate.
- Onomatopoeia@lemmy.cafeEnglish2 days
How is radio slower than light? Isn’t it all part of the EM spectrum?
- slazer2au@lemmy.worldEnglish2 days
Light is pure energy. While radio is energy it also contains information which means it is slower.
- safesyrup@feddit.orgEnglish2 days
That is not true. The propagation speed of light and radio waves in the same medium is exactly the same. It’s both electromagnetic waves
- 2 days
Yeah sure, you could do that.
Speed of light does not change. So you’re still looking at a stupid long latency.
How do you block and unblock the light quickly? The faster this goes the more data per second you’ll get.
- neopenguin@lemmy.worldEnglish2 days
Keep in mind, our sun is just one of hundreds of billions of stars in our galaxy. So, this would be like writing a message on a grain of sand, adding it to 20 or so dump truck loads of sand, spreading it out, and trying to pick out your message from the surface of Mars.
Look up The Fermi Paradox.
In this case basically, even if you could do this, which practically we couldn’t, there won’t be anyone to hear it and if there is we won’t be here to get the response.
- wilt@sh.itjust.worksEnglish2 days
Within the Fermi Paradox is the Dark Forest Hypothesis, essentially: we can’t see other civilizations doing this, and the theory is that if they did they are wiped out immediately by other civilizations.
The Three Body Problem is a good novel exploring this.
It is akin to being invisible in a dangerous place and then turning on a flashlight and giving your position away to predators.
Man, I was hoping this book series would get a mention here. Blocking out the sun as a means of transmitting a message is something that happens in the series. Or, it’s talked about, at least. It’s been a while since I’ve read it.
- wilt@sh.itjust.worksEnglish1 day
Tap for spoiler
It was using a high power radio transmission through the corona of the sun to act as a lens to magnify the signal, essentially turning our sun into a lighthouse. The shit that happens in the third book is mind melting in comparison. Dimensional attacks (shifting your dimension downwards) from 3D to 2D, by a potentially multidimensional entity, ironically unrelated to the original antagonists, and thus confirming the Dark Forest Hypothesis.
I probably should just read the novel but was was the predatory motivation? Resources?
- wilt@sh.itjust.worksEnglish2 days
It’s complex. Essentially our two systems were close enough to traverse with their technology and it was worth their while due to their systems instability.
The title “Three Body Problem” is referencing their systems three suns and their world’s unstable orbit.
It’s worth the read.
- 2 days
Even if there is life, the speed of light is so slow and signal degradation over distance so high it is unlikely we could detect each other even if everyone was trying.
Yes. Intriguingly, no such signal has ever been received, are we perhaps alone in the universe?
- 2 days
No such signal has ever been pointed at us AND reached us since we’ve been looking (i.e. a length of time that is utterly meaningless in this context).
Fixed that for you.
